Automatic grading of ceramic tiles using machine vision

The authors present a method designed to solve the problem of automatic color grading for industrial inspection. By far the most important obstacle to the solution of this problem is the temporal constancy of the image capturing conditions. They discuss the problems they were confronted with in that respect and the ways they dealt with them. Finally, they present results of correctly grading a series of ceramic tiles, the differences of which were at the threshold of the human perception.<<ETX>>