public static SKImage ApplyMatrix(SKImage Source, float[] mat)
{
SKRectI irect = new SKRectI((int)0, (int)0, Source.Width, Source.Height);
var result = Source.ApplyImageFilter(SKImageFilter.CreateColorFilter(SKColorFilter.CreateColorMatrix(mat)), irect, irect, out SKRectI active, out SKPoint activeclip);
return(result);
}
// Convert bitmap to grayscale and apply contrast to emphasize lines
// For conversion SKColorFilter is used
// However, SKColorFilter is usually set in SKPaint object and applied to canvas when drawn
// To apply it to the bitmap, we have to convert bitmap to image because it's possible to apply filters to images
SKBitmap ConvertBitmapToGray(SKBitmap bitmap, float contr = contrast)
{
SKImage image = SKImage.FromBitmap(bitmap);
SKImageFilter imagefilter = SKImageFilter.CreateColorFilter(SKColorFilter.CreateHighContrast(true, SKHighContrastConfigInvertStyle.NoInvert, contrast));
SKRectI rectout = new SKRectI();
SKPoint pointout = new SKPoint();
image = image.ApplyImageFilter(imagefilter, new SKRectI(0, 0, image.Width, image.Height), new SKRectI(0, 0, image.Width, image.Height), out rectout, out pointout);
return(SKBitmap.FromImage(image));
}
