From 6dc5608d958b6ef0810ee0b819f09f0a7ada747d Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Wed, 31 Jan 2024 20:55:51 -0500
Subject: [PATCH] image: Allow saving CMYK jpegs

`image` can't transform from RGB to CMYK yet, so the only way to
do this is by having a CMYK input.

For example, this works now (and it does a full decode and re-encode):

    Build/lagom/bin/image -o out.jpg \
        Tests/LibGfx/test-inputs/jpg/buggie-cmyk.jpg

Using this to convert `.pam` files written by `mutool extract`
to jpegs is a somewhat convenient method of looking at these
.pam files.
---
 Userland/Utilities/image.cpp | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/Userland/Utilities/image.cpp b/Userland/Utilities/image.cpp
index f56a94085a..eb0b0b0b3c 100644
--- a/Userland/Utilities/image.cpp
+++ b/Userland/Utilities/image.cpp
@@ -125,15 +125,24 @@ static ErrorOr<OwnPtr<Core::MappedFile>> convert_image_profile(LoadedImage& imag
 
 static ErrorOr<void> save_image(LoadedImage& image, StringView out_path, bool ppm_ascii, u8 jpeg_quality)
 {
-    if (!image.bitmap.has<RefPtr<Gfx::Bitmap>>())
-        return Error::from_string_view("Can't save CMYK bitmaps yet, convert to RGB first with --convert-to-color-profile"sv);
-    auto& frame = image.bitmap.get<RefPtr<Gfx::Bitmap>>();
-
     auto stream = [out_path]() -> ErrorOr<NonnullOwnPtr<Core::OutputBufferedFile>> {
         auto output_stream = TRY(Core::File::open(out_path, Core::File::OpenMode::Write));
         return Core::OutputBufferedFile::create(move(output_stream));
     };
 
+    if (image.bitmap.has<RefPtr<Gfx::CMYKBitmap>>()) {
+        auto& cmyk_frame = image.bitmap.get<RefPtr<Gfx::CMYKBitmap>>();
+
+        if (out_path.ends_with(".jpg"sv, CaseSensitivity::CaseInsensitive) || out_path.ends_with(".jpeg"sv, CaseSensitivity::CaseInsensitive)) {
+            TRY(Gfx::JPEGWriter::encode(*TRY(stream()), *cmyk_frame, { .icc_data = image.icc_data, .quality = jpeg_quality }));
+            return {};
+        }
+
+        return Error::from_string_view("Can save CMYK bitmaps only as .jpg, convert to RGB first with --convert-to-color-profile"sv);
+    }
+
+    auto& frame = image.bitmap.get<RefPtr<Gfx::Bitmap>>();
+
     if (out_path.ends_with(".jpg"sv, CaseSensitivity::CaseInsensitive) || out_path.ends_with(".jpeg"sv, CaseSensitivity::CaseInsensitive)) {
         TRY(Gfx::JPEGWriter::encode(*TRY(stream()), *frame, { .icc_data = image.icc_data, .quality = jpeg_quality }));
         return {};