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Toolbar:   contrast  
Menu:   Processing > Adjust > Contrast/Brightness  
Script:   adjContrast  

Use this command to adjust the contrast and/or brightness of an image. Changing contrast and/or brightness means shifting pixel values up or down the tonal range. Note that adjusting the brightness lightens or darkens all colors equally, while increasing the contrast can wash out details in shadows and highlights. If you choose this command, the Contrast/Brightness dialog box will appear with the following options:

Displays the input image frame number. If you want to adjust the contrast and/or brightness of another image, type or select the corresponding value.  

Displays the number of the frame in which the output image will be created. Depending on the Preferences. ImageWarp will set it either to the first available value or to the Input frame number. Type or select another value if you want the output image to be created in a different frame.  

Select this check box to have the image processed in the HLS space. In this case, the changes in contrast will not affect the original saturation of the input image. Otherwise, the saturation will change depending on the changes in the contrast.  

Lets you choose the mode of changing the settings.  
Click Dialog to move the sliders with the mouse or indicate the desired values in the corresponding boxes.  
Click Mouse to change the Brightness and Contrast settings simultaneously by moving your mouse. Moving the mouse downward or upward makes the Contrast slider move left or right respectively. Moving the mouse leftward or rightward makes the Brightness slider move left or right respectively. If you have a wheel mouse attached to your computer, rotating the wheel upward or downward makes the Gamma slider move right or left respectively. To apply the changes, press the left mouse button. To switch to the Dialog mode, press the right mouse button. Note that if the AdjContrast function was called from the script with the MOUSE mode selected, the dialog box will not appear.  
Click Preset if you want to generate a script command that will apply the function without displaying the Contrast/Brightness dialog box. Select the desired values by using the sliders or corresponding boxes, and then click Apply. Make sure the Script Editor is in the Record mode. The AdjContrast function will be recorded into the script with the selected levels, and its Mode parameter will be set to AUTO.  
Move the slider or indicate the desired value in per cent to adjust the brightness (the amount of light that is transmitted or reflected from a given pixel) of the image.  

Move the slider or indicate the desired value in per cent to adjust the contrast (the difference in tone between the dark and light areas of an image).  

Gamma correction lets you pick up detail in an image by enhancing the contrast in very dark or very light areas of the image. This is achieved by changing the midtone values, particularly those at the low end, without significantly affecting the shadows or highlights. The Gamma correction modifies an image by applying standard, nonlinear gamma curves to the intensity scale. A gamma value of 1 is equivalent to the identity curve that does not affect the image. To lighten an image and increase the contrast in its darker areas, increase the gamma by moving the slider to the right or indicating a value greater than "1". To darken the image and emphasize contrast in the lighter areas, decrease in the gamma by moving the slider to the left or indicating a value less than "1".  

Closes the dialog box and applies the function.  

Inserts the corresponding script command into the Script Editor without applying the function.