public void ChangeFormat(ImageBuffer target, IColorQuantizer quantizer, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(target, "target");
Guard.CheckNull(quantizer, "quantizer");
// gathers some information about the target format
Boolean hasSourceAlpha = PixelFormat.HasAlpha();
Boolean hasTargetAlpha = target.PixelFormat.HasAlpha();
Boolean isTargetIndexed = target.PixelFormat.IsIndexed();
Boolean isSourceDeepColor = PixelFormat.IsDeepColor();
Boolean isTargetDeepColor = target.PixelFormat.IsDeepColor();
// step 1 to 3 - prepares the palettes
if (isTargetIndexed) SynthetizePalette(quantizer, target.PixelFormat.GetColorCount(), parallelTaskCount);
// prepares the quantization function
TransformPixelFunction changeFormat = (sourcePixel, targetPixel) =>
{
// if both source and target formats are deep color formats, copies a value directly
if (isSourceDeepColor && isTargetDeepColor)
{
//UInt64 value = sourcePixel.Value;
//targetPixel.SetValue(value);
}
else
{
// retrieves a source image color
Color color = GetColorFromPixel(sourcePixel);
// if alpha is not present in the source image, but is present in the target, make one up
if (!hasSourceAlpha && hasTargetAlpha)
{
Int32 argb = 255 << 24 | color.R << 16 | color.G << 8 | color.B;
color = Color.FromArgb(argb);
}
// sets the color to a target pixel
SetColorToPixel(targetPixel, color, quantizer);
}
// allows to write (obviously) the transformed pixel
return true;
};
// step 5 - generates the target image
IList<Point> standardPath = new StandardPathProvider().GetPointPath(Width, Height);
TransformPerPixel(target, standardPath, changeFormat, parallelTaskCount);
}
public Double CalculateMeanError(ImageBuffer target, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(target, "target");
// initializes the error
Int64 totalError = 0;
// prepares the function
TransformPixelFunction calculateMeanError = (sourcePixel, targetPixel) =>
{
Color sourceColor = GetColorFromPixel(sourcePixel);
Color targetColor = GetColorFromPixel(targetPixel);
totalError += ColorModelHelper.GetColorEuclideanDistance(ColorModel.RedGreenBlue, sourceColor, targetColor);
return false;
};
// performs the image scan, using a chosen method
IList<Point> standardPath = new StandardPathProvider().GetPointPath(Width, Height);
TransformPerPixel(target, standardPath, calculateMeanError, parallelTaskCount);
// returns the calculates RMSD
return Math.Sqrt(totalError/(3.0*Width*Height));
}
