DStretch (Decorrelation Stretch) is a technique used to enhance and emphasize subtle and similar colors in an image where the differences are difficult to discern. Decorrelation Stretch amplifies these differences, making the colors more distinct and easier to analyze.
Originally developed by John Harman as the DStretch application for rock art and ancient murals, the technique also proves beneficial for other fields. In this case, it was applied to the back of a picture frame to reveal hidden texts that were not visible, even with multispectral imaging.