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Leptonica
1.82.0
Image processing and image analysis suite
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#include <string.h>
#include "allheaders.h"
Go to the source code of this file.
Functions | |
PIX * | pixReduceBinary2 (PIX *pixs, l_uint8 *intab) |
PIX * | pixReduceRankBinaryCascade (PIX *pixs, l_int32 level1, l_int32 level2, l_int32 level3, l_int32 level4) |
PIX * | pixReduceRankBinary2 (PIX *pixs, l_int32 level, l_uint8 *intab) |
l_uint8 * | makeSubsampleTab2x (void) |
Subsampled 2x reduction PIX *pixReduceBinary2()
Rank filtered 2x reductions PIX *pixReduceRankBinaryCascade() PIX *pixReduceRankBinary2()
Permutation table for 2x rank binary reduction l_uint8 *makeSubsampleTab2x(void)
Definition in file binreduce.c.
l_uint8* makeSubsampleTab2x | ( | void | ) |
Notes: Permutation table for 2x rank binary reduction This table permutes the bits in a byte, from 0 4 1 5 2 6 3 7 to 0 1 2 3 4 5 6 7
Definition at line 391 of file binreduce.c.
Referenced by pixCompareWithTranslation().
[in] | pixs | |
[in] | intab | [optional]; if null, a table is made here and destroyed before exit |
Notes: (1) After folding, the data is in bytes 0 and 2 of the word, and the bits in each byte are in the following order (with 0 being the leftmost originating pair and 7 being the rightmost originating pair): 0 4 1 5 2 6 3 7 These need to be permuted to 0 1 2 3 4 5 6 7 which is done with an 8-bit table generated by makeSubsampleTab2x().
Definition at line 74 of file binreduce.c.
References L_Bilateral::pixs.
[in] | pixs | 1 bpp |
[in] | level | rank threshold: 1, 2, 3, 4 |
[in] | intab | [optional]; if null, a table is made here and destroyed before exit |
Notes: (1) pixd is downscaled by 2x from pixs. (2) The rank threshold specifies the minimum number of ON pixels in each 2x2 region of pixs that are required to set the corresponding pixel ON in pixd. (3) Rank filtering is done to the UL corner of each 2x2 pixel block, using only logical operations. Then these pixels are chosen in the 2x subsampling process, subsampled, as described above in pixReduceBinary2().
Definition at line 227 of file binreduce.c.
References L_Bilateral::pixs.
Referenced by pixCompareWithTranslation().
PIX* pixReduceRankBinaryCascade | ( | PIX * | pixs, |
l_int32 | level1, | ||
l_int32 | level2, | ||
l_int32 | level3, | ||
l_int32 | level4 | ||
) |
[in] | pixs | 1 bpp |
[in] | level1 | threshold, in the set {0, 1, 2, 3, 4} |
[in] | level2 | threshold, in the set {0, 1, 2, 3, 4} |
[in] | level3 | threshold, in the set {0, 1, 2, 3, 4} |
[in] | level4 | threshold, in the set {0, 1, 2, 3, 4} |
Notes: (1) This performs up to four cascaded 2x rank reductions. (2) Use level = 0 to truncate the cascade.
Definition at line 152 of file binreduce.c.
References L_Bilateral::pixs.