Abstract: A process and device for detecting and evaluating surface cracks in workpieces wherein a picture is produced of the surface of the workpiece by means of a video camera and said picture is digitized and is processed by means of a computer to produce a binary picture of any cracks present and a sorting report is triggered when a preselected threshold level is exceeded. In order to obtain a sorting signal that is independent of the absolute brightness of the original picture a blurred background picture is derived from the original picture levels that have been converted to digitized grey shade levels and subtracted from the original picture, the difference picture formed in this way giving the crack representation.