void LoopTree(bool[] currentTree, int index) { int[] node = treeints[index]; if (node[1] == -1) { if (currentTree.Length == 0) { currentTree = new bool[] { false }; } //Console.Write("0 " + sortednumbers[node[2]] + " "); outputStream.Write(false); outputStream.Write(sortednumbers[node[2]], minBits); numberVals[node[2]] = currentTree.ToArray(); } else { //Console.Write("1"); outputStream.Write(true); bool[] passTree = new bool[currentTree.Length + 1]; if (currentTree.Length > 0) { Array.Copy(currentTree, passTree, currentTree.Length); } passTree[passTree.Length - 1] = true; LoopTree(passTree, node[2]); passTree[passTree.Length - 1] = false; LoopTree(passTree, node[1]); } }
//Compress integer array into BitStream public static BitStreamFIFO Compress(int[] source) { //Compress the array of integers using all different compression techniques, where possible at the same time BitStreamFIFO[] compressionTechniques = new BitStreamFIFO[2]; Parallel.For(0, compressionTechniques.Length, (i, state) => { switch (i) { //Huffmann: generate a dictionary of all used integer values where more frequent values have a code with less bits case 0: compressionTechniques[i] = HuffmanIntArrayCompressor.Compress(source); break; //Variable int length: save smaller integers with less bits than bigger integers case 1: compressionTechniques[i] = VaryingIntLengthIntArrayCompressor.Compress(source); 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; } } //Create a new BitStream to write necessary information for the decompressor BitStreamFIFO compressionInfo = new BitStreamFIFO(); //Calculate the amount of bits needed to save the total length in bits of the compressed data int lengthSaveLength = (int)Math.Ceiling(Math.Log(smallestSize, 2) / 8); //Write data to the compression info compressionInfo.Write(smallestID, 2); //The compression technique used compressionInfo.Write(lengthSaveLength, 6); //The amount of bits needed to save the total length in bits of the compressed data compressionInfo.Write(smallestSize, lengthSaveLength * 8); //The total length in bits of the compressed data //Merge the info about the compression type with the compressed data & return return(BitStreamFIFO.Merge(compressionInfo, compressionTechniques[smallestID])); }
public TreeWalker(int[] sortedNumbers, int[][] treeInts) { sortednumbers = sortedNumbers; treeints = treeInts; numberVals = new bool[sortedNumbers.Length][]; minBits = (int)Math.Ceiling(Math.Log(sortedNumbers.Max() + 1, 2)); minBits = minBits < 1 ? 1 : minBits; outputStream = new BitStreamFIFO(); outputStream.Write((byte)minBits); outputStream.Write(sortedNumbers.Length - 1, minBits); //Console.WriteLine(minBits + " " + sortedNumbers.Length); LoopTree(new bool[0], treeInts.Length - 1); //Console.WriteLine(); }
// This function is used to compress the image using the LZW algorithm public static byte[] Compress(AccessibleBitmap source) { // Add first 255 standard values to LZWDictionary in LZWCompressor.cs string[] LZWDictionary = new string[256]; for (int i = 0; i < 256; i++) { LZWDictionary[i] = ((char)i).ToString(); } List <string> dictionary = new List <string>(LZWDictionary); // Clone dictionary of all bytes Queue <byte> bytes = new Queue <byte>(source.GetRawPixelBytes()); // Get all bytes from the source image BitStreamFIFO bs = new BitStreamFIFO(); // Create bitstream for output int maxDictSize = (int)Math.Pow(2, maxBitCount); // Get maximum dictionary size string encodingString = ((char)bytes.Dequeue()).ToString(); // Create string to add encoding to while (bytes.Count > 0) { // Clear dict if full if (dictionary.Count >= maxDictSize) { dictionary = new List <string>(LZWDictionary); } char b = (char)bytes.Dequeue(); if (dictionary.Contains(encodingString + b)) { encodingString += b; } else { bs.Write(dictionary.FindIndex(x => x.StartsWith(encodingString)), maxBitCount); dictionary.Add(encodingString + b); encodingString = b.ToString(); } } // Write remaining byte to bitstream bs.Write(dictionary.FindIndex(x => x.StartsWith(encodingString)), maxBitCount); // Return the bitstream as byte array return(bs.ToByteArray()); }
//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); }
//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); }
public static BitStreamFIFO Compress(int[] source) { List <int> numbers = new List <int>(); List <int> weights = new List <int>(); foreach (int b in source) { if (numbers.Contains(b)) { weights[numbers.IndexOf(b)]++; } else { numbers.Add(b); weights.Add(1); } } List <int> sortedWeightTmp = weights; sortedWeightTmp.Sort(); int[] sortedWeightsInts = sortedWeightTmp.ToArray(); int[] sortedNumbers = new int[numbers.Count]; int[] sortedWeights = new int[weights.Count]; for (int i = 0; i < sortedWeightTmp.Count; i++) { int oldIndex = weights.IndexOf(sortedWeightsInts[i]); sortedNumbers[i] = numbers[oldIndex]; sortedWeights[i] = weights[oldIndex]; weights[oldIndex] = 0; } /*for (int i = 0; i < sortedNumbers.Length; i++) * { * Console.WriteLine(sortedNumbers[i] + "\t" + sortedWeights[i]); * } * Console.WriteLine();*/ List <int[]> tree = new List <int[]>(); List <int[]> sources = new List <int[]>(); for (int i = 0; i < sortedWeights.Length; i++) { sources.Add(new int[] { sortedWeights[i], -1, i }); } while (sources.Count > 1) { tree.AddRange(sources.GetRange(0, 2)); sources.RemoveRange(0, 2); sources.Add(new int[] { tree[tree.Count - 1][0] + tree[tree.Count - 2][0], tree.Count - 1, tree.Count - 2 }); sources.Sort((s, t) => s[0] - t[0]); } tree.Add(sources[0]); Array.Reverse(sortedNumbers); TreeWalker walker = new TreeWalker(sortedNumbers, tree.ToArray()); BitStreamFIFO outputStream = walker.outputStream; //Console.WriteLine("s" + outputStream.Length); bool[][] numberVals = walker.numberVals; /*int length = 0; * for (int i = 0; i < numberVals.Length; i++) * { * Console.WriteLine(i + "\t" + sortedNumbers[i] + "\t" + sortedWeights[i] + "\t" + BoolArrString(numberVals[i])); * length += sortedWeights[i] * numberVals[i].Length; * }*/ //Console.WriteLine(source.Length); //Console.WriteLine(length); foreach (int i in source) { int index = Array.IndexOf(sortedNumbers, i); outputStream.Write(numberVals[index]); //Console.WriteLine(BoolArrString(numberVals[index]) + "\t" + i); //Console.WriteLine(i); } //Console.WriteLine(source.Length * 8); //Console.WriteLine("length"+outputStream.Length); return(outputStream); }
public static byte[] CompressVertical(AccessibleBitmap source) { byte[] lastpixel = null; // Create variable to store the last pixel int colorCounter = 1; // Create counter for current color BitStreamFIFO bs = new BitStreamFIFO(); // Create new bitstream for all the bits int maxCount = 0; // Create variable to store the max bitcount Queue<PixelArray> output = new Queue<PixelArray>(); // Create list to store all the pixelvalues in // Write one bit to the bitstream, so the decompressor knows to decompress vertically bs.Write(true); // Iterate through every vertical row for (int x = 0; x < source.width; x++) { // Iterate through every pixel in the vertical row for (int y = 0; y < source.height; y++) { // Check if the variable lastpixel is empty if (lastpixel == null) { // If lastpixel is empty, set last pixel to the first pixel lastpixel = source.GetPixel(x, y); } else { // If lastpixel isn't empty, compare last pixel with new pixel if (lastpixel.SequenceEqual(source.GetPixel(x, y))) { // Pixels matched, so increase the counter value colorCounter++; } else { // If the pixels don't match, add the counter with the last pixel to the output queue output.Enqueue(new PixelArray(colorCounter, lastpixel)); // Check if the new countervalue is higher then the last one, if so set maxBitCount to that if (colorCounter > maxCount) maxCount = colorCounter; // Reset the colorCounter and set the last pixel to the new pixel colorCounter = 1; lastpixel = source.GetPixel(x, y); } } } } // Add the remaining pixel(s) to the bitstream output.Enqueue(new PixelArray(colorCounter, lastpixel)); // Check if the new countervalue is higher then the last one, if so set maxBitCount to that if (colorCounter > maxCount) maxCount = colorCounter; // Write the maxCount to the bitstream bs.Write((byte)Math.Ceiling(Math.Log(maxCount, 2))); // Add all the pixels from the queue to the bitstream while (output.Count > 0) { PixelArray pixel = output.Dequeue(); bs.Write(pixel.Count, (int)Math.Ceiling(Math.Log(maxCount, 2))); bs.Write(pixel.Pixel); } // Return the bitsream as a byte[] return bs.ToByteArray(); }
//Compress integer array into BitStream public static BitStreamFIFO Compress(int[] source) { //Get the amount of bits needed to store the longest run int invariableMinBits = (int)Math.Ceiling(Math.Log(source.Max() + 1, 2)); invariableMinBits = invariableMinBits < 1 ? 1 : invariableMinBits; //Initialize List <int> nonExisting = new List <int>(); //Create a list to which all values that aren't present in the source array will be added int minBits = invariableMinBits; //The minimum amount of bits used for variable save bits, related to the list of nonexisting values //Loop trough all possible values within the range of the source values for (int i = 0; i < source.Max(); i++) { //If a value is not present in the source array if (!source.Contains(i)) { //Add current value to the list nonExisting.Add(i); //Set the minimum amount of bits to save this value minBits = (int)Math.Ceiling(Math.Log(i + 1, 2)); minBits = minBits < 1 ? 1 : minBits; //If the amount of unused values is equal to the difference between invariableMinBits and minBits if (nonExisting.Count >= invariableMinBits - minBits) { //Minbits is now the smallest possible amount of bits in which the source array can be saved variable, so stop checking for more unused values break; } } } //Divide the source values in categories with the same minimum amount of bits to be saved in //Create all categories int[][] distancesByPower = new int[invariableMinBits][]; //Loop trough all categories for (int i = 0; i < distancesByPower.Length; i++) { //Define the smalles and biggest value of the current category int minVal = (int)Math.Pow(2, i) - 1; int maxVal = (int)Math.Pow(2, i + 1); //Add all values within the specified range to this category distancesByPower[i] = new List <int>(source).FindAll(x => x < maxVal && x >= minVal).ToArray(); } //Find out which possible minimum amount of bits used will compress the most //Initialize int chosenMinBits = invariableMinBits; //The chosen minimum amount of bits int smallestSize = int.MaxValue; //The size of the compressed data when using the chosen minimum of bits //Loop trough all possible minimum amounts of bits for (int i = 0; i <= invariableMinBits - minBits; i++) { //Calculate the length of the current minimum amount of bits //Initialize int length = 0; //The total length int baseBits = invariableMinBits - i; //Define the current minimum amount of bits //Add the length of all data that will be saved in the minimum amount of bits to the length variable for (int j = 0; j < baseBits; j++) { length += distancesByPower[j].Length * baseBits; } //Loop trough all data that needs more bits to be saved than the minimum for (int j = 0; j < i; j++) { //Define the minimum bits for this value int currentBits = invariableMinBits - j; //Add the minimum bits of this value + the general minimum bits to the length variable, becouse an extra value should be used to indicate the extra amount of bits length += distancesByPower[currentBits - 1].Length * (baseBits + currentBits); } //If the length of this minimum amount of bits is smaller than the chosen amount of bits if (length < smallestSize) { //Set this smallest amount of bits as the chosen amount of bits smallestSize = length; chosenMinBits = baseBits; } } //Create a new BitStream as output BitStreamFIFO bitStream = new BitStreamFIFO(); //Write necessary info for decompressing to the output stream bitStream.Write((byte)chosenMinBits); //The chosen default bits to save values bitStream.Write((byte)(invariableMinBits - chosenMinBits)); //The amount of values that trigger an increase of bits per value //Write all values that trigger an increase of bits per value for (int i = 0; i < invariableMinBits - chosenMinBits; i++) { bitStream.Write(nonExisting[i], chosenMinBits); } //Write all values to the stream //Loop trough all values foreach (int i in source) { //Get the amount of extra bits needed to save this value int extraBits = 0; while (Math.Pow(2, chosenMinBits + extraBits) - 1 < i) { extraBits++; } //Write trigger value to stream if extra bits are needed if (extraBits > 0) { bitStream.Write(nonExisting[extraBits - 1], chosenMinBits); } //Write the value to the stream using the correct amount of bits bitStream.Write(i, chosenMinBits + extraBits); } //Return the compressed data return(bitStream); }
//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); }