ABSTRACT
The most popular are; Linear Fit, Histogram Transformation, Local Histogram Equalization, Curves Transformation, Masked Stretch and Auto Histogram. There are a number of image stretching tools in Pix Insight, optimized for specific situations. Linear Fit tool is unique in that it produces a linear stretch on an image by simply changing the black and white end points. This has been used before, during the first manipulations of the RGB channels, prior to combination into a color image. Histogram Transformation is the standard non-linear stretching tool. It can adjust both highlight and shadow endpoints, mimicking the actions of Linear Fit and adjust the midpoint too, creating the non-linear stretch element. Local Histogram Equalization tool is fantastic at pulling out swathes of nebulosity from seemingly bland images without over-cooking the highlights in non-linear images. As the name implies, it attempts to equalize contrast over the image, so that areas with low contrast have their contrast increased.
