Shape adaptive discrete Fourier transform for coding of irregular image segments

In the paper the new transform adapting to shapes of irregular image segments is introduced, the shape-adaptive (SA) DFT. Its definition is based on periodic data extension rather than data shifts, hence, in contrast to SA DCT segment reconstruction is possible even if part of contour data is missing. Visually the qualities of images recons- tructed from the part of the SA DFT samples is almost as good as for the SA DCT, especially for high compression ratios.