Improved egg crack detection algorithm for modified pressure imaging system

Shell eggs with microcracks are often undetected during egg grading processes. In the past, a modified pressure imaging system was developed to detect eggs with microcracks without adversely affecting the quality of normal intact eggs. The basic idea of the modified pressure imaging system was to apply a short burst of vacuum within a transparent chamber in order to cause a momentary and forced opening in the egg shell with a crack and thus to utilize the changes in image intensities during this process. The intensity changes from dark to bright in the shell surface were recorded by a highresolution digital camera and processed by an image ratio technique. The performance of the imaging system, however, was sometimes compromised by false readings due to motion of intact eggs relative to the camera. The uneven movement of the lid hinged on the chamber was considered as the main cause of motion errors. In this paper, a machine vision technique to compensate the motion errors was developed to reduce the false detection readings caused by motion of intact eggs. The developed motion compensation algorithm is based on motion estimation of individual eggs.