Reversible DCT Mapping Integers to Integers and Lossless Image Compression
可逆的DCT整型变换与无失真图像压缩

In this paper, the authors describe the precedures of DCT (discrete cosine transform) and FFT (fast Fourier transform) which map integers to integers by using lifting scheme and the butterfly configuration of FFT. The transform is reversible, fast and suitable for the lossless image compressions.