The JPEG compression standard is a popular image format. However, at high compression ratios JPEG compression, which uses block-transform coding,
can produce blocking artifacts, or artificially introduced edges within the image. Several post-processing algorithms have been developed to remove
these artifacts. This paper describes an implementation of a post-processing algorithm developed by Ramchandran, Chou, and Crouse (RCC) which is fast
enough for real-time software-only video applications.
The original implementation of the RCC algorithm involved calculating thresholds to identify artificial edges. These calculations proved too expensive for
use in real-time software-only applications. We replaced these calculations with a linear scale approximating ideal threshold values based on a
combination of peak signal-to-noise ratio calculations and subjective visual quality. The resulting filter implementation is available in the
widely-deployed Open Mash streaming media toolkit.
