Algorithms for efficient and accurate edge detection and localization
Ramakrishnan Sundaram · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
The detection of edges in digital imagery based on localizing the zero crossings of filtered image data has been investigated. Truncated time or frequency sampled forms (TSF/FSF) of the Laplacian of Gaussian (LOG) filter are employed in the transform domain. Samples of the image are transformed using the discrete symmetric cosine transform (DSCT) prior to adaptive filtering and the isolation of zero crossings. The DSCT facilitates both control of the edge localization accuracy as well as modular implementation. The adaptive strategy for accepting/rejecting edge transitions at the appropriate locations in the image is based on estimates of the local gradient. This paper evaluates block-based filtering procedures to identify edges in terms of achievable edge localization, signal-to-noise ratio (SNR) around the edge, and computational benefits.