Add matrices

2 months ago · 6aa313f895
4 changed files with 288 additions and 3 deletions
--- a/src/ImageSharp/Formats/Jxl/Metadata/JxlOpsinInverseMatrix.cs
+++ b/src/ImageSharp/Formats/Jxl/Metadata/JxlOpsinInverseMatrix.cs
@ -1,7 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.

-using SixLabors.ImageSharp.Formats.Jxl.IO;
+using SixLabors.ImageSharp.Formats.Jxl.Fields;
+using SixLabors.ImageSharp.Formats.Jxl.Processing;

 namespace SixLabors.ImageSharp.Formats.Jxl.Metadata;

@ -9,7 +10,7 @@ internal sealed class JxlOpsinInverseMatrix : IJxlFields
 {
    public bool AllDefault { get; set; }

-    public JxlMatrix3x3 InverseMatrix { get; set; }
+    public JxlMatrix3x3F InverseMatrix { get; set; }

    public InlineArray3<float> OpsinBiases { get; set; }

--- a/src/ImageSharp/Formats/Jxl/Processing/JxlLoopFilter.cs
+++ b/src/ImageSharp/Formats/Jxl/Processing/JxlLoopFilter.cs
@ -237,7 +237,7 @@ internal sealed class JxlLoopFilter : IJxlFields
                {
                    for (int iy = 0; iy < SigmaBorder; iy++)
                    {
-                        sigmaRow.Slice(offsetBefore + (SigmaPadding - 1 - iy) * sigmaStride, num)
+                        sigmaRow.Slice(offsetBefore + ((SigmaPadding - 1 - iy) * sigmaStride), num)
                                .CopyTo(sigmaRow.Slice(offsetBefore + ((SigmaPadding + iy) * sigmaStride)));
                    }
                }
--- a/src/ImageSharp/Formats/Jxl/Processing/JxlMatrix3x3.cs
+++ b/src/ImageSharp/Formats/Jxl/Processing/JxlMatrix3x3.cs
@ -0,0 +1,142 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.InteropServices;
+
+#pragma warning disable IDE0044 // Add readonly modifier
+#pragma warning disable IDE0051 // Remove unused private members
+
+namespace SixLabors.ImageSharp.Formats.Jxl.Processing;
+
+internal struct JxlMatrix3x3
+{
+    /// <summary>
+    /// Represents the matrix element at 0,0.
+    /// </summary>
+    private double e00;
+
+    /// <summary>
+    /// Represents the matrix element at 0,1.
+    /// </summary>
+    private double e01;
+
+    /// <summary>
+    /// Represents the matrix element at 0,2.
+    /// </summary>
+    private double e02;
+
+    /// <summary>
+    /// Represents the matrix element at 1,0.
+    /// </summary>
+    private double e10;
+
+    /// <summary>
+    /// Represents the matrix element at 1,1.
+    /// </summary>
+    private double e11;
+
+    /// <summary>
+    /// Represents the matrix element at 1,2.
+    /// </summary>
+    private double e12;
+
+    /// <summary>
+    /// Represents the matrix element at 2,0.
+    /// </summary>
+    private double e20;
+
+    /// <summary>
+    /// Represents the matrix element at 2,1.
+    /// </summary>
+    private double e21;
+
+    /// <summary>
+    /// Represents the matrix element at 2,2.
+    /// </summary>
+    private double e22;
+
+    /// <summary>
+    /// Wraps all these values into a Span.
+    /// </summary>
+    /// <returns>A Span with all matrix elements.</returns>
+    public Span<double> AsSpan() => MemoryMarshal.CreateSpan(ref this.e00, 9);
+
+    /// <summary>
+    /// Wraps all these values into a ReadOnlySpan.
+    /// </summary>
+    /// <returns>A ReadOnlySpan with all matrix elements.</returns>
+    public ReadOnlySpan<double> AsReadOnlySpan() => MemoryMarshal.CreateReadOnlySpan(ref this.e00, 9);
+
+    public static void Multiply(in JxlMatrix3x3 a, in JxlMatrix3x3 b, ref JxlMatrix3x3 c)
+    {
+        ReadOnlySpan<double> spanA = a.AsReadOnlySpan();
+        ReadOnlySpan<double> spanB = b.AsReadOnlySpan();
+        Span<double> spanC = c.AsSpan();
+
+        for (int row = 0; row < 3; row++)
+        {
+            int row3 = row * 3;
+            for (int col = 0; col < 3; col++)
+            {
+                double sum = 0d;
+                for (int k = 0; k < 3; k++)
+                {
+                    sum += spanA[row3 + k] * spanB[(k * 3) + col];
+                }
+
+                spanC[row3 + col] = sum;
+            }
+        }
+    }
+
+    public static void Multiply(in JxlMatrix3x3 a, ReadOnlySpan<double> b, Span<double> c)
+    {
+        ReadOnlySpan<double> spanA = a.AsReadOnlySpan();
+
+        for (int row = 0; row < 3; row++)
+        {
+            double sum = 0f;
+            int row3 = row * 3;
+            for (int col = 0; col < 3; col++)
+            {
+                sum += spanA[row3 + col] * b[col];
+            }
+
+            c[row] = sum;
+        }
+    }
+
+    public static bool Invert(ref JxlMatrix3x3 matrix)
+    {
+        ReadOnlySpan<double> m = matrix.AsReadOnlySpan();
+        Span<double> temp =
+        [
+            ((double)m[4] * m[8]) - ((double)m[5] * m[7]),
+            ((double)m[2] * m[7]) - ((double)m[1] * m[8]),
+            ((double)m[1] * m[5]) - ((double)m[2] * m[4]),
+            ((double)m[5] * m[6]) - ((double)m[3] * m[8]),
+            ((double)m[0] * m[8]) - ((double)m[2] * m[6]),
+            ((double)m[2] * m[3]) - ((double)m[0] * m[5]),
+            ((double)m[3] * m[7]) - ((double)m[4] * m[6]),
+            ((double)m[1] * m[6]) - ((double)m[0] * m[7]),
+            ((double)m[0] * m[4]) - ((double)m[1] * m[3]),
+        ];
+
+        double det = (m[0] * temp[0]) + (m[1] * temp[3]) + (m[2] * temp[6]);
+
+        if (Math.Abs(det) < 1e-10)
+        {
+            return false;
+        }
+
+        double idet = 1.0 / det;
+        Span<double> spanM = matrix.AsSpan();
+
+        for (int i = 0; i < 9; i++)
+        {
+            spanM[i] = (double)(temp[i] * idet);
+        }
+
+        return true;
+    }
+}
--- a/src/ImageSharp/Formats/Jxl/Processing/JxlMatrix3x3F.cs
+++ b/src/ImageSharp/Formats/Jxl/Processing/JxlMatrix3x3F.cs
@ -0,0 +1,142 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.InteropServices;
+
+#pragma warning disable IDE0044 // Add readonly modifier
+#pragma warning disable IDE0051 // Remove unused private members
+
+namespace SixLabors.ImageSharp.Formats.Jxl.Processing;
+
+internal struct JxlMatrix3x3F
+{
+    /// <summary>
+    /// Represents the matrix element at 0,0.
+    /// </summary>
+    private float e00;
+
+    /// <summary>
+    /// Represents the matrix element at 0,1.
+    /// </summary>
+    private float e01;
+
+    /// <summary>
+    /// Represents the matrix element at 0,2.
+    /// </summary>
+    private float e02;
+
+    /// <summary>
+    /// Represents the matrix element at 1,0.
+    /// </summary>
+    private float e10;
+
+    /// <summary>
+    /// Represents the matrix element at 1,1.
+    /// </summary>
+    private float e11;
+
+    /// <summary>
+    /// Represents the matrix element at 1,2.
+    /// </summary>
+    private float e12;
+
+    /// <summary>
+    /// Represents the matrix element at 2,0.
+    /// </summary>
+    private float e20;
+
+    /// <summary>
+    /// Represents the matrix element at 2,1.
+    /// </summary>
+    private float e21;
+
+    /// <summary>
+    /// Represents the matrix element at 2,2.
+    /// </summary>
+    private float e22;
+
+    /// <summary>
+    /// Wraps all these values into a Span.
+    /// </summary>
+    /// <returns>A Span with all matrix elements.</returns>
+    public Span<float> AsSpan() => MemoryMarshal.CreateSpan(ref this.e00, 9);
+
+    /// <summary>
+    /// Wraps all these values into a ReadOnlySpan.
+    /// </summary>
+    /// <returns>A ReadOnlySpan with all matrix elements.</returns>
+    public ReadOnlySpan<float> AsReadOnlySpan() => MemoryMarshal.CreateReadOnlySpan(ref this.e00, 9);
+
+    public static void Multiply(in JxlMatrix3x3F a, in JxlMatrix3x3F b, ref JxlMatrix3x3F c)
+    {
+        ReadOnlySpan<float> spanA = a.AsReadOnlySpan();
+        ReadOnlySpan<float> spanB = b.AsReadOnlySpan();
+        Span<float> spanC = c.AsSpan();
+
+        for (int row = 0; row < 3; row++)
+        {
+            int row3 = row * 3;
+            for (int col = 0; col < 3; col++)
+            {
+                float sum = 0f;
+                for (int k = 0; k < 3; k++)
+                {
+                    sum += spanA[row3 + k] * spanB[(k * 3) + col];
+                }
+
+                spanC[row3 + col] = sum;
+            }
+        }
+    }
+
+    public static void Multiply(in JxlMatrix3x3F a, ReadOnlySpan<float> b, Span<float> c)
+    {
+        ReadOnlySpan<float> spanA = a.AsReadOnlySpan();
+
+        for (int row = 0; row < 3; row++)
+        {
+            float sum = 0f;
+            int row3 = row * 3;
+            for (int col = 0; col < 3; col++)
+            {
+                sum += spanA[row3 + col] * b[col];
+            }
+
+            c[row] = sum;
+        }
+    }
+
+    public static bool Invert(ref JxlMatrix3x3F matrix)
+    {
+        ReadOnlySpan<float> m = matrix.AsReadOnlySpan();
+        Span<double> temp =
+        [
+            ((double)m[4] * m[8]) - ((double)m[5] * m[7]),
+            ((double)m[2] * m[7]) - ((double)m[1] * m[8]),
+            ((double)m[1] * m[5]) - ((double)m[2] * m[4]),
+            ((double)m[5] * m[6]) - ((double)m[3] * m[8]),
+            ((double)m[0] * m[8]) - ((double)m[2] * m[6]),
+            ((double)m[2] * m[3]) - ((double)m[0] * m[5]),
+            ((double)m[3] * m[7]) - ((double)m[4] * m[6]),
+            ((double)m[1] * m[6]) - ((double)m[0] * m[7]),
+            ((double)m[0] * m[4]) - ((double)m[1] * m[3]),
+        ];
+
+        double det = (m[0] * temp[0]) + (m[1] * temp[3]) + (m[2] * temp[6]);
+
+        if (Math.Abs(det) < 1e-10)
+        {
+            return false;
+        }
+
+        double idet = 1.0 / det;
+        Span<float> spanM = matrix.AsSpan();
+
+        for (int i = 0; i < 9; i++)
+        {
+            spanM[i] = (float)(temp[i] * idet);
+        }
+
+        return true;
+    }
+}