A general method for recovering missing DCT coefficients in DCT-transformed
images is presented in this work. We model the DCT coefficients recovery
problem as an optimization problem and recover all missing DCT coefficients via
linear programming. The visual quality of the recovered image gradually
decreases as the number of missing DCT coefficients increases. For some images,
the quality is surprisingly good even when more than 10 most significant DCT
coefficients are missing. When only the DC coefficient is missing, the proposed
algorithm outperforms existing methods according to experimental results
conducted on 200 test images. The proposed recovery method can be used for
cryptanalysis of DCT based selective encryption schemes and other applications.Comment: 4 pages, 4 figure