Neighborhood comparison operator

Claim 1

In a neighborhood comparison operator for comparing the digital value of a center pixel of a 3×3 moving window with a threshold value and the values of eight neighbor pixels with the threshold value or the value of the center pixel, said operator having means for storing nine pixel values of a moving 3×3 window of a stream of pixel values in digital form, and having nine comparators, one for each pixel value of the 3×3 window, each adapted to receive said threshold value for comparison, and in the case of the eight neighborhood pixel comparators further adapted to receive the value of said center pixel, and means for selecting for comparison in said eight neighborhood pixel comparators either said threshold for the central pixel value, control means for selecting the sense of comparison from the choice of either greater than, equal to, or less than, an improvement comprising means for appending two bits to the output of said comparators, one bit indicating whether the center pixel is odd or even when counted in sequence for each scan line, and the other indicating whether the scan line is odd or even for each frame, and a memory containing preprogrammed information in a table addressed by the result of comparison and said two appended bits.

Claim 12

A method for real-time video data analysis in a neighborhood comparison operator comprising the steps of storing two consecutive scan lines for analysis in real time with a third line being received, thereby having available a 3-by-3 array of pixels in a moving window, thus making available nine pixel values for comparison, selecting for comparison the values of all pixels with a threshold value, or the values of eight neighboring pixels with the center pixel or selecting for comparison the center pixel with the threshold value, and determining the sense of the comparison from a choice of greater than, equal to, or less than the threshold or center pixel, forming the bit-wise logical OR of the eight neighboring input pixel values, appending two additional bits to the resulting value of each comparison to indicate the even or odd number of the raster scan line and to indicate the even or odd number of the pixel number on that line, and using the resulting number to address a memory containing preprogrammed information, and thereafter using two bits of the memory output to determine which of three values is selected as the output of the neighborhood comparison operator, namely the remaining bits of the memory output; the value of the center pixel; or the bit-wise logical OR of the eight neighboring pixel values.

Claim 13

A method for real-time video data analysis in a neighborhood comparison operator comprising the steps of storing two consecutive scan lines for analysis in real time with a third line being received, thereby having available a 3-by-3 array of pixels in a moving window, thus making available nine pixel values for comparison, selecting for comparison the values of all pixels with a threshold value, or the values of eight neighboring pixels with the center pixel or selecting for comparison the center pixel with the threshold value, and determining the sense of the comparison from a choice of greater than, equal to, or less than the threshold or center pixel, forming the bit-wise logical OR of the eight neighboring input pixel values, appending two additional bits to the resulting value of each comparison to indicate the even or odd number of the raster scan line and to indicate the even or odd number of the pixel number on that line, and using the resulting number to address a memory containing preprogrammed information, and thereafter using two bits of the memory output to determine which of three values is selected as the output of the neighborhood comparison operator, namely the remaining bits of the memory output; the value of the center pixel; or the bit-wise logical OR of the eight neighboring pixel values.