Patent ID: 8411738

Claim:
A vertical scrolling text detector implemented in one or more processors, the vertical scrolling text detector operative to receive a digital video signal comprising vertical scrolling text mixed with a pulldown video sequence comprising primary frames and repeated frames, the vertical scrolling text detector comprising: a motion estimator operative to determine a plurality of motion vectors between blocks of the primary frames; a primary frame motion analyzer operative to: determine a first peak vertical motion vector between first and second primary frames and a second peak vertical motion vector between the second primary frame and a third primary frame, average a value of the first peak vertical motion vector over the first primary frame and its repeated frames to produce a first average, average a value of the second peak vertical motion vector over the second primary frame and its repeated frames to produce a second average, and determine whether the first and second averages are approximately equal; and a consecutive frame motion analyzer operative to: calculate differences in pixel values between blocks of two or more consecutive frames between the first and third primary frames, and in response to said determination that the first and second averages are approximately equal and that the differences in pixel values are greater than a threshold, determine that vertical scrolling text exists in the digital video signal.