Quantization for hybrid video coding

Abstract

Method for coding a video signal using hybrid coding, comprising: reducing temporal redundancy by block based motion compensated prediction in order to establish a prediction error signal; performing quantization on samples of the prediction error signal or on coefficients resulting from a transformation of the prediction error signal into the frequency domain to obtain quantized values, representing quantized samples or quantized coefficients respectively; calculating a quantization efficiency for the quantized values; calculating a zero efficiency for a quantization, when the quantized values are set to zero; selecting the higher efficiency; and maintaining the quantized values or setting quantized values to zero, for further proceeding, depending on the selected efficiency.

Description

FIELD OF THE INVENTION[0001]The invention relates to a method of coding, coder and decoder involving quantization for hybrid video coding and data signals.BACKGROUND OF THE INVENTION[0002]Up to date standardized video coding methods are based on hybrid coding. Hybrid coding provides a coding step in the time domain and a coding step in the spatial domain. First, the temporal redundancy of video signals is reduced by using a block based motion compensated prediction between the image block to be coded and a reference block from an image that has already been transmitted determined by a motion vector. The remaining prediction error samples are arranged in blocks and are transformed into the frequency domain resulting in a block of coefficients. These coefficients are quantized and scanned according to a fixed and well-known zigzag scanning scheme, which starts with the coefficient representing the DC value. According to a typical representation, this coefficient is positioned among th...

AI Technical Summary

Benefits of technology

The present invention provides an improved quantization for hybrid video coding by reducing temporal redundancy and performing quantization on the prediction error signal. The quantization efficiency is calculated and compared to select the highest efficiency for further proceeding. The invention also provides a method for coding video signals based on hybrid coding by deciding whether to transform the prediction error signal into the frequency domain or to maintain it in the spatial domain. The data signal includes side information indicating the domain in which a slice, a macroblock, or a block is coded, which helps in adaptive control. The invention results in a decreased data rate and a more efficient coding mechanism for the side information.

Problems solved by technology

I.e. comparing with a zero efficiency takes into account, that the effort for coding samples or coefficients might be small but on the other hand, there is also provided a disadvantage with respect to the quality of the coded signal.

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