Compresion

modules/compression/include/ips_jpg_at_model.cpp

@@ -0,0 +1,226 @@
+#include <systemc.h>
+
+/**
+ * @brief jpg_output module. Federico Cruz
+ * It takes the image and compresses it into jpeg format
+ * It is done in 4 parts:
+ * 1. Divides the image in 8x8 pixel blocks; for 8-bit grayscale images the a level shift is done by substracting 128 from each pixel.
+ * 2. Discrete Cosine Transform (DCT) of the 8x8 image.
+ * 3. Each transformed 8x8 block is divided by a quantization value for each block entry.
+ * 4. Each quantized 8x8 block is reordered by a Zig-Zag sequence into a array of size 64.
+ * *5. Entropy compression by variable length encoding (huffman). Used to maximize compression. Not implemented here.
+ */
+#define PI 3.1415926535897932384626433832795
+#define Block_rows 8
+#define Block_cols 8
+
+SC_MODULE (jpg_output) {
+
+  //input signals
+  sc_in<sc_int<32> > PixelValue_signal;
+  sc_in<sc_int<32> > row_signal;
+  sc_in<sc_int<32> > col_signal;
+
+  //output signals
+  sc_out<sc_int<8> > Element_signal;
+  sc_in<sc_int<32> > index_signal;
+
+  //compression signals
+  sc_out<sc_int<32> > output_size_signal;
+
+  //-----------Internal variables-------------------
+  //const int Block_rows = 8;
+  //const int Block_cols = 8;
+  double* image;
+  int image_rows = 480;
+  int image_cols = 640;
+  signed char EOB = 127; // end of block
+
+  int quantificator[8][8] = { // quantization table
+  {16,11,10,16,24,40,51,61},
+  {12,12,14,19,26,58,60,55},
+  {14,13,16,24,40,57,69,56},
+  {14,17,22,29,51,87,80,62},
+  {18,22,37,56,68,109,103,77},
+  {24,35,55,64,81,104,113,92},
+  {49,64,78,87,103,121,120,101},
+  {72,92,95,98,112,100,103,99}};
+
+  int zigzag_index[64]={ // zigzag table
+  0,1,5,6,14,15,27,28,
+  2,4,7,13,16,26,29,42,
+  3,8,12,17,25,30,41,43,
+  9,11,18,24,31,40,44,53,
+  10,19,23,32,39,45,52,54,
+  20,22,33,38,46,51,55,60,
+  21,34,37,47,50,56,59,61,
+  35,36,48,49,57,58,62,63};
+
+  sc_event starter_event;
+  sc_event input_event;
+  sc_event output_event;
+  sc_event compression_event;
+
+  // Constructor for compressor
+  SC_HAS_PROCESS(jpg_output);
+    jpg_output(sc_module_name jpg_compressor): sc_module(jpg_compressor){
+      image = new double[image_rows*image_cols];
+      //initialize the image matrix to avoid nan
+      for(int i=0; i<(image_rows*image_cols);i++){
+		image[i]=0;
+	  }
+	  SC_THREAD(starter_operation);
+	  SC_THREAD(input_operation);
+	  SC_THREAD(output_operation);
+	  SC_THREAD(compression_operation);
+  } // End of Constructor
+
+  //------------Code Starts Here-------------------------
+  void Starter() {
+	starter_event.notify(4, SC_NS);
+  }
+
+  void starter_operation(){
+	  while(true) {
+		wait(starter_event);
+        int im_rows = row_signal.read();
+	    if(im_rows%Block_rows==0) {image_rows=im_rows;}
+        else {image_rows=(im_rows/Block_rows+1)*Block_rows;}
+		wait(4, SC_NS);
+		int im_cols = col_signal.read();
+        if(im_cols%Block_cols==0) {image_cols=im_cols;}
+        else {image_cols=(im_cols/Block_cols+1)*Block_cols;}
+	  }
+  }
+
+  void InputPixel() {
+	input_event.notify(8, SC_NS);
+  }
+
+  void input_operation(){
+	  while(true) {
+		wait(input_event);
+		double* i_row = &image[row_signal.read() * image_cols];
+		i_row[col_signal.read()] = double(PixelValue_signal.read());
+	  }
+  }
+
+  //void OutputPixel(int *Pixel, int row, int col) {
+  //  double* i_row = &image[row * image_cols];
+  //  *Pixel = int(i_row[col]);
+  //}
+
+  void OutputByte() {
+	output_event.notify(8, SC_NS);
+  }
+
+  void output_operation(){
+	  while(true) {
+		wait(output_event);
+        Element_signal = image[index_signal.read()];
+	  }
+  }
+
+  void JPEG_compression() {
+	  compression_event.notify(100, SC_NS);
+  }
+
+  void compression_operation() {
+    while(true) {
+		wait(compression_event);
+        int output_size = 0;
+		//Level shift
+		for(int i=0; i<(image_rows*image_cols);i++){
+			image[i]=image[i]-128;
+		}
+		wait(100, SC_NS);
+		int Number_of_blocks = image_rows*image_cols/(Block_rows*Block_cols);
+		int block_output[Number_of_blocks][Block_rows*Block_cols] = {0};
+		int block_output_size[Number_of_blocks] = {0};
+		int block_counter = 0;
+		output_size = 0;
+		for(int row=0; row<image_rows; row+=Block_rows)	{
+		  double* i_row = &image[row * image_cols];
+		  for(int col=0; col<image_cols; col+=Block_cols) { //Divided the image in 8×8 blocks
+			DCT(row,col);
+			Quantization(row,col);
+			ZigZag(row,col,&block_output_size[block_counter],block_output[block_counter]);
+			output_size += block_output_size[block_counter]+1;
+			block_counter++;
+		  }
+		}
+		int output_counter = 0;
+		for(int block_index=0;block_index<Number_of_blocks;block_index++){
+		  for(int out_index=0; out_index<block_output_size[block_index];out_index++){
+			image[output_counter]=block_output[block_index][out_index];
+			output_counter++;
+		  }
+		  image[output_counter]=EOB;
+		  output_counter++;
+		}
+		output_size_signal = output_size;
+	}
+  }  
+
+  void DCT(int row_offset, int col_offset) {
+    wait(400, SC_NS);
+	double cos_table[Block_rows][Block_cols];
+	for (int row = 0; row < Block_rows; row++) //make the cosine table
+	{
+      for (int col = 0; col < Block_cols; col++) {
+        cos_table[row][col] = cos((((2*row)+1)*col*PI)/16);
+	  }
+	}
+    double temp;
+	for(int row=row_offset; row<row_offset+Block_rows; row++)
+	{
+ 	  double* i_row = &image[row * image_cols];
+	  for(int col=col_offset; col<col_offset+Block_cols; col++) {
+		//i_row[col] = cos_table[row-row_offset][col-col_offset];
+		temp = 0.0;
+    	for (int x = 0; x < 8; x++){
+    		double* x_row = &image[(x+row_offset) * image_cols];
+    		for (int y = 0; y < 8; y++) {
+    		  temp += x_row[y+col_offset] * cos_table[x][row-row_offset] * cos_table[y][col-col_offset];
+    		}
+    	}
+    	if ((row-row_offset == 0) && (col-col_offset == 0)) {
+		  temp /= 8.0;
+		}
+    	else if (((row-row_offset == 0) && (col-col_offset != 0)) || ((row-row_offset != 0) && (col-col_offset == 0))){
+    	  temp /= (4.0*sqrt(2.0)); 
+    	}
+        else {
+    	  temp /= 4.0;
+        }
+		i_row[col] = temp;
+      }
+	}
+  }
+
+  void Quantization(int row_offset, int col_offset) {
+    wait(100, SC_NS);
+	for(int row=row_offset; row<row_offset+Block_rows; row++)
+	{
+      double* i_row = &image[row * image_cols];
+ 	  for(int col=col_offset; col<col_offset+Block_cols; col++) {
+		i_row[col] = round(i_row[col]/quantificator[row-row_offset][col-col_offset]);
+	  }
+	}
+  }
+
+  void ZigZag(int row_offset, int col_offset, int *block_output_size, int *block_output) {
+    wait(200, SC_NS);
+	int index_last_non_zero_value = 0; // index to last non-zero in a block zigzag array
+    for(int row=row_offset; row<row_offset+Block_rows; row++)
+	{
+      double* i_row = &image[row * image_cols];
+ 	  for(int col=col_offset; col<col_offset+Block_cols; col++) {
+		int temp_index = zigzag_index[(row-row_offset)*8+(col-col_offset)];
+		block_output[temp_index]=i_row[col];
+	    if(i_row[col] !=0 && temp_index>index_last_non_zero_value) {index_last_non_zero_value = temp_index+1;}
+      }
+	}
+	*block_output_size = index_last_non_zero_value;
+  }
+};