In-loop fidelity enhancement for video compression

Abstract

An encoder for receiving a video frame and performing encoding processes to generate an encoded bitstream includes: a fidelity enhancement block, for performing a fidelity enhancement technique on the video frame utilizing a quad-tree partition, and generating fidelity enhancement information including a parameter associated with the quad-tree partition structure; and an entropy coding block, coupled to the fidelity enhancement block, for encoding the fidelity enhancement information, and embedding the encoded fidelity enhancement information into the encoded bitstream.

1 . An encoder for receiving a video frame and performing encoding processes to generate an encoded bitstream, the encoder comprising:
 a fidelity enhancement block, for performing a fidelity enhancement technique on processed data utilizing a quad-tree partition, and generating fidelity enhancement information comprising at least one parameter associated with a quad-tree partition structure; and   an entropy coding block, coupled to the fidelity enhancement block, for encoding the fidelity enhancement information, and embedding the encoded fidelity enhancement information into the encoded bitstream.   
   
   
       2 . The encoder of  claim 1 , wherein the fidelity enhancement technique comprises Wiener filtering, Kalman filtering, noise reduction, deblurring, regression, and regularization. 
   
   
       3 . The encoder of  claim 1 , wherein the fidelity enhancement block performs Wiener filtering, generates auto correlation and cross correlation matrices for a smaller area of the video frame, and reuses the auto correlation and cross correlation matrices for a larger area of the video frame when the larger area includes the smaller area. 
   
   
       4 . The encoder of  claim 1 , wherein the fidelity enhancement technique is a discrepancy modeling technique comprising DC offset compensation, weighted prediction, and spatial prediction. 
   
   
       5 . The encoder of  claim 1 , further comprising:
 a prediction block, for performing prediction on the video frame to generate prediction residues and prediction information;   a transform and quantization block, coupled to the prediction block, for performing transform and quantization processes on the prediction residues; and   a reconstruction loop, coupled between the transform and quantization block and the prediction block, for reconstructing the video frame according to the prediction residues, the information from the transform and quantization block;   
     wherein the entropy coding block is coupled to the transform and quantization block, and the fidelity enhancement block is in the reconstruction loop. 
   
   
       6 . The encoder of  claim 5 , wherein the reconstruction loop further comprises:
 a deblocking unit, for performing deblocking to generate the processed data for the fidelity enhancement block.   
   
   
       7 . The encoder of  claim 5 , wherein the reconstruction loop further comprises:
 a reference frame buffer, for buffering processed data of a reference frame;   wherein the fidelity enhancement block performs fidelity enhancement on the processed data retrieved from the reference frame buffer.   
   
   
       8 . The encoder of  claim 5 , wherein the reconstruction loop further comprises:
 an inverse quantization and transform unit, coupled to the transform and quantization unit, for performing inverse quantization and transform processes to generate the processed data;   
     wherein the fidelity enhancement block receives the processed data from the inverse quantization and transform unit. 
   
   
       9 . The encoder of  claim 5 , wherein the reconstruction loop further comprises:
 an inverse quantization unit, coupled to the transform and quantization unit, for performing inverse quantization process to generate the processed data;   
     wherein the fidelity enhancement block receives the processed data from the inverse quantization unit. 
   
   
       10 . The encoder of  claim 1 , wherein the encoded fidelity enhancement information is embedded in the encoded bitstream, and a header of the encoded bitstream comprises a pointer for indicating a location of the fidelity enhancement information in the encoded bitstream. 
   
   
       11 . A method for coding a video frame, the method comprising:
 receiving a video frame;   utilizing a quad-tree partition method to determine how to partition the video frame;   partitioning the video frame according to a determination result, and performing fidelity enhancement on the video frame to generate fidelity enhancement parameters; and   encoding the video frame with the fidelity enhancement parameters to generate an encoded bitstream.   
   
   
       12 . The method of  claim 11 , wherein the step of utilizing a quad-tree partition method to determine how to partition the video frame further comprises:
 utilizing a top-down splitting algorithm or a bottom-up merging algorithm and comparing a cost function result for determining how to partition the video frame.   
   
   
       13 . The method of  claim 11 , wherein calculation results for a smaller area of the video frame are reused for a larger area of the video frame when the larger area includes the smaller area. 
   
   
       14 . A method for coding a video frame, the method comprising:
 receiving a video frame;   performing fidelity enhancement on processed data to generate fidelity enhancement information;   encoding the video frame to generate an encoded bitstream;   encoding the fidelity enhancement information, and embedding the encoded fidelity enhancement information into the encoded bitstream; and   generating a pointer indicating a location of the fidelity enhancement information in the encoded bitstream.   
   
   
       15 . The method of  claim 14 , wherein fidelity enhancement comprises filtering and discrepancy modeling. 
   
   
       16 . A method for decoding a bitstream, the method comprising:
 receiving a bitstream;   retrieving a pointer from a header in the bitstream, wherein the pointer indicates a location of fidelity enhancement information in the bitstream;   constructing a video frame by decoding processes; and   performing fidelity enhancement on processed data using the fidelity enhancement information.   
   
   
       17 . The method of  claim 16 , wherein fidelity enhancement comprises filtering and discrepancy modeling. 
   
   
       18 . A decoder for receiving a bitstream to generate a video frame, comprising:
 an entropy decoding unit, for decoding the bitstream to generate residues and fidelity enhancement information, wherein the fidelity enhancement information comprises at least one parameter associated with a quad-tree partition structure; and   a reconstruction loop, coupled to the entropy decoding unit, for reconstructing the video frame from the residues, wherein the reconstruction loop comprises:
 a fidelity enhancement block, for receiving the fidelity enhancement information from the entropy decoding unit, and performing fidelity enhancement according to the quad-tree partition structure derived from the fidelity enhancement information. 
   
   
   
       19 . An encoder for receiving a video frame and performing encoding processes to generate an encoded bitstream, the encoder comprising:
 a prediction block, for performing prediction on the video frame to generate prediction residues and prediction information;   a transform and quantization block, coupled to the prediction block, for performing transform and quantization processes on the prediction residues;   a reconstruction loop, coupled between the transform and quantization block and the prediction block, for reconstructing the video frame according to the prediction residues and the information from the transform and quantization block; wherein the reconstruction loop comprises:
 a reference frame buffer; and 
 a discrepancy modeling block, for performing a discrepancy modeling technique on processed data, and generating discrepancy modeling information; and 
   an entropy coding block, for encoding residues with the discrepancy modeling information into the encoded bitstream.   
   
   
       20 . The encoder of  claim 19 , wherein the discrepancy modeling technique comprises DC offset compensation, weighted prediction, and spatial prediction. 
   
   
       21 . The encoder of  claim 19 , wherein the discrepancy modeling block receives the processed data of a reference frame from the reference frame buffer and performs discrepancy modeling to reduce errors between the reference frame and the video frame. 
   
   
       22 . The encoder of  claim 19 , wherein the discrepancy modeling block receives the processed data of the video frame, performs discrepancy modeling to reduce errors between processed and unprocessed data of the video frame, and stores compensated processed data in the reference frame buffer. 
   
   
       23 . A decoder for receiving a bitstream to generate a video frame, comprising:
 an entropy decoding unit, for decoding the bitstream to generate residues and discrepancy modeling information; and   a reconstruction loop, coupled to the entropy decoding unit, for reconstructing the video frame from the residues, wherein the reconstruction loop comprises:
 a discrepancy modeling block, for receiving the discrepancy modeling information from the entropy decoding unit, and applying a discrepancy modeling technique on processed data according to the discrepancy modeling information. 
   
   
   
       24 . The decoder of  claim 23 , wherein the discrepancy modeling technique comprises DC offset compensation, weighted prediction, and spatial prediction. 
   
   
       25 . The decoder of  claim 23 , wherein the reconstruction loop further comprises a reference frame buffer, and the discrepancy modeling block receives the processed data of a reference frame from the reference frame buffer and performs discrepancy modeling according to the discrepancy modeling information. 
   
   
       26 . The decoder of  claim 23 , wherein the reconstruction loop further comprises a reference frame buffer, and the discrepancy modeling block receives the processed data of the video frame, performs discrepancy modeling according to the discrepancy modeling information, and stores compensated processed data in the reference frame buffer.