RGB Adjustment is a set of actions that applies to red, green and blue channel of particular image. As you can see from the control panel, five various methods can be applied to an image in two various modes. Sliders are used to determine the amount of effect to be applied.

Brightness action adjusts intensity of RGB channels separately, or by checking Lock box, the same amount will be applied to all channels. Choosing Max % mode, sliders amount represents percentage of maximum available channel value, which is 255. The result is increasing or decreasing image intensity.
Choosing Current % mode, sliders amount represents percentage of current channel value. The result is increasing or decreasing image contrast.

ColorStretch action (color stretching) increases MaxVal channel by its slider amount while in the same moment decreases the MinVal channel by its slider amount. MidVal channel is not affected. Depending on choosen mode (Max% or Current%) slider amount is calculated by percentage of value 255, or by percentage of current channel value.
With negative sliders value, inverse effect is obtained, which we call Color Squeezing.

For example:
Pixel channels have values R=30 G=100 B=140. Slider values are SR=SG=SB=10%. (Locked)
Mode is Max% which results the value of 255*10/100 ~ 25. Resulting pixel values are
R= 30-25 = 5 (minimum channel);
G=100 (medium channel is unaffected);
B=140+25 = 175 (maximum channel);

MinMedMax action adjusts MinVal, MidVal and MaxVal channels by its respected slider amount.. Selecting this method, sliders labels change to Mi, Me, Ma.

HSV action adjusts amounts of hue,saturation, value. Selecting this method, sliders labels change to H, S, V.

LMH action is actually three band equalizer. Intensity range (0-255) is devided in three segments: low, medium high. Every segement is associated with appropriate slider value. Selecting this method, sliders labels change to L, M, H.

Applying RGB Adjustment
If you want to apply RGB adjustment on whole image, after setting the type, mode of action and sliders amount, simply press Image button. Adjustment will be applied to whole image.

You can apply RGB adjustment through brush movement, contour and mask as well. For shape selection and brush movement refer to Shapes and Brushes section.

NOTE:
Resultant image is affected by all previously set
Global parameters.
Pressing R, G or B buttons returns slider value to 0 respectively.

Example of RGB Adjustment action. Original picture is on the left, right picture is processed with RGB Adjustment. Click on picture to enlarge.