Improve handling of JPX colorspaces.

3 files changed, 61 insertions, 45 deletions

diff --git a/fitz/filt_jpxd.c b/fitz/filt_jpxd.c
index f5a65851..097d34de 100644
--- a/fitz/filt_jpxd.c
+++ b/fitz/filt_jpxd.c
@@ -19,7 +19,7 @@ static void fz_opj_info_callback(const char *msg, void *client_data)
 }
 
 fz_error
-fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size)
+fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size, fz_colorspace *defcs)
 {
 	fz_pixmap *img;
 	opj_event_mgr_t evtmgr;
@@ -30,7 +30,7 @@ fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size)
 	fz_colorspace *colorspace;
 	unsigned char *p;
 	int format;
-	int n, w, h, depth, sgnd;
+	int a, n, w, h, depth, sgnd;
 	int x, y, k, v;
 
 	if (size < 2)
@@ -79,15 +79,34 @@ fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size)
 	depth = jpx->comps[0].prec;
 	sgnd = jpx->comps[0].sgnd;
 
-	switch (n)
+	if (jpx->color_space == CLRSPC_SRGB && n == 4) { n = 3; a = 1; }
+	else if (jpx->color_space == CLRSPC_SYCC && n == 4) { n = 3; a = 1; }
+	else if (n == 2) { n = 1; a = 1; }
+	else if (n > 4) { n = 4; a = 1; }
+	else { a = 0; }
+
+	if (defcs)
 	{
-	case 1: colorspace = fz_device_gray; break;
-	case 3: colorspace = fz_device_rgb; break;
-	case 4: colorspace = fz_device_cmyk; break;
-	default:
-		/* TODO: SMaskInData */
-		opj_image_destroy(jpx);
-		return fz_throw("unknown jpx colorspace (%d components)", n);
+		if (defcs->n == n)
+		{
+			colorspace = defcs;
+		}
+		else
+		{
+			fz_warn("jpx file and dict colorspaces do not match");
+			fz_drop_colorspace(defcs);
+			defcs = NULL;
+		}
+	}
+
+	if (!defcs)
+	{
+		switch (n)
+		{
+		case 1: colorspace = fz_device_gray; break;
+		case 3: colorspace = fz_device_rgb; break;
+		case 4: colorspace = fz_device_cmyk; break;
+		}
 	}
 
 	img = fz_new_pixmap(colorspace, 0, 0, w, h);
@@ -97,7 +116,7 @@ fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size)
 	{
 		for (x = 0; x < w; x++)
 		{
-			for (k = 0; k < n; k++)
+			for (k = 0; k < n + a; k++)
 			{
 				v = jpx->comps[k].data[y * w + x];
 				if (sgnd)
@@ -106,8 +125,21 @@ fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size)
 					v = v >> (depth - 8);
 				*p++ = v;
 			}
-			*p++ = 255; /* TODO: SMaskInData */
+			if (!a)
+				*p++ = 255;
+		}
+	}
+
+	if (a)
+	{
+		if (n == 4)
+		{
+			fz_pixmap *tmp = fz_new_pixmap(fz_device_rgb, 0, 0, w, h);
+			fz_convert_pixmap(img, tmp);
+			fz_drop_pixmap(img);
+			img = tmp;
 		}
+		fz_premultiply_pixmap(img);
 	}
 
 	opj_image_destroy(jpx);
diff --git a/fitz/fitz.h b/fitz/fitz.h
index f0f3ecdb..4833ffd6 100644
--- a/fitz/fitz.h
+++ b/fitz/fitz.h
@@ -697,7 +697,7 @@ fz_error fz_write_pnm(fz_pixmap *pixmap, char *filename);
 fz_error fz_write_pam(fz_pixmap *pixmap, char *filename, int savealpha);
 fz_error fz_write_png(fz_pixmap *pixmap, char *filename, int savealpha);
 
-fz_error fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size);
+fz_error fz_load_jpx_image(fz_pixmap **imgp, unsigned char *data, int size, fz_colorspace *dcs);
 
 /*
  * Colorspace resources.
diff --git a/pdf/pdf_image.c b/pdf/pdf_image.c
index dc12c232..0b2f2547 100644
--- a/pdf/pdf_image.c
+++ b/pdf/pdf_image.c
@@ -304,22 +304,37 @@ pdf_load_jpx_image(fz_pixmap **imgp, pdf_xref *xref, fz_obj *dict)
 {
 	fz_error error;
 	fz_buffer *buf;
+	fz_colorspace *colorspace;
 	fz_pixmap *img;
 	fz_obj *obj;
 
 	pdf_log_image("jpeg2000\n");
 
+	colorspace = NULL;
+
 	error = pdf_load_stream(&buf, xref, fz_to_num(dict), fz_to_gen(dict));
 	if (error)
 		return fz_rethrow(error, "cannot load jpx image data");
 
-	error = fz_load_jpx_image(&img, buf->data, buf->len);
+	obj = fz_dict_gets(dict, "ColorSpace");
+	if (obj)
+	{
+		error = pdf_load_colorspace(&colorspace, xref, obj);
+		if (error)
+			fz_catch(error, "cannot load image colorspace");
+	}
+
+	error = fz_load_jpx_image(&img, buf->data, buf->len, colorspace);
 	if (error)
 	{
+		if (colorspace)
+			fz_drop_colorspace(colorspace);
 		fz_drop_buffer(buf);
 		return fz_rethrow(error, "cannot load jpx image");
 	}
 
+	if (colorspace)
+		fz_drop_colorspace(colorspace);
 	fz_drop_buffer(buf);
 
 	obj = fz_dict_getsa(dict, "SMask", "Mask");
@@ -333,37 +348,6 @@ pdf_load_jpx_image(fz_pixmap **imgp, pdf_xref *xref, fz_obj *dict)
 		}
 	}
 
-	obj = fz_dict_gets(dict, "ColorSpace");
-	if (obj)
-	{
-		fz_colorspace *original = img->colorspace;
-		img->colorspace = NULL;
-
-		error = pdf_load_colorspace(&img->colorspace, xref, obj);
-		if (error)
-		{
-			fz_drop_colorspace(original);
-			return fz_rethrow(error, "cannot load image colorspace");
-		}
-
-		if (original->n != img->colorspace->n)
-		{
-			fz_warn("jpeg-2000 colorspace (%s) does not match promised colorspace (%s)", original->name, img->colorspace->name);
-			fz_drop_colorspace(img->colorspace);
-			img->colorspace = original;
-		}
-		else
-			fz_drop_colorspace(original);
-
-		if (!strcmp(img->colorspace->name, "Indexed"))
-		{
-			fz_pixmap *conv;
-			conv = pdf_expand_indexed_pixmap(img);
-			fz_drop_pixmap(img);
-			img = conv;
-		}
-	}
-
 	*imgp = img;
 	return fz_okay;
 }