public static Bitmap Decompress(int height, int width, byte[] compressedData)
{
YCbCrSubSample yCbCrSubSamples = DecodeCompressedBytes(height, width, compressedData);
// up sample
YCbCr[,] yCbCrs = UpSample(yCbCrSubSamples);
// change to RGB and write to bitmap
int h = yCbCrs.GetLength(0), w = yCbCrs.GetLength(1);
Bitmap img = new Bitmap(w, h, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
for (int row = 0; row < h; ++row)
{
for (int col = 0; col < w; ++col)
{
img.SetPixel(col, row, ColorChannel.YcbcrToRgb(yCbCrs[row, col]));
}
}
return(img);
}
public static byte[] Compress(Bitmap image)
{
// 1. get YCbCr channels of the image
YCbCr[,] yCbCrs = ColorChannel.ReadYCbCrs(image);
// 2. sub sample
YCbCrSubSample yCbCrSubSamples = SubSample(yCbCrs);
// for each channel, run a sperate thread for DCT, quantized, zigzag sampling
var tasks = new Task[3];
sbyte[] yStream = null, cbStream = null, crStream = null;
tasks[0] = Task.Factory.StartNew(() =>
{
//3,4. DCT sub quantized
sbyte[,] s = DCTSubQuantized(yCbCrSubSamples.Y, LuminanceQuantizationTable);
yStream = ZigZagTransform(s);
});
tasks[1] = Task.Factory.StartNew(() =>
{
sbyte[,] s = DCTSubQuantized(yCbCrSubSamples.Cb, ChrominanceQuantizationTable);
cbStream = ZigZagTransform(s);
});
tasks[2] = Task.Factory.StartNew(() =>
{
sbyte[,] s = DCTSubQuantized(yCbCrSubSamples.Cr, ChrominanceQuantizationTable);
crStream = ZigZagTransform(s);
});
Task.WaitAll(tasks);
// concatennate byte stream
var data = new sbyte[yStream.Length + cbStream.Length + crStream.Length];
yStream.CopyTo(data, 0);
cbStream.CopyTo(data, yStream.Length);
crStream.CopyTo(data, yStream.Length + cbStream.Length);
return(RunLengthEncode(data));
}
private Bitmap DecompressIFrame(byte[] bs)
{
frameMemory = DecodeCompressedBytes(FrameHeight, FrameWidth, bs);
YCbCr[,] yCbCrs = UpSample(frameMemory);
return(ColorChannel.CreateBitmapFromYCbCr(yCbCrs));
}
private byte[] CompressPframe(Bitmap bitmap)
{
YCbCr[,] yCbCrs = ColorChannel.ReadYCbCrs(bitmap);
YCbCrSubSample yCbCrSubSamples = JPEG.SubSample(yCbCrs);
// motion vecotr estimate
var mv = new MotionVector(15);
EstimateResult vecotrDiffs = mv.Estimate(frameMemory, yCbCrSubSamples);
// dct subquantized differences
var tasks = new Task[3];
sbyte[,] yQuantized = null, cbQuantized = null, crQuantized = null;
tasks[0] = Task.Factory.StartNew(() =>
{
yQuantized = DCTSubQuantized(vecotrDiffs.YDiffs, LuminanceQuantizationTable);
});
tasks[1] = Task.Factory.StartNew(() =>
{
cbQuantized = DCTSubQuantized(vecotrDiffs.CbDiffs, ChrominanceQuantizationTable);
});
tasks[2] = Task.Factory.StartNew(() =>
{
crQuantized = DCTSubQuantized(vecotrDiffs.CrDiffs, ChrominanceQuantizationTable);
});
Task.WaitAll(tasks);
//upquantized IDCT, add to frame memory
int yHeight = yCbCrSubSamples.Y.GetLength(0), yWidth = yCbCrSubSamples.Y.GetLength(1), cHeight = yCbCrSubSamples.Cb.GetLength(0), cWidth = yCbCrSubSamples.Cb.GetLength(1);
tasks[0] = Task.Factory.StartNew(() =>
{
yCbCrSubSamples.Y = UpQuantizedIDCT(yHeight, yWidth, yQuantized, LuminanceQuantizationTable);
});
tasks[1] = Task.Factory.StartNew(() =>
{
yCbCrSubSamples.Cb = UpQuantizedIDCT(cHeight, cWidth, cbQuantized, ChrominanceQuantizationTable);
});
tasks[2] = Task.Factory.StartNew(() =>
{
yCbCrSubSamples.Cr = UpQuantizedIDCT(cHeight, cWidth, crQuantized, ChrominanceQuantizationTable);
});
// zigzag RLE differences
sbyte[] yStream = ZigZagTransform(yQuantized);
sbyte[] cbStream = ZigZagTransform(cbQuantized);
sbyte[] crStream = ZigZagTransform(crQuantized);
// concatennate byte stream
var data = new sbyte[vecotrDiffs.Vectors.Length * 2 + yStream.Length + cbStream.Length + crStream.Length];
for (int i = 0, j = 0; i < vecotrDiffs.Vectors.Length; ++i)
{
data[j++] = (sbyte)(vecotrDiffs.Vectors[i].x);
data[j++] = (sbyte)(vecotrDiffs.Vectors[i].y);
}
yStream.CopyTo(data, vecotrDiffs.Vectors.Length * 2);
cbStream.CopyTo(data, yStream.Length + vecotrDiffs.Vectors.Length * 2);
crStream.CopyTo(data, yStream.Length + cbStream.Length + vecotrDiffs.Vectors.Length * 2);
Task.WaitAll(tasks);
AddDifferencesToMemoryFrame(yCbCrSubSamples, vecotrDiffs.Vectors); // update frame memory
return(RunLengthEncode(data));
}
