1 files changed, 66 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_hints.cc b/third_party/jpeg-xl/lib/extras/dec/color_hints.cc
new file mode 100644
index 0000000000..53f7cd0543
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_hints.cc
@@ -0,0 +1,66 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/color_hints.h"
+
+#include <jxl/encode.h>
+
+#include "lib/extras/dec/color_description.h"
+#include "lib/jxl/base/file_io.h"
+
+namespace jxl {
+namespace extras {
+
+Status ApplyColorHints(const ColorHints& color_hints,
+                       const bool color_already_set, const bool is_gray,
+                       PackedPixelFile* ppf) {
+  if (color_already_set) {
+    return color_hints.Foreach(
+        [](const std::string& key, const std::string& /*value*/) {
+          JXL_WARNING("Decoder ignoring %s hint", key.c_str());
+          return true;
+        });
+  }
+
+  bool got_color_space = false;
+
+  JXL_RETURN_IF_ERROR(color_hints.Foreach(
+      [is_gray, ppf, &got_color_space](const std::string& key,
+                                       const std::string& value) -> Status {
+        if (key == "color_space") {
+          JxlColorEncoding c_original_external;
+          if (!ParseDescription(value, &c_original_external)) {
+            return JXL_FAILURE("Failed to apply color_space");
+          }
+          ppf->color_encoding = c_original_external;
+
+          if (is_gray !=
+              (ppf->color_encoding.color_space == JXL_COLOR_SPACE_GRAY)) {
+            return JXL_FAILURE("mismatch between file and color_space hint");
+          }
+
+          got_color_space = true;
+        } else if (key == "icc_pathname") {
+          JXL_RETURN_IF_ERROR(ReadFile(value, &ppf->icc));
+          got_color_space = true;
+        } else {
+          JXL_WARNING("Ignoring %s hint", key.c_str());
+        }
+        return true;
+      }));
+
+  if (!got_color_space) {
+    ppf->color_encoding.color_space =
+        is_gray ? JXL_COLOR_SPACE_GRAY : JXL_COLOR_SPACE_RGB;
+    ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+    ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+    ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+  }
+
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl