5.5.3 Post-Processing

The resulting images had a poor contrast, and contrast-enhancing post-processing was done to improve them. The definition of a picture contrast is :

$contrast = \frac{maxPixelCcolour - minPixelColour} {colourRange}$

The rendered picture had low contrast because there was not much difference between the intensities of the dimmest and brightest pixels. Therefore, the minimum and maximum intensities were calculated, in order to rescale the image pixel intensities. The pixels of minimum intensity were mapped to 0 and the pixels of maximum intensity to 255, with linear interpolation for intermediate pixels. This correction has a similar effect to using a light box for viewing the image from a scanner.