Predictive Encoding in data compression

Idea: Remove mutual redundancy among successive pixels in a region of support (ROS) or neighborhood and encode only the new information. This method is based upon linear prediction. Let us start with 1-D linear predictors. An Nth order linear prediction of x(n) based on N previous samples is generated using a 1-D autoregressive (AR) model. … Read more

Enhanced Reference Picture Selection Mode in data compression

Motion-compensated prediction is accomplished by searching the previous picture for a block similar to the block being encoded. The enhanced reference picture selection mode allows the encoder to search more than one picture to find the best match and then use the best suited picture to perform motion-compensated prediction. Reference picture selection can be accomplished … Read more

Modified Quantization Mode in data compression

In this mode, along with changes in the signalling of changes in quantization parameters, the quantization process is improved in several ways. In the baseline mode, both the luminanace and chrominance components in a block are quantized using the same quantizer. In the modified quantization mode, the quantizer used for the luminance coefficients is different … Read more

Temporal , SNR , and Spatial Scalability Mode | Reference Picture Resampling in data compression

Temporal , SNR , and Spatial Scalability Mode Reference picture resampling allows a reference picture to be “warped” in order to permit the generation of better prediction. It can be used to adaptively alter the resolution of pictures during encoding Reduced – Resolution Update Mode This mode is used for encoding highly active scenes. The … Read more

Deblocking Filter Mode | Reference Picture Selection Mode in data compression

Deblocking Filter Mode This mode is used to remove blocking effects from the 8×8 block edges. This smoothing of block boundaries allows for better prediction. This mode also permits the use of four motion vectors per macroblock and motion vectors that point beyond the edge of the picture Reference Picture Selection Mode This mode is … Read more

Syntax – Based Arithmetic Coding Mode and Advanced Prediction Mode in data compression

Syntax – Based Arithmetic Coding Mode In this mode the variable length codes are replaced with an arithmetic coder. The word length for the upper and lower limits is 16. The option specifies several different Cum Count tables that can be used for arithmetic coding. There are separate Cum Count tables for encoding motion vectors, … Read more