private static void WriteToFile(int width, int height, IEnumerable <int[][]> yBlocks, IEnumerable <int[][]> cbBlocks, IEnumerable <int[][]> crBlocks,
string subsamplingType, QuantizingType quantizingType, int alphaY, int gammaY, int alphaC, int gammaC, int nY, int nC)
{
//*** saving to file
// format: height, width, number of yblocks, yblocks, number of cbBlocks, cbBlocks, number of crBlocks, crBlocks,
// subsampling type,
// quantizing type
// Ny Nc
// alpha gamma
var filename = "test.myjpg";
using (var writer = new BinaryWriter(File.Open(string.Format(filename), FileMode.Create)))
{
writer.Write(height);
writer.Write(width);
writer.Write(yBlocks.Count());
foreach (var block in yBlocks.Select(x => x.ToZigZagArray(8)))
{
block.ForEach(x => writer.Write(x));
}
writer.Write(cbBlocks.Count());
foreach (var block in cbBlocks.Select(x => x.ToZigZagArray(8)))
{
block.ForEach(x => writer.Write(x));
}
writer.Write(crBlocks.Count());
foreach (var block in crBlocks.Select(x => x.ToZigZagArray(8)))
{
block.ForEach(x => writer.Write(x));
}
writer.Write(getSubsamplingCodeByType[subsamplingType]);
writer.Write(getQuantizingCodeByType[quantizingType]);
writer.Write(nY);
writer.Write(nC);
writer.Write(alphaY);
writer.Write(gammaY);
writer.Write(alphaC);
writer.Write(gammaC);
}
Zip7(filename);
}
public static BitmapSource JpegSteps(Image image, int size, string downsamplingType, QuantizingType quantizingType,
int alphaY, int gammaY, int alphaC, int gammaC, int remainingCountY, int remainingCountC)
{
var source = ((BitmapSource)image.Source);
var ycbcr = MainWindow.ToYCbCr(source);
var compY = new byte[size * size];
var compCb = new byte[size * size];
var compCr = new byte[size * size];
for (var i = 0; i < size * size * 4; i += 4)
{
compY[i / 4] = ycbcr[i];
compCb[i / 4] = ycbcr[i + 1];
compCr[i / 4] = ycbcr[i + 2];
}
//*** Downsampling
var matrixY = ToMatrix(compY, size);
var matrixCb = Downsampling(ToMatrix(compCb, size), size, downsamplingType);
var matrixCr = Downsampling(ToMatrix(compCr, size), size, downsamplingType);
//*** Splitting to blocks 8x8 and DCT
var dct = new DiscreteCosineTransformator();
var hSize = size / getHorSizeLossByType[downsamplingType];
var vSize = size / getVertSizeLossByType[downsamplingType];
var yBlocks = SplitTo8x8Matrices(matrixY, size, size).Select(dct.DCT).ToList();
var cbBlocks = SplitTo8x8Matrices(matrixCb, hSize, vSize).Select(dct.DCT).ToList();
var crBlocks = SplitTo8x8Matrices(matrixCr, hSize, vSize).Select(dct.DCT).ToList();
//*** Quantizing
var quantizorY = new JpegQuantisor(alphaY, gammaY);
var quantizorC = new JpegQuantisor(alphaC, gammaC);
switch (quantizingType)
{
case QuantizingType.Nullify:
yBlocks = yBlocks.Select(x => quantizorY.SimpleQuantizing(x, remainingCountY)).ToList();
cbBlocks = cbBlocks.Select(x => quantizorC.SimpleQuantizing(x, remainingCountC)).ToList();
crBlocks = crBlocks.Select(x => quantizorC.SimpleQuantizing(x, remainingCountC)).ToList();
break;
case QuantizingType.AlphaGamma:
yBlocks = yBlocks.Select(quantizorY.QQuantizing).ToList();
cbBlocks = cbBlocks.Select(quantizorC.QQuantizing).ToList();
crBlocks = crBlocks.Select(quantizorC.QQuantizing).ToList();
break;
default:
yBlocks = yBlocks.Select(x => quantizorY.QuantizingRecommended(x, "Y")).ToList();
cbBlocks = cbBlocks.Select(x => quantizorC.QuantizingRecommended(x, "Cb")).ToList();
crBlocks = crBlocks.Select(x => quantizorC.QuantizingRecommended(x, "Cr")).ToList();
break;
}
//*** saving to file
WriteToFile(size, size, yBlocks, cbBlocks, crBlocks, downsamplingType, quantizingType, alphaY, gammaY, alphaC, gammaC, remainingCountY, remainingCountC);
//*** back steps:
//*** back quantizing
switch (quantizingType)
{
case QuantizingType.Nullify:
break;
case QuantizingType.AlphaGamma:
yBlocks = yBlocks.Select(quantizorY.BackQQuantizing).ToList();
cbBlocks = cbBlocks.Select(quantizorC.BackQQuantizing).ToList();
crBlocks = crBlocks.Select(quantizorC.BackQQuantizing).ToList();
break;
default:
yBlocks = yBlocks.Select(x => quantizorY.BackQuantizingRecommended(x, "Y")).ToList();
cbBlocks = cbBlocks.Select(x => quantizorC.BackQuantizingRecommended(x, "Cb")).ToList();
crBlocks = crBlocks.Select(x => quantizorC.BackQuantizingRecommended(x, "Cr")).ToList();
break;
}
//*** back DCT
yBlocks = yBlocks.Select(dct.InverseDCT).ToList();
cbBlocks = cbBlocks.Select(dct.InverseDCT).ToList();
crBlocks = crBlocks.Select(dct.InverseDCT).ToList();
//*** back to whole matrix
var backY = Matrices8x8ToOne(yBlocks.ToList(), size, size);
var backCb = Matrices8x8ToOne(cbBlocks.ToList(), hSize, vSize);
var backCr = Matrices8x8ToOne(crBlocks.ToList(), hSize, vSize);
//*** back downsampling
backCb = BackDownsampling(backCb, size, downsamplingType);
backCr = BackDownsampling(backCr, size, downsamplingType);
compY = MatrixToPixels(backY, size);
compCb = MatrixToPixels(backCb, size);
compCr = MatrixToPixels(backCr, size);
var pixels = new byte[size * size * 4];
for (var i = 0; i < size * size * 4; i += 4)
{
pixels[i] = compY[i / 4];
pixels[i + 1] = compCb[i / 4];
pixels[i + 2] = compCr[i / 4];
}
return(MainWindow.ToRGB(pixels, source));
}
