[gs-commits] mupdf 1.16.1.16 Bug 701397: Allow inverting luminance of

commit 1b3b8a3a7e80a24e8089bff7a410c9d4288dfa83
Author: Tor Andersson <[email protected]>
Date:   Fri Aug 16 17:22:32 2019 +0200

    Bug 701397: Allow inverting luminance of grayscale and BGR images too.

diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c
index 56dfb39..a91fdd3 100644
--- a/source/fitz/pixmap.c
+++ b/source/fitz/pixmap.c
@@ -1022,15 +1022,25 @@ fz_tint_pixmap(fz_context *ctx, fz_pixmap *pix, int black, int white)
 	}
 }
 
-/* Invert luminance in RGB pixmap, but keep the colors as is. */
-static void invert_luminance_rgb(unsigned char *rgb)
+/* Invert luminance in RGB/BGR pixmap, but keep the colors as is. */
+static inline void invert_luminance(int type, unsigned char *s)
 {
 	int r, g, b, y, u, v, c, d, e;
 
 	/* Convert to YUV */
-	r = rgb[0];
-	g = rgb[1];
-	b = rgb[2];
+	if (type == FZ_COLORSPACE_RGB)
+	{
+		r = s[0];
+		g = s[1];
+		b = s[2];
+	}
+	else
+	{
+		r = s[2];
+		g = s[1];
+		b = s[0];
+	}
+
 	y = ((66 * r + 129 * g + 25 * b + 128) >> 8) + 16;
 	u = ((-38 * r - 74 * g + 112 * b + 128) >> 8) + 128;
 	v = ((112 * r - 94 * g - 18 * b + 128) >> 8) + 128;
@@ -1046,9 +1056,18 @@ static void invert_luminance_rgb(unsigned char *rgb)
 	g = (298 * c - 100 * d - 208 * e + 128) >> 8;
 	b = (298 * c + 516 * d + 128) >> 8;
 
-	rgb[0] = r > 255 ? 255 : r < 0 ? 0 : r;
-	rgb[1] = g > 255 ? 255 : g < 0 ? 0 : g;
-	rgb[2] = b > 255 ? 255 : b < 0 ? 0 : b;
+	if (type == FZ_COLORSPACE_RGB)
+	{
+		s[0] = r > 255 ? 255 : r < 0 ? 0 : r;
+		s[1] = g > 255 ? 255 : g < 0 ? 0 : g;
+		s[2] = b > 255 ? 255 : b < 0 ? 0 : b;
+	}
+	else
+	{
+		s[2] = r > 255 ? 255 : r < 0 ? 0 : r;
+		s[1] = g > 255 ? 255 : g < 0 ? 0 : g;
+		s[0] = b > 255 ? 255 : b < 0 ? 0 : b;
+	}
 }
 
 void
@@ -1056,18 +1075,27 @@ fz_invert_pixmap_luminance(fz_context *ctx, fz_pixmap *pix)
 {
 	unsigned char *s = pix->samples;
 	int x, y, n = pix->n;
+	int type = pix->colorspace ? pix->colorspace->type : FZ_COLORSPACE_NONE;
 
-	if (pix->colorspace->type != FZ_COLORSPACE_RGB)
-		fz_throw(ctx, FZ_ERROR_GENERIC, "can only invert luminance of RGB pixmaps");
-
-	for (y = 0; y < pix->h; y++)
+	if (type == FZ_COLORSPACE_GRAY)
 	{
-		for (x = 0; x < pix->w; x++)
+		fz_invert_pixmap(ctx, pix);
+	}
+	else if (type == FZ_COLORSPACE_RGB || type == FZ_COLORSPACE_BGR)
+	{
+		for (y = 0; y < pix->h; y++)
 		{
-			invert_luminance_rgb(s);
-			s += n;
+			for (x = 0; x < pix->w; x++)
+			{
+				invert_luminance(type, s);
+				s += n;
+			}
+			s += pix->stride - pix->w * n;
 		}
-		s += pix->stride - pix->w * n;
+	}
+	else
+	{
+		fz_throw(ctx, FZ_ERROR_GENERIC, "can only invert luminance of Gray and RGB pixmaps");
 	}
 }
 

http://git.ghostscript.com/?p=mupdf.git;a=commit;h=1b3b8a3a7e80a24e8089bff7a410c9d4288dfa83

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