protected override RequestedAction PostRenderImage(ImageState state)
{
var enabled = DetermineEnabled(state);
if (!enabled)
{
return(RequestedAction.None);
}
long colors = 0;
byte dither = GetDitherSetting(state);
bool debug = DetermineDebug(state);
var bitmap = state.destBitmap;
try
{
var data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
var analyzer = new PaletteAnalyzer(data);
bitmap.UnlockBits(data);
colors = analyzer.Colors;
}
catch (Exception)
{
// ignored
}
if (colors > byte.MaxValue)
{
var ditherMax = (byte)(_maxDither * (Math.Min(_maxColors, colors) / _maxColors));
dither = Math.Min(ditherMax, dither);
colors = byte.MaxValue;
}
else
{
dither = 0;
}
var quantizer = new DitheredLuminanceQuantizer(bitmap.Width, (byte)colors, _ditherThreshold, dither, debug);
try
{
var processedBitmap = (Bitmap)quantizer.QuantizeImage(bitmap, 1, 1);
state.destBitmap = processedBitmap;
bitmap.Dispose();
}
catch (Exception)
{
}
return(RequestedAction.None);
}
protected override RequestedAction PostRenderImage(ImageState state)
{
var enabled = DetermineEnabled(state);
if (!enabled)
{
return(RequestedAction.None);
}
// WuQuantizer leads to unwanted effects
// Color vibrancy loss in saturated colors (fixed by introducing luminance in palette calculation)
// Smooth transparent areas are jarry (adjusted by dithering below set threshold on alpha channel only)
long colors = 0;
byte ditherAmount = 0;
var bitmap = state.destBitmap;
try
{
var data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
var analyzer = new PaletteAnalyzer(data);
bitmap.UnlockBits(data);
colors = analyzer.Colors;
}
catch (Exception)
{
// ignored
}
if (colors > 256)
{
ditherAmount = (byte)(_maxdither * (Math.Min(_maxcolors, colors) / _maxcolors));
colors = 256;
}
var quantizer = new DitheredLuminanceQuantizer(state.destBitmap.Width, state.destBitmap.Height, (byte)colors, _ditherThreshold, ditherAmount, DetermineDebug(state));
try
{
state.destBitmap = (Bitmap)quantizer.QuantizeImage(state.destBitmap, 1, 1);
}
catch (Exception)
{
// ignored
}
return(RequestedAction.None);
}
