Image transmission using unequal error protection combined with two-fold turbo coding

Two-fold turbo codes have recently been introduced as the least complex member of the multifold turbo code family, and they have been shown to outperform their conventional symmetric and asymmetric cousins in the waterfall region. The article introduces a simple method that allows two-fold turbo codes to offer bilevel unequal error protection. Also, the application of the unequal error protection to a still image coding technique, i.e. hue-saturation-luminance coding, is explained and the pixel error performance results under Gaussian conditions are presented. According to the simulation results, the proposed scheme outperforms its conventional counterpart by up to 0.7 dB. Furthermore, with the new unequal error protection coding scheme, under certain channel conditions, significant savings in decoder iterations are achieved, without compromising the received image quality. Although the unequal error protection is limited to bilevel within the scope of this article, the same technique can be used to provide multilevel error protection.