8ca2076de1
.. where only 2 filtering modes are potentially tried, instead of all of them. This is fast than the exhaustive 'best' mode, and not much worse. Options for cwebp are: -alpha_filter none -alpha_filter fast (<- default) -alpha_filter best (<- slow) Change-Id: I8cb90ee11b8f981811e013ea4ad5bf72ba3ea7d4
55 lines
1.7 KiB
C
55 lines
1.7 KiB
C
// Copyright 2011 Google Inc. All Rights Reserved.
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//
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// This code is licensed under the same terms as WebM:
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// Software License Agreement: http://www.webmproject.org/license/software/
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// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
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// -----------------------------------------------------------------------------
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//
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// Spatial prediction using various filters
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//
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// Author: Urvang (urvang@google.com)
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#ifndef WEBP_UTILS_FILTERS_H_
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#define WEBP_UTILS_FILTERS_H_
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#include "../webp/types.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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// Filters.
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typedef enum {
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WEBP_FILTER_NONE = 0,
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WEBP_FILTER_HORIZONTAL,
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WEBP_FILTER_VERTICAL,
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WEBP_FILTER_GRADIENT,
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WEBP_FILTER_LAST = WEBP_FILTER_GRADIENT + 1, // end marker
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WEBP_FILTER_BEST,
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WEBP_FILTER_FAST
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} WEBP_FILTER_TYPE;
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typedef void (*WebPFilterFunc)(const uint8_t* in, int width, int height,
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int bpp, int stride, uint8_t* out);
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// Filter the given data using the given predictor.
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// 'in' corresponds to a 2-dimensional pixel array of size (stride * height)
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// in raster order.
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// 'bpp' is number of bytes per pixel, and
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// 'stride' is number of bytes per scan line (with possible padding).
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// 'out' should be pre-allocated.
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extern const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST];
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// Reconstruct the original data from the given filtered data.
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extern const WebPFilterFunc WebPUnfilters[WEBP_FILTER_LAST];
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// Fast estimate of a potentially good filter.
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extern WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,
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int width, int height, int stride);
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#if defined(__cplusplus) || defined(c_plusplus)
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} // extern "C"
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#endif
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#endif /* WEBP_UTILS_FILTERS_H_ */
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