ImageSharp/tests/ImageSharp.Tests/Formats/Jpg/Utils/VerifyJpeg.cs

// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder;
using SixLabors.ImageSharp.PixelFormats;
using Xunit.Abstractions;

namespace SixLabors.ImageSharp.Tests.Formats.Jpg.Utils;

internal static class VerifyJpeg
{
    internal static void VerifySize(IJpegComponent component, int expectedBlocksX, int expectedBlocksY)
    {
        Assert.Equal(new Size(expectedBlocksX, expectedBlocksY), component.SizeInBlocks);
    }

    internal static void VerifyComponent(
        IJpegComponent component,
        Size expectedSizeInBlocks,
        Size expectedSamplingFactors,
        Size expectedSubsamplingDivisors)
    {
        Assert.Equal(expectedSizeInBlocks, component.SizeInBlocks);
        Assert.Equal(expectedSamplingFactors, component.SamplingFactors);
        Assert.Equal(expectedSubsamplingDivisors, component.SubSamplingDivisors);
    }

    internal static void VerifyComponentSizes3(
        IEnumerable<IJpegComponent> components,
        int xBc0,
        int yBc0,
        int xBc1,
        int yBc1,
        int xBc2,
        int yBc2)
    {
        IJpegComponent[] c = components.ToArray();
        Assert.Equal(3, components.Count());

        VerifySize(c[0], xBc0, yBc0);
        VerifySize(c[1], xBc1, yBc1);
        VerifySize(c[2], xBc2, yBc2);
    }

    internal static void SaveSpectralImage<TPixel>(
        TestImageProvider<TPixel> provider,
        LibJpegTools.SpectralData data,
        ITestOutputHelper output = null)
        where TPixel : unmanaged, IPixel<TPixel>
    {
        foreach (LibJpegTools.ComponentData comp in data.Components)
        {
            output?.WriteLine("Min: " + comp.MinVal);
            output?.WriteLine("Max: " + comp.MaxVal);

            using (Image<Rgba32> image = comp.CreateGrayScaleImage())
            {
                string details = $"C{comp.Index}";
                image.DebugSave(provider, details, appendPixelTypeToFileName: false);
            }
        }

        Image<Rgba32> fullImage = data.TryCreateRGBSpectralImage();

        if (fullImage != null)
        {
            fullImage.DebugSave(provider, "FULL", appendPixelTypeToFileName: false);
            fullImage.Dispose();
        }
    }
}