摘要 |
<p>The method involves irradiating a defined section of the product surface (12) by two radiation sources (21,22,23) of different wavelengths, from different directions, and the irradiated surface section is optoelectronically detected. Three radiation sources are used as visible light sources. An image sensor (25), particularly a digital camera is used for the opto-electronic recording. An independent claim is also included for a device for executing the method.</p> |