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LibGfx/JPEG: Make it possible to obtain raw CMYK data from JPEGs

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frame() still returns a regular RGB Bitmap (now lazily converted
from internal CMYK data), but JPEGImageDecoderPlugin now also
implements cmyk_frame().
This commit is contained in:
Nico Weber 2024-01-07 21:49:03 -05:00 • committed by Andreas Kling
parent 51d5397e92
commit 239da5132d
Notes: sideshowbarker 2024-07-17 17:49:11 +09:00
2 changed files with 75 additions and 39 deletions
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111
Userland/Libraries/LibGfx/ImageFormats/JPEGLoader.cpp
View file

@ -452,7 +452,10 @@ struct JPEGLoadingContext {
Optional<Scan> current_scan {};
Vector<Component, 4> components;
RefPtr<Gfx::Bitmap> bitmap;
RefPtr<Gfx::CMYKBitmap> cmyk_bitmap;
u16 dc_restart_interval { 0 };
HashMap<u8, HuffmanTable> dc_tables;
HashMap<u8, HuffmanTable> ac_tables;
@ -1649,43 +1652,26 @@ static void invert_colors_for_adobe_images(JPEGLoadingContext const& context, Ve
}
}
static void cmyk_to_rgb(JPEGLoadingContext const& context, Vector<Macroblock>& macroblocks)
static ErrorOr<void> cmyk_to_rgb(JPEGLoadingContext& context)
{
if (context.options.cmyk == JPEGDecoderOptions::CMYK::Normal)
invert_colors_for_adobe_images(context, macroblocks);
VERIFY(context.cmyk_bitmap);
VERIFY(!context.bitmap);
for (u32 vcursor = 0; vcursor < context.mblock_meta.vcount; vcursor += context.sampling_factors.vertical) {
for (u32 hcursor = 0; hcursor < context.mblock_meta.hcount; hcursor += context.sampling_factors.horizontal) {
for (u8 vfactor_i = context.sampling_factors.vertical - 1; vfactor_i < context.sampling_factors.vertical; --vfactor_i) {
for (u8 hfactor_i = context.sampling_factors.horizontal - 1; hfactor_i < context.sampling_factors.horizontal; --hfactor_i) {
u32 mb_index = (vcursor + vfactor_i) * context.mblock_meta.hpadded_count + (hcursor + hfactor_i);
auto* c = macroblocks[mb_index].y;
auto* m = macroblocks[mb_index].cb;
auto* y = macroblocks[mb_index].cr;
auto* k = macroblocks[mb_index].k;
for (u8 i = 0; i < 8; ++i) {
for (u8 j = 0; j < 8; ++j) {
u8 const pixel = i * 8 + j;
context.bitmap = TRY(Bitmap::create(BitmapFormat::BGRx8888, { context.frame.width, context.frame.height }));
static constexpr auto max_value = NumericLimits<u8>::max();
auto const black_component = max_value - k[pixel];
int const r = ((max_value - c[pixel]) * black_component) / max_value;
int const g = ((max_value - m[pixel]) * black_component) / max_value;
int const b = ((max_value - y[pixel]) * black_component) / max_value;
c[pixel] = clamp(r, 0, max_value);
m[pixel] = clamp(g, 0, max_value);
y[pixel] = clamp(b, 0, max_value);
}
}
}
}
for (int y = 0; y < context.frame.height; ++y) {
for (int x = 0; x < context.frame.width; ++x) {
auto const& cmyk = context.cmyk_bitmap->scanline(y)[x];
u8 k = 255 - cmyk.k;
context.bitmap->scanline(y)[x] = Color((255 - cmyk.c) * k / 255, (255 - cmyk.m) * k / 255, (255 - cmyk.y) * k / 255).value();
}
}
context.cmyk_bitmap = nullptr;
return {};
}
static void ycck_to_rgb(JPEGLoadingContext const& context, Vector<Macroblock>& macroblocks)
static void ycck_to_cmyk(JPEGLoadingContext const& context, Vector<Macroblock>& macroblocks)
{
// 7 - Conversions between colour encodings
// YCCK is obtained from CMYK by converting the CMY channels to YCC channel.
@ -1693,7 +1679,7 @@ static void ycck_to_rgb(JPEGLoadingContext const& context, Vector<Macroblock>& m
// To convert back into RGB, we only need the 3 first components, which are baseline YCbCr
ycbcr_to_rgb(context, macroblocks);
// RGB to CMYK, as mentioned in https://www.smcm.iqfr.csic.es/docs/intel/ipp/ipp_manual/IPPI/ippi_ch15/functn_YCCKToCMYK_JPEG.htm#functn_YCCKToCMYK_JPEG
// RGB to CMY, as mentioned in https://www.smcm.iqfr.csic.es/docs/intel/ipp/ipp_manual/IPPI/ippi_ch15/functn_YCCKToCMYK_JPEG.htm#functn_YCCKToCMYK_JPEG
for (u32 vcursor = 0; vcursor < context.mblock_meta.vcount; vcursor += context.sampling_factors.vertical) {
for (u32 hcursor = 0; hcursor < context.mblock_meta.hcount; hcursor += context.sampling_factors.horizontal) {
for (u8 vfactor_i = 0; vfactor_i < context.sampling_factors.vertical; ++vfactor_i) {
@ -1710,8 +1696,6 @@ static void ycck_to_rgb(JPEGLoadingContext const& context, Vector<Macroblock>& m
}
}
}
cmyk_to_rgb(context, macroblocks);
}
static ErrorOr<void> handle_color_transform(JPEGLoadingContext const& context, Vector<Macroblock>& macroblocks)
@ -1725,7 +1709,7 @@ static ErrorOr<void> handle_color_transform(JPEGLoadingContext const& context, V
switch (*context.color_transform) {
case ColorTransform::CmykOrRgb:
if (context.components.size() == 4) {
cmyk_to_rgb(context, macroblocks);
// Nothing to do here.
} else if (context.components.size() == 3) {
// Note: components.size() == 3 means that we have an RGB image, so no color transformation is needed.
} else {
@ -1736,7 +1720,7 @@ static ErrorOr<void> handle_color_transform(JPEGLoadingContext const& context, V
ycbcr_to_rgb(context, macroblocks);
break;
case ColorTransform::YCCK:
ycck_to_rgb(context, macroblocks);
ycck_to_cmyk(context, macroblocks);
break;
}
@ -1746,9 +1730,7 @@ static ErrorOr<void> handle_color_transform(JPEGLoadingContext const& context, V
// No App14 segment is present, assuming :
// - 1 components means grayscale
// - 3 components means YCbCr
// - 4 components means CMYK
if (context.components.size() == 4)
cmyk_to_rgb(context, macroblocks);
// - 4 components means CMYK (Nothing to do here).
if (context.components.size() == 3)
ycbcr_to_rgb(context, macroblocks);
@ -1782,6 +1764,28 @@ static ErrorOr<void> compose_bitmap(JPEGLoadingContext& context, Vector<Macroblo
return {};
}
static ErrorOr<void> compose_cmyk_bitmap(JPEGLoadingContext& context, Vector<Macroblock>& macroblocks)
{
if (context.options.cmyk == JPEGDecoderOptions::CMYK::Normal)
invert_colors_for_adobe_images(context, macroblocks);
context.cmyk_bitmap = TRY(Gfx::CMYKBitmap::create_with_size({ context.frame.width, context.frame.height }));
for (u32 y = context.frame.height - 1; y < context.frame.height; y--) {
u32 const block_row = y / 8;
u32 const pixel_row = y % 8;
for (u32 x = 0; x < context.frame.width; x++) {
u32 const block_column = x / 8;
auto& block = macroblocks[block_row * context.mblock_meta.hpadded_count + block_column];
u32 const pixel_column = x % 8;
u32 const pixel_index = pixel_row * 8 + pixel_column;
context.cmyk_bitmap->scanline(y)[x] = { (u8)block.y[pixel_index], (u8)block.cb[pixel_index], (u8)block.cr[pixel_index], (u8)block.k[pixel_index] };
}
}
return {};
}
static bool is_app_marker(Marker const marker)
{
return marker >= JPEG_APPN0 && marker <= JPEG_APPN15;
@ -1931,7 +1935,10 @@ static ErrorOr<void> decode_jpeg(JPEGLoadingContext& context)
TRY(dequantize(context, macroblocks));
inverse_dct(context, macroblocks);
TRY(handle_color_transform(context, macroblocks));
TRY(compose_bitmap(context, macroblocks));
if (context.components.size() == 4)
TRY(compose_cmyk_bitmap(context, macroblocks));
else
TRY(compose_bitmap(context, macroblocks));
return {};
}
@ -1985,6 +1992,9 @@ ErrorOr<ImageFrameDescriptor> JPEGImageDecoderPlugin::frame(size_t index, Option
m_context->state = JPEGLoadingContext::State::BitmapDecoded;
}
if (m_context->cmyk_bitmap)
TRY(cmyk_to_rgb(*m_context));
return ImageFrameDescriptor { m_context->bitmap, 0 };
}
@ -1995,4 +2005,27 @@ ErrorOr<Optional<ReadonlyBytes>> JPEGImageDecoderPlugin::icc_data()
return OptionalNone {};
}
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;
}
ErrorOr<NonnullRefPtr<CMYKBitmap>> JPEGImageDecoderPlugin::cmyk_frame()
{
VERIFY(natural_frame_format() == NaturalFrameFormat::CMYK);
if (m_context->state < JPEGLoadingContext::State::BitmapDecoded) {
if (auto result = decode_jpeg(*m_context); result.is_error()) {
m_context->state = JPEGLoadingContext::State::Error;
return result.release_error();
}
m_context->state = JPEGLoadingContext::State::BitmapDecoded;
}
return *m_context->cmyk_bitmap;
}
}

3
Userland/Libraries/LibGfx/ImageFormats/JPEGLoader.h
View file

@ -39,6 +39,9 @@ public:
virtual ErrorOr<ImageFrameDescriptor> frame(size_t index, Optional<IntSize> ideal_size = {}) override;
virtual ErrorOr<Optional<ReadonlyBytes>> icc_data() override;
virtual NaturalFrameFormat natural_frame_format() const override;
virtual ErrorOr<NonnullRefPtr<CMYKBitmap>> cmyk_frame() override;
private:
JPEGImageDecoderPlugin(NonnullOwnPtr<JPEGLoadingContext>);