public static IntegerMatrix ReadScanData(byte[] scanDataBytes, DhtHeader dhtHeader, Sof3Header sof3Header, SosHeader sosHeader, UInt16[] slices)
{
int columnsCount = GetImageWidth(slices);
int rowsCount = sof3Header.LinesNumber;
int rowIndex = 0, columnIndex = 0;
IntegerMatrix resMatrix = new IntegerMatrix(rowsCount, columnsCount);
ushort normalSliceWidth = slices[1];
List <int> decompressionValueList = new List <int>();
Dictionary <string, byte>[] huffmanCodeValueMapsArray = RawReader.GetHuffmanCodeValueMapsArray(dhtHeader);
BitArray scanDataBitArray = RawReader.GetScanDataBitArray(scanDataBytes);
int index = 0, huffmanCodeIndex = 0;
BitArray huffmanCodeBitArray = new BitArray(1);
string huffmanCodeString = null;
byte huffmanValue = 0;
int componentIndex = 0;
int componentValueIndex = 0, componentValue = 0;
int[] previousComponentValues = RawReader.GetInitialComponentValues(sof3Header);
int lastIndex = GetLastDecompressionValueIndex(sof3Header, slices);
int lastSliceFirstDecompressionValueIndex = GetLastSliceFirstDecompressionValueIndex(sof3Header, slices);
int sliceSize = slices[1] * sof3Header.LinesNumber;
Dictionary <string, byte> huffmanCodeValueMap = huffmanCodeValueMapsArray[GetHuffmanTableIndex(rowIndex, columnIndex, sosHeader)];
while (componentValueIndex <= lastIndex && index < scanDataBitArray.Length)
{
huffmanCodeBitArray[huffmanCodeIndex] = scanDataBitArray[index];
huffmanCodeString = huffmanCodeBitArray.ToBitString();
if (huffmanCodeValueMap.TryGetValue(huffmanCodeString, out huffmanValue))
{
int differenceCodeValue = 0;
index++;
if (huffmanValue > 0)
{
//Read difference code
int finalIndex = index + huffmanValue - 1;
differenceCodeValue = GetDifferenceCodeValue(scanDataBitArray, index, finalIndex, huffmanValue);
index = finalIndex + 1;
}
else
{
differenceCodeValue = 0;
}
componentValue = previousComponentValues[componentIndex] + differenceCodeValue;
previousComponentValues[componentIndex] = componentValue;
decompressionValueList.Add(componentValue);
resMatrix[rowIndex, columnIndex] = componentValue;
componentValueIndex++;
huffmanCodeBitArray = new BitArray(1);
huffmanCodeIndex = 0;
rowIndex = GetNextRowIndex(componentValueIndex, lastSliceFirstDecompressionValueIndex, sliceSize, slices);
columnIndex = GetNextColumnIndex(componentValueIndex, lastSliceFirstDecompressionValueIndex, sliceSize, slices);
huffmanCodeValueMap = huffmanCodeValueMapsArray[GetHuffmanTableIndex(rowIndex, columnIndex, sosHeader)];
bool initComponentValuesRequired =
(columnIndex == 0) ||
((columnIndex > 0) && (columnIndex % normalSliceWidth == 0));
if (initComponentValuesRequired)
{
previousComponentValues = GetInitialComponentValues(sof3Header);
}
componentIndex = GetComponentIndex(rowIndex, columnIndex);
}
else
{
//Read huffman code
index++;
huffmanCodeIndex++;
huffmanCodeBitArray.Length++;
}
}
return(resMatrix);
}
