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  "body": "\n## Summary\n\nShearlets are a multiscale system of functions on $\\R^2$ obtained from one generating function by parabolic dilations, shears and translations.\nLike [[curvelets|VEVPDJ8S7B]], they resolve directions and represent images with smooth edges sparsely.\nUnlike curvelets, they change direction by shearing instead of rotating, and shears with integer parameters preserve the integer lattice.\nThis makes the passage from the continuous theory to digital algorithms on pixel grids direct.\n\n## Explanations\n\n### L1 human\n\nA shear tilts a picture sideways, as when a deck of cards is pushed so that it leans.\nA shearlet is a small thin wave packet that is stretched more in one direction than the other and then tilted by a shear.\nDifferent shears point the packet in different directions, and different scales make it finer.\nSince shears with integer amounts move grid points to grid points, the system fits naturally on a grid of pixels.\n",
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