Reversible Contrast Stretching for Digital Images
Isabela Elena Bănescu, Alina Mihaela Badea, Liviu Andrei Necula, Ioan-Catalin Dragoi, Henri-George Coandă, Dinu Coltuc · 2025
This paper deals with reversible contrast enhancement for images with a limited range of graylevels. Image enhancement is directly approached by the classical contrast stretching that linearly expands image histogram over the entire graylavel scale. The original image is recovered by embedding in the enhanced version the data necessary for contrast stretching reversal. The sparsity of the enhanced image histogram ensures reversible embedding at the cost of least significant bit substitution. Experimental results for classical low contrast test images are provided.