diff --git a/wavelet2d/demo/imagedemo2.cpp b/wavelet2d/demo/imagedemo2.cpp new file mode 100644 index 0000000..cf2154b --- /dev/null +++ b/wavelet2d/demo/imagedemo2.cpp @@ -0,0 +1,341 @@ +//============================================================================ +// Name : imagedemo2.cpp +// Author : Rafat Hussain +// Version : +// Copyright : +// Description : Image Approximation using symmetric or periodic extension 2D DWT +//============================================================================ + +// IMPORTANT - Algorithm used to display Image is imprecise because of int 8 overflow issues +// and it shouldn't be used to judge the performance of the DWT. The DWT and IDWT outputs +// should be used for performance measurements. I have used maximum value rescaling to +// solve overflow issues and , obviously, it is going to result in suboptimal performance but +// it is good enough for demonstration purposes. + +#include +#include +#include +#include +#include +#include +#include +#include "wavelet2s.h" +#include "cv.h" +#include "highgui.h" +#include "cxcore.h" + +using namespace std; +using namespace cv; + +void findthresh(vector &vector1, int N, double& t){ + sort(vector1.begin(), vector1.end(), greater()); + t = vector1.at(N-1); +} + +void* maxval(vector > &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* maxval1(vector &arr, double &max){ + max = 0; + for (unsigned int i =0; i < arr.size(); i++) { + if (max <= arr[i]){ + max = arr[i]; + } + + } + 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 > vec1(rows, vector(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; + } + + } + + string nm = "db2"; + vector l1,h1,l2,h2; + filtcoef(nm,l1,h1,l2,h2); + // unsigned int lf=l1.size(); + // int rows_n =(int) (rows+ J*(lf-1)); + // int cols_n =(int) (cols + J * ( lf -1)); + + // Finding 2D DWT Transform of the image using symetric extension algorithm + // Extension is set to 0 (eg., int e = 0) + + vector length; + vector output,flag; + int J =6; + dwt_2d(vec1,J,nm,output,flag,length); + + double max; + vector length2; + // This algorithm computes DWT of image of any given size. Together with convolution and + // subsampling operations it is clear that subsampled images are of different length than + // dyadic length images. In order to compute the "effective" size of DWT we do additional + // calculations. + dwt_output_dim_sym(length,length2,J); + // length2 is gives the integer vector that contains the size of subimages that will + // combine to form the displayed output image. The last two entries of length2 gives the + // size of DWT ( rows_n by cols_n) + + int siz = length2.size(); + int rows_n=length2[siz-2]; + int cols_n = length2[siz-1]; + + vector > dwtdisp(rows_n, vector(cols_n)); + dispDWT(output,dwtdisp, length ,length2, J); + + // dispDWT returns the 2D object dwtdisp which will be displayed using OPENCV's image + // handling functions + + vector > dwt_output= dwtdisp; + + // Storing the DWT coefficients in two different vectors that will be used to approximate + // Image with two different sets of chosen coefficients. + + vector dwt_coef1; + vector dwt_coef2; + + dwt_coef1 = output; + dwt_coef2 = output; + + maxval(dwt_output,max);// max value is needed to take care of overflow which happens because + // of convolution operations performed on unsigned 8 bit images + + //Displaying Scaled Image + // Creating Image in OPENCV + IplImage *cvImg; // image used for output + CvSize imgSize; // size of output image + + imgSize.width = cols_n; + imgSize.height = rows_n; + + 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 > dwt_hold(rows_n, vector( cols_n)); + 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 <= (length2[0]) && j <= (length2[1]) ) { + ((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); + + // Case 1 : Only 10% of the largest coefficients are considered + + // Output is the 1D DWT vector + + int n_coef1= int (output.size()/ 10); + cout << n_coef1 << endl; + + // Finding Threshold Value corresponding to n_coef1 + + vector temp1; + cout << "size: " << (int) temp1.size() << "\n"; + cout << "capacity: " << (int) temp1.capacity() << "\n"; + cout << "max_size: " << (int) temp1.max_size() << "\n"; + for (unsigned int i =0; i < dwt_coef1.size(); i++) { + double tempval = abs(dwt_coef1[i]); + temp1.push_back(tempval); + + } + + double thresh1= 0.0; + findthresh(temp1,n_coef1,thresh1); + cout << "thresh" << thresh1 << endl; + + ofstream temp("temp.txt"); + for (unsigned int i =0; i < temp1.size(); i++){ + temp << temp1[i] << " " ; + } + + // Reset coeffficients value depending on threshold value + + + for (unsigned int i =0; i < dwt_coef1.size(); i++) { + double temp = abs(dwt_coef1[i]); + + if (temp < thresh1){ + dwt_coef1.at(i)= 0.0; + + } + + } + + + // Finding IDWT + + vector > idwt_output(rows, vector(cols)); + + idwt_2d( dwt_coef1,flag, nm, idwt_output,length); + + double max1; + maxval(idwt_output,max1); + + //Displaying Reconstructed Image + + IplImage *dvImg; + CvSize dvSize; // size of output image + + dvSize.width = idwt_output[0].size(); + dvSize.height = idwt_output.size(); + + cout << idwt_output.size() << idwt_output[0].size() << endl; + dvImg = cvCreateImage( dvSize, 8, 1 ); + + for (int i = 0; i < dvSize.height; i++ ){ + for (int j = 0; j < dvSize.width; j++ ){ + if ( idwt_output[i][j] <= 0.0){ + idwt_output[i][j] = 0.0; + } + ((uchar*)(dvImg->imageData + dvImg->widthStep*i))[j] = + (char) ((idwt_output[i][j] / max1) * 255 ) ; + } + } + + cvNamedWindow( "10% Coeff Reconstructed Image", 1 ); // creation of a visualisation window + cvShowImage( "10% Coeff Reconstructed Image", dvImg ); // image visualisation + cvWaitKey(); + cvDestroyWindow("10% Coeff Reconstructed Image"); + cvSaveImage("recon.bmp",dvImg); + + + // Case 2 : Only 2% of the largest coefficients are considered + + // Output is the 1D DWT vector + + int n_coef2= int (output.size()/ 50); + cout << n_coef2 << endl; + + // Finding Threshold Value corresponding to n_coef1 + + vector temp2; + + for (unsigned int i =0; i < dwt_coef2.size(); i++) { + double tempval = abs(dwt_coef2[i]); + temp2.push_back(tempval); + + } + + double thresh2= 0.0; + findthresh(temp2,n_coef2,thresh2); + cout << "thresh" << thresh2 << endl; + + + // Reset coeffficients value depending on threshold value + + + for (unsigned int i =0; i < dwt_coef2.size(); i++) { + double temp = abs(dwt_coef2[i]); + + if (temp < thresh2){ + dwt_coef2.at(i)= 0.0; + + } + + } + + + // Finding IDWT + + vector > idwt_output2(rows, vector(cols)); + + idwt_2d( dwt_coef2,flag, nm, idwt_output2,length); + + double max2; + maxval(idwt_output2,max2); + + + + //Displaying Reconstructed Image + + IplImage *dvImg2; + CvSize dvSize2; // size of output image + + dvSize2.width = idwt_output2[0].size(); + dvSize2.height = idwt_output2.size(); + + cout << idwt_output2.size() << idwt_output2[0].size() << endl; + dvImg2 = cvCreateImage( dvSize2, 8, 1 ); + + for (int i = 0; i < dvSize2.height; i++ ) { + for (int j = 0; j < dvSize2.width; j++ ) { + if ( idwt_output2[i][j] <= 0.0){ + idwt_output2[i][j] = 0.0; + } + ((uchar*)(dvImg2->imageData + dvImg2->widthStep*i))[j] = + (char) ((idwt_output2[i][j]/ max2) * 255 ) ; + } + } + + cvNamedWindow( "2% Coeff Reconstructed Image", 1 ); // creation of a visualisation window + cvShowImage( "2% Coeff Reconstructed Image", dvImg2 ); // image visualisation + cvWaitKey(); + cvDestroyWindow("2% Coeff Reconstructed Image"); + cvSaveImage("recon2.bmp",dvImg2); + + + return 0; +} \ No newline at end of file