Horizontal and Vertical Projection Segmentation for License Plate Images

Horizontal and vertical projection segmentation of license plate images serves a critical function as one of the essential steps in license plate localization. This technique separates character regions from background areas in license plate images by analyzing pixel distribution patterns along both horizontal and vertical axes. In implementation, horizontal projection typically involves summing pixel values row-wise to identify character height boundaries, while vertical projection sums column-wise to determine character width boundaries. The segmentation process enables more accurate identification and localization of license plates by isolating text regions from complex backgrounds. Therefore, horizontal-vertical projection segmentation forms an indispensable component in license plate recognition algorithms, providing vital clues about plate regions and significantly improving recognition accuracy and reliability. Advanced implementations often incorporate thresholding techniques and peak detection algorithms to handle varying lighting conditions and character spacing.