New Encoding of 8×8 DCT to make H.264 Lossless

This paper presents a fast algorithm to compute the 8times8 discrete cosine transform (DCT), using a new error-free encoding which partially overcomes the quantization error of digital implementation due to finite-precision effect. The proposed encoding scheme, named as algebraic integer quantization (AIQ), is achieved by obtaining the exact representation of the transcendental functions. The proposed AIQ-based 8times8 DCT can be used as an alternative transform for H.264 encoders, which results in a simple, parallel, and multiplication-free architecture, and also minimizes the complexity and the hardware cost of the quantizer/dequantizer. The authors propose an initial FPGA implementation where the system can run at 100 MHz, and satisfies all real time constraints for digital multimedia applications