public static float[] Load <TPixel>([NotNull] string path, ImageNormalizationMode normalization, [CanBeNull] Action <IImageProcessingContext <TPixel> > modify) where TPixel : struct, IPixel <TPixel>
{
using (Image <TPixel> image = Image.Load <TPixel>(path))
{
if (modify != null)
{
image.Mutate(modify);
}
if (typeof(TPixel) == typeof(Alpha8))
{
return(Load(image as Image <Alpha8>, normalization));
}
if (typeof(TPixel) == typeof(Rgb24))
{
return(Load(image as Image <Rgb24>, normalization));
}
if (typeof(TPixel) == typeof(Argb32))
{
return(Load(image as Image <Argb32>, normalization));
}
if (typeof(TPixel) == typeof(Rgba32))
{
return(Load(image as Image <Rgba32>, normalization));
}
throw new InvalidOperationException($"The {typeof(TPixel).Name} pixel format isn't currently supported");
}
}
private static Vector4 Normalize <TPixel>(this TPixel pixel, ImageNormalizationMode normalization) where TPixel : struct, IPixel <TPixel>
{
switch (normalization)
{
case ImageNormalizationMode.Sigmoid: return(pixel.ToVector4()); // Already in the [0,1] range
case ImageNormalizationMode.Normal: return(Vector4.Subtract(pixel.ToVector4() * 2, Vector4.One));
case ImageNormalizationMode.None: return(pixel.ToVector4() * 255f); // Rescale in the [0,255] range
default: throw new ArgumentOutOfRangeException(nameof(normalization), "Invalid normalization mode");
}
}
private static unsafe float[] Load(Image <Rgb24> image, ImageNormalizationMode normalization)
{
int resolution = image.Height * image.Width;
float[] sample = new float[resolution * 3];
fixed(Rgb24 *p0 = &image.DangerousGetPinnableReferenceToPixelBuffer())
fixed(float *psample = sample)
{
for (int i = 0; i < resolution; i++)
{
Vector4 pixels = p0[i].Normalize(normalization);
psample[i] = pixels.X;
psample[i + resolution] = pixels.Y;
psample[i + 2 * resolution] = pixels.Z;
}
}
return(sample);
}
private static unsafe float[] Load(Image <Rgba32> image, ImageNormalizationMode normalization)
{
int resolution = image.Height * image.Width;
float[] sample = new float[resolution * 4];
fixed(Rgba32 *p0 = image.GetPixelSpan())
fixed(float *psample = sample)
{
for (int i = 0; i < resolution; i++)
{
Vector4 pixels = p0[i].Normalize(normalization);
psample[i] = pixels.X;
psample[i + resolution] = pixels.Y;
psample[i + 2 * resolution] = pixels.Z;
psample[i + 3 * resolution] = pixels.W;
}
}
return(sample);
}
private static unsafe float[] Load(Image <Alpha8> image, ImageNormalizationMode normalization)
{
int resolution = image.Height * image.Width;
float[] sample = new float[resolution];
fixed(Alpha8 *p0 = &image.DangerousGetPinnableReferenceToPixelBuffer())
fixed(float *psample = sample)
for (int i = 0; i < resolution; i++)
{
switch (normalization)
{
case ImageNormalizationMode.Sigmoid: psample[i] = p0[i].PackedValue / 255f; break;
case ImageNormalizationMode.Normal: psample[i] = p0[i].PackedValue * 2 / 255f - 1; break;
case ImageNormalizationMode.None: psample[i] = p0[i].PackedValue; break;
default: throw new ArgumentOutOfRangeException(nameof(normalization), "Invalid normalization mode");
}
}
return(sample);
}