ImageSharp/tests/ImageSharp.Tests/Formats/Jpg/ReferenceImplementationsTests.AccurateDCT.cs

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

using SixLabors.ImageSharp.Formats.Jpeg.Components;
using SixLabors.ImageSharp.Tests.Formats.Jpg.Utils;
using Xunit.Abstractions;

namespace SixLabors.ImageSharp.Tests.Formats.Jpg;

[Trait("Format", "Jpg")]
public partial class ReferenceImplementationsTests
{
    public class AccurateDCT : JpegFixture
    {
        public AccurateDCT(ITestOutputHelper output)
            : base(output)
        {
        }

        [Theory]
        [InlineData(42)]
        [InlineData(1)]
        [InlineData(2)]
        public void ForwardThenInverse(int seed)
        {
            float[] data = Create8x8RandomFloatData(-1000, 1000, seed);

            Block8x8F b0 = Block8x8F.Load(data);

            Block8x8F b1 = ReferenceImplementations.AccurateDCT.TransformFDCT(ref b0);
            Block8x8F b2 = ReferenceImplementations.AccurateDCT.TransformIDCT(ref b1);

            this.CompareBlocks(b0, b2, 1e-4f);
        }
    }
}