From 5e4476ff714a3eb0cbeba42dc21acaa110efdea9 Mon Sep 17 00:00:00 2001 From: Přemysl Eric Janouch Date: Sat, 25 Dec 2021 19:14:44 +0100 Subject: Improve gdk-pixbuf colour management --- fiv-io.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 76 insertions(+), 22 deletions(-) diff --git a/fiv-io.c b/fiv-io.c index c20d445..3341f46 100644 --- a/fiv-io.c +++ b/fiv-io.c @@ -266,7 +266,7 @@ fiv_io_profile_cmyk( } static void -fiv_io_profile_xrgb( +fiv_io_profile_xrgb32( cairo_surface_t *surface, FivIoProfile source, FivIoProfile target) { #ifndef HAVE_LCMS2 @@ -300,7 +300,7 @@ fiv_io_profile_xrgb( // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static void -fiv_io_profile_finalize_page(cairo_surface_t *page, FivIoProfile target) +fiv_io_profile_xrgb32_page(cairo_surface_t *page, FivIoProfile target) { GBytes *bytes = NULL; gsize len = 0; @@ -313,7 +313,7 @@ fiv_io_profile_finalize_page(cairo_surface_t *page, FivIoProfile target) // TODO(p): Animations need to be composited in a linear colour space. for (cairo_surface_t *frame = page; frame != NULL; frame = cairo_surface_get_user_data(frame, &fiv_io_key_frame_next)) - fiv_io_profile_xrgb(frame, source, target); + fiv_io_profile_xrgb32(frame, source, target); if (source) fiv_io_profile_free(source); @@ -333,16 +333,36 @@ fiv_io_profile_finalize(cairo_surface_t *image, FivIoProfile target) // occurs beforehands, and also for correct alpha compositing. // FIXME: This assumes that if the first frame is opaque, they all are. if (cairo_image_surface_get_format(page) == CAIRO_FORMAT_RGB24) - fiv_io_profile_finalize_page(page, target); + fiv_io_profile_xrgb32_page(page, target); } return image; } -// --- Wuffs ------------------------------------------------------------------- - // From libwebp, verified to exactly match [x * a / 255]. #define PREMULTIPLY8(a, x) (((uint32_t) (x) * (uint32_t) (a) * 32897U) >> 23) +static void +fiv_io_premultiply_argb32(cairo_surface_t *surface) +{ + int w = cairo_image_surface_get_width(surface); + int h = cairo_image_surface_get_height(surface); + unsigned char *data = cairo_image_surface_get_data(surface); + int stride = cairo_image_surface_get_stride(surface); + + for (int y = 0; y < h; y++) { + uint32_t *dstp = (uint32_t *) (data + stride * y); + for (int x = 0; x < w; x++) { + uint32_t argb = dstp[x], a = argb >> 24; + dstp[x] = a << 24 | + PREMULTIPLY8(a, 0xFF & (argb >> 16)) << 16 | + PREMULTIPLY8(a, 0xFF & (argb >> 8)) << 8 | + PREMULTIPLY8(a, 0xFF & argb); + } + } +} + +// --- Wuffs ------------------------------------------------------------------- + static bool pull_passthrough(const wuffs_base__more_information *minfo, wuffs_base__io_buffer *src, wuffs_base__io_buffer *dst, GError **error) @@ -900,7 +920,7 @@ load_jpeg_finalize(cairo_surface_t *surface, bool cmyk, if (cmyk) fiv_io_profile_cmyk(surface, source, destination); else - fiv_io_profile_xrgb(surface, source, destination); + fiv_io_profile_xrgb32(surface, source, destination); if (source) fiv_io_profile_free(source); @@ -1660,18 +1680,8 @@ load_libheif_image(struct heif_image_handle *handle, GError **error) } // TODO(p): Test real behaviour on real transparent images. - if (has_alpha && !heif_image_handle_is_premultiplied_alpha(handle)) { - for (int y = 0; y < h; y++) { - uint32_t *dstp = (uint32_t *) (dst + dst_stride * y); - for (int x = 0; x < w; x++) { - uint32_t argb = dstp[x], a = argb >> 24; - dstp[x] = a << 24 | - PREMULTIPLY8(a, 0xFF & (argb >> 16)) << 16 | - PREMULTIPLY8(a, 0xFF & (argb >> 8)) << 8 | - PREMULTIPLY8(a, 0xFF & argb); - } - } - } + if (has_alpha && !heif_image_handle_is_premultiplied_alpha(handle)) + fiv_io_premultiply_argb32(surface); heif_item_id exif_id = 0; if (heif_image_handle_get_list_of_metadata_block_IDs( @@ -2048,6 +2058,28 @@ fail: #endif // HAVE_LIBTIFF -------------------------------------------------------- #ifdef HAVE_GDKPIXBUF // ------------------------------------------------------ +static cairo_surface_t * +load_gdkpixbuf_argb32_unpremultiplied(GdkPixbuf *pixbuf) +{ + int w = gdk_pixbuf_get_width(pixbuf); + int h = gdk_pixbuf_get_height(pixbuf); + cairo_surface_t *surface = + cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h); + + guint length = 0; + guchar *src = gdk_pixbuf_get_pixels_with_length(pixbuf, &length); + int src_stride = gdk_pixbuf_get_rowstride(pixbuf); + uint32_t *dst = (uint32_t *) cairo_image_surface_get_data(surface); + for (int y = 0; y < h; y++) { + const guchar *p = src + y * src_stride; + for (int x = 0; x < w; x++) { + *dst++ = (uint32_t) p[3] << 24 | p[0] << 16 | p[1] << 8 | p[2]; + p += 4; + } + } + return surface; +} + static cairo_surface_t * open_gdkpixbuf( const gchar *data, gsize len, FivIoProfile profile, GError **error) @@ -2060,8 +2092,24 @@ open_gdkpixbuf( if (!pixbuf) return NULL; - cairo_surface_t *surface = - gdk_cairo_surface_create_from_pixbuf(pixbuf, 1, NULL); + bool custom_argb32 = profile && gdk_pixbuf_get_has_alpha(pixbuf) && + gdk_pixbuf_get_colorspace(pixbuf) == GDK_COLORSPACE_RGB && + gdk_pixbuf_get_n_channels(pixbuf) == 4 && + gdk_pixbuf_get_bits_per_sample(pixbuf) == 8; + + cairo_surface_t *surface = NULL; + if (custom_argb32) + surface = load_gdkpixbuf_argb32_unpremultiplied(pixbuf); + else + surface = gdk_cairo_surface_create_from_pixbuf(pixbuf, 1, NULL); + + cairo_status_t surface_status = cairo_surface_status(surface); + if (surface_status != CAIRO_STATUS_SUCCESS) { + set_error(error, cairo_status_to_string(surface_status)); + cairo_surface_destroy(surface); + g_object_unref(pixbuf); + return NULL; + } const char *orientation = gdk_pixbuf_get_option(pixbuf, "orientation"); if (orientation && strlen(orientation) == 1) { @@ -2083,7 +2131,13 @@ open_gdkpixbuf( } g_object_unref(pixbuf); - return fiv_io_profile_finalize(surface, profile); + if (custom_argb32) { + fiv_io_profile_xrgb32_page(surface, profile); + fiv_io_premultiply_argb32(surface); + } else { + surface = fiv_io_profile_finalize(surface, profile); + } + return surface; } #endif // HAVE_GDKPIXBUF ------------------------------------------------------ -- cgit v1.2.3-70-g09d2