public Bitmap DecodeImage(Stream inps)
{
if (inps == null)
{
return(null);
}
// !!!{{ TODO: add the decoding code here
IEntropyCodec c = new DeflateCodec();
c.BinaryStream = inps;
c.Open(false);
uint magic = (uint)c.GetBits(32);
if (magic != MAGIC)
{
return(null);
}
int width, height;
width = (int)c.GetBits(16);
height = (int)c.GetBits(16);
if (width < 1 || height < 1)
{
return(null);
}
Bitmap result = new Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
int gr = c.Get();
if (gr < 0)
{
goto fin;
}
result.SetPixel(x, y, Color.FromArgb(gr, gr, gr));
}
}
fin:
c.Close();
return(result);
// !!!}}
}
public void EncodeImage(Bitmap inp, Stream outs)
{
if (inp == null ||
outs == null)
{
return;
}
int width = inp.Width;
int height = inp.Height;
if (width < 1 || height < 1)
{
return;
}
// !!!{{ TODO: add the encoding code here
IEntropyCodec c = new DeflateCodec();
c.MaxSymbol = 255;
if (c.MaxSymbol < 255)
{
throw new Exception("Unappropriate codec used (alphabet too small)!");
}
c.BinaryStream = outs;
c.Open(true);
// file header: [ MAGIC, width, height ]
c.PutBits(MAGIC, 32);
c.PutBits(width, 16);
c.PutBits(height, 16);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
Color col = inp.GetPixel(x, y);
int gr = Draw.RgbToGray(col.R, col.G, col.B);
c.Put(gr & 0xff);
}
}
c.Close();
// !!!}}
}
