/// <inheritdoc />
public Bitmap Transform(Bitmap bitmap, IDistribution distribution)
{
if (bitmap is null)
{
throw new ArgumentNullException(nameof(bitmap));
}
if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)
{
throw new NotSupportedException(Errors.NotSupported);
}
var cdf = GetCDF(bitmap);
//get the new pixel values, according to a selected distribution
var newPixels = _service.TransformToByte(cdf, distribution);
var bitmapData = bitmap.LockBits(
new Rectangle(0, 0, bitmap.Width, bitmap.Height),
ImageLockMode.ReadWrite, bitmap.PixelFormat);
var options = new ParallelOptions()
{
MaxDegreeOfParallelism = Environment.ProcessorCount
};
var step = Image.GetPixelFormatSize(PixelFormat.Format32bppArgb) / 8;
var size = bitmap.Size;
var stride = bitmapData.Stride;
var(dstWidth, dstHeight) = (size.Width, size.Height);
unsafe
{
var startPtr = (byte *)bitmapData.Scan0.ToPointer();
Parallel.For(0, dstHeight, options, y =>
{
//get a start address
var ptr = startPtr + y * stride;
for (int x = 0; x < dstWidth; ++x, ptr += step)
{
//get a new pixel value, transofrming by a quantile
ptr[0] = ptr[1] = ptr[2] = newPixels[ptr[0]];
}
});
}
bitmap.UnlockBits(bitmapData);
return(bitmap);
}
public byte[] TransformToByte(decimal[] cdf, IDistribution distribution) => _service.TransformToByte(cdf, distribution);
