Algorithms for adaptive transform edge detection

Edge detection in grayscale digital images based on the locations of zero c rossings has been investigated. Samples of the image are transformed using the discrete symmetric cosine transform (DSCT) and filtered using truncated time or frequency sampled forms of the Laplacian-of-Gaussian (I,OG) filter . This correspondence presents and evaluates adaptive block-based filtering procedures to localize edges based on discrete circular and teal transform s. Measures of the signal-to-noise ratio (SNR) and edge localization are pr ovided.