In addition to the quantization precision value, you can specify the range of values that you want GeoExpress to keep during quantization.
If the input image contains minimum or maximum values that are far removed from the rest of the pixel values, then you may want to manually specify minimum and maximum values. For example, if the input image contains a maximum value of 32,000, but does not contain any pixel values between 20,000 and 32,000, then you may want to specify a maximum value of 20,000. In this example, GeoExpress changes all pixel values greater than 20,000 to 20,000. If you manually constrain the quantization range, you can improve the appearance of images that have very little data near the minimum and maximum values.
To specify a range of values for quantization, enter minimum and maximum values on the Quantization tab. You can specify one minimum and one maximum value for all the bands in an image, or you can specify individual values for each band.