Visual quality improvement techniques of HDPhoto/JPEG-XR

Microsoft´s recently proposed new image compression codec HDPhoto is currently undergoing ISO standardization as JPEG-XR. Even though performance measurements carried out by the JPEG committee indicated that the PSNR performance of HDPhoto is competitive, the visual performance of HDPhoto showed notable deficits, both in subjective and objective tests. This paper introduces various techniques that improve the visual performance of HDPhoto without leaving the current codestream definition. Objective measurements performed by the author indicate that the modified encoder, while staying backwards compatible to the current standard proposition, improves visual performance significantly, and the performance of the modified encoder is similar to JPEG.