Vision system with adjustment for variations in imaged surface reflectivity

摘要

The image pipeline for a vision system includes a series of digital image processing boards controlled by a computer. A video camera generates from a laser beam reflected from the target surface an RS-170 analog video signal which is converted to a digital signal for processing. Bins of digitizing parameters suitable for several target surface reflectivities are stored in computer memory. The appropriate bin is selected from histogram data of pixel intensity levels generated by one of the image processing boards using digitizing parameters from a reference bin. Improved imaging, especially of black surfaces, is achieved by scanning a laser beam to generate a light stripe over a number of image frames using the digitizing parameters from the selected bin and integrating the data from the successive frames using the image processing boards.