Eppley Institute for Cancer Research

University of Nebraska Medical Center

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Color Selection Dialog Box

Where is it accessed?

The color selection dialog box is accessed by double clicking the legend next to the detector image.

What does it do?

Allows the user to change the image coloring.  The color information is stored in the project file.


The image is always scaled to color data among 256 possible colors.  The range is evenly spaced by taking the (Max-Min)/255.  The color dialog box determines which color is assigned to an image value scaled to 0-255.  It accomplishes this by allowing the user to select up to two line segments for each primary color that describe the value of the color as the index moves from 0 to 255.  In the image above for the color Red, at location 0 it will start with a value of 255.  At location 1 its value will be 254.  Finally by location 255 its value will be 0.  This set of parameters describes two lines.  The first run from 0 to the swing point.  The second from the swing point to 255.  First line starts at 255 and ends at 254.  The second line starts at 254 and ends at zero.  The overall effect is a line that goes from 255 to 0 as the index goes from 0 to 255.  The Blue case describes a constant value of 255 from indexes 0 to 255.