Patent Document ID: 20160014433
Application ID: 14327236
Patent Status: 0

Claim One:
1. A processor implemented method for detecting block errors in a video sequence having a plurality of frames, the frame being composed of a plurality of top fields and a plurality of bottom fields, comprising the steps of: a. detecting a scene change and determining a set of frames corresponding to a single scene; b. detecting motion between two consecutive top fields or between two consecutive bottom fields corresponding to the set of frames determined in step a, and determining one or more blocks in the top field or bottom field having motion, wherein each block is a matrix of predetermined size containing pixels; c. determining one or more candidate blocks within the top field or bottom field determined in step b, comprising the steps of: calculating a vertical gradient for the motion area of the current top field and current bottom field; thresholding the vertical gradient using a predefined threshold; processing the thresholded image using a morphological operation for getting regions corresponding to block errors; determining a corresponding horizontal edge and a corresponding vertical edge for each rectangular region; and creating one or more candidate blocks using the horizontal edge and the vertical edge; and d. verifying the candidate blocks for determining the blocks with block error, comprising the steps of: determining number of intensity transitions in horizontal direction within the candidate blocks, and comparing the number of transitions with a first predefined threshold; if the number of intensity transitions is greater than the first predefined threshold then getting two separate sub-blocks each for even and odd vertical lines of the candidate blocks, and determining standard deviation for each of the sub-blocks; comparing the standard deviation for each of the sub-blocks with a second predefined threshold; if the standard deviation is lesser than the second predefined threshold then creating a transition map for the block; and verifying the number of sign changes within the transition map; and verifying the presence of repeating pattern in the transition map using a FFT pattern detection module.