Patent ID: 8547481

Claim:
A preprocessor for black box detection in a video frame or field comprising: a chain of pixel buffers including at least one first pixel buffer and a last pixel buffer, each pixel buffer receiving pixel data of a predetermined line of the video frame or field from a prior pixel buffer in said chain, temporarily storing said pixel data for one pixel period and outputting said pixel data to a next pixel buffer in said chain, a first pixel buffer receiving pixel data from a video source; an absolute difference unit having a first input receiving said pixel data stored in a predetermined one of said at least one first pixel buffer, a second input receiving pixel data stored in said last pixel buffer and an output forming an absolute value of a difference pixel data received at said first input and pixel data receive at said second input; a comparator having a first input receiving a predetermined threshold value, a second input receiving said absolute value and an output generating a greater than signal if said absolute value is greater than said predetermined threshold value; a pixel counter toggled by a pixel clock each pixel period thereby storing a pixel count corresponding to a location within the video line of said pixel data stored in said last pixel buffer; a memory connected to said predetermined first pixel buffer, said last pixel buffer, said comparator and said pixel counter, said memory operable to store a first pixel count equal to said pixel count of said pixel counter and store left pixel data equal to said pixel data of said last pixel buffer upon a first instance of said greater than signal from said comparator during said predetermined line, and store a last pixel count equal to said pixel count of said pixel counter and store right pixel data equal to said pixel data of said predetermined first pixel buffer upon each instance of said greater than signal from said comparator during said predetermined line.