LibGfx: Allow images to report that they are originally grayscale

...and implement it in JPEGLoader. Since it's easy to get the grayscale data off a Bitmap, don't add a grayscale_frame() accessor.
Author: https://github.com/nico Commit: https://github.com/SerenityOS/serenity/commit/d8ada20bae Pull-request: https://github.com/SerenityOS/serenity/pull/22650 Reviewed-by: https://github.com/LucasChollet ✅
2024-01-07 22:18:18 -05:00 · 2024-01-07 22:18:18 -05:00 · d8ada20bae · 2024-07-17 11:30:54 +09:00
commit d8ada20bae
parent 239da5132d
2 changed files with 6 additions and 1 deletions
--- a/Userland/Libraries/LibGfx/ImageFormats/ImageDecoder.h
+++ b/Userland/Libraries/LibGfx/ImageFormats/ImageDecoder.h
@ -31,6 +31,7 @@ struct VectorImageFrameDescriptor {

 enum class NaturalFrameFormat {
    RGB,
+    Grayscale,
    CMYK,
    Vector,
 };
--- a/Userland/Libraries/LibGfx/ImageFormats/JPEGLoader.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/JPEGLoader.cpp
@ -2010,7 +2010,11 @@ NaturalFrameFormat JPEGImageDecoderPlugin::natural_frame_format() const
    if (m_context->state == JPEGLoadingContext::State::Error)
        return NaturalFrameFormat::RGB;
    VERIFY(m_context->state >= JPEGLoadingContext::State::HeaderDecoded);
-    return m_context->components.size() == 4 ? NaturalFrameFormat::CMYK : NaturalFrameFormat::RGB;
+    if (m_context->components.size() == 1)
+        return NaturalFrameFormat::Grayscale;
+    if (m_context->components.size() == 4)
+        return NaturalFrameFormat::CMYK;
+    return NaturalFrameFormat::RGB;
 }

 ErrorOr<NonnullRefPtr<CMYKBitmap>> JPEGImageDecoderPlugin::cmyk_frame()