Fix errors

Signed-off-by: Mattias Andrée <maandree@kth.se>

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;
 }