... diagonal matrices corresponding to Uand D are denoted respectively byQUand Q D . They have as elements the raster scanned 2D DFT values of the 2D sequences {lU(p, q)}and {d( p, q)}, denoted ... observed (noisy and degraded) image, the original undistorted image, andthe noise process, respectively, all of which have been lexicographically ordered, and D the resultingdegradation matrix. ... is added resulting in a blurred signal-to-noise ratio (SNR) of20 dB. The degraded channels are shown in Fig. 29.2. Three different experiments were performedwith the available degraded data....