Scalable image coder for mobile device

Image compression methods provide users the option to reduce the size of image data and significant amount of time for transmission of images. A perceptually lossless coder is desired to generate perceptually high quality image with higher compression ratio. In this paper, a prototype of the scalable image coder based on the just noticeable distortion (JND) profile with subband discrete cosine transform (SBDCT) is built in the personal digital assistant (PDA). The coding scheme based on JND profile and SBDCT provides computational scalability, decodable by any current JPEG-compliance decoder and therefore permitting easy integration with any current JPEG- compliance image systems. To further evaluate this prototype, simulations in Pocket PC emulator and the actual implementation of the coder in PDA is carried out.