// decompress the compressed file back to image
public static Bitmap DecompressImage(String inFile)
{
// read in compressed file
ImageData file = ReadCompressImage(inFile);
return(JPEG.Decompress(file.Height, file.Width, file.Data));
}
private byte[] CompressIframe(Bitmap bitmap)
{
YCbCr[,] yCbCrs = ColorChannel.ReadYCbCrs(bitmap);
YCbCrSubSample yCbCrSubSamples = JPEG.SubSample(yCbCrs);
//DCT subquantized
// for each channel, run a sperate thread for DCT, quantized, zigzag sampling, and RLE
var tasks = new Task[3];
sbyte[,] yQuantized = null, cbQuantized = null, crQuantized = null;
tasks[0] = Task.Factory.StartNew(() =>
{
yQuantized = DCTSubQuantized(yCbCrSubSamples.Y, LuminanceQuantizationTable);
});
tasks[1] = Task.Factory.StartNew(() =>
{
cbQuantized = DCTSubQuantized(yCbCrSubSamples.Cb, ChrominanceQuantizationTable);
});
tasks[2] = Task.Factory.StartNew(() =>
{
crQuantized = DCTSubQuantized(yCbCrSubSamples.Cr, ChrominanceQuantizationTable);
});
Task.WaitAll(tasks);
// upquantized IDCT, store as 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(() =>
{
frameMemory.Y = UpQuantizedIDCT(yHeight, yWidth, yQuantized, LuminanceQuantizationTable);
});
tasks[1] = Task.Factory.StartNew(() =>
{
frameMemory.Cb = UpQuantizedIDCT(cHeight, cWidth, cbQuantized, ChrominanceQuantizationTable);
});
tasks[2] = Task.Factory.StartNew(() =>
{
frameMemory.Cr = UpQuantizedIDCT(cHeight, cWidth, crQuantized, ChrominanceQuantizationTable);
});
// zigzag RLE
sbyte[] yStream = ZigZagTransform(yQuantized);
sbyte[] cbStream = ZigZagTransform(cbQuantized);
sbyte[] crStream = ZigZagTransform(crQuantized);
// 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);
Task.WaitAll(tasks);
return(RunLengthEncode(data));
}
// compress the jpeg image at the specified path to the output file path
public static CompressResult CompressImage(String inFile, String outFile)
{
var bitmap = new Bitmap(inFile);
byte[] data = JPEG.Compress(bitmap);
var image = new ImageData(bitmap.Height, bitmap.Width, data);
WriteCompressImage(outFile, image);
return(new CompressResult(image.Height * image.Width * 3, data.Length));
}
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));
}