tsai
/
ImageSharp
mirror of https://github.com/SixLabors/ImageSharp
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Merge HLG base/derived class into one; abbreviate transfer function class name

pull/3153/head
winscripter 4 weeks ago
parent
f2ccbacb43
commit
e315e04bc5
2 changed files with 58 additions and 66 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 71
      src/ImageSharp/Formats/Jxl/Cms/TransferFunctions/JxlHlgTransferFunction.cs
  2. 53
      src/ImageSharp/Formats/Jxl/Cms/TransferFunctions/JxlHybridLogGammaTransferFunction.cs

71
src/ImageSharp/Formats/Jxl/Cms/TransferFunctions/JxlHybridLogGammaTransferFunctionBase.cs → src/ImageSharp/Formats/Jxl/Cms/TransferFunctions/JxlHlgTransferFunction.cs
View File

@ -1,33 +1,78 @@
// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.
using System.Numerics;
using SixLabors.ImageSharp.Formats.Jxl.Processing;
namespace SixLabors.ImageSharp.Formats.Jxl.Cms.TransferFunctions;
/// <summary>
/// Base class for HLG transfer function.
/// Hybrid Log Gamma transfer function.
/// </summary>
internal abstract class JxlHybridLogGammaTransferFunctionBase
internal sealed class JxlHlgTransferFunction
{
// Shared constants used by transfer functions
protected const float A = 0.17883277f;
protected const float RA = 1.0f / A;
protected const float B = 1 - (4 * A);
protected const float C = 0.5599107295f;
protected const float Inverse12 = 1.0f / 12.0f;
private const float A = 0.17883277f;
private const float RA = 1.0f / A;
private const float B = 1 - (4 * A);
private const float C = 0.5599107295f;
private const float Inverse12 = 1.0f / 12.0f;
private const float HiAdd = B * Inverse12;
private const float HiMul = 0.003639807079052639f; // MathF.Exp(-C * RA) * Inverse12
private const float HiPow = 8.067285659607931f; // RA * JxlMath.InverseLog2E
/// <summary>
/// Initializes a new instance of the <see cref="JxlHlgTransferFunction"/> class.
/// </summary>
/// <remarks>
/// Use static methods. Don't instantiate this class.
/// </remarks>
private JxlHlgTransferFunction()
{
}
public static Vector<float> EncodedFromDisplay(Vector<float> x)
{
Vector<float> sign = Vector.Create(0x80000000u).As<uint, float>();
Vector<float> originalSign = x & sign;
x = Vector.AndNot(sign, x);
Vector<int> belowInverse12 = Vector.LessThan(x, Vector.Create(Inverse12));
Vector<float> lo = Vector.SquareRoot(Vector.Create(3.0f) * x);
Vector<float> hi = (Vector.Create(A * JxlMath.InverseLog2E) * Vector.Log2((Vector.Create(12f) * x) + Vector.Create(-B))) + Vector.Create(C);
Vector<float> magnitude = Vector.ConditionalSelect(belowInverse12, lo, hi);
return Vector.AndNot(sign, magnitude) | originalSign;
}
public static Vector<float> DisplayFromEncoded(Vector<float> x)
{
Vector<float> sign = Vector.Create(0x80000000u).As<uint, float>();
Vector<float> originalSign = x & sign;
x = Vector.AndNot(sign, x);
Vector<int> below05 = Vector.LessThan(x, Vector.Create(0.5f));
Vector<float> lo = x * (x * Vector.Create(1f / 3f));
Vector<float> hi = (Pow2(x * Vector.Create(HiPow)) * Vector.Create(HiMul)) + Vector.Create(HiAdd);
Vector<float> magnitude = Vector.ConditionalSelect(below05, lo, hi);
return Vector.AndNot(sign, magnitude) | originalSign;
}
private static Vector<float> Pow2(Vector<float> x) => JxlSimdUtils.FastPow2f(x);
/// <summary>
/// Converts encoded signal to display signal.
/// </summary>
/// <param name="encoded">The encoded signal</param>
/// <returns>The display signal</returns>
protected static double DisplayFromEncoded(double encoded) => Ootf(InverseOotf(encoded));
public static double DisplayFromEncoded(double encoded) => Ootf(InverseOotf(encoded));
/// <summary>
/// Converts display signal to encoded signal.
/// </summary>
/// <param name="display">The display signal</param>
/// <returns>The encoded signal</returns>
protected static double EncodedFromDisplay(double display) => Oetf(InverseOetf(display));
public static double EncodedFromDisplay(double display) => Oetf(InverseOetf(display));
/// <summary>
/// Opto-Electronic Transfer Function - converts
@ -39,7 +84,7 @@ internal abstract class JxlHybridLogGammaTransferFunctionBase
/// </remarks>
/// <param name="s">Scene light</param>
/// <returns>Digital video signal</returns>
private static double Oetf(double s)
public static double Oetf(double s)
{
if (s == 0)
{
@ -70,7 +115,7 @@ internal abstract class JxlHybridLogGammaTransferFunctionBase
/// </remarks>
/// <param name="e">Digital video signal</param>
/// <returns>Scene light</returns>
private static double InverseOetf(double e)
public static double InverseOetf(double e)
{
if (e == 0)
{
@ -100,7 +145,7 @@ internal abstract class JxlHybridLogGammaTransferFunctionBase
/// </remarks>
/// <param name="s">Input signal</param>
/// <returns>Digital video signal</returns>
private static double Ootf(double s) => s;
public static double Ootf(double s) => s;
/// <summary>
/// Inverse Opto-Optical Transfer Function - as-is.
@ -110,5 +155,5 @@ internal abstract class JxlHybridLogGammaTransferFunctionBase
/// </remarks>
/// <param name="s">Digital video signal</param>
/// <returns>Scene light</returns>
private static double InverseOotf(double s) => s;
public static double InverseOotf(double s) => s;
}

53
src/ImageSharp/Formats/Jxl/Cms/TransferFunctions/JxlHybridLogGammaTransferFunction.cs
View File

@ -1,53 +0,0 @@
// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.
using System.Numerics;
using SixLabors.ImageSharp.Formats.Jxl.Processing;
namespace SixLabors.ImageSharp.Formats.Jxl.Cms.TransferFunctions;
internal sealed class JxlHybridLogGammaTransferFunction : JxlHybridLogGammaTransferFunctionBase
{
private const float HiAdd = B * Inverse12;
private const float HiMul = 0.003639807079052639f; // MathF.Exp(-C * RA) * Inverse12
private const float HiPow = 8.067285659607931f; // RA * JxlMath.InverseLog2E
/// <summary>
/// Initializes a new instance of the <see cref="JxlHybridLogGammaTransferFunction"/> class.
/// </summary>
/// <remarks>
/// Use static methods. Don't instantiate this class.
/// </remarks>
private JxlHybridLogGammaTransferFunction()
{
}
public static Vector<float> EncodedFromDisplay(Vector<float> x)
{
Vector<float> sign = Vector.Create(0x80000000u).As<uint, float>();
Vector<float> originalSign = x & sign;
x = Vector.AndNot(sign, x);
Vector<int> belowInverse12 = Vector.LessThan(x, Vector.Create(Inverse12));
Vector<float> lo = Vector.SquareRoot(Vector.Create(3.0f) * x);
Vector<float> hi = (Vector.Create(A * JxlMath.InverseLog2E) * Vector.Log2((Vector.Create(12f) * x) + Vector.Create(-B))) + Vector.Create(C);
Vector<float> magnitude = Vector.ConditionalSelect(belowInverse12, lo, hi);
return Vector.AndNot(sign, magnitude) | originalSign;
}
public static Vector<float> DisplayFromEncoded(Vector<float> x)
{
Vector<float> sign = Vector.Create(0x80000000u).As<uint, float>();
Vector<float> originalSign = x & sign;
x = Vector.AndNot(sign, x);
Vector<int> below05 = Vector.LessThan(x, Vector.Create(0.5f));
Vector<float> lo = x * (x * Vector.Create(1f / 3f));
Vector<float> hi = (Pow2(x * Vector.Create(HiPow)) * Vector.Create(HiMul)) + Vector.Create(HiAdd);
Vector<float> magnitude = Vector.ConditionalSelect(below05, lo, hi);
return Vector.AndNot(sign, magnitude) | originalSign;
}
private static Vector<float> Pow2(Vector<float> x) => x * x;
}
Write Preview
Loading…
Cancel
Save