[gtk/wip/otte/color-profiles: 99/111] png: Handle color profiles
- From: Benjamin Otte <otte src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/wip/otte/color-profiles: 99/111] png: Handle color profiles
- Date: Sat, 2 Oct 2021 02:53:26 +0000 (UTC)
commit ae57b9d770b0c24638a68bfadec12cb00195cc75
Author: Benjamin Otte <otte redhat com>
Date: Mon Sep 27 04:53:23 2021 +0200
png: Handle color profiles
gdk/loaders/gdkpng.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 109 insertions(+), 1 deletion(-)
---
diff --git a/gdk/loaders/gdkpng.c b/gdk/loaders/gdkpng.c
index 7130620af8..11450660ce 100644
--- a/gdk/loaders/gdkpng.c
+++ b/gdk/loaders/gdkpng.c
@@ -19,6 +19,7 @@
#include "gdkpngprivate.h"
+#include "gdkcolorprofileprivate.h"
#include "gdkintl.h"
#include "gdkmemoryformatprivate.h"
#include "gdkmemorytextureprivate.h"
@@ -26,6 +27,7 @@
#include "gdktexture.h"
#include "gdktextureprivate.h"
#include "gsk/ngl/fp16private.h"
+
#include <png.h>
#include <stdio.h>
@@ -206,6 +208,100 @@ unpremultiply_float_to_16bit (guchar *data,
}
}
+static GdkColorProfile *
+gdk_png_get_color_profile (png_struct *png,
+ png_info *info)
+{
+ GdkColorProfile *profile;
+ guchar *icc_data;
+ png_uint_32 icc_len;
+ char *name;
+ double gamma;
+ cmsCIExyY whitepoint;
+ cmsCIExyYTRIPLE primaries;
+ cmsToneCurve *curve;
+ cmsHPROFILE lcms_profile;
+ int intent;
+
+ if (png_get_iCCP (png, info, &name, NULL, &icc_data, &icc_len))
+ {
+ GBytes *bytes = g_bytes_new (icc_data, icc_len);
+
+ profile = gdk_color_profile_new_from_icc_bytes (bytes, NULL);
+ g_bytes_unref (bytes);
+ if (profile)
+ return profile;
+ }
+
+ if (png_get_sRGB (png, info, &intent))
+ return g_object_ref (gdk_color_profile_get_srgb ());
+
+ /* If neither of those is valid, the result is sRGB */
+ if (!png_get_valid (png, info, PNG_INFO_gAMA) &&
+ !png_get_valid (png, info, PNG_INFO_cHRM))
+ return g_object_ref (gdk_color_profile_get_srgb ());
+
+ if (!png_get_gAMA (png, info, &gamma))
+ gamma = 2.4;
+
+ if (!png_get_cHRM (png, info,
+ &whitepoint.x, &whitepoint.y,
+ &primaries.Red.x, &primaries.Red.y,
+ &primaries.Green.x, &primaries.Green.y,
+ &primaries.Blue.x, &primaries.Blue.y))
+ {
+ if (gamma == 2.4)
+ return g_object_ref (gdk_color_profile_get_srgb ());
+
+ whitepoint = (cmsCIExyY) { 0.3127, 0.3290, 1.0 };
+ primaries = (cmsCIExyYTRIPLE) {
+ { 0.6400, 0.3300, 1.0 },
+ { 0.3000, 0.6000, 1.0 },
+ { 0.1500, 0.0600, 1.0 }
+ };
+ }
+ else
+ {
+ primaries.Red.Y = 1.0;
+ primaries.Green.Y = 1.0;
+ primaries.Blue.Y = 1.0;
+ }
+
+ curve = cmsBuildGamma (NULL, 1.0 / gamma);
+ lcms_profile = cmsCreateRGBProfile (&whitepoint,
+ &primaries,
+ (cmsToneCurve*[3]) { curve, curve, curve });
+ profile = gdk_color_profile_new_from_lcms_profile (lcms_profile, NULL);
+ /* FIXME: errors? */
+ if (profile == NULL)
+ profile = g_object_ref (gdk_color_profile_get_srgb ());
+ cmsFreeToneCurve (curve);
+
+ return profile;
+}
+
+static void
+gdk_png_set_color_profile (png_struct *png,
+ png_info *info,
+ GdkColorProfile *profile)
+{
+ /* FIXME: allow deconstructing RGB profiles into gAMA and cHRM instead of
+ * falling back to iCCP */
+ if (profile == gdk_color_profile_get_srgb ())
+ {
+ png_set_sRGB_gAMA_and_cHRM (png, info, /* FIXME */ PNG_sRGB_INTENT_PERCEPTUAL);
+ }
+ else
+ {
+ GBytes *bytes = gdk_color_profile_get_icc_profile (profile);
+ png_set_iCCP (png, info,
+ "ICC profile",
+ 0,
+ g_bytes_get_data (bytes, NULL),
+ g_bytes_get_size (bytes));
+ }
+}
+
/* }}} */
/* {{{ Public API */
@@ -223,6 +319,7 @@ gdk_load_png (GBytes *bytes,
guchar *buffer = NULL;
guchar **row_pointers = NULL;
GBytes *out_bytes;
+ GdkColorProfile *color_profile;
GdkTexture *texture;
int bpp;
G_GNUC_UNUSED gint64 before = GDK_PROFILER_CURRENT_TIME;
@@ -334,6 +431,8 @@ gdk_load_png (GBytes *bytes,
return NULL;
}
+ color_profile = gdk_png_get_color_profile (png, info);
+
bpp = gdk_memory_format_bytes_per_pixel (format);
stride = width * bpp;
if (stride % 8)
@@ -344,6 +443,7 @@ gdk_load_png (GBytes *bytes,
if (!buffer || !row_pointers)
{
+ g_object_unref (color_profile);
g_free (buffer);
g_free (row_pointers);
png_destroy_read_struct (&png, &info, NULL);
@@ -360,8 +460,12 @@ gdk_load_png (GBytes *bytes,
png_read_end (png, info);
out_bytes = g_bytes_new_take (buffer, height * stride);
- texture = gdk_memory_texture_new (width, height, format, out_bytes, stride);
+ texture = gdk_memory_texture_new_with_color_profile (width, height,
+ format,
+ color_profile,
+ out_bytes, stride);
g_bytes_unref (out_bytes);
+ g_object_unref (color_profile);
g_free (row_pointers);
png_destroy_read_struct (&png, &info, NULL);
@@ -388,11 +492,13 @@ gdk_save_png (GdkTexture *texture)
int y;
GdkTexture *mtexture;
GdkMemoryFormat format;
+ GdkColorProfile *color_profile;
int png_format;
int depth;
width = gdk_texture_get_width (texture);
height = gdk_texture_get_height (texture);
+ color_profile = gdk_color_profile_get_srgb (); /* FIXME: refactor saving */
mtexture = gdk_texture_download_texture (texture);
format = gdk_memory_texture_get_format (GDK_MEMORY_TEXTURE (mtexture));
@@ -472,6 +578,8 @@ gdk_save_png (GdkTexture *texture)
PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
+ gdk_png_set_color_profile (png, info, color_profile);
+
png_write_info (png, info);
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
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