An Effective Two-stage Screen Positioning Method Based on Improved Binary SIFT Descriptor

With the popularization of smart screens, screen bonding technology has gradually developed. This paper uses the SIFT algorithm to recognize the LCD screen. Aiming at the problem of long matching time and large memory usage for its 128-dimensional floating-point descriptor, this paper proposes an improved binary descriptor, which can effectively increase the percentage of correct matching between key points and reduce the matching time by 1/3. After recognizing the object, this paper proposes a two-stage positioning method. We use the screen center obtained by the SIFT algorithm as the seed to perform Flood-fill processing, and obtain the four inner corners of the LCD screen through sub-pixel corner detection to accurately calculate the screen center. Finally, it is verified through experiments that the positioning error can be kept within 2.5 pixels, and the angle error can be kept within 0.9 degrees, which can meet the screen fitting accuracy requirements.