Steerable Pyramid
Pyramid, or pyramid representation, is a type of Scale model, multi-scale Signal (information theory), signal Knowledge representation, representation developed by the computer vision, image processing and signal processing communities, in which a signal or an image is subject to repeated smoothing and Downsampling, subsampling. Pyramid representation is a predecessor to scale space, scale-space representation and multiresolution analysis. Pyramid generation There are two main types of pyramids: lowpass and bandpass. A lowpass pyramid is made by smoothing the image with an appropriate smoothing filter and then subsampling the smoothed image, usually by a factor of 2 along each coordinate direction. The resulting image is then subjected to the same procedure, and the cycle is repeated multiple times. Each cycle of this process results in a smaller image with increased smoothing, but with decreased spatial sampling density (that is, decreased image resolution). If illustrated gra ...
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