Parameters are the graylevel values in the input image corresponding to the minimum and maximum graylevels in the output image, and the number of quantization steps in the output image. The minimum and maximum graylevel values default to the input image's graylevel minimum and maximum, respectively. Pixels in the input image with graylevel values outside that range are saturated at the range boundaries. Note that and need not necessarily be identical to the true image graylevel minimum and maximum. The Saturate Graylevels command retains all pixels with graylevel values in a specified range, and saturates all other graylevels at the appropriate range boundary.
Parameters are the minimum and maximum graylevel of the range to be retained.
I as where and are the minimum and maximum graylevel values to be retained, as specified in the dialog. The default for the threshold parameter is computed from the minimum and maximum graylevel values as . I as where t is the threshold graylevel specified in the dialog. The Threshold Graylevels command is useful for simple segmentation and classification tasks. The Adaptive Stretch command performs a spatially variable graylevel transformation, where a different linear stretch function is computed for each pixel.