Off-image detection circuit for an image analyzer

摘要

An image analyzer system and a method of analyzing image information contained in serial scan lines of pixels in which some of the pixels have valid data values representing image information while other pixels have invalid data values not representing characteristics of the image to be analyzed. Off image detector circuitry is utilized to generate output signals to neighborhood transformation logic when one or more pixels in a neighborhood contain invalid values. Preferably, the off image detector means monitors the status of a control line which indicates whether valid or invalid pixels are being transferred over a bus to a stage of the image analyzer system. The detector circuitry operates to store the number of valid pixels in subsequent scan lines presented to the stage. This comparison is utilized to detect invalid pixel values which may be contained in each neighborhood.