public static Bitmap ToGrayscale(Bitmap source)
{
using (var colorMatrix = new ColorMatrix())
{
colorMatrix.SetSaturation(0f);
return ColorSpaceTransformation.ToColorSpace(source, colorMatrix);
}
}
public static Bitmap ToSepia(Bitmap source)
{
using (ColorMatrix saturation = new ColorMatrix())
using (ColorMatrix rgbFilter = new ColorMatrix())
{
saturation.SetSaturation(0f);
rgbFilter.SetScale(1.0f, 0.95f, 0.82f, 1.0f);
saturation.SetConcat(rgbFilter, saturation);
return ColorSpaceTransformation.ToColorSpace(source, saturation);
}
}
public static Bitmap ToGreyScale(this Bitmap bmp)
{
if (bmp == null) return null;
var height = bmp.Height;
var width = bmp.Width;
var bmpGrayscale = Bitmap.CreateBitmap(width, height, Bitmap.Config.Argb8888);
var canvas = new Canvas(bmpGrayscale);
var paint = new Paint();
var cm = new ColorMatrix();
cm.SetSaturation(0);
var filter = new ColorMatrixColorFilter(cm);
paint.SetColorFilter(filter);
canvas.DrawBitmap(bmp, 0, 0, paint);
return bmpGrayscale;
}
protected override Bitmap Transform(Bitmap source)
{
int width = source.Width;
int height = source.Height;
Bitmap bitmap = Bitmap.CreateBitmap(width, height, Bitmap.Config.Argb8888);
Canvas canvas = new Canvas(bitmap);
ColorMatrix saturation = new ColorMatrix();
saturation.SetSaturation(0f);
Paint paint = new Paint();
paint.SetColorFilter(new ColorMatrixColorFilter(saturation));
canvas.DrawBitmap(source, 0, 0, paint);
source.Recycle();
return bitmap;
}
protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
{
base.OnElementChanged(e);
if (Element == null)
{
return;
}
var matrixColor = new ColorMatrix();
filterColor = new ColorMatrixColorFilter(matrixColor);
var matrixGray = new ColorMatrix();
matrixGray.SetSaturation(0);
filterGray = new ColorMatrixColorFilter(matrixGray);
}
public Bitmap Transform(Bitmap source)
{
Bitmap result = Bitmap.CreateBitmap(source.Width, source.Height, source.GetConfig());
Bitmap noise;
try
{
noise = picasso.Load(Resource.Drawable.noise).Get();
}
catch (Exception)
{
throw new Exception("Failed to apply transformation! Missing resource.");
}
BitmapShader shader = new BitmapShader(noise, Shader.TileMode.Repeat, Shader.TileMode.Repeat);
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.SetSaturation(0);
ColorMatrixColorFilter filter = new ColorMatrixColorFilter(colorMatrix);
Paint paint = new Paint(PaintFlags.AntiAlias);
paint.SetColorFilter(filter);
Canvas canvas = new Canvas(result);
canvas.DrawBitmap(source, 0, 0, paint);
paint.SetColorFilter(null);
paint.SetShader(shader);
paint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.Multiply));
canvas.DrawRect(0, 0, canvas.Width, canvas.Height, paint);
source.Recycle();
noise.Recycle();
return result;
}
private ImageView GetBrushImageWithColor(ImageView brushImage, Android.Graphics.Color color)
{
ImageView toReturn = new ImageView (context);
using (Bitmap sourceBitmap = brushImage.DrawingCache) {
if (sourceBitmap != null) {
float R = (float)color.R;
float G = (float)color.G;
float B = (float)color.B;
float[] colorTransform =
{
R / 255f ,0 ,0 ,0, 0, // R color
0, G / 255f , 0 ,0 ,0 // G color
,0 ,0 , B / 255f, 0, 0 // B color
,0 ,0 ,0 ,1f ,0f
};
ColorMatrix colorMatrix = new ColorMatrix ();
colorMatrix.SetSaturation (0f); //Remove Colour
colorMatrix.Set (colorTransform);
ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter (colorMatrix);
Paint paint = new Paint ();
paint.SetColorFilter (colorFilter);
Bitmap mutableBitmap = sourceBitmap.Copy (Bitmap.Config.Argb8888, true);
toReturn.SetImageBitmap (mutableBitmap);
Canvas canvas = new Canvas (mutableBitmap);
canvas.DrawBitmap (mutableBitmap, 0, 0, paint);
}
}
return toReturn;
}
public static Bitmap changeBitmapContrastBrightness (Bitmap bmp, float contrast, float brightness)
{
ColorMatrix cm = new ColorMatrix (new float[] {
contrast, 0, 0, 0, brightness,
0, contrast, 0, 0, brightness,
0, 0, contrast, 0, brightness,
0, 0, 0, 1, 0
});
cm.SetSaturation (0);
Bitmap ret = Bitmap.CreateBitmap (bmp.Width, bmp.Height, bmp.GetConfig ());
Canvas canvas = new Canvas (ret);
Paint paint = new Paint ();
paint.SetColorFilter (new ColorMatrixColorFilter (cm));
canvas.DrawBitmap (bmp, 0, 0, paint);
return ret;
}