Method and apparatus for video decoding to improve picture quality based on picture quality estimation, in the presence of noise

A device for decoding video data that is encoded by bit rate control, comprising:

• a processor in communication with a memory, the memory including code which when accessed by the process causes the process to:
• decode the encoded video data;
• evaluate picture quality estimation information including information about a bit stream byte size of a decoded video frame (SIZE), the number of 4-fragment macro blocks included in the video frame (4 MV), and the number of skip-mode macro blocks included in the video frame (SKIP);
• determine a picture quality of the video data based on a correlation between the picture quality estimation information and a Signal-to-Noise Ratio (SNR), wherein the correlation between the picture quality estimation information and SNR is given by using a bit stream byte size of the video frame, the number of the skip-mode macro blocks in the video frame, and the number of the 4-fragment macro blocks;
• and output the video data by applying a picture quality improving algorithm to the video data, if the determined picture quality is lower than a predetermined level.

An apparatus for providing a decoded video output comprising:

• a processor in communication with a memory, said processor accessing code in said memory which provides instruction to said processor to execute the steps of:
• receiving and decoding an encoded video signal;
• determining a picture quality of said decoded video signal based on at least one of a bit stream byte size of a decoded video frame (SIZE), the number of 4-fragment macro blocks included in the video frame (4 MV), and the number of skip-mode macro blocks included in the video frame (SKIP);
• correlating said picture quality with a Signal-to-Noise Ratio (SNR), wherein the SNR is estimated by using the bit stream byte size of the video frame, the number of the skip-mode macro blocks in the video frame, and the number of the 4-fragment macro blocks, and said picture quality of the video signal is determined based on the estimated SNR;
• and outputting the decoded video signal to a picture quality improving algorithm if the determined picture quality is greater than a predetermined level.