Hybrid Coding of Images for Digital Cellular Channel

Abstract

In this paper, a hybrid image coding scheme is proposed for progressive transmission of images over digital cellular channels. In this algorithm the image is decomposed into multiple pyramid layers. The proposed scheme employs the concept of feedback to retrieve the information lost due to coding. The bands are transmitted according to the descending order of their respective entropies. These bands are encoded by using the vector quantization (VQ) concept. The Northern American digital cellular standard (IS-54) has been used as the wireless communication environment. Application of the proposed scheme is investigated for vehicle speeds of 0.16 km/h and 100 km/h with a channel signal-to-noise ratio of 22 dB. Simulation results using a standard test images show the significant advantage of the proposed technique over the existing algorithms in terms of the bit rate and the visual quality.