From 1c8cf6ae7275eebc3a5686dca410231155b76d75 Mon Sep 17 00:00:00 2001 From: Benjamin Otte Date: Mon, 27 Sep 2021 04:53:23 +0200 Subject: [PATCH] png: Handle color profiles --- gdk/loaders/gdkpng.c | 120 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 119 insertions(+), 1 deletion(-) diff --git a/gdk/loaders/gdkpng.c b/gdk/loaders/gdkpng.c index 1c4c79b522..06f1100a58 100644 --- a/gdk/loaders/gdkpng.c +++ b/gdk/loaders/gdkpng.c @@ -21,11 +21,13 @@ #include "gdkcolorspace.h" #include "gdkintl.h" +#include "gdklcmscolorspaceprivate.h" #include "gdkmemoryformatprivate.h" #include "gdkmemorytextureprivate.h" #include "gdkprofilerprivate.h" #include "gdktexture.h" #include "gdktextureprivate.h" + #include #include @@ -127,6 +129,102 @@ png_simple_warning_callback (png_structp png, { } +static GdkColorSpace * +gdk_png_get_color_space (png_struct *png, + png_info *info, + GError **error) +{ + GdkColorSpace *space; + 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); + + space = gdk_color_space_new_from_icc_profile (bytes, error); + g_bytes_unref (bytes); + return space; + } + + if (png_get_sRGB (png, info, &intent)) + return g_object_ref (gdk_color_space_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_space_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_space_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 }); + space = gdk_lcms_color_space_new_from_lcms_profile (lcms_profile); + cmsFreeToneCurve (curve); + + return space; +} + +static gboolean +gdk_png_set_color_space (png_struct *png, + png_info *info, + GdkColorSpace *space) +{ + /* FIXME: allow deconstructing RGB color spaces into gAMA and cHRM instead of + * falling back to iCCP */ + if (space == gdk_color_space_get_srgb ()) + { + png_set_sRGB_gAMA_and_cHRM (png, info, /* FIXME */ PNG_sRGB_INTENT_PERCEPTUAL); + return TRUE; + } + else + { + GBytes *bytes = gdk_color_space_save_to_icc_profile (space, NULL); + if (bytes == NULL) + return FALSE; + png_set_iCCP (png, info, + "ICC profile", + 0, + g_bytes_get_data (bytes, NULL), + g_bytes_get_size (bytes)); + g_bytes_unref (bytes); + return TRUE; + } +} + /* }}} */ /* {{{ Public API */ @@ -144,6 +242,7 @@ gdk_load_png (GBytes *bytes, guchar *buffer = NULL; guchar **row_pointers = NULL; GBytes *out_bytes; + GdkColorSpace *color_space; GdkTexture *texture; int bpp; G_GNUC_UNUSED gint64 before = GDK_PROFILER_CURRENT_TIME; @@ -255,6 +354,13 @@ gdk_load_png (GBytes *bytes, return NULL; } + color_space = gdk_png_get_color_space (png, info, error); + if (color_space == NULL) + { + png_destroy_read_struct (&png, &info, NULL); + return NULL; + } + bpp = gdk_memory_format_bytes_per_pixel (format); stride = width * bpp; if (stride % 8) @@ -265,6 +371,7 @@ gdk_load_png (GBytes *bytes, if (!buffer || !row_pointers) { + g_object_unref (color_space); g_free (buffer); g_free (row_pointers); png_destroy_read_struct (&png, &info, NULL); @@ -281,8 +388,12 @@ 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_space (width, height, + format, + color_space, + out_bytes, stride); g_bytes_unref (out_bytes); + g_object_unref (color_space); g_free (row_pointers); png_destroy_read_struct (&png, &info, NULL); @@ -309,12 +420,14 @@ gdk_save_png (GdkTexture *texture) int y; GdkMemoryTexture *memtex; GdkMemoryFormat format; + GdkColorSpace *color_space; int png_format; int depth; width = gdk_texture_get_width (texture); height = gdk_texture_get_height (texture); format = gdk_texture_get_format (texture); + color_space = gdk_texture_get_color_space (texture); switch (format) { @@ -403,8 +516,13 @@ gdk_save_png (GdkTexture *texture) PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); + if (!gdk_png_set_color_space (png, info, color_space)) + color_space = gdk_color_space_get_srgb (); + png_write_info (png, info); + memtex = gdk_memory_texture_from_texture (texture, format, color_space); + #if G_BYTE_ORDER == G_LITTLE_ENDIAN png_set_swap (png); #endif