diff options
Diffstat (limited to 'src/blind-invert-luma.c')
| -rw-r--r-- | src/blind-invert-luma.c | 78 |
1 files changed, 67 insertions, 11 deletions
diff --git a/src/blind-invert-luma.c b/src/blind-invert-luma.c index aa3b260..c83b8dc 100644 --- a/src/blind-invert-luma.c +++ b/src/blind-invert-luma.c @@ -7,19 +7,29 @@ #include <string.h> #include <unistd.h> -USAGE("[-i] mask-stream") +USAGE("[-iw] mask-stream") static void process_xyza(struct stream *colour, struct stream *mask, size_t n) { size_t i; - double w, y; + double w, y, yo, X, Z; + X = D65_XYY_X / D65_XYY_Y; + Z = 1 / D65_XYY_Y - 1 - X; for (i = 0; i < n; i += colour->pixel_size) { w = ((double *)(mask->buf + i))[1]; w *= ((double *)(mask->buf + i))[3]; - y = ((double *)(colour->buf + i))[3]; - y = (1 - y) * w + y * (1 - w); - ((double *)(colour->buf + i))[3] = y; + yo = ((double *)(colour->buf + i))[1]; + y = (1 - yo) * w + yo * (1 - w); + ((double *)(colour->buf + i))[0] += (y - yo) * X; + ((double *)(colour->buf + i))[1] = y; + ((double *)(colour->buf + i))[2] += (y - yo) * Z; + /* + * Explaination: + * Y is the luma and ((X / Xn - Y / Yn), (Z / Zn - Y / Yn)) + * is the chroma (according to CIELAB), where (Xn, Yn, Zn) + * is the white point. + */ } } @@ -27,20 +37,60 @@ static void process_xyza_i(struct stream *colour, struct stream *mask, size_t n) { size_t i; - double w, y; + double w, y, yo, X, Z; + X = D65_XYY_X / D65_XYY_Y; + Z = 1 / D65_XYY_Y - 1 - X; for (i = 0; i < n; i += colour->pixel_size) { w = 1 - ((double *)(mask->buf + i))[1]; w *= ((double *)(mask->buf + i))[3]; - y = ((double *)(colour->buf + i))[3]; - y = (1 - y) * w + y * (1 - w); - ((double *)(colour->buf + i))[3] = y; + yo = ((double *)(colour->buf + i))[1]; + y = (1 - yo) * w + yo * (1 - w); + ((double *)(colour->buf + i))[0] += (y - yo) * X; + ((double *)(colour->buf + i))[1] = y; + ((double *)(colour->buf + i))[2] += (y - yo) * Z; + } +} + +static void +process_xyza_w(struct stream *colour, struct stream *mask, size_t n) +{ + size_t i; + double w, y, yo, X, Z; + for (i = 0; i < n; i += colour->pixel_size) { + X = ((double *)(mask->buf + i))[0]; + Z = ((double *)(mask->buf + i))[2]; + w = ((double *)(mask->buf + i))[1]; + w *= ((double *)(mask->buf + i))[3]; + yo = ((double *)(colour->buf + i))[1]; + y = (1 - yo) * w + yo * (1 - w); + ((double *)(colour->buf + i))[0] += (y - yo) * X; + ((double *)(colour->buf + i))[1] = y; + ((double *)(colour->buf + i))[2] += (y - yo) * Z; + } +} + +static void +process_xyza_iw(struct stream *colour, struct stream *mask, size_t n) +{ + size_t i; + double w, y, yo, X, Z; + for (i = 0; i < n; i += colour->pixel_size) { + X = ((double *)(mask->buf + i))[0]; + Z = ((double *)(mask->buf + i))[2]; + w = 1 - ((double *)(mask->buf + i))[1]; + w *= ((double *)(mask->buf + i))[3]; + yo = ((double *)(colour->buf + i))[1]; + y = (1 - yo) * w + yo * (1 - w); + ((double *)(colour->buf + i))[0] += (y - yo) * X; + ((double *)(colour->buf + i))[1] = y; + ((double *)(colour->buf + i))[2] += (y - yo) * Z; } } int main(int argc, char *argv[]) { - int invert = 0; + int invert = 0, whitepoint = 0; struct stream colour, mask; void (*process)(struct stream *colour, struct stream *mask, size_t n) = NULL; @@ -48,6 +98,9 @@ main(int argc, char *argv[]) case 'i': invert = 1; break; + case 'w': + whitepoint = 1; + break; default: usage(); } ARGEND; @@ -64,10 +117,13 @@ main(int argc, char *argv[]) einit_stream(&mask); if (!strcmp(colour.pixfmt, "xyza")) - process = invert ? process_xyza_i : process_xyza; + process = invert ? whitepoint ? process_xyza_iw : process_xyza_i + : whitepoint ? process_xyza_w : process_xyza; else eprintf("pixel format %s is not supported, try xyza\n", colour.pixfmt); + fprint_stream_head(stdout, &colour); + efflush(stdout, "<stdout>"); process_two_streams(&colour, &mask, STDOUT_FILENO, "<stdout>", process); return 0; } |