public void Reduce(IReadOnlyDictionary <RGBColor, RGBColor> palette)
{
_reduced = new RGBColor[_width, _height];
using (var bmp = new Bitmap(_width, _height)) {
for (var x = 0; x < _width; x++)
{
for (var y = 0; y < _height; y++)
{
var color = _pixels[x, y];
var reduced = _reduced[x, y] = palette[color];
bmp.SetPixel(x, y, reduced);
}
}
var directory = Path.GetDirectoryName(_filename);
var filename = Path.GetFileName(_filename);
directory = Path.Combine(directory, $"reduced-{palette.Count}");
Directory.CreateDirectory(directory);
bmp.Save(Path.Combine(directory, filename));
}
Reduced = new PixelIndexer(_reduced);
}
public Image(string filename)
{
_filename = filename;
_name = Path.GetFileNameWithoutExtension(filename);
using (var bmp = new Bitmap(filename)) {
_width = bmp.Width;
_height = bmp.Height;
// Lock the bitmap's bits.
var rect = new Rectangle(0, 0, _width, _height);
var bmpData = bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat);
// Get the address of the first line.
var ptr = bmpData.Scan0;
// Declare an array to hold the bytes of the bitmap.
var stride = bmpData.Stride;
var bytes = Math.Abs(stride) * _height;
var rgbValues = new byte[bytes];
// Copy the RGB values into the array.
System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes);
// Unlock the bits.
bmp.UnlockBits(bmpData);
_pixels = _reduced = new RGBColor[_width, _height];
Parallel.For(0, _height, y => {
var strideSpan = y * stride;
for (var x = 0; x < _width; x++)
{
var pos = strideSpan + x * 3;
_pixels[x, y] = new RGBColor(rgbValues[pos + 2], rgbValues[pos + 1], rgbValues[pos]);
}
});
}
Raw = Reduced = new PixelIndexer(_pixels);
}