Under Global Parameters, we consider two types of parameters: pre-processing and post-processing, parameters. Those parameters affect image processing in both modes: brush actions and actions applied to complete image if not explicitly stated otherwise.

Color Restrictions

Color Restriction panel is used for image pre-processing. Parameters set by this option are used for image pre-processing. Those parameters actually control which pixels will be processed by some action.

As you can see from the above picture, there are 15 restrictions available. When 0 restriction is selected (default), no restrictions are applied prior to image processing.

Epsilon slider is used to determine the tolerance of restriction. When set to 0 (default), no tolerance exist.

On the right part of this page, every restriction is discussed under its respected ordering number.

1.
This restriction limits action only to pixels having maximum color value above some value given by Epsilon slider.
2.
This restriction limits action only to pixels having minimum color value below some value given by Epsilon slider.
3.
This restriction limits action only to pixels having color similar to foreground color. If Epsilon has zero value, pixels must have equal color, if Epsilon has some positive value, action is applied to pixels having color in the range [ foreground - Epsilon, foreground + Epsilon].
4.
This restriction limits action only to pixels having color with equal RGB components value. Tolerance (+/-) is given again by Epsilon slider value.
5., 6, 7.
These restrictions limit action only to pixels having red component of type MaxVal, MidVal or MinVal respectively. Tolerance is given by Epsilon slider value.
8., 9., 10.
These restrictions limit action only to pixels having maximum, medium or minimum green component value respectively, with tolerance given by Epsilon slider value.
11., 12., 13.
These restrictions limit action only to pixels having maximum, medium or minimum blue component value respectively, with tolerance given by Epsilon slider value.
14.
This restriction prohibits action on randomly chosen pixels. Epsilon value has no meaning with this restriction type.
15.
This restriction is similar to restriction type 3. except that instead of foreground color, background color is considered.

Transparency & Channels of Interest

This panel is used to determine some very important parameters for image pre-processing and image post-processing.

As you can see from the above picture, only sliderTransparency is not considered into account when applying brush actions. All other parameters apply for both brush and complete image actions.

Transparency slider is used to determine transparency percent between edited and original image. Edited image is actually copy of current image, but with some action applied on it. New final image is constructed by merging edited and original image by the means of transparency value. Transparency value of zero denotes that only edited image will be final image. Transparency of 100 % means that no actions will be visible on final image. If transparency value is somewhere in between, final image pixels are calculated by the formula:
Final_pixel =
Edited_pixel*(1 - Transparency/100) + Original_pixel*(Transparency/100)

PixelVary slider is used to determine the amount of pixel variation after some action. If pixelvary amount is higher then zero, every pixel in edited image is post-processed by applying random variation on it's pixel color vector. Randomization occurs by formula:
Pixel_color = Pixel_color + random(- PixelVary, + PixelVary)

Mutation slider is used to determine the probability of genetic pixel color mutation that will be applied after some action. If mutation amount is higher then zero, every pixel in edited image is post-processed by applying random mutation on it's pixel color vector. Higher the amount higher will be the probability of single bit color mutation.

Channels of Interest

Selecting channels of interest (COI) is determined by three check boxes. By default all three boxes are checked, which means that action is applied to all three pixel color RGB components (channels) . If you want to apply action only on one channel, simply uncheck the other two channels.

Multiplication Scaling Color
Selected color in the color box represents, RGB value used to divide color value resulted from pixels multiplication. Selecting new color is done by clicking on the color box. After this action, color dialog menu is popped up. Select desired color and press OK button to accept color change.

Upper Color Limit
After each arithmetic operation on some pixel, we have to check if new RGB value exceeds component boundaries. As previously stated, each RGB component (channel) can have value in the range [0,255]. If resulting pixel value (or some of its component) exceeds this range, color clipping must be applied in order to obtain result in given range. Pixopedia_24 supports three techniques of color clipping and all of them works in the same range.

If, for any reason, you want to restrict the bottom limit for any component (by default it is 0 for all component), simply click on color box and select a new color from color dialog menu.

Bottom Color Limit
This parameter is similar to above, except that this color denotes upper limit, which is 255 for all components (channels). You can select any color you wish by clicking color box related to this parameter.