GIMP/Gradient
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[edit] The Basics
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There are several ways to blend with GIMP, as it allows you to make gradient in many different methods.
On the right side you can see default settings for gradient. Here's short (and then long) description about everything there:
-
- Mode - you can select mode here (more information in the Modes article)
- Opacity - set whether gradient will be transparent or fully visible
- Gradient - type of gradient
- Offset - effects how far along the start colour in the gradient begins
- Shape - shape of gradient
- Repeat - way of repeating
- Dithering - helps reduce banding by dithering the gradient.
- Adaptive supersampling - try to refine the gradient in high contrast areas. Choose how much difference is required before supersampling activates, and how hard GIMP tries to get good quality samples.
[edit] Opacity
This bar controls the transparency of the gradient. Any value between 0.0 and 100.0 is possible with 100 being fully opaque and 0 being fully transparent. The default value is 100.
[edit] Gradient
There are hundreds of types of gradients in GIMP. Neons, flags, flares and much more. All of them have their own effect, but only few use selected colours. Here's short description of them:
- FG to BG (HSV anti-clockwise) - using HSV palette, moves counter-clockwise
- FG to BG (HSV clockwise hue) - using HSV palette, moves clockwise
- FG to BG (RGB) - using RGB palette
- FG to Transparent - moves from foreground colour to transparent.
Next to it you can see a flip option (
). It just changes the direction of gradient ( for example instead of FG to BG, BG to FG ).
[edit] Offset
Increasing offset effects what visual range the gradient is drawn in. when offset is equal to 0, as by default, the gradient begins at the start of the blending line; when offset is equal to 50, the gradient begins at the halfway point in the blending line, and earlier points are rendered with the same colour as the leftmost colour in the gradient. Maximal value of this option is 100.0, which makes the gradient have only one colour.
[edit] Shape
There are eleven shapes for gradient. If you count two as the same ( that one is symmetrical or asymmetrical ), then there are only nine. Here's a description of them.
- Linear - just goes from some colour to other as long as you select it. It gets lighter on every line
- Bi-linear - same as linear but goes to two sides
- Radial - creates a radial using same method
- Square - creates a square using same method
- Conical (sym/asym) -
- Shaped (angular/spherical/dimpled) - fits the gradient to the shape of the selection.
- Spiral (cw/ccw) - creates a spiral determined by the length of the line
[edit] Repeat
There are three options for repeating:
- None - just doesn't repeat
- Sawtooth wave - once passing the end of the gradient, begins again at the start
- Triangular wave - once passing the end of the gradient, blends backwards until the start, and then begins blending forward again..
You can use them with those shapes: Linear, Bi-linear, Radial, Square, Conical (sym), Conical (asym). It doesn't take any effect in the last two.
[edit] Dithering
Dithering reduces possible banding in the rendered gradient. If your gradient includes deliberately banded areas, turn dithering off in order to preserve them. If the result must be very precise, consider turning dithering off also (dithering trades spatial resolution for colour resolution, which is only good if you have spatial resolution to spare.)
[edit] Adaptive Supersampling
Adaptive supersampling identifies areas that seem to have high contrast and tries to improve the precision of the rendering only at these points. The general effect is that areas of high contrast are smoothed out; One easy way to see this is comparing the appearance s of a 'sawtooth wave' repeated gradient with and without supersampling enabled. The options in this section allow you to control
- How much contrast is considered 'high contrast'
- How much GIMP will try to improve the sample quality before accepting the result (this comes into action when the additional samples' relationship to each other is also considered as high contrast)
See supersampling for a detailed explanation
