Add an image tool

This is meant to provide a convenient way to produce images in
specific color states and memory formats.

docs/reference/gtk/gtk4-image-tool.rst

@@ -0,0 +1,82 @@
+.. _gtk4-image-tool(1):
+
+====================
+gtk4-image-tool
+====================
+
+-----------------------
+Image Utility
+-----------------------
+
+:Version: GTK
+:Manual section: 1
+:Manual group: GTK commands
+
+SYNOPSIS
+--------
+|   **gtk4-image-tool** <COMMAND> [OPTIONS...] <FILE>...
+|
+|   **gtk4-image-tool** compare [OPTIONS...] <FILE1> <FILE2>
+|   **gtk4-image-tool** convert [OPTIONS...] <FILE1> <FILE2>
+|   **gtk4-image-tool** info [OPTIONS...] <FILE>
+|   **gtk4-image-tool** relabel [OPTIONS...] <FILE1> <FILE2>
+|   **gtk4-image-tool** show [OPTIONS...] <FILE>
+
+DESCRIPTION
+-----------
+
+``gtk4-image-tool`` can perform various operations on images.
+
+COMMANDS
+--------
+
+Information
+^^^^^^^^^^^
+
+The ``info`` command shows general information about the image, such
+as its format and color state.
+
+Showing
+^^^^^^^
+
+The ``show`` command displays the image.
+
+Compare
+^^^^^^^
+
+The ``compare`` command compares two images. If any differences are found,
+the exit code is 1. If the images are identical, it is 0.
+
+``--output=FILE``
+
+  Save the differences as a png image in ``FILE``.
+
+``--quiet``
+
+  Don't write results to stdout.
+
+Conversion
+^^^^^^^^^^
+
+The ``convert`` command converts the image to a different format or color state.
+
+``--format=FORMAT``
+
+  Convert to the given format. The supported formats can be listed
+  with ``--format=list``.
+
+``--color-state=COLORSTATE``
+
+  Convert to the given color state. The supported color states can be
+  listed with ``--format=list``.
+
+Relabeling
+^^^^^^^^^^
+
+The ``relabel`` command changes the color state of an image without conversion.
+This can be useful to produce wrong color renderings for diagnostics.
+
+``--color-state=COLORSTATE``
+
+  Convert to the given color state. The supported color states can be
+  listed with ``--format=list``.

docs/reference/gtk/meson.build

@@ -85,6 +85,7 @@ rst_files = [
   [ 'gtk4-broadwayd', '1' ],
   [ 'gtk4-builder-tool', '1' ],
   [ 'gtk4-encode-symbolic-svg', '1', ],
+  [ 'gtk4-image-tool', '1' ],
   [ 'gtk4-launch', '1', ],
   [ 'gtk4-query-settings', '1', ],
   [ 'gtk4-rendernode-tool', '1' ],

tools/gtk-image-tool-compare.c

@@ -0,0 +1,121 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+#include "testsuite/reftests/reftest-compare.h"
+
+void
+do_compare (int          *argc,
+            const char ***argv)
+{
+  GOptionContext *context;
+  gboolean opt_quiet = FALSE;
+  char **filenames = NULL;
+  char *opt_filename = NULL;
+  const GOptionEntry entries[] = {
+    { "output", 'o', 0, G_OPTION_ARG_FILENAME, &opt_filename, N_("Output file"), N_("FILE") },
+    { "quiet", 'q', 0, G_OPTION_ARG_NONE, &opt_quiet, "Don't talk", NULL },
+
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE…") },
+    { NULL, }
+  };
+  GdkTexture *texture[2];
+  GdkTexture *diff;
+  GError *error = NULL;
+
+  g_set_prgname ("gtk4-image-tool compare");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Compare two images"));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr (_("No image file specified\n"));
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) != 2)
+    {
+      g_printerr (_("Can only accept two image files\n"));
+      exit (1);
+    }
+
+  for (int i = 0; i < 2; i++)
+    {
+      texture[i] = gdk_texture_new_from_filename (filenames[i], &error);
+      if (texture[i] == NULL)
+        {
+          g_printerr (_("Failed to load %s: %s\n"), filenames[i], error->message);
+          exit (1);
+        }
+    }
+
+  diff = reftest_compare_textures (texture[0], texture[1]);
+
+  if (opt_filename && diff)
+    {
+      if (!gdk_texture_save_to_png (diff, opt_filename))
+        {
+          g_printerr (_("Could not save diff image to %s\n"), opt_filename);
+          exit (1);
+        }
+    }
+
+  if (!opt_quiet)
+    {
+      if (diff)
+        {
+          if (opt_filename)
+            g_print (_("Differences witten to %s.\n"), opt_filename);
+          else
+            g_print (_("The images are different.\n"));
+        }
+      else
+        g_print (_("No differences.\n"));
+    }
+
+  if (diff)
+    exit (1);
+
+  g_strfreev (filenames);
+  g_free (opt_filename);
+  g_object_unref (texture[0]);
+  g_object_unref (texture[1]);
+}

tools/gtk-image-tool-convert.c

@@ -0,0 +1,157 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+
+static void
+save_image (const char      *filename,
+            const char      *output,
+            GdkMemoryFormat  format,
+            GdkColorState   *color_state)
+{
+  GdkTexture *orig;
+  GdkTextureDownloader *downloader;
+  GBytes *bytes;
+  gsize stride;
+  GdkTexture *texture;
+  GdkMemoryTextureBuilder *builder;
+
+  orig = load_image_file (filename);
+  downloader = gdk_texture_downloader_new (orig);
+
+  gdk_texture_downloader_set_format (downloader, format);
+  gdk_texture_downloader_set_color_state (downloader, color_state);
+
+  bytes = gdk_texture_downloader_download_bytes (downloader, &stride);
+
+  builder = gdk_memory_texture_builder_new ();
+  gdk_memory_texture_builder_set_bytes (builder, bytes);
+  gdk_memory_texture_builder_set_stride (builder, stride);
+  gdk_memory_texture_builder_set_format (builder, format);
+  gdk_memory_texture_builder_set_color_state (builder, color_state);
+  gdk_memory_texture_builder_set_width (builder, gdk_texture_get_width (orig));
+  gdk_memory_texture_builder_set_height (builder, gdk_texture_get_height (orig));
+
+  texture = gdk_memory_texture_builder_build (builder);
+
+  if (g_str_has_suffix (output, ".tiff"))
+    gdk_texture_save_to_tiff (texture, output);
+  else
+    gdk_texture_save_to_png (texture, output);
+
+  g_object_unref (texture);
+  g_bytes_unref (bytes);
+  gdk_texture_downloader_free (downloader);
+  g_object_unref (orig);
+  g_object_unref (builder);
+}
+
+void
+do_convert (int          *argc,
+            const char ***argv)
+{
+  GOptionContext *context;
+  char **filenames = NULL;
+  char *format_name = NULL;
+  char *colorstate_name = NULL;
+  const GOptionEntry entries[] = {
+    { "format", 0, 0, G_OPTION_ARG_STRING, &format_name, N_("Format to use"), N_("FORMAT") },
+    { "color-state", 0, 0, G_OPTION_ARG_STRING, &colorstate_name, N_("Color state to use"), N_("COLORSTATE") },
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE…") },
+    { NULL, }
+  };
+  GError *error = NULL;
+  GdkMemoryFormat format = GDK_MEMORY_DEFAULT;
+  GdkColorState *color_state = gdk_color_state_get_srgb ();
+
+  g_set_prgname ("gtk4-image-tool convert");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Convert the image to a different format or color state."));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr (_("No image file specified\n"));
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) != 2)
+    {
+      g_printerr (_("Can only accept a single image file and output file\n"));
+      exit (1);
+    }
+
+  if (format_name)
+    {
+      if (!find_format_by_name (format_name, &format))
+        {
+          char **names;
+          char *suggestion;
+
+          names = get_format_names ();
+          suggestion = g_strjoinv ("\n  ", names);
+
+          g_printerr (_("Not a memory format: %s\nPossible values:\n  %s\n"),
+                      format_name, suggestion);
+          exit (1);
+        }
+    }
+
+  if (colorstate_name)
+    {
+      color_state = find_color_state_by_name (colorstate_name);
+      if (!color_state)
+        {
+          char **names;
+          char *suggestion;
+
+          names = get_color_state_names ();
+          suggestion = g_strjoinv ("\n  ", names);
+
+          g_printerr (_("Not a color state: %s\nPossible values:\n  %s\n"),
+                      colorstate_name, suggestion);
+          exit (1);
+        }
+    }
+
+  save_image (filenames[0], filenames[1], format, color_state);
+
+  g_strfreev (filenames);
+}

tools/gtk-image-tool-info.c

@@ -0,0 +1,103 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+static const char *
+get_format_name (GdkMemoryFormat format)
+{
+  GEnumClass *class;
+  GEnumValue *value;
+  const char *name;
+
+  class = g_type_class_ref (GDK_TYPE_MEMORY_FORMAT);
+  value = g_enum_get_value (class, format);
+  name = value->value_nick;
+  g_type_class_unref (class);
+
+  return name;
+}
+
+static void
+file_info (const char *filename)
+{
+  GdkTexture *texture;
+
+  texture = load_image_file (filename);
+
+  g_print ("%s %dx%d\n", _("Size:"), gdk_texture_get_width (texture), gdk_texture_get_height (texture));
+  g_print ("%s %s\n", _("Format:"), get_format_name (gdk_texture_get_format (texture)));
+  g_print ("%s %s\n", _("Color state:"), get_color_state_name (gdk_texture_get_color_state (texture)));
+
+  g_object_unref (texture);
+}
+
+void
+do_info (int          *argc,
+         const char ***argv)
+{
+  GOptionContext *context;
+  char **filenames = NULL;
+  const GOptionEntry entries[] = {
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE") },
+    { NULL, }
+  };
+  GError *error = NULL;
+
+  g_set_prgname ("gtk4-image-tool info");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Provide information about the image."));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr (_("No image file specified\n"));
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) > 1)
+    {
+      g_printerr (_("Can only accept a single image file\n"));
+      exit (1);
+    }
+
+  file_info (filenames[0]);
+
+  g_strfreev (filenames);
+}

tools/gtk-image-tool-relabel.c

@@ -0,0 +1,137 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+
+static void
+relabel_image (const char      *filename,
+               const char      *output,
+               GdkColorState   *color_state)
+{
+  GdkTexture *orig;
+  GdkTextureDownloader *downloader;
+  GBytes *bytes;
+  gsize stride;
+  GdkTexture *texture;
+  GdkMemoryTextureBuilder *builder;
+
+  orig = load_image_file (filename);
+  downloader = gdk_texture_downloader_new (orig);
+
+  gdk_texture_downloader_set_format (downloader, gdk_texture_get_format (orig));
+  gdk_texture_downloader_set_color_state (downloader, gdk_texture_get_color_state (orig));
+
+  bytes = gdk_texture_downloader_download_bytes (downloader, &stride);
+
+  builder = gdk_memory_texture_builder_new ();
+  gdk_memory_texture_builder_set_bytes (builder, bytes);
+  gdk_memory_texture_builder_set_stride (builder, stride);
+  gdk_memory_texture_builder_set_width (builder, gdk_texture_get_width (orig));
+  gdk_memory_texture_builder_set_height (builder, gdk_texture_get_height (orig));
+  gdk_memory_texture_builder_set_format (builder, gdk_texture_get_format (orig));
+  gdk_memory_texture_builder_set_color_state (builder, color_state);
+
+  texture = gdk_memory_texture_builder_build (builder);
+
+  if (g_str_has_suffix (output, ".tiff"))
+    gdk_texture_save_to_tiff (texture, output);
+  else
+    gdk_texture_save_to_png (texture, output);
+
+  g_object_unref (texture);
+  g_bytes_unref (bytes);
+  gdk_texture_downloader_free (downloader);
+  g_object_unref (orig);
+  g_object_unref (builder);
+}
+
+void
+do_relabel (int          *argc,
+            const char ***argv)
+{
+  GOptionContext *context;
+  char **filenames = NULL;
+  char *colorstate_name = NULL;
+  const GOptionEntry entries[] = {
+    { "color-state", 0, 0, G_OPTION_ARG_STRING, &colorstate_name, N_("Color state to use"), N_("COLORSTATE") },
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE…") },
+    { NULL, }
+  };
+  GError *error = NULL;
+  GdkColorState *color_state = gdk_color_state_get_srgb ();
+
+  g_set_prgname ("gtk4-image-tool relabel");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Change the color state of the image without conversion."));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr (_("No image file specified\n"));
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) != 2)
+    {
+      g_printerr (_("Can only accept a single image file and output file\n"));
+      exit (1);
+    }
+
+  if (colorstate_name)
+    {
+      color_state = find_color_state_by_name (colorstate_name);
+      if (!color_state)
+        {
+          char **names;
+          char *suggestion;
+
+          names = get_color_state_names ();
+          suggestion = g_strjoinv (", ", names);
+
+          g_printerr (_("Not a color state: %s\nPossible values: %s\n"),
+                      colorstate_name, suggestion);
+          exit (1);
+        }
+    }
+
+  relabel_image (filenames[0], filenames[1], color_state);
+
+  g_strfreev (filenames);
+}

tools/gtk-image-tool-show.c

@@ -0,0 +1,129 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+static void
+set_window_title (GtkWindow  *window,
+                  const char *filename)
+{
+  char *name;
+
+  name = g_path_get_basename (filename);
+  gtk_window_set_title (window, name);
+  g_free (name);
+}
+
+static void
+quit_cb (GtkWidget *widget,
+         gpointer   user_data)
+{
+  gboolean *is_done = user_data;
+
+  *is_done = TRUE;
+
+  g_main_context_wakeup (NULL);
+}
+
+static void
+show_file (const char *filename)
+{
+  GdkTexture *texture;
+  GtkWidget *sw;
+  GtkWidget *window;
+  gboolean done = FALSE;
+  GtkWidget *picture;
+
+  texture = load_image_file (filename);
+
+  picture = gtk_picture_new_for_paintable (GDK_PAINTABLE (texture));
+  gtk_picture_set_can_shrink (GTK_PICTURE (picture), FALSE);
+  gtk_picture_set_content_fit (GTK_PICTURE (picture), GTK_CONTENT_FIT_SCALE_DOWN);
+
+  sw = gtk_scrolled_window_new ();
+  gtk_scrolled_window_set_propagate_natural_width (GTK_SCROLLED_WINDOW (sw), TRUE);
+  gtk_scrolled_window_set_propagate_natural_height (GTK_SCROLLED_WINDOW (sw), TRUE);
+  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), picture);
+
+  window = gtk_window_new ();
+  set_window_title (GTK_WINDOW (window), filename);
+  gtk_window_set_child (GTK_WINDOW (window), sw);
+
+  gtk_window_present (GTK_WINDOW (window));
+  g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
+
+  while (!done)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_object_unref (texture);
+}
+
+void
+do_show (int          *argc,
+         const char ***argv)
+{
+  GOptionContext *context;
+  char **filenames = NULL;
+  const GOptionEntry entries[] = {
+    { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE") },
+    { NULL, }
+  };
+  GError *error = NULL;
+
+  g_set_prgname ("gtk4-image-tool show");
+  context = g_option_context_new (NULL);
+  g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_set_summary (context, _("Show the image."));
+
+  if (!g_option_context_parse (context, argc, (char ***)argv, &error))
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_option_context_free (context);
+
+  if (filenames == NULL)
+    {
+      g_printerr (_("No image file specified\n"));
+      exit (1);
+    }
+
+  if (g_strv_length (filenames) > 1)
+    {
+      g_printerr (_("Can only accept a single image file\n"));
+      exit (1);
+    }
+
+  show_file (filenames[0]);
+
+  g_strfreev (filenames);
+}

tools/gtk-image-tool-utils.c

@@ -0,0 +1,223 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+
+GdkTexture *
+load_image_file (const char *filename)
+{
+  GError *error = NULL;
+  GdkTexture *texture;
+
+  texture = gdk_texture_new_from_filename (filename, &error);
+  if (!texture)
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  return texture;
+}
+
+gboolean
+find_format_by_name (const char      *name,
+                     GdkMemoryFormat *format)
+{
+  GEnumClass *class;
+  GEnumValue *value;
+
+  class = g_type_class_ref (GDK_TYPE_MEMORY_FORMAT);
+
+  value = g_enum_get_value_by_nick (class, name);
+  if (value)
+    *format = value->value;
+
+  g_type_class_unref (class);
+
+  return value != NULL;
+}
+
+char **
+get_format_names (void)
+{
+  GEnumClass *class;
+  GStrvBuilder *builder;
+  char **res;
+
+  builder = g_strv_builder_new ();
+  class = g_type_class_ref (GDK_TYPE_MEMORY_FORMAT);
+
+  for (int i = 0; i < class->n_values; i++)
+    {
+      if (class->values[i].value == GDK_MEMORY_N_FORMATS)
+        continue;
+      g_strv_builder_add (builder, class->values[i].value_nick);
+    }
+
+  g_type_class_unref (class);
+
+  res = g_strv_builder_end (builder);
+
+  g_strv_builder_unref (builder);
+
+  return res;
+}
+
+GdkColorState *
+find_color_state_by_name (const char *name)
+{
+  GdkCicpParams *params = NULL;
+  GdkColorState *color_state = NULL;
+  GError *error = NULL;
+
+  if (g_strcmp0 (name, "srgb") == 0)
+    color_state = gdk_color_state_get_srgb ();
+  else if (g_strcmp0 (name, "srgb-linear") == 0)
+    color_state = gdk_color_state_get_srgb_linear ();
+  else if (g_strcmp0 (name, "rec2100-pq") == 0)
+    color_state = gdk_color_state_get_rec2100_pq ();
+  else if (g_strcmp0 (name, "rec2100-linear") == 0)
+    color_state = gdk_color_state_get_rec2100_linear ();
+  else if (g_strcmp0 (name, "display-p3") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 12);
+      gdk_cicp_params_set_transfer_function (params, 13);
+      gdk_cicp_params_set_matrix_coefficients (params, 0);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_FULL);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+  else if (g_strcmp0 (name, "xyz") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 10);
+      gdk_cicp_params_set_transfer_function (params, 8);
+      gdk_cicp_params_set_matrix_coefficients (params, 0);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_FULL);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+  else if (g_strcmp0 (name, "rec2020") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 9);
+      gdk_cicp_params_set_transfer_function (params, 1);
+      gdk_cicp_params_set_matrix_coefficients (params, 0);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_FULL);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+  else if (g_strcmp0 (name, "rec2100-hlg") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 9);
+      gdk_cicp_params_set_transfer_function (params, 18);
+      gdk_cicp_params_set_matrix_coefficients (params, 0);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_FULL);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+  else if (g_strcmp0 (name, "yuv") == 0 ||
+           g_strcmp0 (name, "bt601") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 1);
+      gdk_cicp_params_set_transfer_function (params, 13);
+      gdk_cicp_params_set_matrix_coefficients (params, 6);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_NARROW);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+  else if (g_strcmp0 (name, "bt709") == 0)
+    {
+      params = gdk_cicp_params_new ();
+
+      gdk_cicp_params_set_color_primaries (params, 1);
+      gdk_cicp_params_set_transfer_function (params, 1);
+      gdk_cicp_params_set_matrix_coefficients (params, 6);
+      gdk_cicp_params_set_range (params, GDK_CICP_RANGE_NARROW);
+
+      color_state = gdk_cicp_params_build_color_state (params, &error);
+    }
+
+  if (error)
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+      exit (1);
+    }
+
+  g_clear_object (&params);
+
+  return color_state;
+}
+
+char **
+get_color_state_names (void)
+{
+  static const char *names[] = {
+    "srgb", "srgb-linear", "display-p3", "xyz", "rec2020",
+    "rec2100-pq", "rec2100-linear", "rec2100-hlg",
+    "yuv", "bt601", "bt709",
+    NULL,
+  };
+
+  return g_strdupv ((char **) names);
+}
+
+char *
+get_color_state_name (GdkColorState *color_state)
+{
+  char **names;
+  char *name = NULL;
+
+  names = get_color_state_names ();
+
+  for (int i = 0; names[i]; i++)
+    {
+      GdkColorState *cs = find_color_state_by_name (names[i]);
+      if (gdk_color_state_equal (cs, color_state))
+        {
+          name = g_strdup (names[i]);
+          break;
+        }
+    }
+
+  g_strfreev (names);
+
+  return name;
+}

tools/gtk-image-tool.c

@@ -0,0 +1,127 @@
+/*  Copyright 2024 Red Hat, Inc.
+ *
+ * GTK is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * GTK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GTK; see the file COPYING.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+#include <gtk/gtk.h>
+#include "gtk-image-tool.h"
+
+
+static void G_GNUC_NORETURN
+usage (void)
+{
+  g_print (_("Usage:\n"
+             "  gtk4-image-tool [COMMAND] [OPTION…] FILE…\n"
+             "\n"
+             "Perform various tasks on images.\n"
+             "\n"
+             "Commands:\n"
+             "  compare      Show differences between two images\n"
+             "  convert      Convert the image to a different format or color state\n"
+             "  info         Show general information about the image\n"
+             "  relabel      Change the color state of the image without conversion\n"
+             "  show         Show the image\n"
+             "\n"));
+  exit (1);
+}
+
+static GLogWriterOutput
+log_writer_func (GLogLevelFlags   level,
+                 const GLogField *fields,
+                 gsize            n_fields,
+                 gpointer         user_data)
+{
+  gsize i;
+  const char *domain = NULL;
+  const char *message = NULL;
+
+  for (i = 0; i < n_fields; i++)
+    {
+      if (g_strcmp0 (fields[i].key, "GLIB_DOMAIN") == 0)
+        domain = fields[i].value;
+      else if (g_strcmp0 (fields[i].key, "MESSAGE") == 0)
+        message = fields[i].value;
+    }
+
+  if (message != NULL && !g_log_writer_default_would_drop (level, domain))
+    {
+      const char *prefix;
+      switch (level & G_LOG_LEVEL_MASK)
+        {
+        case G_LOG_LEVEL_ERROR:
+          prefix = "ERROR";
+          break;
+        case G_LOG_LEVEL_CRITICAL:
+          prefix = "CRITICAL";
+          break;
+        case G_LOG_LEVEL_WARNING:
+          prefix = "WARNING";
+          break;
+        default:
+          prefix = "INFO";
+          break;
+        }
+      g_printerr ("%s-%s: %s\n", domain, prefix, message);
+    }
+
+  return G_LOG_WRITER_HANDLED;
+}
+
+int
+main (int argc, const char *argv[])
+{
+  g_set_prgname ("gtk-image-tool");
+
+  g_log_set_writer_func (log_writer_func, NULL, NULL);
+
+  gtk_init_check ();
+
+  gtk_test_register_all_types ();
+
+  if (argc < 2)
+    usage ();
+
+  if (strcmp (argv[1], "--help") == 0)
+    usage ();
+
+  argv++;
+  argc--;
+
+  if (strcmp (argv[0], "compare") == 0)
+    do_compare (&argc, &argv);
+  else if (strcmp (argv[0], "convert") == 0)
+    do_convert (&argc, &argv);
+  else if (strcmp (argv[0], "info") == 0)
+    do_info (&argc, &argv);
+  else if (strcmp (argv[0], "relabel") == 0)
+    do_relabel (&argc, &argv);
+  else if (strcmp (argv[0], "show") == 0)
+    do_show (&argc, &argv);
+  else
+    usage ();
+
+  return 0;
+}

tools/gtk-image-tool.h

@@ -0,0 +1,19 @@
+
+#pragma once
+
+void do_compare     (int *argc, const char ***argv);
+void do_convert     (int *argc, const char ***argv);
+void do_info        (int *argc, const char ***argv);
+void do_relabel     (int *argc, const char ***argv);
+void do_show        (int *argc, const char ***argv);
+
+GdkTexture * load_image_file (const char *filename);
+
+
+gboolean        find_format_by_name      (const char      *name,
+                                          GdkMemoryFormat *format);
+char **         get_format_names         (void);
+GdkColorState * find_color_state_by_name (const char      *name);
+
+char **         get_color_state_names    (void);
+char *          get_color_state_name     (GdkColorState   *color_state);

tools/meson.build

@@ -49,6 +49,14 @@ gtk_tools = [
                         'gtk-rendernode-tool-show.c',
                         'gtk-rendernode-tool-utils.c',
                         '../testsuite/reftests/reftest-compare.c'], [libgtk_dep] ],
+  ['gtk4-image-tool', ['gtk-image-tool.c',
+                       'gtk-image-tool-info.c',
+                       'gtk-image-tool-compare.c',
+                       'gtk-image-tool-convert.c',
+                       'gtk-image-tool-relabel.c',
+                       'gtk-image-tool-show.c',
+                       'gtk-image-tool-utils.c',
+                        '../testsuite/reftests/reftest-compare.c'], [libgtk_dep] ],
   ['gtk4-update-icon-cache', ['updateiconcache.c', '../gtk/gtkiconcachevalidator.c' ] + extra_update_icon_cache_objs, [ libgtk_dep ] ],
   ['gtk4-encode-symbolic-svg', ['encodesymbolic.c'], [ libgtk_static_dep ] ],
 ]