Xerox XEScan Solution User Guide

 

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In the histogram window the x-axis shows the brightness values and the y-axis the frequency of occurrence of 
each RGB-value. The left side of the x-axis represents values of low intensity (black), while the right side shows 
values of high intensity (white). 
 

 

 
 

 
For an optimal contrast adjustment, the black and white points can be set. The contrast filters determine two 
points for each color channel (red, green, blue). Every color value below the first point will be interpreted as black. 
Similarly, each color value above the second point is seen as white. This shall ensure that the scanned original 
contains a "pure" white without a gray haze, and a "pure" black with full saturation. The values ranging between 
the two points will be transformed to the full contrast range of 0 to 100 % to guarantee an optimal color 
reproduction. 
 
Below the histogram window the color bars corresponding to the RGB-values (red, green, blue) are displayed. 
Their length represents the active range of the contrast filter. The empty area to the left of each color bar shows 
which range is set to 100 % black, the empty area to the right of each color bar represents pure white. 
 
The black point (left side) is set with the left mouse button; the white point (right side) with the right mouse button. 
Usually all three color bars are moved together. However, you may explicitly enable or disable the control of each 
primary color. 
 

 

 
 
Automatically Setting the Black and White Points 
 
For most applications it is sufficient to let the program determine the black and white points automatically, using 
the Suggest button. 
 
 
Manually Setting the Black and White Points 
 
For all colors 

To set the black and white points for all colors simultaneously, the check boxes for Red, Green and Blue must be 
activated. Set the black point with the left mouse button and the white point with the right mouse button.