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Image tools: added ComputeDifferenceImage function
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3 files changed

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‎Common/interface/ImageTools.h‎

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Original file line numberDiff line numberDiff line change
@@ -85,6 +85,36 @@ void DILIGENT_GLOBAL_FUNCTION(GetImageDifference)(
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Uint32 Threshold,
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ImageDiffInfo REF ImageDiff);
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// clang-format off
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/// Compute the difference image
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///
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/// \param [in] Width Image width
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/// \param [in] Height Image height
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/// \param [in] NumChannels Number of channels in the image
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/// \param [in] pImage1 Pointer to the first image data
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/// \param [in] Stride1 Row stride of the first image data, in bytes
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/// \param [in] pImage2 Pointer to the second image data
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/// \param [in] Stride2 Row stride of the second image data, in bytes
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/// \param [out] pDiffImage Pointer to the difference image data
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/// \param [in] DiffStride Row stride of the difference image data, in bytes
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/// \param [in] NumDiffChannels Number of channels in the difference image.
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/// If 0, the number of channels will be the same as in the input images.
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/// \param [in] Scale Scale factor for the difference image
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void DILIGENT_GLOBAL_FUNCTION(ComputeDifferenceImage)(
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Uint32 Width,
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Uint32 Height,
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Uint32 NumChannels,
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const void* pImage1,
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Uint32 Stride1,
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const void* pImage2,
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Uint32 Stride2,
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void* pDiffImage,
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Uint32 DiffStride,
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Uint32 NumDiffChannels DEFAULT_INITIALIZER(0),
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float Scale DEFAULT_INITIALIZER(1.f));
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// clang-format on
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#include "../../Primitives/interface/UndefRefMacro.h"
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DILIGENT_END_NAMESPACE // namespace Diligent

‎Common/src/ImageTools.cpp‎

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Original file line numberDiff line numberDiff line change
@@ -102,6 +102,70 @@ void GetImageDifference(Uint32 Width,
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}
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}
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void ComputeDifferenceImage(
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Uint32 Width,
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Uint32 Height,
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Uint32 NumChannels,
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const void* pImage1,
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Uint32 Stride1,
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const void* pImage2,
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Uint32 Stride2,
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void* pDiffImage,
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Uint32 DiffStride,
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Uint32 NumDiffChannels,
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float Scale)
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{
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if (pImage1 == nullptr || pImage2 == nullptr || pDiffImage == nullptr)
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{
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UNEXPECTED("Image pointers cannot be null");
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return;
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}
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if (Stride1 < Width * NumChannels)
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{
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UNEXPECTED("Stride1 is too small. It must be at least ", Width * NumChannels, " bytes long.");
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return;
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}
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if (Stride2 < Width * NumChannels)
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{
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UNEXPECTED("Stride2 is too small. It must be at least ", Width * NumChannels, " bytes long.");
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return;
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}
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if (DiffStride < Width * NumDiffChannels)
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{
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UNEXPECTED("DiffStride is too small. It must be at least ", Width * NumDiffChannels, " bytes long.");
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return;
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}
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if (NumDiffChannels == 0)
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{
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NumDiffChannels = NumChannels;
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}
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for (Uint32 row = 0; row < Height; ++row)
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{
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const Uint8* pRow1 = reinterpret_cast<const Uint8*>(pImage1) + row * Stride1;
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const Uint8* pRow2 = reinterpret_cast<const Uint8*>(pImage2) + row * Stride2;
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Uint8* pDiffRow = reinterpret_cast<Uint8*>(pDiffImage) + row * DiffStride;
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for (Uint32 col = 0; col < Width; ++col)
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{
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for (Uint32 ch = 0; ch < NumDiffChannels; ++ch)
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{
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int ChannelDiff = ch == 3 ? 255 : 0;
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if (ch < NumChannels)
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{
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ChannelDiff = std::abs(static_cast<int>(pRow1[col * NumChannels + ch]) - static_cast<int>(pRow2[col * NumChannels + ch]));
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ChannelDiff = std::min(255, static_cast<int>(ChannelDiff * Scale));
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}
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pDiffRow[col * NumDiffChannels + ch] = static_cast<Uint8>(ChannelDiff);
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}
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}
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}
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}
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} // namespace Diligent
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107171
extern "C"
@@ -118,4 +182,19 @@ extern "C"
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{
119183
Diligent::GetImageDifference(Width, Height, NumChannels, pImage1, Stride1, pImage2, Stride2, Threshold, ImageDiff);
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}
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void Diligent_ComputeDifferenceImage(Diligent::Uint32 Width,
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Diligent::Uint32 Height,
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Diligent::Uint32 NumChannels,
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const void* pImage1,
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Diligent::Uint32 Stride1,
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const void* pImage2,
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Diligent::Uint32 Stride2,
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void* pDiffImage,
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Diligent::Uint32 DiffStride,
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Diligent::Uint32 NumDiffChannels,
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float Scale)
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{
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Diligent::ComputeDifferenceImage(Width, Height, NumChannels, pImage1, Stride1, pImage2, Stride2, pDiffImage, DiffStride, NumDiffChannels, Scale);
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}
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}

‎Tests/DiligentCoreTest/src/Common/ImageToolsTest.cpp‎

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Original file line numberDiff line numberDiff line change
@@ -29,6 +29,7 @@
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#include <cmath>
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#include "gtest/gtest.h"
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#include <array>
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using namespace Diligent;
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@@ -77,4 +78,77 @@ TEST(Common_ImageTools, GetImageDifference)
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}
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}
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TEST(Common_ImageTools, ComputeDifferenceImage)
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{
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constexpr Uint32 Width = 3;
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constexpr Uint32 Height = 2;
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constexpr Uint32 Stride1 = 11;
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constexpr Uint32 Stride2 = 12;
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// clang-format off
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constexpr char Image1[Stride1 * Height] = {
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1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20,
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9, 8, 7, 5, 6, 4, 3, 2, 1, 30, 40,
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};
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constexpr char Image2[Stride2 * Height] = {
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1, 2, 3, 5, 8, 8, 7, 8, 9, 10, 20, 30,
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// ^ ^ ^
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// -1 -3 -2
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6, 4, 2, 5, 6, 4, 7, 6, 1, 40, 50, 60,
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// ^ ^ ^ ^ ^
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// 3 4 5 4 4
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};
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// clang-format on
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{
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// clang-format off
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constexpr std::array<Uint8, Width * Height * 3> RefDiffImage = {
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0, 0, 0, 1, 3, 2, 0, 0, 0,
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3, 4, 5, 0, 0, 0, 4, 4, 0,
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};
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// clang-format on
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std::array<Uint8, Width * Height * 3> DiffImage{};
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ComputeDifferenceImage(Width, Height, 3, Image1, Stride1, Image2, Stride2, DiffImage.data(), Width * 3);
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EXPECT_EQ(DiffImage, RefDiffImage);
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}
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// 3 channels -> 4 channels
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{
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// clang-format off
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constexpr std::array<Uint8, Width * Height * 4> RefDiffImage = {
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0, 0, 0, 255, 1, 3, 2, 255, 0, 0, 0, 255,
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3, 4, 5, 255, 0, 0, 0, 255, 4, 4, 0, 255,
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};
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// clang-format on
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std::array<Uint8, Width * Height * 4> DiffImage{};
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ComputeDifferenceImage(Width, Height, 3, Image1, Stride1, Image2, Stride2, DiffImage.data(), Width * 4, 4);
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EXPECT_EQ(DiffImage, RefDiffImage);
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}
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// 3 channels -> 2 channels
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{
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// clang-format off
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constexpr std::array<Uint8, Width * Height * 2> RefDiffImage = {
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0, 0, 1, 3, 0, 0,
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3, 4, 0, 0, 4, 4,
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};
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// clang-format on
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std::array<Uint8, Width * Height * 2> DiffImage{};
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ComputeDifferenceImage(Width, Height, 3, Image1, Stride1, Image2, Stride2, DiffImage.data(), Width * 2, 2);
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EXPECT_EQ(DiffImage, RefDiffImage);
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}
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// 3 channels -> 4 channels + scale
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{
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// clang-format off
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constexpr std::array<Uint8, Width * Height * 4> RefDiffImage = {
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0, 0, 0, 255, 2, 6, 4, 255, 0, 0, 0, 255,
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6, 8, 10, 255, 0, 0, 0, 255, 8, 8, 0, 255,
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};
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// clang-format on
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std::array<Uint8, Width * Height * 4> DiffImage{};
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ComputeDifferenceImage(Width, Height, 3, Image1, Stride1, Image2, Stride2, DiffImage.data(), Width * 4, 4, 2.f);
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EXPECT_EQ(DiffImage, RefDiffImage);
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}
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}
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} // namespace

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