Patent ID: 7596275

Claim:
A method for processing an empty-status of a target comprising: directing radiation at a target with at least one radiation source; detecting the directed radiation that passes through the target with at least one radiation detector; generating an image of the target, the image including a plurality of pixels arranged in rows and columns, each of the plurality of pixels is assigned a brightness intensity based on the detecting; and processing the target image based on the brightness intensity of each of the plurality of pixels to declare the target as empty or non-empty in accordance with a first predetermined criterion, the processing including: identifying a region of the target in the target image; and determining an interior of the target from the identified target region, including: identifying a first wall and a second wall of the target; identifying a floor of the target; and identifying a ceiling of the target, including: determining whether a correlation in mean brightness intensity from one pixel row to an adjacent lower pixel row in the container region meets a predetermined correlation threshold when the one pixel row is shifted to right or left, beginning from a top of the container region; and upon determining that the correlation in mean brightness intensity between one of the upper pixel rows in the container region when shifted to the left or right and an adjacent lower one of the pixels no longer meets the predetermined correlation, identifying the one upper pixel row as the target ceiling.