//Decompress byte array into aBitmap with help of width, length and bitdepth
public static AccessibleBitmapBitwise Decompress(BitStreamFIFO inBits, AccessibleBitmapBitwise inBitmap, out BitStreamFIFO restBits, int bitLayer)
{
//Read necessary info from BitStream
bool currentVal = inBits.ReadBool();
Queue <int> runs = new Queue <int>(VaryingIntArrayCompressor.Decompress(ref inBits));
int pixelsToGo = runs.Dequeue() + 1;
//Iterate trough all pixels
for (int y = 0; y < inBitmap.height; y++)
{
for (int x = 0; x < inBitmap.width; x++)
{
//Set the bit of the current pixel to the value of the current run
inBitmap.SetPixelBit(x, y, bitLayer, currentVal);
//Decrease the length of the current run & check if the end has bin reached
pixelsToGo--;
if (pixelsToGo == 0 && (x * y != (inBitmap.height - 1) * (inBitmap.width - 1)))
{
//Read the new run length from the BitStream & reverse the run bit
pixelsToGo = runs.Dequeue() + 1;
//Toggle bit value
currentVal = !currentVal;
}
}
}
//Return rest of bits & return bitmap
restBits = inBits;
return(inBitmap);
}
//Decompress byte array into aBitmap with help of width, length and bitdepth
public static AccessibleBitmapBytewise Decompress(byte[] inBytes, AccessibleBitmapBytewise inBitmap, out byte[] restBytes, int byteLayer)
{
//Create a AccessibleBitmapbitwise class from the incoming AccessibleBitmapbytewise class, for better access to individual bits
AccessibleBitmapBitwise outputBitmap = new AccessibleBitmapBitwise(inBitmap);
//Create a BitStreamFIFO class from the incoming bytes, to feed into the decompression algorithms
BitStreamFIFO bitStream = new BitStreamFIFO(inBytes);
//Loop trough all bit layers of current byte layer
for (int i = byteLayer * 8; i < byteLayer * 8 + 8; i++)
{
//Read compression type as a 3-bit integer
int compressionType = bitStream.ReadInt(3);
//Decompress using the correct compression type
switch (compressionType)
{
//Uncompressed
case 0:
outputBitmap = UncompressedBitmapCompressorBitwise.Decompress(bitStream, outputBitmap, out bitStream, i);
break;
//Bit channel compressed as 8-bit integers
case 1:
outputBitmap = ByteArrayCompressorBitwise.Decompress(bitStream, outputBitmap, out bitStream, i);
break;
//Run length encoding
case 2:
outputBitmap = RunLengthEncodingCompressorBitwise.Decompress(bitStream, outputBitmap, out bitStream, i);
break;
//Run length encoding vertical
case 3:
outputBitmap = RunLengthEncodingCompressorVerticalBitwise.Decompress(bitStream, outputBitmap, out bitStream, i);
break;
//To add a decompression type add a new case like the existing ones
//Unknown compression type: error
default:
throw new Exception("Unexisting compression type");
}
}
//Remove the bytes used for this channel from the incoming byte array and pass the rest of them to the next channel
restBytes = new byte[bitStream.Length / 8];
Array.Copy(inBytes, inBytes.Length - (bitStream.Length / 8), restBytes, 0, restBytes.Length);
//Return the modified bitmap as AccessibleBitmapbytewise so the rest of the channels can be added to complete it
return(new AccessibleBitmapBytewise(outputBitmap.GetAccessibleBitmap()));
}
//Decompress byte array into aBitmap with help of width, length and bitdepth
public static AccessibleBitmapBitwise Decompress(BitStreamFIFO inBits, AccessibleBitmapBitwise inBitmap, out BitStreamFIFO restBits, int bitLayer)
{
//Decompress the incoming data to an array of integers
int[] ints = VaryingIntArrayCompressor.Decompress(ref inBits);
//Initialize
int intIndex = 0; //The index in the array of intergers, from where the next integer should be taken
bool[] tmpBools = new bool[8]; //The array of bits from which bits will be read to be applied to pixels
int boolIndex = 8; //The index in the array of bits, from where the next bit should be taken
//Add the data from the array of integers to the incoming bitmap
//Loop trough all lines of pixels
for (int y = 0; y < inBitmap.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < inBitmap.width; x++)
{
//If index is 8, all bits are used, so tmpBools should be renewed by using the next integer in the array of integers
if (boolIndex == 8)
{
//Reset the index to 0, so the next bit will be read from the start
boolIndex = 0;
//Convert the next integer in the array to a bool array, and write it to tmpBools
tmpBools = new BitStreamFIFO().IntToBoolArray(ints[intIndex], 8);
//Increase the index of the integer array, so the next integer will be read correctly
intIndex++;
}
//Write the bit of this channel from the correct position in the array of bits to the current pixel
inBitmap.SetPixelBit(x, y, bitLayer, tmpBools[boolIndex]);
//Increase index for next bit
boolIndex++;
}
}
//Set the output BitStream to the remaining bits of the input BitStream
restBits = inBits;
//Return the modified AccessibleBitmapBitwise so the rest of the channels can be added to complete it
return(inBitmap);
}
//Compress aBitmap into byte array
public static BitStreamFIFO Compress(AccessibleBitmapBitwise source, int bitLayer)
{
//Initialize
List <int> distances = new List <int>(); //A list containing all the lenghts of same bits
int tempDistance = -1; //The length of one run of bits with the same value, while it is not saved yet: -1 becouse it will be increased before the first check
bool lastVal = source.GetPixelBit(0, 0, bitLayer); //The bit value of the last checked pixel, to compare with the current pixel: set value to the value of the first pixel so the first check will succeed
//Loop trough all lines of pixels
for (int y = 0; y < source.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < source.width; x++)
{
//Take value of the current pixel
bool currentBool = source.GetPixelBit(x, y, bitLayer);
//If the value of the bit of this pixel matches the value of the bit of the previous pixel
if (currentBool == lastVal)
{
//Values are the same, so increase current run
tempDistance++;
}
else
{
//Values are not the same, so save the run
distances.Add(tempDistance);
//Set the bit value for the next comparison to the bit value of this pixel
lastVal = currentBool;
//Reset the run length for the new run
tempDistance = 0;
}
}
}
//Save the last run becouse this never happens in the loop
distances.Add(tempDistance);
//Save the bit value of the first pixel, because the decompressor needs to know this
bool initialVal = source.GetPixelBit(0, 0, bitLayer);
//Compress the array of run lengths using different techniques
BitStreamFIFO bitStream = VaryingIntArrayCompressor.Compress(distances.ToArray());
//Combine the inititial bit value with the compressed data of the runs, then return the BitStream
return(BitStreamFIFO.Merge(new BitStreamFIFO(new bool[] { initialVal }), bitStream));
}
//Compress aBitmap into byte array
public static BitStreamFIFO Compress(AccessibleBitmapBitwise source, int bitLayer)
{
//Initialize
List <int> ints = new List <int>(); //List of all integers generated from the bits of this channel
bool[] tmpBools = new bool[8]; //The collection of bits that will be converted to an interger
int index = 0; //The index in tmpBools where a new bit should be inserted
//Loop trough all lines of pixels
for (int y = 0; y < source.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < source.width; x++)
{
//Write bit of current pixel to the correct position in tmpBools
tmpBools[index] = source.GetPixelBit(x, y, bitLayer);
//Increase index for next bit
index++;
//If index is 8, tmpBools is full
if (index == 8)
{
//Set index to 0, so the next bit will be written to the start
index = 0;
//Convert tmpBools to an integer & add the result to the list of integers
ints.Add(new BitStreamFIFO().BoolArrayToInt(tmpBools));
}
}
}
//If index is not 0, it has not been reset at last, so tmpBools should be saved for the last bits it contains
if (index > 0)
{
//Convert tmpBools to an integer & add the result to the list of integers
ints.Add(new BitStreamFIFO().BoolArrayToInt(tmpBools));
}
//Compress the obtained array of integers using different techniques
BitStreamFIFO bitStream = VaryingIntArrayCompressor.Compress(ints.ToArray());
//Return the output array
return(bitStream);
}
//Compress aBitmap into byte array
public static BitStreamFIFO Compress(AccessibleBitmapBitwise source, int bitLayer)
{
//Creates a new BitStreamFIFO object where all bits will be written to
BitStreamFIFO bitStream = new BitStreamFIFO();
//Loop trough all lines of pixels
for (int y = 0; y < source.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < source.width; x++)
{
//Write the bit of this channel from the current pixel to the output BitStream
bitStream.Write(source.GetPixelBit(x, y, bitLayer));
}
}
//Return the BitStream
return(bitStream);
}
//Decompress byte array into aBitmap with help of width, length and bitdepth
public static AccessibleBitmapBitwise Decompress(BitStreamFIFO inBits, AccessibleBitmapBitwise inBitmap, out BitStreamFIFO restBits, int bitLayer)
{
//Read necessary info from BitStream
bool currentVal = inBits.ReadBool(); //The bit value of the first run
//Decompress the BitStream to a queue of integers
Queue <int> runs = new Queue <int>(VaryingIntArrayCompressor.Decompress(ref inBits));
//Initialize
int pixelsToGo = runs.Dequeue() + 1; //The amount of pixels that should be written before the next run starts
//Loop trough all lines of pixels
for (int y = 0; y < inBitmap.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < inBitmap.width; x++)
{
//Set the bit of the current pixel to the value of the current run
inBitmap.SetPixelBit(x, y, bitLayer, currentVal);
//Decrease the length of the current run
pixelsToGo--;
//If the end of the run has been reached
if (pixelsToGo == 0 && (x * y != (inBitmap.height - 1) * (inBitmap.width - 1)))
{
//Read the new run length from the BitStream
pixelsToGo = runs.Dequeue() + 1;
//Toggle bit value, because a bit can just have 2 values, and this run cannot have the same value as the previous run
currentVal = !currentVal;
}
}
}
//Set the output BitStream to the remaining bits of the input BitStream
restBits = inBits;
//Return the modified AccessibleBitmapBitwise so the rest of the channels can be added to complete it
return(inBitmap);
}
//Compress aBitmap into byte array
public static BitStreamFIFO Compress(AccessibleBitmapBitwise source, int bitLayer)
{
//Initialize vars
BitStreamFIFO bitStream = new BitStreamFIFO();
List <int> distances = new List <int>();
int tempDistance = -1;
bool lastVal = source.GetPixelBit(0, 0, bitLayer);
//Iterate trough pixels
for (int y = 0; y < source.height; y++)
{
for (int x = 0; x < source.width; x++)
{
//Take value of pixel & compare with previous value
bool currentBool = source.GetPixelBit(x, y, bitLayer);
if (currentBool == lastVal)
{
//Values are the same, so increase current run
tempDistance++;
}
else
{
//Values are not the same, so save the run and create a new one
distances.Add(tempDistance);
lastVal = currentBool;
tempDistance = 0;
}
}
}
//Save the last run becouse this never happens in the loop
distances.Add(tempDistance);
bool initialVal = source.GetPixelBit(0, 0, bitLayer);
bitStream.Write(initialVal);
BitStreamFIFO output = BitStreamFIFO.Merge(bitStream, VaryingIntArrayCompressor.Compress(distances.ToArray()));
return(output);
}
//Decompress byte array into aBitmap with help of width, length and bitdepth
public static AccessibleBitmapBitwise Decompress(BitStreamFIFO inBits, AccessibleBitmapBitwise inBitmap, out BitStreamFIFO restBits, int bitLayer)
{
//Add the data from this stream to the incoming bitmap
//Loop trough all lines of pixels
for (int y = 0; y < inBitmap.height; y++)
{
//Loop trough all pixels in this line
for (int x = 0; x < inBitmap.width; x++)
{
//Write the bit of this channel from the input BitStream to the current pixel
inBitmap.SetPixelBit(x, y, bitLayer, inBits.ReadBool());
}
}
//Set the output BitStream to the remainder of the input BitStream
restBits = inBits;
//Return the modified bitmap so the rest of the channels can be added to complete it
return(inBitmap);
}
//Compress aBitmap into byte array
public static byte[] Compress(AccessibleBitmapBytewise source, int byteLayer)
{
//Loop trough all layers of bits, where possible at the same time
AccessibleBitmapBitwise aBitmap = new AccessibleBitmapBitwise(source);
BitStreamFIFO[] byteLayers = new BitStreamFIFO[8];
Parallel.For(byteLayer * 8, byteLayer * 8 + 8, (z, state) => //for(int z = byteLayer * 8; z < byteLayer * 8 + 8; z++)
{
//Compress image using all different compression techniques, where possible at the same time
BitStreamFIFO[] compressionTechniques = new BitStreamFIFO[4];
Parallel.For(0, compressionTechniques.Length, (i, state2) =>
{
switch (i)
{
//Uncompressed (only used if no compression technique is smaller)
case 0:
compressionTechniques[i] = UncompressedBitmapCompressorBitwise.Compress(aBitmap, z);
break;
//Compress bit channel as an integer array using several techniques, using 8-bit integers
case 1:
compressionTechniques[i] = ByteArrayCompressorBitwise.Compress(aBitmap, z);
break;
//Run length compression: save the length of a sequence of bit values instead of saving them seperately
case 2:
compressionTechniques[i] = RunLengthEncodingCompressorBitwise.Compress(aBitmap, z);
break;
//Run length compression vertical: run length compression, but scan the pixels horizontally, becouse with some images this yields better results
case 3:
compressionTechniques[i] = RunLengthEncodingCompressorVerticalBitwise.Compress(aBitmap, z);
break;
//To add a compression technique, add a new case like the existing ones and increase the length of new byte[??][]
}
});
//Choose the smallest compression type
//Initialize
int smallestID = 0; //The ID of the smallest compression type
int smallestSize = int.MaxValue; //The size ofthe smallest compression type: int.MaxValue is assigned to make sure that the first compression to be checked will be smaaller than this value
//Loop trough all saved compression techniques
for (int i = 0; i < compressionTechniques.Length; i++)
{
//If the current technique is smaller than the smallest technique which has been checked
if (compressionTechniques[i].Length < smallestSize)
{
//Mark this technique as smallest
smallestSize = compressionTechniques[i].Length;
smallestID = i;
}
}
//Merge the number of the compression type of this layer with corresponding bitStream
BitStreamFIFO tmpStream = new BitStreamFIFO();
tmpStream.Write(smallestID, 3); //This 3-bit integer indicates which technique the decompressor should use, and should be before the image data
byteLayers[z % 8] = BitStreamFIFO.Merge(tmpStream, compressionTechniques[smallestID]);
});
//Combine all bitstreams & convert the result to a byte array
byte[] outputStream = BitStreamFIFO.Merge(byteLayers).ToByteArray();
//Return the data of all the bit channels combined
return(outputStream);
}
