Peak Transform for Efficient Image Representation and Coding

In this work, we introduce a nonlinear geometric transform, called peak transform for efficient image representation and coding. The proposed peak transform is able to convert high-frequency signals into low-frequency ones, making them much easier to be compressed. To maximize the tranform coding gain, we develop a dynamic programming solution for optimum peak transform design. Based on peak transform (PT), we design an image encoder, called PT encoder, for efficient image compression. Our extensive experimental results demonstrate that the peak transform is able to reduce the signal energy in high-frequency subbands by up to 60%. The PT image encoder outperforms the state-of-the-art JPEG-2000 and H.264 (INTRA) encoders by up to 2-3 dB in PSNR (peak signal-to-noise ratio), especially for images with a significant amount of high-frequency components.