CHARACTER AND PATTERN RECOGNITION BASED ON MOIRE IMAGES

摘要

The paper presents a novel method for recognizing raised or indented characters or patterns on industrial samples by using a combination of moiré interferometry technique with optical character recognition (OCR) and pattern recognition. Patterns recognized with this method are of low contrast, and conventional recognition schemes require complex optics and lighting. Raised characters on tires, vin code tags, credit cards, indented characters on metal, wrinkles on skin and embossment on buttons are some examples. The proposed method uses the moiré interferometry technique to obtain a gray scale image of patterns such that their heights are represented in gray scale. This eliminates the need for special optics for each application.