SUPPRESSION OF SALT AND PEPPER NOISE BASED ON YOUDEN-DESIGNS

This paper presents a new class of algorithms based on Youden designs to detect and restore edges present in an image imbedded by mixture or ''salt and pepper'' noise. The mixture noise consists of a uncorrelat ed or correlated noisy background plus uncorrelated impulsive noise. T he objective is to restore pixels affected by the impulsive part of th e mixture noise. The approach is to consider that these pixels have lo st their true value and their estimate is obtained via the normal equa tion that yields the least sum of square error (LSSE). This procedure is known in the literature as ''The Missing Value Approach Problem''. The estimates are introduced into the image data and an ANOVA techniqu e based on Youden design is carried out. We introduce Youden designs w hich are special Symmetric Balanced Incomplete block (SBIB) designs, t he pertinent statistical tests and estimates of the factor effects. We derive the estimate of the missing value for the uncorrelated noise e nvironment as well as for the correlated one. The high level of perfor mance of these algorithms can be evaluated visually via the input/outp ut images and objectively via the input/output signal-to-noise ratio ( SNR). (C) 1998 Elsevier Science Inc. All rights reserved.