public void DCT_Insertion_Test()
{
var bmap = new Bitmap(inputImagePath);
double[] pixelArray = getPixelArray(bmap);
IDCT dct = DCT.CreateParallelDCT();
double[] forward = dct.Forward(pixelArray);
double[] signal = Enumerable.Repeat(0d, 5000).ToArray();
signal[3000] = 750;
var insert_point = 30000;
var fSignal = dct.Forward(signal);
for (int i = insert_point; i < insert_point + fSignal.Length; i++)
{
forward[i] += fSignal[i - insert_point];
}
var output = setPixelMatrix(bmap, dct.Backward(forward));
output.Save(outputImagePath);
}
public void DCT_Back_Fort_Test()
{
var bmap = new Bitmap(inputImagePath);
double[] pixelArray = getPixelArray(bmap);
IDCT dct = DCT.CreateParallelDCT();
var output = setPixelMatrix(bmap, dct.Backward(dct.Forward(pixelArray)));
output.Save(outputImagePath);
}
public void DCT_detection_Test()
{
var bmap = new Bitmap(inputImagePath);
double[] pixelArray = getPixelArray(bmap);
IDCT dct = DCT.CreateParallelDCT();
double[] forward = dct.Forward(pixelArray);
const int signalSize = 5000;
double[] signal = Enumerable.Repeat(0d, signalSize).ToArray();
signal[3000] = 750;
var insert_point = 30000;
var fSignal = dct.Forward(signal);
for (int i = insert_point; i < insert_point + fSignal.Length; i++)
{
forward[i] += fSignal[i - insert_point];
}
var output = setPixelMatrix(bmap, dct.Backward(forward));
output.Save(outputImagePath);
var bmapMarked = new Bitmap(outputImagePath);
var forwardedMarked = dct.Forward(getPixelArray(bmapMarked));
double[] extractedSignal = Enumerable.Repeat(0d, signalSize).ToArray();
for (int i = insert_point; i < insert_point + fSignal.Length; i++)
{
extractedSignal[i - insert_point] = Math.Abs(forward[i] - forwardedMarked[i]);
}
var bacwardextractedSignal = dct.Backward(extractedSignal);
var mean = bacwardextractedSignal.Sum() / bacwardextractedSignal.Length;
Console.WriteLine(mean);
}
public JpegEncoder(IPixelMapper pixelMapper, IDCT dct)
{
this.pixelMapper = pixelMapper;
this.dct = dct;
}
/// <summary>
/// Setups the specified segments.
/// </summary>
/// <param name="segments">The segments.</param>
/// <exception cref="System.Exception">
/// missing SOF marker or SOS has wrong length or SOS length inconsistent with number of
/// components or Unknown component selector or Repeated component selector or bad Td value
/// or bad Ta value or Total sampling factors too large. or bad spectral selection bounds or
/// progressive AC coefficients for more than one component or bad successive approximation
/// values or Excessive DC component or Too many components or Too many components or Bad RST marker
/// </exception>
public override void Setup(IEnumerable <SegmentBase> segments)
{
Length = GetLength(Bytes);
var n = Length;
var StartOfFrameSegment = segments.OfType <StartOfFrame>().FirstOrDefault();
var DefineHuffmanTableSegment = segments.OfType <DefineHuffmanTable>().FirstOrDefault();
var DefineRestartIntervalSegment = segments.OfType <DefineRestartInterval>().FirstOrDefault() ?? new DefineRestartInterval(null);
var DefineQuantizationTableSegment = segments.OfType <DefineQuantizationTable>().FirstOrDefault();
if (StartOfFrameSegment == null)
{
throw new Exception("missing SOF marker");
}
if (n < 6 || 4 + (2 * (int)StartOfFrameSegment.TypeOfImage) < n || n % 2 != 0)
{
throw new Exception("SOS has wrong length");
}
Bytes.ReadFull(TempData, 0, n);
byte lnComp = TempData[0];
if (n != 4 + 2 * lnComp)
{
throw new Exception("SOS length inconsistent with number of components");
}
Scan[] scan = new Scan[MAXIMUM_NUMBER_COMPONENTS];
int totalHV = 0;
for (int i = 0; i < lnComp; i++)
{
int cs = TempData[1 + (2 * i)];
int compIndex = -1;
for (int j = 0; j < (int)StartOfFrameSegment.TypeOfImage; j++)
{
Component compv = StartOfFrameSegment.Components[j];
if (cs == compv.ComponentIdentifier)
{
compIndex = j;
}
}
if (compIndex < 0)
{
throw new Exception("Unknown component selector");
}
scan[i].ComponentIndex = (byte)compIndex;
for (int j = 0; j < i; j++)
{
if (scan[i].ComponentIndex == scan[j].ComponentIndex)
{
throw new Exception("Repeated component selector");
}
}
totalHV += StartOfFrameSegment.Components[compIndex].HorizontalSamplingFactor * StartOfFrameSegment.Components[compIndex].VerticalSamplingFactor;
scan[i].Td = (byte)(TempData[2 + (2 * i)] >> 4);
if (scan[i].Td > MAXIMUM_TH)
{
throw new Exception("bad Td value");
}
scan[i].Ta = (byte)(TempData[2 + (2 * i)] & 0x0f);
if (scan[i].Ta > MAXIMUM_TH)
{
throw new Exception("bad Ta value");
}
}
if (StartOfFrameSegment.TypeOfImage != ImageType.GreyScale && totalHV > 10)
{
throw new Exception("Total sampling factors too large.");
}
int zigStart = 0;
int zigEnd = Block.BlockSize - 1;
int ah = 0;
int al = 0;
if (StartOfFrameSegment.Progressive)
{
zigStart = (int)TempData[1 + (2 * lnComp)];
zigEnd = (int)TempData[2 + (2 * lnComp)];
ah = (int)(TempData[3 + (2 * lnComp)] >> 4);
al = (int)(TempData[3 + (2 * lnComp)] & 0x0f);
if ((zigStart == 0 && zigEnd != 0) || zigStart > zigEnd || zigEnd >= Block.BlockSize)
{
throw new Exception("bad spectral selection bounds");
}
if (zigStart != 0 && lnComp != 1)
{
throw new Exception("progressive AC coefficients for more than one component");
}
if (ah != 0 && ah != al + 1)
{
throw new Exception("bad successive approximation values");
}
}
int h0 = StartOfFrameSegment.Components[0].HorizontalSamplingFactor;
int v0 = StartOfFrameSegment.Components[0].VerticalSamplingFactor;
int mxx = (StartOfFrameSegment.Width + (8 * h0) - 1) / (8 * h0);
int myy = (StartOfFrameSegment.Height + (8 * v0) - 1) / (8 * v0);
if (img1 == null && img3 == null)
{
makeImg(mxx, myy, StartOfFrameSegment);
}
if (StartOfFrameSegment.Progressive)
{
for (int i = 0; i < lnComp; i++)
{
int compIndex = scan[i].ComponentIndex;
if (ProgressiveCoefficients[compIndex] == null)
{
ProgressiveCoefficients[compIndex] = new Block[mxx * myy * StartOfFrameSegment.Components[compIndex].HorizontalSamplingFactor * StartOfFrameSegment.Components[compIndex].VerticalSamplingFactor];
for (int j = 0; j < ProgressiveCoefficients[compIndex].Length; j++)
{
ProgressiveCoefficients[compIndex][j] = new Block();
}
}
}
}
Bytes.Bits = new BitsBuffer();
int mcu = 0;
byte expectedRST = SegmentTypes.Restart0;
var b = new Block();
int[] dc = new int[MAXIMUM_NUMBER_COMPONENTS];
int bx, by, blockCount = 0;
for (int my = 0; my < myy; my++)
{
for (int mx = 0; mx < mxx; mx++)
{
for (int i = 0; i < lnComp; i++)
{
int compIndex = scan[i].ComponentIndex;
int hi = StartOfFrameSegment.Components[compIndex].HorizontalSamplingFactor;
int vi = StartOfFrameSegment.Components[compIndex].VerticalSamplingFactor;
Block qt = DefineQuantizationTableSegment.quant[StartOfFrameSegment.Components[compIndex].QuatizationTableDestSelector];
for (int j = 0; j < hi * vi; j++)
{
if (lnComp != 1)
{
bx = hi * mx + j % hi;
by = vi * my + j / hi;
}
else
{
int q = mxx * hi;
bx = blockCount % q;
by = blockCount / q;
blockCount++;
if (bx * 8 >= StartOfFrameSegment.Width || by * 8 >= StartOfFrameSegment.Height)
{
continue;
}
}
if (StartOfFrameSegment.Progressive)
{
b = ProgressiveCoefficients[compIndex][by * mxx * hi + bx];
}
else
{
b = new Block();
}
if (ah != 0)
{
refine(b, DefineHuffmanTableSegment.HuffmanCodes[acTable, scan[i].Ta], zigStart, zigEnd, 1 << al);
}
else
{
int zig = zigStart;
if (zig == 0)
{
zig++;
var value = DefineHuffmanTableSegment.HuffmanCodes[dcTable, scan[i].Td].DecodeHuffman(Bytes);
if (value > 16)
{
throw new Exception("Excessive DC component");
}
var dcDelta = Bytes.receiveExtend(value);
dc[compIndex] += dcDelta;
b[0] = dc[compIndex] << al;
}
if (zig <= zigEnd && EndOfBlockRun > 0)
{
EndOfBlockRun--;
}
else
{
var huffv = DefineHuffmanTableSegment.HuffmanCodes[acTable, scan[i].Ta];
for (; zig <= zigEnd; zig++)
{
var value = huffv.DecodeHuffman(Bytes);
var val0 = (byte)(value >> 4);
var val1 = (byte)(value & 0x0f);
if (val1 != 0)
{
zig += val0;
if (zig > zigEnd)
{
break;
}
var ac = Bytes.receiveExtend(val1);
b[unzig[zig]] = ac << al;
}
else
{
if (val0 != 0x0f)
{
EndOfBlockRun = (ushort)(1 << val0);
if (val0 != 0)
{
EndOfBlockRun |= (ushort)Bytes.DecodeBits(val0);
}
EndOfBlockRun--;
break;
}
zig += 0x0f;
}
}
}
}
if (StartOfFrameSegment.Progressive)
{
if (zigEnd != Block.BlockSize - 1 || al != 0)
{
ProgressiveCoefficients[compIndex][by * mxx * hi + bx] = b;
continue;
}
}
for (int zig = 0; zig < Block.BlockSize; zig++)
{
b[unzig[zig]] *= qt[zig];
}
IDCT.Transform(b);
byte[] dst = null;
int offset = 0;
int stride = 0;
if (StartOfFrameSegment.TypeOfImage == ImageType.GreyScale)
{
dst = img1.Pixels;
stride = img1.Stride;
offset = img1.Offset + 8 * (by * img1.Stride + bx);
}
else
{
switch (compIndex)
{
case 0:
dst = img3.YPixels;
stride = img3.YStride;
offset = img3.YOffset + 8 * (by * img3.YStride + bx);
break;
case 1:
dst = img3.CBPixels;
stride = img3.CStride;
offset = img3.COffset + 8 * (by * img3.CStride + bx);
break;
case 2:
dst = img3.CRPixels;
stride = img3.CStride;
offset = img3.COffset + 8 * (by * img3.CStride + bx);
break;
case 3:
throw new Exception("Too many components");
default:
throw new Exception("Too many components");
}
}
for (int y = 0; y < 8; y++)
{
int y8 = y * 8;
int yStride = y * stride;
for (int x = 0; x < 8; x++)
{
int c = b[y8 + x];
if (c < -128)
{
c = 0;
}
else if (c > 127)
{
c = 255;
}
else
{
c += 128;
}
dst[yStride + x + offset] = (byte)c;
}
}
}
}
mcu++;
if (DefineRestartIntervalSegment.RestartInterval > 0 && mcu % DefineRestartIntervalSegment.RestartInterval == 0 && mcu < mxx * myy)
{
Bytes.ReadFull(TempData, 0, 2);
if (TempData[0] != 0xff || TempData[1] != expectedRST)
{
throw new Exception("Bad RST marker");
}
expectedRST++;
if (expectedRST == SegmentTypes.Restart7 + 1)
{
expectedRST = SegmentTypes.Restart0;
}
Bytes.Bits = new BitsBuffer();
dc = new int[MAXIMUM_NUMBER_COMPONENTS];
EndOfBlockRun = 0;
}
}
}
}