Comments on “An Analog 2-D DCT Processor”

In the paper “An analog 2-D DCT processor,” authors have presented a row-column method for computing 2-D discrete cosine transform (DCT). They have reported minimum peak signal-to-noise ratios (PSNR) 40.6 dB and 31.4 dB for 4-point and 8-point DCT, respectively. The main objective of this comment letter is to point out that those PSNR values are not correctly calculated. The actual minimum PSNR values are shown to be 24.7 dB and 22.7 dB for 4-point and 8-point DCT, respectively. Similarly, maximum PSNR values are corrected in this letter.