WORKING WITH GIMP SOFTWARE

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WORKING WITH GIMP SOFTWARE

Post by Horus »

GIMP TUTORIAL, BASIC CROPPING METHOD & SAVING THE FILE

Well I suppose we have to start somewhere so hopefully she will not mind, but I have chosen one of LLL’s pictures as an example of what we can try to do to improve it. These are only my own opinions and they are not a criticism or intended to be too technical in the photographic sense, rather just something we can alter using the program. Some of you will already know how to do this particular operation, but it may not be a bad idea to just go along with everyone else and start getting the hang of using this program. The general idea will be to use some of the tools and see how they work, hopefully this will build up into a general working knowledge as we go along. I will open up another thread for general questions so as not to clutter this one and as they arise we can post the explanations in this thread and it will become a reference that we can fall back on when using the program on our own pictures. So rather than have a fixed series of tutorials we will just leave it to people who have a question to ask it on the discussion thread, don’t feel intimidated by others maybe knowing more than you do, if you can’t get your head around something just ask and someone will be able to explain (I hope)

So I thought that we could start by looking at the picture and deciding what needs to be done to improve it. First off the sky is good, but the trees are quite dark, there are some phone wires on the left that spoil the picture and that little bit of building on the right is not really interesting enough to be included. I will not even mention that bloody great big Scarab that ruins most pictures, :lol: Keefy I understand the reasoning behind you having it, but as it can be so easily removed using an editing program, can it not be a little bit more discreet? :up

First off if everyone else can down load the picture by right clicking their mouse on it and selecting the ‘Save As’ option. (I prefer to save this type of copy straight to my Desktop as its easier to find again)

Open up your GIMP program and select FILE from the top main menu, then from the drop down menu choose OPEN. A dialogue box will open and you will need to navigate to where your picture is stored, in this screen shot you will see that all of my drives are displayed (quite a few) and if I highlight my DESKTOP (green box) you can see the COOLPIX 073.jpg highlighted (magenta box) and a thumbnail of the chosen picture (blue box) You need only to click OPEN to select the file.

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Now that the picture is loaded you can see it within its own boundary box, the actual size can be altered by going to VIEW in the main menu and selection the ZOOM option. There are lots of options to choose from, but +150% to 200% is usually sufficient for working with. Note that using the FULL SCREEN option will lose your minimise, re-size and close buttons at the top right of your screen, to get them back again you need to again select VIEW and uncheck the tick by clicking on FULL SCREEN again and it will revert back.
The other two PALLETS are the TOOLS PALLET and the LAYERS PALLET. If the LAYERS PALLET is not visible you can make it so bu holding down your ‘Ctrl’ key and pressing ‘L’ on your keyboard. Both PALLETS can be moved around to suit your needs by clicking in the bar at the top and holding your left mouse button down while dragging it to another location, this is very useful when you have lots of things open on your screen.

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Lets make a start by cropping the picture to take out some of the dark area at the bottom of the picture and also the stray bit of building on the right. In the TOOLS PALLET select the item that looks a bit like a craft knife, (green box) this is the crop tool. When you click on this another menu will drop down to display the settings that you may change, this happens with all the tools and may contain completely different settings for each one depending upon the tool you are using. There are lots of options, but for now just look at the ASPECT RATIO (blue box) this is a way of setting up a different crop size. In this case we do not want it to change the relative size of our picture so we will make sure that the FIXED ASPECT RATIO has a tick in the box alongside, this ensures that any rectangle we pull by clicking down on the picture and while holding the left button down we drag it out to a suitable size box, this new size is always at the same scale as the original picture (see magenta box) and the section that will be cropped is darkened. If you select an area and it is not what you want, just drag out another box and the old one will disappear.

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When you are happy with the new size just hit your keyboard ENTER key and it will be cropped to the new size.

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Now all we need to do is to save this to somewhere that we can find it again, so we need to go to FILE and choose the SAVE AS option. Notice that we can choose where to save our file to, as previously I am saving mine to my DESKTOP (green box) for easy location. Now this is important! Notice how the default file is the same name as your original …………………… BUT it has the file extension .xcf (blue box) after the file name and NOT .jpg. The reason for this is that we are saving a GIMP work in progress picture that may contain many layers all of which can be modified at any time that we decide to re-open the picture. If we saved it as a .jpg it would just become another basic picture with no way to change anything back again. So click the save button and notice how the name in the blue banner at the very top of your screen has changed to read .xcf after the name and not .jpg as it was when you first opened the picture.

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Try all this for yourselves and try saving the file and then closing the GIMP program. Open it up again, but this time select the same file but with the .xcf extension and it should open up your cropped picture and not your original. So once you have done this it will be easy to crop any future pictures and save them.


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Re: WORKING WITH GIMP SOFTWARE

Post by Ruby Slippers »

Righto, Horus! Done that! :up

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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

Well done :up
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Re: WORKING WITH GIMP SOFTWARE

Post by Kiya »

Ok done :) ....after cropping & closed, the pic went to Desktop then I had to close the GIMP program, am I supposed to be left with the Gimp still open? is this ok ?

I did open it again with the .xcf

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Re: WORKING WITH GIMP SOFTWARE

Post by LovelyLadyLux »

:( :( :( Told you I'm the S L O W one. Have to leave it for an hour and come back later.

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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

Number 2 CLONING OUT A PROBLEM AREA

This can be achieved in several ways, if it is a small area then simply choosing the CLONE icon from the TOOLS PALLET is the easiest to use. Once again after selecting the icon which looks like a stationary stamp (green box) you will see another drop down menu with settings you can change. For a start you need to choose a suitable brush for what you will be using it for, you can change the brush by clicking on the BRUSH FLY-OUT menu (blue box) and select from the list you see. A good rule of thumb is if you want to delete or clone an area the a solid brush is better, but sometimes you may need a more softer brush that will blend more at the edges, for that you should choose a more blurry looking brush. Try experimenting with the different brush types and varying their opacity level, you can always undo each move by going to the EDIT menu at the top and selecting the UNDO option, each click will take you back one step at a time. For now it is probably best to just change the level in the OPACITY settings to one that suits your needs. Either drag the shaded area left or right with your mouse or use the small bar on the extreme right (magenta box) and increase or decrease by clicking above or below the small dividing line. Alternatively place your mouse pointer on the exact spot between the shaded and the white areas (red box) and while holding down your mouse button drag the slider bar left or right. This method will be the same on many of the slider bars you see in the TOOLS menu.

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Once you have selected a suitable brush by clicking on the BRUSH icon and I suggest that you use this one from the list for this particular exercise, but by all means experiment yourselves with other brushes. Just remember that so long as you DO NOT save your changes you can either keep using the UNDO option to take you back, or even close the picture down and open it up again and it will be the same as when you first saved it.

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Below is a picture of the suggested settings, these will vary depending upon what you are doing, use lower OPACITY to blend edges in more smoothly as the brush will be more gentle and smaller or larger brush sizes to clone large or small areas or tight spots in your picture.

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The clone brush will show as a dotted circle and the idea is to choose an area that is similar to the part you want to cover over. With lines it is usually best to pick a position just above or below the line you are covering as the colour will be a better match, then after positioning your mouse cursor, hold down the ‘Ctrl’ key whilst left clicking your mouse, this will select the area to CLONE FROM (blue box).Next move your mouse to a place anywhere on the line you want to cover and while keeping your left mouse button held down, WIPE your pointer (circle in green box) in an upwards right to left diagonal sweep along the line. You may have to do this several times to fully blend it back in again, but obviously this is very much dependant upon the skill of the user, so practice makes perfect.

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After a bit of cloning out for the wires I also added a few clouds using the same method and tidied up the bottom edge using the same clone tool, here is the result so far.

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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

HOW THE PALLETS WORK

OK so far I have figured out how these various PALLETS work, just for clarification a PALLET is just a another name for small menu window that appears for any specific task we need to use. So because we need to view the different layers that go to make up most of our edited pictures, we will need to see the LAYERS pallet at all times. The same goes for the TOOLS PALLET, we need to be able to pick different tools at will from a list, therefore we need to view the TOOLS PALLET at all times, this principle will apply to everything we use within this program.

Here are a few things to understand about these PALLETS, (also called Windows) each one can be accessed by going to the WINDOWS option in the Main Menu Bar at the top of your screen and selecting DOCKABLE DIALOGUES. As you move your mouse over the words DOCKABLE DIALOGUES you will see another FLY-OUT menu become visible and it contains a long list of items starting with TOOL OPTIONS and ending with ERROR CONSOLE.

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As you move your mouse over any of these options and select one of them by left clicking on the name, you will see a small PALLET (window) appear on your screen. Each time you click on a new item another PALLET will appear and so on until you stop selecting them, note how each one has some things that are similar and some things that are not, so depending upon what they do they will show different information. Imagine them to be like a set of playing cards and to save you the trouble I have displayed them all here on one screen. View it in as large a detail as you can and have a good look at each one and notice the similarities and the differences between them, but don’t panic we will only be using a few of them, I have only displayed them all so that you can get a feel for what they all are and how each one looks.

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Lets have closer look at a smaller selection at the top left of the ‘deck of cards’ above, note how they all have some common features. In the (magenta boxes) you can see the programs name for that particular PALLET, so we can see the DEVICES, OPTIONS & LAYERS pallets in this picture. In the (blue boxes) we can see a small left pointing arrow, this activates another FLY-OUT menu, but we will come to that later.

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In the (green boxes) are crosses, a typical Windows icon used to close a window or pallet and that is exactly what they do, clicking on the 'X' will make that PALLET disappear again as in the case of the DEVICES pallet which you can see is now missing from this picture. (see the red crossed lines)

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So in brief you can open any PALLET you wish by going to WINDOWS > DOCKABLE DIALOGUES and choosing the pallets you want, to close them again just click on the ‘X’

I will follow this up shortly with how to set up the complete tools pallet that we all need, but for now just familiarise yourselves with this part, don’t worry about messing anything up as we will start everything afresh later on. It is also worth me mentioning that although we are attempting to set up a working set of icon related tools that we can all recognise as we go along, that all of these things are still available to you by using the Main Menu Bar at the top of the work window and just selecting it from the various drop down menus.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

RESTORING THE TOOLS PALLET

Before we go any further and now that you all know how to open and close the various PALLETS as described in the previous tutorial, it will be best if everyone starts with A COMPLETELY CLEAN WORKSPACE. So using the ‘X’ at the top corner, delete any and all Pallet windows that are showing in your workspace window, you should be left with a completely blank space with just the top MAIN MENU BAR and the background pattern visible. It is important that we all do this so that we are working together, you may add any customisations you wish at a later date, but for now it will avoid confusion if you just display the items as I describe them.

After clearing the Workspace go to the MAIN MENU BAR, choose WINDOWS and select the option NEW TOOLBOX.

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Afterwards you will see the following:

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This new toolbar is too long to fit our needs, so we need to change the size. We can do this by positioning our mouse pointer in any of the following positions and while holding our left mouse button down we drag outward or diagonally (if on a corner) to the size we require. You will need to pull the sides out, squash the top downwards etc until to have a suitable sized box. Make sure that your mouse pointer is EXACTLY on the corner intersection, or on the outer edge lines and you will see a double directional arrow appear, this tells you it is selected properly.

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Try to finish up with a box that is about as wide as the word COLOURS on the top menu bar (example Y) and a height of about half your own screen (example X)
When you have finished the resizing you can drag it up to the top left hand corner by clicking your left mouse button on the blue bar at the top of this toolbar and dragging it whilst keeping the button held down.

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We need to add another item to this toolbox, so once again go to the MAIN MENU BAR and choose WINDOWS, then DOCKABLE DIALOGUES, then TOOL OPTIONS.
(Note: this is the procedure we did in the previous tutorial and now you are putting what you learned into practice)
You will now see the TOOL OPTIONS pallet on your workspace as well as your re-sized Toolbox.
We do not want the two items to be separate so we will join them together, we do this by holding our left mouse button down in the area indicated by the (magenta box) and dragging it to where the (green cross) is shown on the Toolbox and dropping it there and it will change to a combined Toolbox.
(Note: it is important that you pick up and drop in the areas indicated or it will not work)

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If you have done it properly then it should look like this:

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So that is your TOOLBOX returned to your screen again and this procedure can be repeated if ever you lose it again. Hopefully when you close down your program correctly by first clicking the X (top right corner) to close your picture, then once again to close the program altogether, it will still be there when you open the program up again.

Finally, you can switch the visibility of all the PALLETS on or off by pressing your ‘Tab’ key.

Next I will deal with the LAYERS window then we are nearly done. :up
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Re: WORKING WITH GIMP SOFTWARE

Post by Ruby Slippers »

I'm a bit 'out of the loop' here at the moment, Horus, but I will get to it as soon as I can! I'm teaching in the mornings and various other things going on in the afternoons so I'm too tired to really do your explanations justice! It's a good job you are not setting exams! :lol: I'm looking forward to getting to grips with this though - and thanks so much for taking the time and trouble to do it! :up

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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

SETTING UP THE LAYERS PALLET

Well hopefully everyone will have gotten rid of everything else they had previously on the GIMP workspace main window and following the above tutorial they will now have a new TOOLBOX that looks EXACTLY like this one. Make sure that you can see 6 icons across and you make it just long enough that the slider bar on the right side disappears. You should do this by referring to the previous tutorial and slowly pulling the bottom edge down until it ‘flips’ over to having no slider bar on the right hand side and pulling the sides out to give you the 6 icon width.

Note, you may change this at a later date to suit yourselves, but for now stick with these settings so that I know what you are all seeing is the same as what I am seeing.
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Next we need to add the LAYERS pallet window, it is one of the ‘deck of cards’ list that I showed you earlier and it is accessed by going to your MAIN MENU BAR and selecting WINDOWS then DOCKABLE DIALOGUES exactly as we did in the earlier tutorial. We only need to click down onto the LAYERS option and we will see this appear on our workspace area.
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At this point let me explain, all of the PALLETS as shown in the “deck of cards” screen shot can be chosen at any time and closed at any time so as not to clutter up your screen. You may open up just the one, or multiple ones, it all depends upon what you are needing at the time.
Because we don’t want to clutter up our workspace if we have several PALLETS open at the same time, we can use the ‘Docking’ options which really help us because they all get stacked together with just a small ‘tab’ visible to show us which ones are there. So if we have say 5 Pallets open we would see one window with 5 tabs at the top and if we had only 3 then we would only see 3 ‘tabs’ at the top.
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We can add as many other Pallets to the original one as we like, but the basic size will remain the same. All that will happen when the top bar is full, is that another directional arrow will appear on the left hand side of the ‘Tab’ bar at the top. (magenta boxes) You may use these arrows to move left or right to scroll through a longer list of items, as I said before, it keeps things neat and tidy and takes up little space.
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There are two easy way to create combined PALLETS, the first method is to open all of the ones you require and then by clicking and holding down your mouse on its ‘name tag’ (magenta boxes) drag it and drop it into the first window, in our case it is the LAYERS pallet, drop it somewhere in the indicated area (green block) and repeat this with any others you want to add.
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The second method is to open up a single new LAYERS pallet as described previously, but this time click on the single left pointing small arrow in the ‘Tab’ bar opposite the word ‘Layers’ (green box). This will create a FLY-OUT menu, the second option down is ‘ADD TAB’ hovering your mouse over this will bring up another FLY-OUT menu showing all the various TOOL options. Clicking on any TOOL option will place it into you LAYERS window. You will need to repeat the above procedure for each TOOL option you add.
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Use any method you like to create a LAYERS pallet, but only choose the following options:
LAYERS > then add > CHANNELS > then add > PATHS, when you have finished move it over to the top right of your work area and open up your previously saved picture again.

It should look EXACTLY like this (apart from the picture size)
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So now you should all be able to figure out how to create a new TOOLBOX pallet to suit our needs and to create a separate LAYERS pallet to go with it. Some people may require a bit more help so just ask, but try to follow what I have shown above and to get a feel for what we have done to arrive at this new WORK AREA.

When you have achieved what I am showing in the last picture and I stress that we all need to be seeing exactly the same, then make a post over on the discussions thread (not here) or ask for more help, when we are all at the same position we can move on, no pressure we have all Winter to learn this in.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

GIMP TUTORIAL EXERCISE No 1

OK lets try using some of the tools we have loaded and see how they can help us with our pictures.
Fist of all click on the ‘Butterfly Image’ thumbnail to enlarge it, then right click the image and using the SAVE AS option, save it to somewhere you can find it again when required.

BUTTERFLY IMAGE
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Open up your GIMP program and after checking that your TOOLBOX and Layer pallets are still there, go to your MAIN MENU BAR and choose ‘Open’ and at the next menu select our saved ‘Butterfly Image’ picture.

If you still have the old picture loaded you can remove it by doing a single left click on the ‘X’ icon at the top right of your GIMP program before loading the new picture. Remember that clicking the ‘X’ icon again when there is no picture visible will close the GIMP program down again.
So the rule is always, 1st click shuts down the picture, 2nd click shuts down the program.

Once it is loaded you will notice a number of things wrong with it, mainly that the Butterfly is too dark to see it clearly, so if we could lighten it a bit we could salvage this picture.

You will find out that there are lots of methods of manipulating your pictures in an editing package such as this, far too many to describe each one in detail so we will content ourselves with using just the one method for today. What we must be careful of is changing things like ‘Brightness & Contrast’ which would of course make the Butterfly more visible, but it would have a knock on effect to the rest of the picture, either making it too light or too dark in places.

So how can we adjust only the Butterfly without affecting everything else? The answer is to only select the Butterfly and just change that while leaving everything else as it was. One of the best ways with a shape like this is a tool that can intelligently help us to follow the outer shape as we select it and one such tool exists in our TOOLBOX, it is the one that looks like a pair of scissors.

It also helps if you enlarge the area that you want to work with, so first of all using your + (plus) key on your keyboard, tap it to bring the Butterfly up to a decent viewing size on your screen. Don’t worry if you overdo it, you just tap your – (minus) key to zoom back out again.

Now click the ‘Scissor’ icon in the TOOLBOX menu. (magenta box) 6th icon on the top row.
As you move your mouse pointer back onto the picture you will see the pointer and a small scissors icon alongside.
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Start by placing your pointer as accurately as possible somewhere on the edge of the wing and make a left click, a small dot will appear. Move around the edge in smallish increments while making more clicks, don’t worry too much about fiddly areas as these will not make much difference when its all finished.
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Keep going until you can click back on the top of the first dot you made and notice how the line tries to reshape itself as you go along. When you have gone all round hit your ‘Enter’ key and it will change to a line of ‘Marching Ants’ around the shape you selected.
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At this point you can hit your – (minus) key until the size is reduced again.

Our shape is now selected and ready to modify, we can do this quite easily by using another PALLET called ‘CURVES’ Luckily this pallet is already on our TOOLBOX and it is the 5th icon along on the 6th row down (magenta box)
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Click on the ‘Curves’ icon and then click your mouse ANYWHERE in the empty space around your picture.
DON’T PANIC! Yes I know all your other pallets have disappeared, that’s OK as once you close this ‘Curves’ pallet back down by clicking on the ‘X’ (top corner) they will all reappear again, clever eh?
So it should now look like this.
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Now here is the magic you have all been waiting for, place your mouse pointer on the intersection of the two lines as shown in the (magenta box) and while holding it down, drag it to the intersection of the two lines as shown in the (blue box)
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Clicking OK at the bottom of the ‘Curves’ pallet will close it down and return your TOOLBOX & LAYERS pallets. All you need to do to complete the operation is to deselect the line of ‘Marching Ants’ around the outside. Go to your MAIN MENU BAR and choose ‘SELECT’ then from the drop down menu choose ‘NONE’ (the red cross)

That’s it folks, another rubbish picture rescued.
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So in brief you can use the above method to select any part of a picture and using the ‘Curves’ pallet you can change the way the selection looks. For tutorial reasons I have given you fixed places to start and finish moving the ‘curve line’ so as to achieve a desirable result, obviously this is a user dependant choice that you need to make on each and every part you select and modify. Feel free to play about with some of your own pictures and move the curve lines about and experiment by starting at different points along the line, you will be surprised at some of the results you will get.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

SAVING A FILE IN ANOTHER FORMAT

When you have completed your modification of any picture file you will probably want to save it as a Jpeg or BMP or some other format. A work in progress is always saved with the file extension of .xcf this is a GIMP file extension and can only be read by the GIMP program, so to make it viewable in other picture programs or viewers you will have to give it a different file extension. There are many to choose from, but the most efficient and most commonly used is .Jpeg or .jpg, they are both the same file type but may be written slightly differently, but more often it is .jpg.

In the GIMP program you cannot use the normal option of ‘Save As’ which is common to a lot of software, instead you EXPORT your file. So go to your MAIN MENU BAR and select FILE > then choose > EXPORT and you will see another dialogue box appear.
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In the (magenta box) you type in the name for your file, you do not need to type in the extension as it will be done automatically further on. In this case you can see I have called mine ‘Peacock 2’

Choose where you want to save the file, (green box) mine is again saved to my Desktop.

By clicking the + (plus) or (minus) in the small square (red box) you should get a drop down menu that lists all of the available file extensions.

Use the slider bar on the right hand side to move the list up or down.

Choose the Jpeg/jpg option by clicking on it and it should add that file extension to your picture name.

Clicking the EXPORT button will bring up another smaller window, click on the EXPORT button (red box) should complete the task.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

USING THE ‘MAGIC WAND’ TOOL EXERCISE 2

OK folks, we have learned how to use the CUT (scissors) icon in our TOOLBOX to trace around the outside of a shape to select it. Then after we select a shape using this tool option we can manipulate that particular selection in many different ways, we can change its colour, sharpen it, change the brightness & contrast, copy it, delete it and many more things to numerous to list here. So you must think of this tools as just being a means of selecting a particular area or shape within your picture.

This as you can see is a really useful tool, but there is another tool that does the same thing, but by using a different method and it is the MAGIC WAND tool and it is the 4th icon along (red box) on the top row of our toolbox. Note that when you select it, the menu below the tools list will change and you will see several items that are selectable by you and are changed by you to suit any particular task you are doing.

Take a look at the THRESHOLD slider (blue box) this changes a particular value up or down, it may take you a little practice to get used to using it, but you can change the number displayed inside the box in several ways.

METHOD (1) You can click the little boxes on either side of the dividing bar (green dots) and the numbers will go up or down accordingly.

METHOD (2) You can do a normal ‘highlighting swipe’ with your mouse over the numbers and then just type in a new one.

METHOD (3) Slowly move your mouse pointer to be just above the bottom line of the slider bar (blue box) and your pointer will change into a double Left/Right arrow, move in any direction to change the numbers.

METHOD (4) Again slowly move your mouse pointer to be just below the top line of the slider bar (magenta box) and your pointer will change into a single vertical arrow. While keeping the vertical arrow visible, move left or right then left click your mouse at the place you stop, this will make the slider ‘jump’ to that new position and change the numbers accordingly.

Changing the values in this slider bar is essential in using the tool effectively

TIP: THE METHOD DESCRIBED ABOVE WORKS WITH ALL TOOLBOX SLIDER BARS.

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So while referring to the above image let us try out the Magic Wand tool, let me start by explaining how this particular tool works. Some areas are best selected by means of their colour or shading, so look at the sky in this copy of Grandads picture and you can see that there are lots of different shades, this tool allows us to select a shade by clicking our mouse pointer on any particular area within the picture. The software will then select all of the adjacent pixels that are the same shade or colour as the one you were on when you clicked your mouse, however this is not really very practical as we may find that we have only selected a very few pixels. We can make it select more pixels by telling the program to be less fussy and to also pick the shade or colours that are ‘close’ to the pixel we clicked on, that gives us a bigger range of the colour/shade that gets selected. It works on the principle of the lower the number in the slider the more sensitive it will be and only choose pixels that are a close match to the one we picked. If we increase the number, then it becomes less sensitive in what it chooses as a match for our original pixel and will add a far greater range of ‘near’ colour/shade matches.

To see this in action choose the MAGIC WAND tool and open up Grandads picture by copying it in the usual way and putting it into the GIMP program. After reading the part about adjusting the slider bar, set the number as close as you can to 10 (a decimal point or two either way doesn’t matter). Then click your mouse somewhere on the picture as close to the centre of the (magenta box) as you can estimate (located just above the 4th chimney) and you should see a selection that resembles the area I have outlined in green. It will not be exactly the same because you are unlikely to select the same pixel as I did, but just so long a sit looks similar, its OK. as this is for demonstration purposes only.

Now step backwards by holding down your ‘Ctrl’ key and hitting the ‘Z’ key at the same time, each time you do this it will take you back 1 step undoing your previous actions each time.

Now make yourselves 3 clicks at different places in the sky area and see how the selections differ as the program selects what it sees as closely matching pixels while dumping your previous selection. You will now need to make 3 Ctrl + Z’ds to get you back with nothing selected again, alternatively you can just go to your MAIN MENU BAR and choose SELECT then > NONE, (this will always deselect everything).

Some times you need to have a low slider number simply to select an area that may have very similar coloured pixels to another area nearby that you don’t want to select, so you have to keep selecting small islands of pixels until you select the complete area you want to modify. However if every time you clicked somewhere different and the previous selection was dumped it would not be much use to you. There is however a way of making single selections that keep adding onto each other to build up a complex selection.

You do this by changing the MODE, alongside of the Mode Option are 4 small icons, (cyan box) clicking each one results in a different set of choices. The default is the first one ‘Replace the current selection’ and that is what you have just used. As it says, each time you click another selection it will replace the previous one you made.

The next one to that is the ‘Add to the current selection’ icon and as the name implies you would click this icon if you wanted to make multiple selections that kept adding together.

The 3rd icon is the ‘Subtract from the current selection’ icon and is used to remove a selection that you no longer need or have picked by mistake. We will ignore the 4th icon for now.

So try using the three icons and adding to and removing selection areas in your picture.

Finally just for fun, make sure that you have nothing selected in your picture and change the value in the slider to 100. Click on the 1st Mode icon (Replace the current selection) and make a single click as close as possible to the centre of the ‘Yellow Dot’ Hopefully this will have selected the whole of the sky and you can see the ‘Marching Ants’ around the edges. Now you have this area selected you can mess about with the CURVES tool as you did in the ‘Peacock’ picture and change the sky colour and brightness to some degree.

Making selections in this way can be very useful because it may suit you better at some time to use the part that is not selected (the buildings and water). You can do this quite easily by going to your MAIN MENU BAR and choose SELECT then > INVERT, the only difference you may see is the ‘Marching Ants’ are now around the lower portion of the picture.

So get practicing and post any queries in the discussion thread, here’s a quick play around I did with granddads picture using this selection tool to change things around (not claiming it is any good though).

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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

SOME THINGS TO KNOW ABOUT LAYERS

So hopefully by now you have got to grips with the two tools we can use for selecting areas and have been doing some practicing. I ended up over on the discussion thread by having a bit of fun with Grandad by adding a new sky and a few more changes to his DOVEDALE EDITED image, afterwards a few of you were guessing as to how I had actually done this, so I thought showing you how would give us a good introduction to using LAYERS, with this in mind I have done the following tutorial.

Layers are a very important part of your photo editing and it will pay you to understand what they are and how to use them. Most of you probably have some idea, but for those that do not I will briefly cover what they are. A Layer is best thought of as a single page in a book, or better still as a pane of glass, when you first open up your new image it will show as a small thumbnail of that same image over in the LAYERS pallet, now try to imagine that this image has been painted onto a piece of clear glass and what you see in the Layers pallet is just one of possibly many sheets of glass. Anything that you place over the background image may cover up parts or all of that picture and anything placed behind it may only show through in places or not at all.

To try and explain this concept a little better take a look at this tranquil scene of a village green, a pond, a couple of Swans with a lovely blue sky with a few clouds in it.
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It is actually made up from several pictures just to demonstrate how the Layers work, we have a portion taken from this original picture to create our main background.
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We have a section taken from a picture of some water.
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Next a couple of Swans were ‘Copied’ from this picture.
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Finally from my stock folder of sky pictures I chose this one to be the new sky.
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When all the Layers are stacked together it is like looking at the following stack of glass plates.
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This is putting things a little simply in order to explain how Layers work and it will probably leave you with many more questions, but for now just try to take in this concept of how layers can be put together so as to create a final image. It is also possible and in some cases even necessary to move layers into different positions so as to achieve a desired effect. When looking at this particular stack, notice that Layers 2 & 3 are actually interchangeable because there is nothing that can be obscured if they changed positions, but if we were to move layer 1 behind layer 2 then the Swans would not be visible as the water would cover them up. The same logic would apply to Layer 4, it cannot be brought forward of Layer 3 as it has to show clouds behind the trees. So when you are considering what your final image will look like try to picture everything as a stack of images with whatever is on the front one covering up anything else below it, only clear areas can show something beneath. Individual Layers can also be switched ON or OFF (made visible or not visible) by clicking on the ‘EYE’ icon alongside of each Layer

I will leave you to have a think about this for a few days and possibly figure out how I changed Grandads picture, then we will continue with more about the Layers Pallet and how it can help us.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

THE GIMP TOOLBOX

This will help explain the GIMP tool box and hopefully will clarify what each tool does.

The Toolbox is the point of easy access to all the main tools within GIMP.

The tools break down into three primary groups of tools, namely selection, paint and transform tools, with a few miscellaneous tools falling outside these groups.

By default, below the Toolbox is docked the Tool Options dialog, but if you prefer you can remove the dialog from that position and dock it into another raft of dockable dialogs or have it float free on its own. Personally I leave it docked below the Toolbox as that seems the best use of space.

The Tool Options dialog displays various options for adjusting the way that each tool operates. The information displayed varies depending on which tool is currently selected.


Selection Tools
The selection tools offer a range of ways to select areas of images to allow you to work on some pixels without affecting those surrounding them. All of these tools share the same main tool options, including the operating Mode, Ant-aliasing and Feather edges.

(Note that Anti-Aliasing is a method of fooling the eye into thinking that a jagged edge is really smooth)

Rectangle Select Tool – this allows rectangular areas to be selected and offers further options to allow precise positioning and rounded corners.

Ellipse Select Tool – this allows circles and squashed circles to be selected and shares all of its options with the Rectangle Select Tool, though obviously without the Rounded corners option.

Free Select Tool – this is simple tool that can be used to draw a line freely or by clicking on individual points that are then connected by straight lines.

Fuzzy Select Tool – basically this selects areas of an image that are of a similar colour to the point of the image that is clicked – it only makes a single continuous selection.

Select By Colour Tool – this operates in a very similar way to the Fuzzy Select Tool but may produce multiple unconnected selections.

Scissors Select Tool – this automatically attempts to draw a selection by looking for the edge of elements within an image based upon marker points that the user places.

Foreground Select Tool – the effectiveness of this tool can vary depending on the image it is being used on, but it can be an easy and effective way to make complex selections’


Paint Tools, These offer a range of ways to change the appearance of individual pixels or groups of pixels.

Bucket Fill Tool – this will fill a selection with the foreground colour or, if there is no selection, the complete active layer will be filled.

Blend Tool – can be used for a range of effects, including editing layer masks, with the option to produce custom gradients.

Pencil Tool – offers a selection of hard edged drawing tools with options to edit and create new types.

Paintbrush Tool – largely the same as the Pencil Tool but with softer anti-aliased edges.

Eraser Tool – offers same options as the Pencil Tool and Paintbrush Tool, but removes colour rather than adding.

Airbrush Tool – the same options, plus Rate and Pressure controls which affect the opacity.

Ink Tool – offers a range of options to help emulate different styles of fountain pen nib.

Clone Tool – allows users to copy pixels from one part of an image to another part.

Healing Tool – this copies pixels from one area but combines them with existing pixels to help hide blemishes and imperfections.

Perspective Clone Tool – allows pixels from one area to be copied to another area with perspective applied automatically.

Blur/Sharpen Tool – effective tool for applying targeted blur and can also reduce effects of anti-aliasing.

Smudge Tool – neighbouring pixels can be blended together in an organic manner.

Dodge/Burn Tool – digital interpretations of the photographic techniques for lightening and darkening targeted parts of an image.


Transform Tools. Apart from the first two listed here, the transform tools can generally operate on layers, selections and paths.

Alignment Tool – offers controls to allow layers to be aligned or distributed relatively to different items.

Crop Tool – allows users to change shape and size of an image.

Rotate Tool – individual layers, locked layers and paths and selections can be rotated.

Scale Tool – simply resizes with options to maintain proportions.

Shear Tool – gives the ability to make the selected part apparently lean.

Perspective Tool – give the control to apply the effect of perspective to parts of an image.

Flip Tool – options to flip vertically and horizontally.


Miscellaneous Tools. This last group of tools cover several important but standalone features.

Paths Tool – often referred to as the pen tool, it allows the production of Bezier curves.

Colour Picker Tool – select colour from a single pixel or the average of a group of pixels.

Zoom Tool – offers options to zoom in and out of the working image.

Measure Tool – can be used to find a selection of measurements including angles.

Move Tool – has the option to move the active layer or select a layer by clicking on the image.

Text Tool – allows you to apply text through the text editor and apply text to a path.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

EXERCISE 2 ADDING AND USING ANOTHER LAYER

In this exercise we will be doing a simple editing task of replacing the sky in an image by adding another Layer. So as Kiya thought that the Sycamore tree picture I posted o the Autumn Leaves thread was a good candidate we ill use it, just do as previously instructed by right clicking on the image and then saving it to somewhere on your PC.

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Now we need to make this picture into something we can edit and we need to add something called an ALPHA CHANNEL. Don’t get too uptight about this technical term, it is just something we need to do in order for us to modify the picture and it is easy enough to do.

Make sure that the SYCAMORE image is highlighted in your Layers Pallet.

Go to your MAIN MENU BAR and select LAYERS, from the drop down menu choose TRANSPARENCY > then choose APLHA CHANNEL and that’s it.

(if you are actually looking at your title alongside the Sycamore thumbnail when you choose it you may even be quick enough to see the text change slightly, but don’t worry if you don’t)

If you want to see what this actually does, then try this experiment before starting this task properly. Open up any picture you like and use your ERASER tool and do a quick erase of some of the sky, I bet you could not see any difference could you?

Now do enough Ctrl + Z’s to get you back to your un-erased picture again, this time follow the instructions for adding the ALPHA CHANNEL and then use your ERASER tool again, can you now see a clear ‘chequered’ background appearing where you erased the sky?
This is why we need an ALPHA CHANNEL to be added.


So to continue ………………..
After you have made your Sycamore image into an ALPHA CHANNEL we need to add a sky picture into our images in the LAYERS pallet so we can use that as our replacement sky.

I have saved you the trouble of finding one by adding this one for you to copy, do the usual and save it to your PC
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To add this to our existing Sycamore layers go to your MAIN MENU BAR and select FILE, at the drop down menu choose > OPEN AS LAYERS and again choose the TUTORIAL SKY picture from your PC location.

(Note: if you get any messages asking about RGB colour etc, just select CONVERT and it should load)

The next thing you will have noticed is that this has covered up your SYCAMORE image. This is easily sorted out by left clicking your mouse on the thumbnail image and while holding it down drag it on top of the Sycamore image. Alternatively just make sure that your Sycamore image is the one that is highlighted and simply click on the small green arrow at the bottom of the Layers Pallet to move it up.

(Note: This highlighting and clicking on the green arrow can be used to rearrange the Layers into any order you like.)

The idea now is to select the sky area in our SYCAMORE image and using either EDIT > CUT or EDIT > CLEAR to get rid of the sky in our image. You have learned two techniques so far, you could use the SCISSORS and cut around the shapes or you could use the MAGIC WAND and keep selecting areas and deleting them, but there is another method available.

Because we have quite a large area of solid colour we can also use the SELECT BY COLOUR TOOL (5th icon along on the top row). This tool will select all pixels of a similar colour and is very useful for this type of picture. It has all the usual options and settings that you can change so it works the same as the other tools you have learned to use which is very handy.

Now I suggest that you use this tool and set the THRESHOLD at around 50% and click somewhere in the Sky area and you should get all those lovely ‘Marching Ants’

Now EDIT > CUT or EDIT > CLEAR the selected area and remember to deselect the image by using (SELECT > NONE)

If you didn’t quite get everything then just do some more selecting and cutting until you are happy with the result.

Finally we need to lighten that sky up a little, so highlight the sky layer and click on your CURVES tool that you used previously and click and hold your mouse button about central on the straight diagonal line and then drag it diagonally towards the top left corner until you are happy with the results.

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So there you have it, one way that by employing the tools we have already learned to use we can make our dull skies look a lot better, so that should keep you all busy practicing on your old holiday snaps. :lol:
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

GIMP TUTORIAL, USING THE SCISSORS SELECTION TOOL

Tutorial Using the Scissors Tool in Gimp

MAKING THE SELECTION
Open your image in the usual way and select the SCISSORS Tool

Make sure that the 1st small box is checked in the MODE menu “Replace the current selection” (blue box).

Continue clicking the mouse pointer along the outline you wish to select, note that smaller spaces between clicks will give a more defined edge to your selection, as you move around the edge you will see that the line tries to follow the profile of the shape you are selecting.
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You must always complete the loop by clicking back onto your starting point again, this will result in either an outline shape, or a partial outline shape with a straight line back to your starting point.

Once you have made your selection you need to confirm it by moving your pointer to somewhere INSIDE of the selected area (indicated by blue circle)and left clicking.
The area is now selected and will show this by a line of ‘Marching Ants’ around the outline.
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In this selected mode you may carry out any of the modifications allowed within the GIMP programme, from copying, deleting, Hue & Saturation, Brightness & Contrast, Curves and many more operations you may need to carry out.

To demonstrate this I have used the option to EDIT then CUT to remove the wings.
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Once you have completed your actions, select ‘None’ from the SELECT menu to remove the ‘Marching Ants’

MODIFYING THE SELECTION
Some times we need to modify the selection we have made, but the first thing to remember is that there must already be a selection existing. So in this example I have selected the whole of the Butterfly’s wings, but I later decide that I will only need to delete the top part of the wing, so I need to modify my original selection as follows:

Removing part of the Selection.
Change the MODE by clicking on the 3rd box along “Subtract from the current selection” (green box) and using the method described above, select the part you do not want to include in the selection.
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Once you have done this, again left click within the new selected area and another set of ‘Marching Ants’ will appear, this is your SUBTRACTED area.
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So if we once more do the EDIT then CUT option, you can see that only the top part of the wing is removed, afterwards deselect in the usual way.
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ADDING SOMETHING TO OUR SELECTION.
As well as removing something from our selection we can also add something we may have forgotten, in this case it is the Butterfly’s head. To do this we must again change the MODE selection by choosing the 2nd box along “Add to the current selection” (magenta box).

We can then use the normal selection method to click around the head and the usual series of dots will appear as we go along (shown here in magenta). Again clicking in the newly selected area will ADD it to our selection and if we again do an EDIT then CUT it will also remove the head from our Butterfly.
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At the time of writing I have not yet figured out what exactly the 4th button along “Intersect with the current selection” actually does or is supposed to do, no doubt further experimentation by us all using the above options will make this option clearer as we progress.

NOTE. I have noticed that sometimes it is difficult to remove a single dot or two after changing your mind about using the scissors tool and the deselect ‘None’ option is not available and the Ctrl +Z option does not clear the dots. If this happens just select another tool from the Toolbox and click somewhere off your picture and the selected dots should disappear.
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Re:GIMP TUTORIAL, USING THE 'SMUDGE' TOOL

Post by Horus »

Using the SMUDGE Tool in GIMP

The SMUDGE tool is quite a handy one, but it needs to be used selectively.

It is very easy to use, but that can sometimes make it a problem especially if you do not fully understand what you are doing with it and how it works. It is difficult to fully explain how to use it as all images will require different settings, so this tutorial is just to get you familiar with what it does and how changing different settings will affect the results.

Basically all the SMUDGE tool does is to ‘Push’ pixels from one place to another and for that reason alone it can be very useful, especially for filling in a few missing pixels or to blend in a hard edge between two items.

Let us take Grandads Stags in the Glen picture as an example, if we look closely we can see that the sky does not quite touch the land and there is a halo effect around the Stags, it is possible to avoid this happening in the first place or at least minimise the effect, but that method is for a later tutorial, so for now we will try to remedy some of the current defects by using the SMUDGE tool only.

As I said before, all the tool does is to push pixels about, so if we simply push some sky pixels down towards the top of the hills then that should do the trick by removing the white halo area, but before we can do that we have a few choices to make.
We must choose a brush shape.
We must choose how big the brush is going to be.
We must choose the angle of the brush.
We must choose how much opacity we have for the pixels we are pushing.
And how hard we make the edges of the movement of the pixels.

Now all this may sound very complicated, but rest assured that it is not, it is no more difficult than using your paint brush tool or eraser tool, in fact they almost all work in a similar manner. To help you to understand better, download the colour swatch below and open it up in your GIMP program as you would a normal picture.

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Now I hope that you can all remember how we moved the slide bar pointers along when we did the ‘Magic Wand’ tutorial and I told you at the time that all these sliders would work in the same way regardless of which tool you have selected.

So first of all select the SMUDGE tool, third icon from the left, 5th row down (green box)

Next we need to select a brush, so click on the ‘Brush’ icon (magenta box) and from the ‘drop down’ menu that appears choose the 3 rd Round brush (blue box) then click anywhere on the background to close the ‘drop down’ menu again.
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Now set up all the sliders to look the same as my example below, there is no real logic to the settings I have used and they are only for my demonstration purposes and to give you all the same brush settings.
Remember that by clicking on the ‘Up’ & ‘Down’ small squares to the right of the slider numbers (indicated by Red dots in the above image) it will change them more accurately. This is very handy after using the slider bar arrows to roughly position your slider bar to the approximate location.

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Now position the left hand edge of your brush in the MAGENTA square next to the BLUE line and whilst holding your left mouse button down, swipe it all the way to the left across the YELLOW square and off the other side.

Next drop the number in the bottom slider (the RATE) down to around 75% and positioning your brush just above the first example repeat the sweep across the YELLOW square.

Now repeat the above move after reducing the RATE to 50%

Finally change the RATE to 25% and repeat the move.

So we can see from the swatch below that with the OPACITY set at 100% it is the change in the RATE that makes the PUSH of the pixels less stronger, notice how at 25% the BLUE line is not pushed as far over, so we can say that the RATE setting is a bit like the strength of the PUSH.

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Now let us see what happens when we set the OPACITY at different values.
We have already seen that with a RATE of 100% and an OPACITY of 100%, all the pixels get PUSHED across very strongly. So we will leave the RATE set very high at 100% but this time we will change the OPACITY, so let us start by dropping that to 50% and repeating the same exercise in the RED square.

Now repeat this with 25%, 12% & 5% OPACITY and you should get a similar result to mine.

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Using a combination of these settings you can determine a suitable brush size to use and play around with the OPACITY & RATE values to achieve a suitable blend of how the pixels are PUSHED from one place to another.

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The angle of the brush can be changed so as to suit the shape you are tidying up, at present the brush is at a 90 degree angle. You can see the effect of changing the angle by moving your ANGLE slider all the way to the right and it will rotate the oval shape of the brush from vertical to being horizontal. The best way to think of it is as a clock face using only the big finger to point at the numbers.

-180 would be 9 O’clock
-150 would be 10 O’clock
-120 would be 11 O’clock
-90 would be 12 O’clock
And so on, as you move the slider the brushe's shape will rotate either left or right and the numbers indicate the actual degrees of rotation, but it is unlikely that anyone ever needs to be that precise, a good guess is usually good enough.

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Finally there are lots of other brush shapes that you can choose from, so when you want to use this particular tool it is as well that you experiment so as to understand how different setting will affect the outcome. So once again, it may seem complicated, but it isn’t, just get some practice in by using this tool and any old picture and start pushing some pixels around to see how it works, remember to play about with the brush types, the ANGLES, the OPACITY & the RATE not forgetting different brush sizes.

Here is a section of Grandads skyline with some pixels ‘SMUDGED’ downwards to close up the white halo.
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PRACTICE MAKES PERFECT!
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

GIMP TUTORIAL
MAKING SELECTIONS USING THE ‘SHRINK’ 'GROW' & ‘FEATHER’ OPTIONS

When cutting and pasting new items such as skies, people, animals etc. into your images people will often comment that they look false. This is mainly due to either a sharp edge around the pasted item or alternatively a (usually) white ‘halo’ effect along an edge or around the item that was copied and pasted.

The reason for this effect is that the selection tool you used to isolate the item makes a decision based upon the surrounding pixel colours and stops the selection at what it assumes to be the edge. This often results in jagged or very sharp edges that make the selection stand out as being unreal when it is pasted into another image.

What we need to do is to make sure that we have selected right up to the boundary of the selection and that we make the transition from one shape (the selected image) so that it blends more smoothly into the main image we are using.

The two options we will look at are ‘SHRINK’ & ‘FEATHER’

FEATHER is a common command that may be applied to lots of actions, but for now we will just apply it to making selections with the ‘Magic Wand’ or the ‘Scissors’ tool, it works the same using either tool.

SHRINK does exactly as it says and it will ‘shrink’ any selection we may make by the amount of pixels that we tell it to use. The opposite of ‘shrink’ is GROW and the two can be said to be interchangeable as it depends upon the circumstances when you choose either option.

As an example, if you had a Red ball on a white background and you selected the ‘Red’ ball, the selection would stop at the edge of the RED pixels, but to make sure we had no ‘White’ pixels selected we could SHRINK the selection to ensure we were still in the Red colour.

On the other hand if we had chosen to select the ‘White’ background for deletion, as in the case of a sky, then we would GROW the selection to ensure that we had cut into the Red ball by a few pixels.

So let use do a practical example of using these two techniques.

First of all open your GIMP programme and create a ‘New’ image by selecting File > New and entering the new size as 700 x 350 then click OK.

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Once you have created the ‘New Image’ use your paint bucket tool and fill the new window with solid BLACK colour.

Now copy and then open the 10 Ball image in Gimp.
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Select the Ten Ball picture by highlighting the bar at the top and then choose the ‘Magic Wand’ tool. (green box)

Set the THRESHHOLD (blue box) to 100% and click the ‘Magic Wand’ anywhere in the white area of the Ten Ball image and you will see the Marching Ants around the outer square and the outside of the ball.

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Because we do not actually want to select the white area, we need to INVERT our selection. To do this click on the SELECT menu option (ON THE TEN BALL IMAGE) (magenta box) and at the drop down menu choose ‘Invert’ (green box) and the Marching Ants will now only be around the Red Ball and that is what we want as our selection.
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It is at this point that most people will choose to Copy the selection and paste it into their main picture.
So while keeping the ‘Ten Ball’ image window highlighted, go to EDIT (green box) and select COPY (magenta box)

IMPORTANT, you now need to make the other image (the black rectangle active) to do this click anywhere on the top bar (highlighted in yellow)

You are now working in the other window so you must now use the menu options just below the Yellow Highlighting and NOT the menu in the ‘Ten Ball’ window.

Continue by PASTING the ‘Copied’ image into the Black Rectangle image.
Usually this positions the ‘pasted’ image near the centre and we need to ‘Move’ this to the right hand side of the rectangle.

We do this by selecting the MOVE tool (blue box) and clicking our mouse on the ‘Pasted’ selection and while holding the button down we can move it over to the right hand side of the black rectangle.

When we are happy with the ‘Move’ we need to lock it in as part of the BLACK RECTANGLE image, to do this click on the small ‘Anchor’ icon at the base of the Layers pallet (cyan box) at it becomes a part of the main image and can no longer be moved separately.

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That completes a ‘normal’ Copy & Paste of one item into another image, but take the time to look at a larger view and you will see the white lines or halo’s around the Red Ball.

We could of course use one of the other methods such as SMUDGE to tidy up the edges, but that is very time consuming and an easier way exists.

Go back again to your Red Ball image and it should still be selected with a line of Marching Ants around the outside, if not then repeat the original selection up to the point when you ‘inverted’ the selection.

Again using only the Red Ball image menu bar for these operations, instead of just selecting the ‘Copy’ option we will make some changes first.

Once again click on the SELECT menu icon (green box) and then select the option SHRINK (magenta box).

Another sub-menu will appear (blue box) and in this box we enter the number of pixels by which we want our selection to ‘Shrink’ by, in this case we will enter the number 1 by either typing it in or by using the up/down arrows, then clicking OK.

We have now reduced or ‘shrunk’ our selection by one pixel all around the ball, we can in other instances type in any number we like to suit the occasion. If you wish to see how this would affect the selection, try instead entering the number 50 in the box and then clicking OK and the selection will shrink by about half the ball diameter, use ‘Ctrl + Z’ to dismiss that choice and enter the number 1 as previously.

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The next thing that we can do is to FEATHER the edge of our selection. All that ‘Feathering’ means is that instead of us say having a pure Red or pure Black coloured pixel at the edge which usually results in a sharp line, we can soften the pixels colours so that they ‘fade’ through the range of edge colour or colours and so appear less sharp, this is called ‘feathering’ The amount of FEATHER can be varied and in the same way that Shrink would move the selection inwards from the edges by a given amount of pixels, so the number in the FEATHER box increase the width of the pixels that the FEATHER will use to blend the edges.
Imagine it to be similar to an ink blot spreading through blotting paper, the ink colour will fade as it spreads outwards from the centre of the ink blot, feathering can be compared to that.
Remember also that FEATHER can be applied to some other types of tools in the Gimp programme.

So to continue, still working with the Red Ball image and menus, once again click on the SELECT menu (green box) and choose the FEATHER option from the drop down menu (magenta box).

Another sub-menu similar to the Shrink menu will appear and it works exactly the same way, this time type in the number 2 in the box and then click OK.

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Still in the Red ball window & menus make your usual EDIT > then COPY.

Finally click on the header once more in your BLACK RECTANGLE image to make it the ‘active’ image and using the Menus in that window select EDIT > then PASTE and the shrunk & feathered selection will again be pasted into your black rectangle. Reposition it as done previously and again click the ‘Anchor’ icon in the Layers pallet to fix the selection.

Now if you zoom up the level of the finished image you will see a noticeable difference between the outer edges of the two Copy & Pasted red balls.

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Again this is another tool that needs some experimentation and using the methods described you can tailor it to suit most situations. The numbers that I have given for this tutorial of 1 for shrink and 2 for feather are a general guidance only and will need to be adjusted for individual images, but are a good rule of thumb.

So to recap, you may make a selection by using the Magic Wand or the Scissors tools.

You may choose to Copy & Paste that selection without any further modifications.

If you wish you may refine that selection by using the Shrink, Grow or Feather options to give your selection a better edge.

You may use any combination of the Shrink, Grow or Feather options, therefore you may Shrink or Grow without adding a Feather if you wish, alternatively you may use both options as additions to your original selection or none at all.

The only requirement is that you make these additions BEFORE you Copy & Paste the selection.
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Re: WORKING WITH GIMP SOFTWARE

Post by Horus »

ADDING A SHADOW, GIMP TUTORIAL

Sometimes it is nice to have shadows in images, especially nice sunny ones as they can add to the effect. If you have such a picture and wish you had a nice shadow to set it off you can use several methods, one way is to physically use your painting skills to add one, or you could just let GIMP do the work for you.

First of all you need to select a suitable image to add a shadow to, so for my demonstration I have chosen this bronze statue which you may download by right clicking the image and choosing to save it somewhere on your PC.

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Open up your GIMP programme in the usual way and import the “Statue” picture. It is always worth looking at any picture you intend to use and decide if or not it may need a bit of Brightness, Contrast or Colour correction doing to it before adding your shadow as a dull image will not look very good.

After carrying out any adjustments make a “Selection” of the statue by using your SCISSORS tool as we have done previously in other exercises, remember that you always need an object to be ‘actively selected’ before you can add a shadow to it. It is up to you to decide on how precise you make the selection, sometimes just a rough outline is sufficient for your needs, whereas at other times such as with this statue, we want the shadow profile to look fairly distinct when seen against the grass. It does not matter at which point on the outline you start making your selection as the program adds the shadow relevant to your final selection being vertical.

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After making your outline selection and hitting the ENTER key, it will change to a ‘Marching Ants’ outline. We can now add the shadow by going to your Main Menu and selecting
FILTERS > then LIGHT & SHADOW > then PERSPECTIVE.

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Another drop down menu will appear that asks you to enter your required settings. I have shown them all in the image below and briefly explained their purpose, but I will go into more detail as we go through the tutorial.

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The ANGLE of the shadow (red box) can be easily set by typing in the required angle in the slider box, or by moving the slider bar itself to the required angle, if precision is required then use the small up and down arrows to the right of the number box and determines at what angle your shadow will be in your image.

Some slight confusion may occur due to the slider bar moving from Left to Right in order to INCREASE the angle, but this results in your shadow moving in a Right to Left arc as zero degrees start on the RIGHT and increase to 180 degrees on the LEFT. Therefore your shadow will rotate in an arc of 180 degrees and if looked at as a clock face then it would be moving backwards:
0 degrees would be 3, O-clock
30 degrees would be 2, O-clock
60 degrees would be 1, O-clock
90 degrees would be 12, O-clock
120 degrees would be 11, O-clock
150 degrees would be 10, O-clock
180 degrees would be 9, O-clock
You may type in any number between 0 & 180 degrees, although the very low or very high numbers are sometimes hard to see. Also notice how in addition to rotating the shadow itself changes shape dependant upon the angle you choose.

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There is another setting which is the “Relative distance of horizon” (green box) which has a range of 0 to 24.1 and it is a strange one, well at least to me it is. The only thing I can say is that it seems to make the shadow ‘Fatter’ but quite what that has to do with “Relative distance of horizon” I haven’t yet figured out, so I think its best to just think of it as making your shadow wider. It will of course have it’s uses because like anything else in photo manipulation and editing it is down to the users interpretation, so in some cases you may feel that the shadow you have added looks a little too wide or too thin for the kind of effect you are looking for, so this can be a good adjustment setting and should not be overlooked.

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The “Relative Length of shadow” (blue box) is fairly self explanatory insomuch as it will change the length of the falling shadow as a fraction of the selected item. Therefore a length of 1 is of equal length, whereas .5 would be a half and so on, it is also possible to produce long evening shadows by increasing the size beyond 1, but this will need care as overlong shadows don’t always look good.

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The “Blur Radius” (orange box” will determine how sharp the edge of your shadow will be, low numbers will just take the sharpness off the outline, whereas larger numbers will make the shadow a lot less distinctive.

The “Colour” button, usually defaults to Black, but by double clicking the button it will bring up the colour pallet and if you wish you may choose another colour. It is worth mentioning here that it is not worth changing this even if you want a shade of grey for your shadow as this can be easily done using the OPACITY level.

The “Opacity” slider will adjust the shadow from being a solid colour to being fully opaque.

Here is my efforts of adding a shadow and I have listed the settings that I used.

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As I said it is not a precise art and you need to experiment in order to get the best results and again it is case of practice makes perfect. :up
Image

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