public unsafe void Issue1640 <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : unmanaged, IPixel <TPixel>
{
if (!TestEnvironment.Is64BitProcess)
{
return;
}
// https://github.com/SixLabors/ImageSharp/discussions/1640
// Test using isolated memory to ensure clean buffers for reference
provider.Configuration = Configuration.CreateDefaultInstance();
var options = new HistogramEqualizationOptions
{
Method = HistogramEqualizationMethod.AdaptiveTileInterpolation,
LuminanceLevels = 4096,
ClipHistogram = false,
ClipLimit = 350,
NumberOfTiles = 8
};
using Image <TPixel> image = provider.GetImage();
using Image <TPixel> referenceResult = image.Clone(ctx =>
{
ctx.HistogramEqualization(options);
ctx.Resize(image.Width / 4, image.Height / 4, KnownResamplers.Bicubic);
});
using Image <TPixel> processed = image.Clone(ctx =>
{
ctx.HistogramEqualization(options);
ctx.Resize(image.Width / 4, image.Height / 4, KnownResamplers.Bicubic);
});
ValidatorComparer.VerifySimilarity(referenceResult, processed);
}
private static HistogramEqualizationProcessor <TPixel> GetProcessor <TPixel>(HistogramEqualizationOptions options)
where TPixel : struct, IPixel <TPixel>
{
HistogramEqualizationProcessor <TPixel> processor;
switch (options.Method)
{
case HistogramEqualizationMethod.Global:
processor = new GlobalHistogramEqualizationProcessor <TPixel>(options.LuminanceLevels, options.ClipHistogram, options.ClipLimitPercentage);
break;
case HistogramEqualizationMethod.AdaptiveTileInterpolation:
processor = new AdaptiveHistEqualizationProcessor <TPixel>(options.LuminanceLevels, options.ClipHistogram, options.ClipLimitPercentage, options.Tiles);
break;
case HistogramEqualizationMethod.AdaptiveSlidingWindow:
processor = new AdaptiveHistEqualizationSWProcessor <TPixel>(options.LuminanceLevels, options.ClipHistogram, options.ClipLimitPercentage, options.Tiles);
break;
default:
processor = new GlobalHistogramEqualizationProcessor <TPixel>(options.LuminanceLevels, options.ClipHistogram, options.ClipLimitPercentage);
break;
}
return(processor);
}
public void GlobalHistogramEqualization_CompareToReferenceOutput <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : unmanaged, IPixel <TPixel>
{
using (Image <TPixel> image = provider.GetImage())
{
var options = new HistogramEqualizationOptions
{
Method = HistogramEqualizationMethod.Global,
LuminanceLevels = 256,
};
image.Mutate(x => x.HistogramEqualization(options));
image.DebugSave(provider);
image.CompareToReferenceOutput(ValidatorComparer, provider, extension: "png");
}
}
public void Issue984 <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : struct, IPixel <TPixel>
{
using (Image <TPixel> image = provider.GetImage())
{
var options = new HistogramEqualizationOptions()
{
Method = HistogramEqualizationMethod.AdaptiveTileInterpolation,
LuminanceLevels = 256,
ClipHistogram = true,
NumberOfTiles = 10
};
image.Mutate(x => x.HistogramEqualization(options));
image.DebugSave(provider);
}
}
public void Adaptive_TileInterpolation_10Tiles_WithClipping <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : struct, IPixel <TPixel>
{
using (Image <TPixel> image = provider.GetImage())
{
var options = new HistogramEqualizationOptions
{
Method = HistogramEqualizationMethod.AdaptiveTileInterpolation,
LuminanceLevels = 256,
ClipHistogram = true,
NumberOfTiles = 10
};
image.Mutate(x => x.HistogramEqualization(options));
image.DebugSave(provider);
image.CompareToReferenceOutput(ValidatorComparer, provider);
}
}
/// <summary>
/// Equalizes the histogram of an image to increases the contrast.
/// </summary>
/// <param name="source">The image this method extends.</param>
/// <param name="options">The histogram equalization options to use.</param>
/// <returns>The <see cref="IImageProcessingContext"/> to allow chaining of operations.</returns>
public static IImageProcessingContext HistogramEqualization(
this IImageProcessingContext source,
HistogramEqualizationOptions options) =>
source.ApplyProcessor(HistogramEqualizationProcessor.FromOptions(options));
/// <summary>
/// Equalizes the histogram of an image to increases the contrast.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="source">The image this method extends.</param>
/// <param name="options">The histogram equalization options to use.</param>
/// <returns>The <see cref="Image{TPixel}"/>.</returns>
public static IImageProcessingContext <TPixel> HistogramEqualization <TPixel>(this IImageProcessingContext <TPixel> source, HistogramEqualizationOptions options)
where TPixel : struct, IPixel <TPixel>
=> source.ApplyProcessor(GetProcessor <TPixel>(options));
