GIMP Basics
The
GIMP
is a free image editing tool.
However, since nothing is obvious, it is a real pain to learn.
There are also a few design errors.
Basic Hints
| Simple Icon Example
Basic Hints
- If you want to increase the size of a layer,
then you must also increase the size of the image.
- The Eye Dropper tool in the Change Color DialogBox does not work.
Instead use the Color Picker (Eye Dropper) from the Toolbox or select
The keyboard shortcut works in some cases, just press the ctrl key.
(Works with the pencil and paintbrush tools, not with the fill tool.)
By default, this tool only works with the selected layer. To capture any visible color
(ie, a color in another layer), in the Color Picker / Tool Options panel,
check Sample merged.
- New text is added on its own layer. To reposition it, hold down the Alt key.
To make icons, it must be merged to its background.
- Once text is added, it is easy to edit ..
unless it was entered via
Then there is no way to edit it.
(See solution in next section.)
- The Lock pixels icon is located at the top of the Layers window.
It shows (and controls) the lock state for the currently selected layer.
- The icon next to the eyeball is a chain - it does not lock the layer.
(Since there is no hint window, this was hard to find.)
In GIMP 8.6, the Eye Dropper tool in the Change Color DialogBox
is broken
- it always returns black.
According to
the old GIMP 2.8 color dialogbox help
- Color picker
- The color picker has a completely different behavior, than the color picker tool.
Instead of picking the colors from the active image,
you're able to pick colors from the entire screen.
|
Simple Icon Example
I was trying to create an icon.
To start, I selected
File / Create / Logos / Chrome...
|
I entered Screen Capture and it created an 818x162 image.
Since icons are square, I wanted to move the second word under the first.
In most of the other programs I use, this is simple -
just enter text mode and add a return.
Well ... I never figured out how to do that.
Apparently, because the text was modified to look pretty when the logo
was created, basic text editing is now disabled.
I tried to create the logo with a return between the words -
I eventually gave up and used the procedure described below.
The solution turned out to be simple
- Create multiline text in the image
- With the text layer active, select
Filters / Alpha to Logo / Chrome...
|
However, I found that after writing the following.
Original work around
As an alternative, I decided to simply
select the text and drag it to the new location.
Well, that was a lot harder than expected.
This is what finally worked.
- Double the height of the image (to provide space for the new line of text)
Just type - *2 - next to the existing height and press enter.
There will be an option to also resize the layers - select yes.
Select Resize.
- Collapse the text and shadow layers into a single layer
- Click the eyeball to hide the background layer
- Right click and select Merge Visible Layers...
- If you include the background layer, you will have extra cleanup work later
- Cut and paste to rearrange the text
- Draw a selection box around the second word - use Rectangle Select Tool
- Cut the selection - Ctrl-x
- Paste the selection - Ctrl-v this creates a new floating layer
- Use the mouse to position the floating layer
- Paste the result (which collapses the layers) by clicking outside the text
- If the height of the original layer was not increased,
then the pasted image just disappears.
- Crop and resize image (which is now too wide, and to make the smaller image square)
- Use the Crop Tool (looks like a razor knife)
- Outline an area and press enter
- Use
again and copy the larger number to the smaller.
The crop step was included to quickly determine the larger number.
Be sure to also resize the layers.
- Fix the background layer
- When the layers were resized, the color in the background layer was not
extended to the new section. From the menu, select
- Click on the color you want to copy
- Use the Bucket Fill Tool to color the lower (white) section
- Note that the Eye Dropper tool in the Change Color DialogBox does not work
in GIMP 8.2.
- Another way to select an existing color is to press the ctrl key and click on something.
This works with the Pencil Tool, but not with the Bucket Fill Tool.
- Resize the image
- Resize Canvas clips the image, this shrinks it
- Be sure the height and width are linked
- Use 256, 128, or 64 - your choice
- To make the default background transparent, select that layer and use
Layer / Transparency / Add Alpha Channel
|
Then the Eraser will work. You may not need this step.
- Merge all the layers together
Image / Merge Visible Layers...
|
- Be sure all the layers are visible
- If you use Flatten Image, then the transparency will be lost
- Create the smaller icons
- Each icon is placed on a different layer
- Make a copy of the base (large) icon layer - use either the double window icon or
right click the layer and select Duplicate Layer
- For each addition layer, divide the layer size by 2 - 64x64 32x32 16x16.
Right click the layer and select Scale Layer....
Either type in the new size, or just type "/2" after the current size (nice shortcut).
Be sure the height and width are linked.
- Repeat until all sizes are created - should be sure to include 32x32 and 16x16
- Also include a 48x48 icon (used by Windows Explorer)
- The order of the layers does not matter
- Save the file
- Enter a filename with the ico extension
- On the next screen, be sure to select
32 bpp, 8-bit alpha, no palette for each image.
For Delphi 5, be sure that no layer has png compression selected or
the program will not compile.
- Click Export
It appears that Windows XP only uses the 16x16, 32x32, and 48x48 icons.
Other systems use larger ones.
Author:
Robert Clemenzi