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 grayscale value. The left side of the x-axis represents values of low intensity (black), while the right side 
displays values of high intensity (white). The black point (left side) is controlled with the left mouse button, 
whereas the white point (right side) is set with the right mouse button. 
 
 

 
For an optimal contrast adjustment, the black and white points can be set. A contrast filter determines two points 
for each grayscale value. Every grayscale value below the first point is interpreted as black. Similarly, each 
grayscale value above the second point is seen as white. This adjustment ensures that during scanning a "pure" 
white without a gray haze and a "pure" black with full saturation is read. The values between the two points will be 
transformed to the full contrast range of 0 % to 100 % to achieve an optimal reproduction of the grayscale values. 
 
 
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. The program sets the black point where it spotted the darkest pixel and sets the white point at 
the highest intensity. 
 
Manually Setting the Black and White Points 
 
Set the black point with the left mouse button and the white point with the right mouse button or with the color 
pickers at each side of the histogram.