Commit a866cd69 authored by Pat David's avatar Pat David

Add images and minor editing of new Ofnuts tutorials

Add some images to help readers locate options.
Fix minor changes in text and formatting.
parent 57cb76cf
......@@ -7,23 +7,38 @@ Template: page_author
Making a circle-shaped image
============================
**Foreword:** There are no circular images. There are only rectangular images.
There are no circular images. There are only rectangular images.
But there can be images where corners are transparent, so that only a circle shows.
* First, make sure that your layer has an "alpha channel" (*Layer>Transparency>Add alpha channel*)(if it's grayed out, it means you already have one)
* Create a circular selection with the "Ellipse select tool (the 2nd one in the toolbox).
Use the "Tool options" dialog (*Windows>Dockable dialogs>Tool options* (top of list)).
In light of this:
* First, make sure that your layer has an "alpha channel".
<div class='MenuCmd'><span>Layer → Transparency → Add alpha channel</span></div>
if it's grayed out it means you already have one
<figure><img src='add-alpha.png' alt='GIMP Add Alpha Channel Dialog'></figure>
* Create a circular selection with the "Ellipse select tool" (the 2nd one in the toolbox).
<figure><img src='ellipse.png' alt='GIMP Ellipse Select Tool'></figure>
Use the "Tool options" dialog
<div class="MenuCmd"><span>Windows → Dockable dialogs → Tool options</span></div>
<figure><img src='tool-options.png' alt='GIMP Tool Options'></figure>
* If you want a true circle, use the *Fixed* option: select *Aspect ratio* and enter `1:1`.
* Depending on what kind of marks you have, you can use:
* The diagonal framing (default): click on one corner, drag across a full diagonal and release at the opposite corner,
* The radial framing (check *Expand from center* in the Tool options): click on the center, drag across a half diagonal release on a corner.
* If the selection isn't perfect on the first try, you can move it (click around the middle) or extend it (click inside, near a border or a corner).
* Once you have the required selection, invert the selection (*Select>Invert*, or Ctrl-I) so that everything is selected, except your circle
* Erase the selection (*Edit>Clear* or [Delete] key). You should have your central circle left, surrounded by a checkerboard pattern
* Once you have the required selection, invert the selection (*Select&nbsp;→&nbsp;Invert*, or Ctrl-I) so that everything is selected, except your circle
* Erase the selection (*Edit&nbsp;→&nbsp;Clear* or [Delete] key). You should have your central circle left, surrounded by a checkerboard pattern
(this checkerboard is not part of the image, it just indicates the transparent parts of the image).
* You can reduce the checkerboard to the minimum by auto-cropping the image (*Image>Autocrop image*)
* You can reduce the checkerboard to the minimum by auto-cropping the image (*Image&nbsp;→&nbsp;Autocrop image*)
* Last, save the image in a format that supports transparency, like PNG (JPEG doesn't support transparent images...)
* If you are going to work further on the picture, save ist as XCF (Gimp native format).
* If you are going to work further on the picture, save it as XCF (Gimp native format).
<small>
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......@@ -4,8 +4,7 @@ Modified: 2016-09-04T20:54:21-05:00
Author: Ofnuts
Template: page_author
What is my "Gimp profile" and where do I find it?
=================================================
## What is my "Gimp profile" and where do I find it?
The "Gimp profile" is a directory/folder (actually a directory tree) where Gimp keeps information that pertains to you, the user:
* your windows and dialogs setup
......@@ -13,19 +12,29 @@ The "Gimp profile" is a directory/folder (actually a directory tree) where Gimp
* your keyboard shortcuts
* your brushes, gradients, palettes, patterns, fonts, scripts, plugins and brush dynamics (as opposed to those installed for the benefits of all users).
## Locating the Gimp profile
### Locating the Gimp profile
Since it is a personal folder, Gimp keeps it with others files that also belong to you, usually:
* In Windows XP: `C:\Documents and Settings\{your_id}\.gimp-2.8` (ie, a "sibling" of "Application Data" and "My Documents")
* In Vista, Windows 7 and later versions: `C:\Users\{your_id}\.gimp-2.8` (ie, a "sibling" of "Application Data" and "My Documents")
* In Linux: `/home/{your_id}/.gimp-2.8` (a.k.a. `~/.gimp-2.8`)
* In OSX: `/Users/{your_id}/Library/GIMP/2.8/` or possibly `/Users/{your_id}/Library/Application Support/GIMP/2.8/` (this could depend on the Gimp build you use).
* In Windows XP:
`C:\Documents and Settings\{your_id}\.gimp-2.8`
(ie, a "sibling" of "Application Data" and "My Documents")
* In Vista, Windows 7 and later versions:
`C:\Users\{your_id}\.gimp-2.8`
(ie, a "sibling" of "Application Data" and "My Documents")
* In Linux:
`/home/{your_id}/.gimp-2.8`
(a.k.a. `~/.gimp-2.8`)
* In OSX:
`/Users/{your_id}/Library/GIMP/2.8/`
or possibly
`/Users/{your_id}/Library/Application Support/GIMP/2.8/`
(this could depend on the Gimp build you use).
The `.gimp-2.8` part is of course version-dependent, so in the near future you may have to look for `.gimp-2.9` (or you may still be using `.gimp-2.6`).
If you run several versions in parallel, you will have a profile for each, i.e., distinct profiles for Gimp 2.6 and Gimp 2.8, while all the successive updates to Gimp 2.8 will use the same profile.
### If you don't find it in the locations above
#### If you don't find it in the locations above
* If you are on Linux or OSX, keep in mind that the leading dot in the name makes many tools "omit" to display it,
so you may have to explicitly ask your file explorer to display hidden files to navigate to it.
......@@ -34,19 +43,20 @@ for instance because the user profile has been moved to another partition/drive
Here are two tricks to find it (they both assume that Gimp can run):
#### Trick #1
##### Trick #1
* *Edit>Preferences* and open the *Folders* tree in the left pane of the dialog.
* *EditPreferences* and open the *Folders* tree in the left pane of the dialog.
* If you click on any of the folders (for instance, Brushes), the right pane will normally display two folders:
* The non-writable one is the one that holds system-wide features (brushes in this case), located somewhere in the Gimp installation tree
* The writable one is your own brushes folder in your Gimp profile: the Gimp profile is its parent folder.
<figure><img src='folders.png' alt='GIMP Preferences Folders'></figure>
* The non-writable one is the one that holds system-wide features (brushes in this case), located somewhere in the Gimp installation tree
* The writable one is your own brushes folder in your Gimp profile: the Gimp profile is its parent folder.
#### Trick #2
##### Trick #2
* Open Filters/Python-fu/Console
* Enter this: `print gimp.directory` and srtoke [Enter]
## When to use the Gimp profile
### When to use the Gimp profile
Your Gimp profile is the right place to install additional material (scripts, plugins, brushes, palettes, fonts, gradients...).
It is a much better place than the system Gimp installation folder:
......@@ -55,7 +65,7 @@ It is a much better place than the system Gimp installation folder:
* The additional items will not be wiped out by a Gimp re-installation
* They are more likely to be backed up since they are part of the user's data
## Repairing the Gimp profile
### Repairing the Gimp profile
Gimp Startup failures can be caused by profile problems. In that case it is pointless to re-install Gimp,
since the re-installed version will re-use the existing profile and therefore fail in the same way.
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......@@ -4,120 +4,130 @@ Modified: 2016-09-04T21:58:31-05:00
Author: Ofnuts
Template: page_author
Pros and cons of various images formats from a Gimp perspective
===============================================================
XCF
---
## Pros and cons of various images formats from a GIMP perspective
### XCF
### Pros
#### Pros
* Native Gimp image format. Everything is saved: layers, selections, channels, paths
* The Native GIMP image format. Everything is saved: layers, selections, channels, paths and more.
### Cons
#### Cons
* Not a "display" format, even if you can find codecs to display thumbnails of XCF image in file explorers.
* Bulky
* Color channels are coded on 8 bits (in Gimp 2.8)
* Bulky.
* Color channels are coded in 8 bits (in GIMP 2.8).
### Recommended uses
#### Recommended uses
* Saving all Gimp work
* Saving all GIMP work.
JPG
---
### Pros
### JPG
#### Pros
* Compresses the files quite efficiently.
* Universally supported for display
* Universally supported for display.
### Cons
#### Cons
* Compression is "lossy" and it slightly alters the image data. In case of global changes (color, contrast...) repeated file editing will slowly degrade the image quality.
* Compression is "_lossy_" and it slightly alters the image data. In case of global changes (color, contrast...) repeated file editing will slowly degrade the image quality.
* At good quality levels, compression is invisible in photography, but can be seen (so called "artifacts") in computer-generated graphics and text.
* Doesn't support transparency
* Color channels are coded on 8 bits
* Doesn't support transparency.
* Color channels are coded on 8 bits.
### Recommended uses
#### Recommended uses
* Display of photography
* Storage of photography
[A more complete FAQ on the subject](http://www.faqs.org/faqs/jpeg-faq/part1/)
PNG
---
### Pros
### PNG
#### Pros
* Lossless format, all pixels are kept.
* Supports partial transparency.
* Produces small files with most computer graphics.
* Supported by all browsers.
* Lossless format, all pixels are kept
* Supports partial transparency
* Produces small files with most computer graphics
* Supported by all browsers
#### Cons
### Cons
* Complex images (photos) are bulky.
* Color channels are coded in 8 bits.
* Complex images (photos) are bulky
* Color channels are coded on 8 bits
#### Recommended uses
### Recommended uses
* Web page widgets: banners, buttons, frames, etc...
* Computer graphics.
* Screenshots (unless this screenshot contain mostly a photo).
* Web page widgets: banners, buttons, frames,...
* Computer graphics
* Screenshots (unless this screenshot contain mostly a photo)
GIF
---
### Pros
* Universally supported for animation
### GIF
#### Pros
* Universally supported for animation.
### Cons
#### Cons
* Only 256 colors per image, leads to blocky look
(a modern variant supports 256 colors per frame, but Gimp doesn't use it)
* Supports transparency but only as fully transparent/fully opaque
* Only 256 colors per image, leads to blocky look.
(a modern variant supports 256 colors per frame, but GIMP doesn't use it).
* Supports transparency but only as fully transparent/fully opaque.
### Recommended uses
#### Recommended uses
* Small animated images (in all other still-image uses PNG is a better alternative,
and for bigger animation modern HTML supports video)
TIFF
----
### Pros
* Small animated images.
(in all other still-image uses PNG is a better alternative, and for bigger animation modern HTML supports video)
* Lossless format, all pixels are kept
* Color channels can be coded in 16 bits
* Can store several images (layers)
---
### TIFF
#### Pros
* Lossless format, all pixels are kept.
* Color channels can be coded in 16 bits.
* Can store several images (layers).
* Supported by all image processing software.
### Cons
#### Cons
* Can be bulky on complex images
* Can be bulky on complex images.
### Recommended uses
#### Recommended uses
* Storage and exchange of high quality images
* Storage and exchange of high quality images.
Raw images formats (NEF (Nikon), CR2 (Canon)...)
------------------------------------------------
---
### Raw images formats (NEF (Nikon), CR2 (Canon)...)
### Pros
#### Pros
* No loss of information from the camera sensor (in theory)
* High-depth color channels (12 or 14-bit)
* No loss of information from the camera sensor (in theory).
* High-depth color channels (12 or 14-bit).
### Cons
#### Cons
* Proprietary (except DNG)
* Proprietary (except DNG).
* Content format can change without notice (new camera models), this can impact support by your favorite software.
* Bulky
* Not suitable for display
### Recommended uses
* Bulky.
* Not suitable for display.
#### Recommended uses
* Storage of camera output, but a secondary copy in some universal format could be a good idea.
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