tests/JpegGainmapTest.cpp

/*
 * Copyright 2023 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/codec/SkAndroidCodec.h"
#include "include/codec/SkCodec.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkImageEncoder.h"
#include "include/core/SkSize.h"
#include "include/core/SkStream.h"
#include "include/core/SkTypes.h"
#include "include/encode/SkJpegEncoder.h"
#include "include/private/SkGainmapInfo.h"
#include "include/private/SkGainmapShader.h"
#include "include/private/SkJpegGainmapEncoder.h"
#include "src/codec/SkJpegMultiPicture.h"
#include "src/codec/SkJpegSegmentScan.h"
#include "tests/Test.h"
#include "tools/Resources.h"

#include <cstdint>
#include <cstring>
#include <memory>
#include <utility>
#include <vector>

DEF_TEST(Codec_jpegSegmentScan, r) {
    const struct Rec {
        const char* path;
        size_t sosSegmentCount;
        size_t eoiSegmentCount;
        size_t testSegmentIndex;
        uint8_t testSegmentMarker;
        size_t testSegmentOffset;
        uint16_t testSegmentParameterLength;
    } recs[] = {
            {"images/wide_gamut_yellow_224_224_64.jpeg", 11, 15, 10, 0xda, 9768, 12},
            {"images/CMYK.jpg", 7, 8, 1, 0xee, 2, 14},
            {"images/b78329453.jpeg", 10, 23, 3, 0xe2, 154, 540},
            {"images/brickwork-texture.jpg", 8, 28, 12, 0xc4, 34183, 42},
            {"images/brickwork_normal-map.jpg", 8, 28, 27, 0xd9, 180612, 0},
            {"images/cmyk_yellow_224_224_32.jpg", 19, 23, 2, 0xed, 854, 2828},
            {"images/color_wheel.jpg", 10, 11, 2, 0xdb, 20, 67},
            {"images/cropped_mandrill.jpg", 10, 11, 4, 0xc0, 158, 17},
            {"images/dog.jpg", 10, 11, 5, 0xc4, 177, 28},
            {"images/ducky.jpg", 12, 13, 10, 0xc4, 3718, 181},
            {"images/exif-orientation-2-ur.jpg", 11, 12, 2, 0xe1, 20, 130},
            {"images/flutter_logo.jpg", 9, 27, 21, 0xda, 5731, 8},
            {"images/grayscale.jpg", 6, 16, 9, 0xda, 327, 8},
            {"images/icc-v2-gbr.jpg", 12, 25, 24, 0xd9, 43832, 0},
            {"images/mandrill_512_q075.jpg", 10, 11, 7, 0xc4, 393, 31},
            {"images/mandrill_cmyk.jpg", 19, 35, 16, 0xdd, 574336, 4},
            {"images/mandrill_h1v1.jpg", 10, 11, 1, 0xe0, 2, 16},
            {"images/mandrill_h2v1.jpg", 10, 11, 0, 0xd8, 0, 0},
            {"images/randPixels.jpg", 10, 11, 6, 0xc4, 200, 30},
            {"images/wide_gamut_yellow_224_224_64.jpeg", 11, 15, 10, 0xda, 9768, 12},
    };

    for (const auto& rec : recs) {
        auto stream = GetResourceAsStream(rec.path);
        if (!stream) {
            continue;
        }

        // Ensure that we get the expected number of segments for a scan that stops at StartOfScan.
        auto sosSegmentScan = SkJpegSeekableScan::Create(stream.get());
        REPORTER_ASSERT(r, rec.sosSegmentCount == sosSegmentScan->segments().size());

        // Rewind and now go all the way to EndOfImage.
        stream->rewind();
        auto eoiSegmentScan =
                SkJpegSeekableScan::Create(stream.get(), SkJpegSegmentScanner::kMarkerEndOfImage);
        REPORTER_ASSERT(r, rec.eoiSegmentCount == eoiSegmentScan->segments().size());

        // Verify the values for a randomly pre-selected segment index.
        const auto& segment = eoiSegmentScan->segments()[rec.testSegmentIndex];
        REPORTER_ASSERT(r, rec.testSegmentMarker == segment.marker);
        REPORTER_ASSERT(r, rec.testSegmentOffset == segment.offset);
        REPORTER_ASSERT(r, rec.testSegmentParameterLength == segment.parameterLength);
    }
}

DEF_TEST(Codec_jpegMultiPicture, r) {
    const char* path = "images/iphone_13_pro.jpeg";
    auto stream = GetResourceAsStream(path);
    REPORTER_ASSERT(r, stream);

    auto segmentScan = SkJpegSeekableScan::Create(stream.get());
    REPORTER_ASSERT(r, segmentScan);

    // Extract the streams for the MultiPicture images.
    auto mpStreams = SkJpegExtractMultiPictureStreams(segmentScan.get());
    REPORTER_ASSERT(r, mpStreams);
    size_t numberOfImages = mpStreams->images.size();

    // Decode them into bitmaps.
    std::vector<SkBitmap> bitmaps(numberOfImages);
    for (size_t i = 0; i < numberOfImages; ++i) {
        auto imageStream = std::move(mpStreams->images[i].stream);
        if (i == 0) {
            REPORTER_ASSERT(r, !imageStream);
            continue;
        }
        REPORTER_ASSERT(r, imageStream);

        std::unique_ptr<SkCodec> codec = SkCodec::MakeFromStream(std::move(imageStream));
        REPORTER_ASSERT(r, codec);

        SkBitmap bm;
        bm.allocPixels(codec->getInfo());
        REPORTER_ASSERT(
                r, SkCodec::kSuccess == codec->getPixels(bm.info(), bm.getPixels(), bm.rowBytes()));
        bitmaps[i] = bm;
    }

    // Spot-check the image size and pixels.
    REPORTER_ASSERT(r, bitmaps[1].dimensions() == SkISize::Make(1512, 2016));
    REPORTER_ASSERT(r, bitmaps[1].getColor(0, 0) == 0xFF3B3B3B);
    REPORTER_ASSERT(r, bitmaps[1].getColor(1511, 2015) == 0xFF101010);
    REPORTER_ASSERT(r, bitmaps[2].dimensions() == SkISize::Make(576, 768));
    REPORTER_ASSERT(r, bitmaps[2].getColor(0, 0) == 0xFF010101);
    REPORTER_ASSERT(r, bitmaps[2].getColor(575, 767) == 0xFFB5B5B5);
}

// Decode an image and its gainmap.
template <typename Reporter>
void decode_all(Reporter& r,
                std::unique_ptr<SkStream> stream,
                SkBitmap& baseBitmap,
                SkBitmap& gainmapBitmap,
                SkGainmapInfo& gainmapInfo) {
    // Decode the base bitmap.
    std::unique_ptr<SkCodec> baseCodec = SkCodec::MakeFromStream(std::move(stream));
    REPORTER_ASSERT(r, baseCodec);
    baseBitmap.allocPixels(baseCodec->getInfo());
    REPORTER_ASSERT(r,
                    SkCodec::kSuccess == baseCodec->getPixels(baseBitmap.info(),
                                                              baseBitmap.getPixels(),
                                                              baseBitmap.rowBytes()));
    std::unique_ptr<SkAndroidCodec> androidCodec =
            SkAndroidCodec::MakeFromCodec(std::move(baseCodec));
    REPORTER_ASSERT(r, androidCodec);

    // Extract the gainmap info and stream.
    std::unique_ptr<SkStream> gainmapStream;
    REPORTER_ASSERT(r, androidCodec->getAndroidGainmap(&gainmapInfo, &gainmapStream));
    REPORTER_ASSERT(r, gainmapStream);

    // Decode the gainmap bitmap.
    std::unique_ptr<SkCodec> gainmapCodec = SkCodec::MakeFromStream(std::move(gainmapStream));
    REPORTER_ASSERT(r, gainmapCodec);
    SkBitmap bm;
    bm.allocPixels(gainmapCodec->getInfo());
    gainmapBitmap.allocPixels(gainmapCodec->getInfo());
    REPORTER_ASSERT(r,
                    SkCodec::kSuccess == gainmapCodec->getPixels(gainmapBitmap.info(),
                                                                 gainmapBitmap.getPixels(),
                                                                 gainmapBitmap.rowBytes()));
}

// Render an applied gainmap.
SkBitmap render_gainmap(const SkImageInfo& renderInfo,
                        float renderHdrRatio,
                        const SkBitmap& baseBitmap,
                        const SkBitmap& gainmapBitmap,
                        const SkGainmapInfo& gainmapInfo,
                        int x,
                        int y) {
    SkRect baseRect = SkRect::MakeXYWH(x, y, renderInfo.width(), renderInfo.height());

    float scaleX = gainmapBitmap.width() / static_cast<float>(baseBitmap.width());
    float scaleY = gainmapBitmap.height() / static_cast<float>(baseBitmap.height());
    SkRect gainmapRect = SkRect::MakeXYWH(baseRect.x() * scaleX,
                                          baseRect.y() * scaleY,
                                          baseRect.width() * scaleX,
                                          baseRect.height() * scaleY);

    SkRect dstRect = SkRect::Make(renderInfo.dimensions());

    sk_sp<SkImage> baseImage = SkImage::MakeFromBitmap(baseBitmap);
    sk_sp<SkImage> gainmapImage = SkImage::MakeFromBitmap(gainmapBitmap);
    sk_sp<SkShader> shader = SkGainmapShader::Make(baseImage,
                                                   baseRect,
                                                   SkSamplingOptions(),
                                                   gainmapImage,
                                                   gainmapRect,
                                                   SkSamplingOptions(),
                                                   gainmapInfo,
                                                   dstRect,
                                                   renderHdrRatio,
                                                   renderInfo.refColorSpace());

    SkBitmap result;
    result.allocPixels(renderInfo);
    result.eraseColor(SK_ColorTRANSPARENT);
    SkCanvas canvas(result);

    SkPaint paint;
    paint.setShader(shader);
    canvas.drawRect(dstRect, paint);

    return result;
}

// Render a single pixel of an applied gainmap and return it.
SkColor4f render_gainmap_pixel(float renderHdrRatio,
                               const SkBitmap& baseBitmap,
                               const SkBitmap& gainmapBitmap,
                               const SkGainmapInfo& gainmapInfo,
                               int x,
                               int y) {
    SkImageInfo testPixelInfo = SkImageInfo::Make(
            1, 1, kRGBA_F16_SkColorType, kPremul_SkAlphaType, SkColorSpace::MakeSRGB());
    SkBitmap testPixelBitmap = render_gainmap(
            testPixelInfo, renderHdrRatio, baseBitmap, gainmapBitmap, gainmapInfo, x, y);
    return testPixelBitmap.getColor4f(0, 0);
}

static bool approx_eq(float x, float y, float epsilon) { return std::abs(x - y) < epsilon; }

static bool approx_eq_rgb(const SkColor4f& x, const SkColor4f& y, float epsilon) {
    return approx_eq(x.fR, y.fR, epsilon) && approx_eq(x.fG, y.fG, epsilon) &&
           approx_eq(x.fB, y.fB, epsilon);
}

DEF_TEST(AndroidCodec_jpegGainmap, r) {
    const struct Rec {
        const char* path;
        SkISize dimensions;
        SkColor originColor;
        SkColor farCornerColor;
        float logRatioMin;
        float logRatioMax;
        float hdrRatioMin;
        float hdrRatioMax;
        SkGainmapInfo::Type type;
    } recs[] = {
            {"images/iphone_13_pro.jpeg",
             SkISize::Make(1512, 2016),
             0xFF3B3B3B,
             0xFF101010,
             0.f,
             1.f,
             1.f,
             2.71828f,
             SkGainmapInfo::Type::kMultiPicture},
            {"images/jpegr.jpg",
             SkISize::Make(1008, 756),
             0xFFCACACA,
             0xFFC8C8C8,
             -2.3669f,
             2.3669f,
             1.f,
             10.6643f,
             SkGainmapInfo::Type::kJpegR_HLG},
            {"images/hdrgm.jpg",
             SkISize::Make(188, 250),
             0xFFE9E9E9,
             0xFFAAAAAA,
             -2.209409f,
             2.209409f,
             1.f,
             9.110335f,
             SkGainmapInfo::Type::kHDRGM},
    };

    for (bool useFileStream : {false, true}) {
        for (const auto& rec : recs) {
            auto stream = GetResourceAsStream(rec.path, useFileStream);
            REPORTER_ASSERT(r, stream);

            SkBitmap baseBitmap;
            SkBitmap gainmapBitmap;
            SkGainmapInfo gainmapInfo;
            decode_all(r,
                       GetResourceAsStream(rec.path, useFileStream),
                       baseBitmap,
                       gainmapBitmap,
                       gainmapInfo);

            // Spot-check the image size and pixels.
            REPORTER_ASSERT(r, gainmapBitmap.dimensions() == rec.dimensions);
            REPORTER_ASSERT(r, gainmapBitmap.getColor(0, 0) == rec.originColor);
            REPORTER_ASSERT(
                    r,
                    gainmapBitmap.getColor(rec.dimensions.fWidth - 1, rec.dimensions.fHeight - 1) ==
                            rec.farCornerColor);

            // Verify the gainmap rendering parameters.
            constexpr float kEpsilon = 1e-3f;
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMin.fR, rec.logRatioMin, kEpsilon));
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMin.fG, rec.logRatioMin, kEpsilon));
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMin.fB, rec.logRatioMin, kEpsilon));

            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMax.fR, rec.logRatioMax, kEpsilon));
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMax.fG, rec.logRatioMax, kEpsilon));
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fLogRatioMax.fB, rec.logRatioMax, kEpsilon));

            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fHdrRatioMin, rec.hdrRatioMin, kEpsilon));
            REPORTER_ASSERT(r, approx_eq(gainmapInfo.fHdrRatioMax, rec.hdrRatioMax, kEpsilon));

            REPORTER_ASSERT(r, gainmapInfo.fType == rec.type);
        }
    }
}

#ifdef SK_ENCODE_JPEG
DEF_TEST(AndroidCodec_jpegGainmapTranscode, r) {
    const char* path = "images/iphone_13_pro.jpeg";
    SkBitmap baseBitmap[2];
    SkBitmap gainmapBitmap[2];
    SkGainmapInfo gainmapInfo[2];

    // Decode an MPF-based gainmap image.
    decode_all(r, GetResourceAsStream(path), baseBitmap[0], gainmapBitmap[0], gainmapInfo[0]);

    constexpr float kEpsilon = 1e-2f;
    for (size_t i = 0; i < 2; ++i) {
        SkDynamicMemoryWStream encodeStream;
        bool encodeResult = false;

        if (i == 0) {
            // Transcode to JpegR.
            encodeResult = SkJpegGainmapEncoder::EncodeJpegR(&encodeStream,
                                                             baseBitmap[0].pixmap(),
                                                             SkJpegEncoder::Options(),
                                                             gainmapBitmap[0].pixmap(),
                                                             SkJpegEncoder::Options(),
                                                             gainmapInfo[0]);
        } else {
            // Transcode to HDRGM.
            encodeResult = SkJpegGainmapEncoder::EncodeHDRGM(&encodeStream,
                                                             baseBitmap[0].pixmap(),
                                                             SkJpegEncoder::Options(),
                                                             gainmapBitmap[0].pixmap(),
                                                             SkJpegEncoder::Options(),
                                                             gainmapInfo[0]);
        }
        REPORTER_ASSERT(r, encodeResult);

        // Decode the just-encoded JpegR or HDRGM.
        auto decodeStream = std::make_unique<SkMemoryStream>(encodeStream.detachAsData());
        decode_all(r, std::move(decodeStream), baseBitmap[1], gainmapBitmap[1], gainmapInfo[1]);

        // Verify that the representations are different.
        REPORTER_ASSERT(r, gainmapInfo[0].fType != gainmapInfo[1].fType);
        if (i == 0) {
            // JpegR will have different rendering parameters.
            REPORTER_ASSERT(r, gainmapInfo[0].fLogRatioMin != gainmapInfo[1].fLogRatioMin);
        } else {
            // HDRGM will have the same rendering parameters.
            REPORTER_ASSERT(
                    r,
                    approx_eq_rgb(
                            gainmapInfo[0].fLogRatioMin, gainmapInfo[1].fLogRatioMin, kEpsilon));
            REPORTER_ASSERT(
                    r,
                    approx_eq_rgb(
                            gainmapInfo[0].fLogRatioMax, gainmapInfo[1].fLogRatioMax, kEpsilon));
            REPORTER_ASSERT(
                    r,
                    approx_eq_rgb(
                            gainmapInfo[0].fGainmapGamma, gainmapInfo[1].fGainmapGamma, kEpsilon));
            REPORTER_ASSERT(
                    r, approx_eq(gainmapInfo[0].fEpsilonSdr, gainmapInfo[1].fEpsilonSdr, kEpsilon));
            REPORTER_ASSERT(
                    r, approx_eq(gainmapInfo[0].fEpsilonHdr, gainmapInfo[1].fEpsilonHdr, kEpsilon));
            REPORTER_ASSERT(
                    r,
                    approx_eq(gainmapInfo[0].fHdrRatioMin, gainmapInfo[1].fHdrRatioMin, kEpsilon));
            REPORTER_ASSERT(
                    r,
                    approx_eq(gainmapInfo[0].fHdrRatioMax, gainmapInfo[1].fHdrRatioMax, kEpsilon));
        }

#ifdef SK_ENABLE_SKSL
        // Render a few pixels and verify that they come out the same. Rendering requires SkSL.
        const struct Rec {
            int x;
            int y;
            float hdrRatio;
            SkColor4f expectedColor;
        } recs[] = {
                {1446, 1603, 1.05f, {0.984375f, 1.004883f, 1.008789f, 1.f}},
                {1446, 1603, 100.f, {1.147461f, 1.170898f, 1.174805f, 1.f}},
        };

        for (const auto& rec : recs) {
            SkColor4f p0 = render_gainmap_pixel(
                    rec.hdrRatio, baseBitmap[0], gainmapBitmap[0], gainmapInfo[0], rec.x, rec.y);
            SkColor4f p1 = render_gainmap_pixel(
                    rec.hdrRatio, baseBitmap[1], gainmapBitmap[1], gainmapInfo[1], rec.x, rec.y);

            REPORTER_ASSERT(r, approx_eq_rgb(p0, p1, kEpsilon));
        }
#endif  // SK_ENABLE_SKSL
    }
}
#endif  // SK_ENCODE_JPEG