Terms
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Definitions
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Aliasing
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Artifacts in an image that can appear as a result of reducing an image's size. When the size of an image is reduced, original pixels are downsampled to create fewer pixels. Aliasing that occurs as a result of size reduction normally appears as "stair-step" patterns (especially in high contrast images), or as "Moire" (ripple-effect) patterns.
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Anti-aliasing
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Any method for correcting aliasing (see above). The method discussed in this chapter is low-pass filtering (see below).
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Bicubic interpolation
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Output pixel values are calculated from a weighted average of pixels in the nearest 4-by-4 neighborhood.
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Bilinear interpolation
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Output pixel values are calculated from a weighted average of pixels in the nearest 2-by-2 neighborhood.
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Geometric operation
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An operation that modifies the spatial relations between pixels in an image. Examples include resizing (growing or shrinking), rotating, and shearing.
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Interpolation
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The process by which we estimate an image value at a location in between image pixels.
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Nearest neighbor interpolation
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Output pixel values are assigned the value of the pixel that the point falls within. No other pixels are considered.
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