Method and apparatuses for removing blocking effect in a motion picture decoder
Patent 6144700 Issued on November 7, 2000. Estimated Expiration Date: 
May 14, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 14, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesDirectional running average segmentation Method of correcting an image signal decoded in block units Blocking effect attenuation apparatus for high definition television receiver Image signal compressing and expansion with filter means to eliminate blocking effect Transform artifact reduction process Post-processing method and apparatus for use in a video signal decoding apparatus Patent #: 5852682 InventorAssigneeApplicationNo. 856474 filed on 05/14/1997US Classes:375/240.03, Quantization375/240.24, Block coding382/199, Pattern boundary and edge measurements382/251QuantizationExaminersPrimary: Kelley, ChrisAssistant: Bayless, David Attorney, Agent or FirmInternational ClassG06K 009/00Foreign Application Priority Data1996-05-14 KRAbstractMethods and apparatus for removing blocking effect in a motion picture decoder are provided. Boundary pixel values of a current block and corresponding adjacent blocks are extracted boundary. A mean value for the resulting difference values between the extracted pixel values of the current and adjacent blocks is calculated. The calculated mean value is limited within a range of -(1/2) quantization step size to (1/2) quantization step size. The limited mean value is added to the each of the pixel values of the current block to generate. In another aspect, absolute values for the difference values between boundary pixel values of the current and adjacent blocks are calculated. The calculated absolute values are compared with a threshold level to determine whether the current block contains an edge. Therefore, only the current block not having an edge is selected and filtered, thereby removing the blocking effect due to a quantization error without having distortion to the original data.Other References
Field of SearchMotion dependent key signal generation or scene change detectionMotion vector generation Discrete cosine or sine transform Interframe coding (e.g., difference or motion detection) Predictive coding Lossless compression Transform coding Quantization Pattern boundary and edge measurements BANDWIDTH REDUCTION OR EXPANSION | |
