2D DWT and IDWT using OPENCV and a 512 by 512 grayscale image.

demo/imagedemo1.cpp

@@ -0,0 +1,192 @@
+//============================================================================
+// Name        : imagedemo1.cpp
+// Author      : Rafat Hussain
+// Version     :
+// Copyright   : 
+// Description : 2D DWT and IDWT using OPENCV and a 512 by 512 grayscale image.
+//============================================================================
+
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+#include <cmath>
+#include "cv.h"
+#include "highgui.h"
+#include "cxcore.h"
+#include "wavelet.h"
+
+using namespace std;
+using namespace cv;
+
+void* maxval(vector<vector<double> > &arr, double &max){
+	max = 0;
+	for (unsigned int i =0; i < arr.size(); i++) {
+		for (unsigned int j =0; j < arr[0].size(); j++) {
+			if (max <= arr[i][j]){
+				max = arr[i][j];
+			}
+		}
+	}
+	return 0;
+}
+
+void* minval(vector<vector<double> > &arr, double &min){
+	min = 10000;
+	for (unsigned int i =0; i < arr.size(); i++) {
+		for (unsigned int j =0; j < arr[0].size(); j++) {
+			if (min >= arr[i][j]){
+				min = arr[i][j];
+			}
+		}
+	}
+	return 0;
+}
+
+int main() {
+	IplImage* img = cvLoadImage("lena512.bmp");
+	if (!img){
+		cout << " Can't read Image. Try Different Format." << endl;
+		exit(1);
+	}
+	int height, width;
+	height = img->height;
+    width = img->width;
+    int nc = img->nChannels;
+ //   uchar* ptr2 =(uchar*) img->imageData;
+    int pix_depth = img->depth;
+    CvSize size;
+    size.width =width;
+    size.height=height;
+    cout << "depth" << pix_depth <<  "Channels" << nc << endl;
+
+
+    cvNamedWindow("Original Image", CV_WINDOW_AUTOSIZE);
+	cvShowImage("Original Image", img);
+	cvWaitKey();
+	cvDestroyWindow("Original Image");
+	cvSaveImage("orig.bmp",img);
+
+
+   int rows =(int) height;
+   int cols =(int) width;
+   Mat matimg(img);
+
+   vector<vector<double> > vec1(rows, vector<double>(cols));
+
+
+    int k =1;
+   for (int i=0; i < rows; i++) {
+	   for (int j =0; j < cols; j++){
+		   unsigned char temp;
+     temp = ((uchar*) matimg.data + i * matimg.step)[j  * matimg.elemSize() + k ];
+     vec1[i][j] = (double) temp;
+	   }
+
+   }
+
+     int rr1,cc1;
+ 	 string nm = "db4";
+ 	 // Finding DWT output dimensions as the DWT output is zeropadded
+     dwt_output_dim(vec1, rr1, cc1 );
+ 	int J = 2;
+ 	vector<double> flag;
+    vector<vector<double> >  dwt_output(rr1, vector<double>(cc1));
+    cout << rr1 << cc1 << "size of op" << endl;
+    // Computing 2d DWT ( vec1 is the signal while dwt_output is the DWT output)
+ 	dwt_2d(vec1, J, nm, dwt_output,flag );
+
+   cout << "dwt size" << dwt_output.size() << dwt_output[0].size() << endl;
+
+   double max,min;
+
+   maxval(dwt_output,max);
+   minval(dwt_output,min);
+   cout << "maxval" << max << "  minval" << min << endl;
+
+   //Displaying Scaled Image
+      // Creating Image in OPENCV
+   	  IplImage *cvImg; // image used for output
+      CvSize imgSize; // size of output image
+
+      imgSize.width = cc1;
+      imgSize.height = rr1;
+
+      cvImg = cvCreateImage( imgSize, 8, 1 );
+      // dwt_hold is created to hold the dwt output as further operations need to be
+      // carried out on dwt_output in order to display scaled images.
+      vector<vector<double> > dwt_hold(rr1, vector<double>(cc1));
+      dwt_hold = dwt_output;
+
+     // Setting coefficients of created image to the scaled DWT output values
+      for (int i = 0; i < imgSize.height; i++ ) {
+      for (int j = 0; j < imgSize.width; j++ ){
+		  if ( dwt_output[i][j] <= 0.0){
+			  dwt_output[i][j] = 0.0;
+		  }
+		  if ( i <= (imgSize.height/pow(2.0,double(J))) && j <= (imgSize.width/pow(2.0,double(J))) ) {
+      ((uchar*)(cvImg->imageData + cvImg->widthStep*i))[j] =
+       (char) ( (dwt_output[i][j] / max) * 255.0);
+		  } else {
+       ((uchar*)(cvImg->imageData + cvImg->widthStep*i))[j] =
+       (char) (dwt_output[i][j]) ;
+	  }
+	  }
+	  }
+
+	  cvNamedWindow( "DWT Image", 1 ); // creation of a visualisation window
+       cvShowImage( "DWT Image", cvImg ); // image visualisation
+	   cvWaitKey();
+	   cvDestroyWindow("DWT Image");
+	   cvSaveImage("dwt.bmp",cvImg);
+	// Finding IDWT
+	   vector<vector<double>  > final(rr1, vector<double>(cc1));
+	   idwt_2d(dwt_hold,flag, nm ,final);
+
+	   // Removing Zeropadding
+
+	   zero_remove(vec1,final);
+
+	   //Displaying Reconstructed Image
+
+	   IplImage *dvImg;
+	   CvSize dvSize; // size of output image
+
+	   dvSize.width = final[0].size();
+	   dvSize.height = final.size();
+
+	   dvImg = cvCreateImage( dvSize, 8, 1 );
+
+	      for (int i = 0; i < dvSize.height; i++ )
+	      for (int j = 0; j < dvSize.width; j++ )
+	          ((uchar*)(dvImg->imageData + dvImg->widthStep*i))[j] =
+	          (char) (final[i][j]) ;
+
+		  cvNamedWindow( "Reconstructed Image", 1 ); // creation of a visualisation window
+	       cvShowImage( "Reconstructed Image", dvImg ); // image visualisation
+		   cvWaitKey();
+		   cvDestroyWindow("Reconstructed Image");
+		   cvSaveImage("recon.bmp",dvImg);
+       ofstream diff("diff.dat");
+       for (unsigned int i=0; i < final.size(); i++) {
+    	for (unsigned int j = 0; j < final[0].size(); j++) {
+    		diff << final[i][j]-vec1[i][j] << " " ;
+    	}
+    	diff << endl;
+        }
+       ofstream recon("recon.dat");
+       for (unsigned int i=0; i < final.size(); i++) {
+    	for (unsigned int j = 0; j < final[0].size(); j++) {
+    		recon << (int)final[i][j] << " " ;
+    	}
+    	recon << endl;
+        }
+       ofstream orig("orig.dat");
+              for (unsigned int i=0; i < vec1.size(); i++) {
+           	for (unsigned int j = 0; j < vec1[0].size(); j++) {
+           		orig << (int)vec1[i][j] << " " ;
+           	}
+           	orig << endl;
+               }
+	return 0;
+}