private void ApplyWhiteBalance(IMagickImage image)
{
using (var mask = image.Clone())
{
mask.ColorSpace = ColorSpace.HSB;
mask.Negate(Channels.Green);
using (var newMask = mask.Separate(Channels.Green).First())
{
using (var maskBlue = mask.Separate(Channels.Blue).First())
{
newMask.Composite(maskBlue, CompositeOperator.Multiply);
}
newMask.ContrastStretch((Percentage)0, WhiteBalance);
newMask.InverseOpaque(new MagickColor("white"), new MagickColor("black"));
double maskMean = GetMean(newMask);
double redRatio = GetRatio(image, Channels.Red, newMask, maskMean);
double greenRatio = GetRatio(image, Channels.Green, newMask, maskMean);
double blueRatio = GetRatio(image, Channels.Blue, newMask, maskMean);
var matrix = new MagickColorMatrix(3, redRatio, 0, 0, 0, greenRatio, 0, 0, 0, blueRatio);
image.ColorMatrix(matrix);
}
}
}
