Generalized PCM coding of Images

Pulse-code modulation (PCM) with embedded quantization allows the rate of the PCM bitstream to be reduced by simply removing a fixed number of least significant bits from each codeword. Although this source coding technique is extremely simple, it has poor coding efficiency. In this paper, we present a generalized PCM (GPCM) algorithm for images that simply removes bits from each codeword. In contrast to PCM, however, the number and the specific bits that a GPCM encoder removes in each codeword depends on its position in the bitstream and the statistics of the image. Since GPCM allows the encoding to be performed with different degrees of computational complexity, it can adapt to the computational resources that are available in each application. Experimental results show that GPCM outperforms PCM with a gain that depends on the rate, the computational complexity of the encoding, and the degree of inter-pixel correlation of the image.This work was supported by the Spanish Government CYCIT under Grant TEC2009-09146. The work of M. Morbee was supported by the Special Research Fund of Ghent University. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Zhou Wang.Prades Nebot, J.; Morbee, M.; Delp, E. (2012). Generalized PCM coding of Images. IEEE Transactions on Image Processing. 21(8):3801-3806. doi:10.1109/TIP.2012.2197015S3801380621

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