Add color management support to gdk_pixbuf_save

This patch adds an icc-profile option to a GdkPixbuf which can
be used to read or write an embedded ICC profile.

Add PNG support for now, but other image formats are awaiting
review.

2 files changed, 120 insertions, 0 deletions

diff --git a/demos/Makefile.am b/demos/Makefile.am
index c8c9bbb1c5..81e07f427a 100644
--- a/demos/Makefile.am
+++ b/demos/Makefile.am
@@ -24,6 +24,7 @@ LDADDS = 								\
 noinst_PROGRAMS = 		\
 	testpixbuf-drawable 	\
 	testanimation 		\
+	testpixbuf-color	\
 	testpixbuf-save		\
 	testpixbuf-scale 	\
 	pixbuf-demo
@@ -52,6 +53,7 @@ test-inline-pixbufs.h: $(pixbuf_csource_deps) apple-red.png gnome-foot.png
 testpixbuf_DEPENDENCIES = $(DEPS)
 testpixbuf_drawable_DEPENDENCIES = $(DEPS)
 testpixbuf_save_DEPENDENCIES = $(DEPS)
+testpixbuf_color_DEPENDENCIES = $(DEPS)
 testpixbuf_scale_DEPENDENCIES = $(DEPS)
 testanimation_DEPENDENCIES = $(DEPS)
 pixbuf_demo_DEPENDENCIES = $(DEPS)
@@ -59,6 +61,7 @@ pixbuf_demo_DEPENDENCIES = $(DEPS)
 testpixbuf_LDADD = $(LDADDS)
 testpixbuf_drawable_LDADD = $(LDADDS)
 testpixbuf_save_LDADD = $(LDADDS)
+testpixbuf_color_LDADD = $(LDADDS)
 testpixbuf_scale_LDADD = $(LDADDS)
 testanimation_LDADD = $(LDADDS)
 pixbuf_demo_LDADD = $(LDADDS)
@@ -66,6 +69,7 @@ pixbuf_demo_LDADD = $(LDADDS)
 testpixbuf_SOURCES = testpixbuf.c pixbuf-init.c
 testpixbuf_drawable_SOURCES = testpixbuf-drawable.c pixbuf-init.c
 testpixbuf_save_SOURCES = testpixbuf-save.c
+testpixbuf_color_SOURCES = testpixbuf-color.c
 testpixbuf_scale_SOURCES = testpixbuf-scale.c pixbuf-init.c
 testanimation_SOURCES = testanimation.c pixbuf-init.c
 pixbuf_demo_SOURCES = pixbuf-demo.c pixbuf-init.c
diff --git a/demos/testpixbuf-color.c b/demos/testpixbuf-color.c
new file mode 100644
index 0000000000..b87d850a0e
--- /dev/null
+++ b/demos/testpixbuf-color.c
@@ -0,0 +1,116 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
+
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+#include <gtk/gtk.h>
+
+#define ICC_PROFILE             "/usr/share/color/icc/bluish.icc"
+#define ICC_PROFILE_SIZE        3966
+
+static gboolean
+save_image_png (const gchar *filename, GdkPixbuf *pixbuf, GError **error)
+{
+	gchar *contents = NULL;
+	gchar *contents_encode = NULL;
+	gsize length;
+	gboolean ret;
+	gint len;
+
+	/* get icc file */
+	ret = g_file_get_contents (ICC_PROFILE, &contents, &length, error);
+	if (!ret)
+		goto out;
+	contents_encode = g_base64_encode ((const guchar *) contents, length);
+	ret = gdk_pixbuf_save (pixbuf, filename, "png", error,
+			       "tEXt::Software", "Hello my name is dave",
+			       "icc-profile", contents_encode,
+			       NULL);
+	len = strlen (contents_encode);
+	g_debug ("ICC profile was %i bytes", len);
+out:
+	g_free (contents);
+	g_free (contents_encode);
+	return ret;
+}
+
+static gboolean
+save_image_verify (const gchar *filename, GError **error)
+{
+	gboolean ret = FALSE;
+	GdkPixbuf *pixbuf = NULL;
+	const gchar *option;
+	gchar *icc_profile = NULL;
+	gsize len = 0;
+
+	/* load */
+	pixbuf = gdk_pixbuf_new_from_file (filename, error);
+	if (pixbuf == NULL)
+		goto out;
+
+	/* check values */
+	option = gdk_pixbuf_get_option (pixbuf, "icc-profile");
+	if (option == NULL) {
+		*error = g_error_new (1, 0, "no profile set");
+		goto out;
+	}
+
+	/* decode base64 */
+	icc_profile = (gchar *) g_base64_decode (option, &len);
+	if (len != ICC_PROFILE_SIZE) {
+		*error = g_error_new (1, 0, "profile length invalid, got %i", len);
+		g_file_set_contents ("error.icc", icc_profile, len, NULL);
+		goto out;
+	}
+
+	/* success */
+	ret = TRUE;
+out:
+	if (pixbuf != NULL)
+		g_object_unref (pixbuf);
+	g_free (icc_profile);
+	return ret;
+}
+
+int
+main (int argc, char **argv)
+{
+	GdkWindow *root;
+	GdkPixbuf *pixbuf;
+	gboolean ret;
+	gint retval = 1;
+	GError *error = NULL;
+
+	gtk_init (&argc, &argv);
+
+	gtk_widget_set_default_colormap (gdk_rgb_get_colormap ());
+
+	root = gdk_get_default_root_window ();
+	pixbuf = gdk_pixbuf_get_from_drawable (NULL, root, NULL,
+					       0, 0, 0, 0, 150, 160);
+
+	/* PASS */
+	g_debug ("try to save PNG with a profile");
+	ret = save_image_png ("icc-profile.png", pixbuf, &error);
+	if (!ret) {
+		g_warning ("FAILED: did not save image: %s", error->message);
+		g_error_free (error);
+		goto out;
+	}
+
+	/* PASS */
+	g_debug ("try to load PNG and get color attributes");
+	ret = save_image_verify ("icc-profile.png", &error);
+	if (!ret) {
+		g_warning ("FAILED: did not load image: %s", error->message);
+		g_error_free (error);
+		goto out;
+	}
+
+	/* success */
+	retval = 0;
+	g_debug ("ALL OKAY!");
+out:
+	return retval;
+}