Basic real-time programmable image-processing operations are accomplished by use of acousto-optic (AO) cells. Instead of frequency-plane filters, the AO cells are placed directly behind the object. The one-dimensional edge-enhancement results with one AO cell can be improved by use of two AO cells that are placed in tandem with contrapropagating sound. The dominant second-derivative operation obtained from the transfer function of the undiffracted order works like a one-dimensional Laplacian operator that enables improved edge enhancement.
© 1998 Optical Society of America
(070.1060) Fourier optics and signal processing : Acousto-optical signal processing
(070.6760) Fourier optics and signal processing : Talbot and self-imaging effects
(100.1160) Image processing : Analog optical image processing
(100.2980) Image processing : Image enhancement
Dongqing Cao, Partha P. Banerjee, and Ting-Chung Poon, "Image Edge Enhancement with Two Cascaded Acousto-Optic Cells with Contrapropagating Sound," Appl. Opt. 37, 3007-3014 (1998)