is greatly assisted with DStretch software, allowing researchers to peer through centuries of weathering, fading and vandalism. The program uses a method called decorrelation stretch, which was originally used by NASA to improve remote sensing images of Mars, but DStretch optimizes it for rock art.
Image of a vandalized (chalked) pictograph in Black Dragon Canyon, Utah, taken under ordinary daylight (shaded) conditions.
The false color images below are screenshots from DStretch on my Samsung smartphone, illustrating several of the filters available in the software that are designed to highlight hidden details.
Learn more: DStretch website.