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Diffstat (limited to 'libs/libqrencode/src/mask.c')
-rw-r--r-- | libs/libqrencode/src/mask.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/libs/libqrencode/src/mask.c b/libs/libqrencode/src/mask.c new file mode 100644 index 0000000000..4bf2371765 --- /dev/null +++ b/libs/libqrencode/src/mask.c @@ -0,0 +1,357 @@ +/* + * qrencode - QR Code encoder + * + * Masking. + * Copyright (C) 2006-2017 Kentaro Fukuchi <kentaro@fukuchi.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#if HAVE_CONFIG_H +# include "config.h" +#endif +#include <stdlib.h> +#include <string.h> +#include <limits.h> +#include <errno.h> + +#include "qrencode.h" +#include "qrspec.h" +#include "mask.h" + +STATIC_IN_RELEASE int Mask_writeFormatInformation(int width, unsigned char *frame, int mask, QRecLevel level) +{ + unsigned int format; + unsigned char v; + int i; + int blacks = 0; + + format = QRspec_getFormatInfo(mask, level); + + for(i = 0; i < 8; i++) { + if(format & 1) { + blacks += 2; + v = 0x85; + } else { + v = 0x84; + } + frame[width * 8 + width - 1 - i] = v; + if(i < 6) { + frame[width * i + 8] = v; + } else { + frame[width * (i + 1) + 8] = v; + } + format= format >> 1; + } + for(i = 0; i < 7; i++) { + if(format & 1) { + blacks += 2; + v = 0x85; + } else { + v = 0x84; + } + frame[width * (width - 7 + i) + 8] = v; + if(i == 0) { + frame[width * 8 + 7] = v; + } else { + frame[width * 8 + 6 - i] = v; + } + format= format >> 1; + } + + return blacks; +} + +/** + * Demerit coefficients. + * See Section 8.8.2, pp.45, JIS X0510:2004. + */ +#define N1 (3) +#define N2 (3) +#define N3 (40) +#define N4 (10) + +#define MASKMAKER(__exp__) \ + int x, y;\ + int b = 0;\ +\ + for(y = 0; y < width; y++) {\ + for(x = 0; x < width; x++) {\ + if(*s & 0x80) {\ + *d = *s;\ + } else {\ + *d = *s ^ ((__exp__) == 0);\ + }\ + b += (int)(*d & 1);\ + s++; d++;\ + }\ + }\ + return b; + +static int Mask_mask0(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER((x+y)&1) +} + +static int Mask_mask1(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER(y&1) +} + +static int Mask_mask2(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER(x%3) +} + +static int Mask_mask3(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER((x+y)%3) +} + +static int Mask_mask4(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER(((y/2)+(x/3))&1) +} + +static int Mask_mask5(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER(((x*y)&1)+(x*y)%3) +} + +static int Mask_mask6(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER((((x*y)&1)+(x*y)%3)&1) +} + +static int Mask_mask7(int width, const unsigned char *s, unsigned char *d) +{ + MASKMAKER((((x*y)%3)+((x+y)&1))&1) +} + +#define maskNum (8) +typedef int MaskMaker(int, const unsigned char *, unsigned char *); +static MaskMaker *maskMakers[maskNum] = { + Mask_mask0, Mask_mask1, Mask_mask2, Mask_mask3, + Mask_mask4, Mask_mask5, Mask_mask6, Mask_mask7 +}; + +#ifdef WITH_TESTS +unsigned char *Mask_makeMaskedFrame(int width, unsigned char *frame, int mask) +{ + unsigned char *masked; + + masked = (unsigned char *)malloc((size_t)(width * width)); + if(masked == NULL) return NULL; + + maskMakers[mask](width, frame, masked); + + return masked; +} +#endif + +unsigned char *Mask_makeMask(int width, unsigned char *frame, int mask, QRecLevel level) +{ + unsigned char *masked; + + if(mask < 0 || mask >= maskNum) { + errno = EINVAL; + return NULL; + } + + masked = (unsigned char *)malloc((size_t)(width * width)); + if(masked == NULL) return NULL; + + maskMakers[mask](width, frame, masked); + Mask_writeFormatInformation(width, masked, mask, level); + + return masked; +} + + +//static int n1; +//static int n2; +//static int n3; +//static int n4; + +STATIC_IN_RELEASE int Mask_calcN1N3(int length, int *runLength) +{ + int i; + int demerit = 0; + int fact; + + for(i = 0; i < length; i++) { + if(runLength[i] >= 5) { + demerit += N1 + (runLength[i] - 5); + //n1 += N1 + (runLength[i] - 5); + } + if((i & 1)) { + if(i >= 3 && i < length-2 && (runLength[i] % 3) == 0) { + fact = runLength[i] / 3; + if(runLength[i-2] == fact && + runLength[i-1] == fact && + runLength[i+1] == fact && + runLength[i+2] == fact) { + if(i == 3 || runLength[i-3] >= 4 * fact) { + demerit += N3; + //n3 += N3; + } else if(i+4 >= length || runLength[i+3] >= 4 * fact) { + demerit += N3; + //n3 += N3; + } + } + } + } + } + + return demerit; +} + +STATIC_IN_RELEASE int Mask_calcN2(int width, unsigned char *frame) +{ + int x, y; + unsigned char *p; + unsigned char b22, w22; + int demerit = 0; + + p = frame + width + 1; + for(y = 1; y < width; y++) { + for(x = 1; x < width; x++) { + b22 = p[0] & p[-1] & p[-width] & p [-width-1]; + w22 = p[0] | p[-1] | p[-width] | p [-width-1]; + if((b22 | (w22 ^ 1))&1) { + demerit += N2; + } + p++; + } + p++; + } + + return demerit; +} + +STATIC_IN_RELEASE int Mask_calcRunLengthH(int width, unsigned char *frame, int *runLength) +{ + int head; + int i; + unsigned char prev; + + if(frame[0] & 1) { + runLength[0] = -1; + head = 1; + } else { + head = 0; + } + runLength[head] = 1; + prev = frame[0]; + + for(i = 1; i < width; i++) { + if((frame[i] ^ prev) & 1) { + head++; + runLength[head] = 1; + prev = frame[i]; + } else { + runLength[head]++; + } + } + + return head + 1; +} + +STATIC_IN_RELEASE int Mask_calcRunLengthV(int width, unsigned char *frame, int *runLength) +{ + int head; + int i; + unsigned char prev; + + if(frame[0] & 1) { + runLength[0] = -1; + head = 1; + } else { + head = 0; + } + runLength[head] = 1; + prev = frame[0]; + + for(i = 1; i < width; i++) { + if((frame[i * width] ^ prev) & 1) { + head++; + runLength[head] = 1; + prev = frame[i * width]; + } else { + runLength[head]++; + } + } + + return head + 1; +} + +STATIC_IN_RELEASE int Mask_evaluateSymbol(int width, unsigned char *frame) +{ + int x, y; + int demerit = 0; + int runLength[QRSPEC_WIDTH_MAX + 1]; + int length; + + demerit += Mask_calcN2(width, frame); + + for(y = 0; y < width; y++) { + length = Mask_calcRunLengthH(width, frame + y * width, runLength); + demerit += Mask_calcN1N3(length, runLength); + } + + for(x = 0; x < width; x++) { + length = Mask_calcRunLengthV(width, frame + x, runLength); + demerit += Mask_calcN1N3(length, runLength); + } + + return demerit; +} + +unsigned char *Mask_mask(int width, unsigned char *frame, QRecLevel level) +{ + int i; + unsigned char *mask, *bestMask; + int minDemerit = INT_MAX; + int blacks; + int bratio; + int demerit; + int w2 = width * width; + + mask = (unsigned char *)malloc((size_t)w2); + if(mask == NULL) return NULL; + bestMask = (unsigned char *)malloc((size_t)w2); + if(bestMask == NULL) { + free(mask); + return NULL; + } + + for(i = 0; i < maskNum; i++) { +// n1 = n2 = n3 = n4 = 0; + demerit = 0; + blacks = maskMakers[i](width, frame, mask); + blacks += Mask_writeFormatInformation(width, mask, i, level); + bratio = (200 * blacks + w2) / w2 / 2; /* (int)(100*blacks/w2+0.5) */ + demerit = (abs(bratio - 50) / 5) * N4; +// n4 = demerit; + demerit += Mask_evaluateSymbol(width, mask); +// printf("(%d,%d,%d,%d)=%d\n", n1, n2, n3 ,n4, demerit); + if(demerit < minDemerit) { + minDemerit = demerit; + memcpy(bestMask, mask, (size_t)w2); + } + } + free(mask); + return bestMask; +} |