Transformation en ondelette en openCV
quelqu'un a-t-il essayé D'implémenter DWT dans opencv ou en C++? J'ai vu des billets plus anciens sur ce sujet et je ne les ai pas trouvés utiles pour moi, parce que j'ai besoin d'un coefficient d'approximation et des détails à la suite de la transformation d'ondelette.
j'ai essayé d'ajouter ce (http://wavelet2d.sourceforge.net/) pour mon projet, mais il ne fonctionne pas aussi bien que prévu.
Et c'est simple, parce que les paramètres j'ai besoin de rapprochement et coefficient détails:
void haar1(float *vec, int n, int w)
{
int i=0;
float *vecp = new float[n];
for(i=0;i<n;i++)
vecp[i] = 0;
w/=2;
for(i=0;i<w;i++)
{
vecp[i] = (vec[2*i] + vec[2*i+1])/sqrt(2.0);
vecp[i+w] = (vec[2*i] - vec[2*i+1])/sqrt(2.0);
}
for(i=0;i<(w*2);i++)
vec[i] = vecp[i];
delete [] vecp;
}
void haar2(float **matrix, int rows, int cols)
{
float *temp_row = new float[cols];
float *temp_col = new float[rows];
int i=0,j=0;
int w = cols, h=rows;
while(w>1 || h>1)
{
if(w>1)
{
for(i=0;i<h;i++)
{
for(j=0;j<cols;j++)
temp_row[j] = matrix[i][j];
haar1(temp_row,cols,w);
for(j=0;j<cols;j++)
matrix[i][j] = temp_row[j];
}
}
if(h>1)
{
for(i=0;i<w;i++)
{
for(j=0;j<rows;j++)
temp_col[j] = matrix[j][i];
haar1(temp_col, rows, h);
for(j=0;j<rows;j++)
matrix[j][i] = temp_col[j];
}
}
if(w>1)
w/=2;
if(h>1)
h/=2;
}
delete [] temp_row;
delete [] temp_col;
}
alors quelqu'un peut m'aider à trouver dwt implémenté en C++ ou me montrer comment extraire des coefficients de code ci-dessus. Merci
18
demandé sur
la lluvia
2013-11-19 16:40:48
3 réponses
Ici est directe et inverse de la transformée en Ondelettes de Haar (utilisé pour le filtrage):
#include "opencv2/opencv.hpp"
#include <iostream>
#include <vector>
#include <stdio.h>
using namespace cv;
using namespace std;
// Filter type
#define NONE 0 // no filter
#define HARD 1 // hard shrinkage
#define SOFT 2 // soft shrinkage
#define GARROT 3 // garrot filter
//--------------------------------
// signum
//--------------------------------
float sgn(float x)
{
float res=0;
if(x==0)
{
res=0;
}
if(x>0)
{
res=1;
}
if(x<0)
{
res=-1;
}
return res;
}
//--------------------------------
// Soft shrinkage
//--------------------------------
float soft_shrink(float d,float T)
{
float res;
if(fabs(d)>T)
{
res=sgn(d)*(fabs(d)-T);
}
else
{
res=0;
}
return res;
}
//--------------------------------
// Hard shrinkage
//--------------------------------
float hard_shrink(float d,float T)
{
float res;
if(fabs(d)>T)
{
res=d;
}
else
{
res=0;
}
return res;
}
//--------------------------------
// Garrot shrinkage
//--------------------------------
float Garrot_shrink(float d,float T)
{
float res;
if(fabs(d)>T)
{
res=d-((T*T)/d);
}
else
{
res=0;
}
return res;
}
//--------------------------------
// Wavelet transform
//--------------------------------
static void cvHaarWavelet(Mat &src,Mat &dst,int NIter)
{
float c,dh,dv,dd;
assert( src.type() == CV_32FC1 );
assert( dst.type() == CV_32FC1 );
int width = src.cols;
int height = src.rows;
for (int k=0;k<NIter;k++)
{
for (int y=0;y<(height>>(k+1));y++)
{
for (int x=0; x<(width>>(k+1));x++)
{
c=(src.at<float>(2*y,2*x)+src.at<float>(2*y,2*x+1)+src.at<float>(2*y+1,2*x)+src.at<float>(2*y+1,2*x+1))*0.5;
dst.at<float>(y,x)=c;
dh=(src.at<float>(2*y,2*x)+src.at<float>(2*y+1,2*x)-src.at<float>(2*y,2*x+1)-src.at<float>(2*y+1,2*x+1))*0.5;
dst.at<float>(y,x+(width>>(k+1)))=dh;
dv=(src.at<float>(2*y,2*x)+src.at<float>(2*y,2*x+1)-src.at<float>(2*y+1,2*x)-src.at<float>(2*y+1,2*x+1))*0.5;
dst.at<float>(y+(height>>(k+1)),x)=dv;
dd=(src.at<float>(2*y,2*x)-src.at<float>(2*y,2*x+1)-src.at<float>(2*y+1,2*x)+src.at<float>(2*y+1,2*x+1))*0.5;
dst.at<float>(y+(height>>(k+1)),x+(width>>(k+1)))=dd;
}
}
dst.copyTo(src);
}
}
//--------------------------------
//Inverse wavelet transform
//--------------------------------
static void cvInvHaarWavelet(Mat &src,Mat &dst,int NIter, int SHRINKAGE_TYPE=0, float SHRINKAGE_T=50)
{
float c,dh,dv,dd;
assert( src.type() == CV_32FC1 );
assert( dst.type() == CV_32FC1 );
int width = src.cols;
int height = src.rows;
//--------------------------------
// NIter - number of iterations
//--------------------------------
for (int k=NIter;k>0;k--)
{
for (int y=0;y<(height>>k);y++)
{
for (int x=0; x<(width>>k);x++)
{
c=src.at<float>(y,x);
dh=src.at<float>(y,x+(width>>k));
dv=src.at<float>(y+(height>>k),x);
dd=src.at<float>(y+(height>>k),x+(width>>k));
// (shrinkage)
switch(SHRINKAGE_TYPE)
{
case HARD:
dh=hard_shrink(dh,SHRINKAGE_T);
dv=hard_shrink(dv,SHRINKAGE_T);
dd=hard_shrink(dd,SHRINKAGE_T);
break;
case SOFT:
dh=soft_shrink(dh,SHRINKAGE_T);
dv=soft_shrink(dv,SHRINKAGE_T);
dd=soft_shrink(dd,SHRINKAGE_T);
break;
case GARROT:
dh=Garrot_shrink(dh,SHRINKAGE_T);
dv=Garrot_shrink(dv,SHRINKAGE_T);
dd=Garrot_shrink(dd,SHRINKAGE_T);
break;
}
//-------------------
dst.at<float>(y*2,x*2)=0.5*(c+dh+dv+dd);
dst.at<float>(y*2,x*2+1)=0.5*(c-dh+dv-dd);
dst.at<float>(y*2+1,x*2)=0.5*(c+dh-dv-dd);
dst.at<float>(y*2+1,x*2+1)=0.5*(c-dh-dv+dd);
}
}
Mat C=src(Rect(0,0,width>>(k-1),height>>(k-1)));
Mat D=dst(Rect(0,0,width>>(k-1),height>>(k-1)));
D.copyTo(C);
}
}
//--------------------------------
//
//--------------------------------
int process(VideoCapture& capture)
{
int n = 0;
const int NIter=4;
char filename[200];
string window_name = "video | q or esc to quit";
cout << "press space to save a picture. q or esc to quit" << endl;
namedWindow(window_name, CV_WINDOW_KEEPRATIO); //resizable window;
Mat frame;
capture >> frame;
Mat GrayFrame=Mat(frame.rows, frame.cols, CV_8UC1);
Mat Src=Mat(frame.rows, frame.cols, CV_32FC1);
Mat Dst=Mat(frame.rows, frame.cols, CV_32FC1);
Mat Temp=Mat(frame.rows, frame.cols, CV_32FC1);
Mat Filtered=Mat(frame.rows, frame.cols, CV_32FC1);
for (;;)
{
Dst=0;
capture >> frame;
if (frame.empty()) continue;
cvtColor(frame, GrayFrame, CV_BGR2GRAY);
GrayFrame.convertTo(Src,CV_32FC1);
cvHaarWavelet(Src,Dst,NIter);
Dst.copyTo(Temp);
cvInvHaarWavelet(Temp,Filtered,NIter,GARROT,30);
imshow(window_name, frame);
double M=0,m=0;
//----------------------------------------------------
// Normalization to 0-1 range (for visualization)
//----------------------------------------------------
minMaxLoc(Dst,&m,&M);
if((M-m)>0) {Dst=Dst*(1.0/(M-m))-m/(M-m);}
imshow("Coeff", Dst);
minMaxLoc(Filtered,&m,&M);
if((M-m)>0) {Filtered=Filtered*(1.0/(M-m))-m/(M-m);}
imshow("Filtered", Filtered);
char key = (char)waitKey(5);
switch (key)
{
case 'q':
case 'Q':
case 27: //escape key
return 0;
case ' ': //Save an image
sprintf(filename,"filename%.3d.jpg",n++);
imwrite(filename,frame);
cout << "Saved " << filename << endl;
break;
default:
break;
}
}
return 0;
}
int main(int ac, char** av)
{
VideoCapture capture(0);
if (!capture.isOpened())
{
return 1;
}
return process(capture);
}
24
répondu
Andrey Smorodov
2014-08-15 17:10:46
Ici est une autre implémentation de la transformée en Ondelettes dans OpenCV Mahavir:
#include <opencv2\highgui\highgui.hpp>
#include <opencv2\core\core.hpp>
#include <opencv2\core\mat.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include<iostream>
#include<math.h>
#include<conio.h>
using namespace std;
using namespace cv;
class image
{
public:
Mat im,im1,im2,im3,im4,im5,im6,temp,im11,im12,im13,im14,imi,imd,imr;
float a,b,c,d;
int getim();
};
int image::getim()
{
im=imread("lena.jpg",0); //Load image in Gray Scale
imi=Mat::zeros(im.rows,im.cols,CV_8U);
im.copyTo(imi);
im.convertTo(im,CV_32F,1.0,0.0);
im1=Mat::zeros(im.rows/2,im.cols,CV_32F);
im2=Mat::zeros(im.rows/2,im.cols,CV_32F);
im3=Mat::zeros(im.rows/2,im.cols/2,CV_32F);
im4=Mat::zeros(im.rows/2,im.cols/2,CV_32F);
im5=Mat::zeros(im.rows/2,im.cols/2,CV_32F);
im6=Mat::zeros(im.rows/2,im.cols/2,CV_32F);
//--------------Decomposition-------------------
for(int rcnt=0;rcnt<im.rows;rcnt+=2)
{
for(int ccnt=0;ccnt<im.cols;ccnt++)
{
a=im.at<float>(rcnt,ccnt);
b=im.at<float>(rcnt+1,ccnt);
c=(a+b)*0.707;
d=(a-b)*0.707;
int _rcnt=rcnt/2;
im1.at<float>(_rcnt,ccnt)=c;
im2.at<float>(_rcnt,ccnt)=d;
}
}
for(int rcnt=0;rcnt<im.rows/2;rcnt++)
{
for(int ccnt=0;ccnt<im.cols;ccnt+=2)
{
a=im1.at<float>(rcnt,ccnt);
b=im1.at<float>(rcnt,ccnt+1);
c=(a+b)*0.707;
d=(a-b)*0.707;
int _ccnt=ccnt/2;
im3.at<float>(rcnt,_ccnt)=c;
im4.at<float>(rcnt,_ccnt)=d;
}
}
for(int rcnt=0;rcnt<im.rows/2;rcnt++)
{
for(int ccnt=0;ccnt<im.cols;ccnt+=2)
{
a=im2.at<float>(rcnt,ccnt);
b=im2.at<float>(rcnt,ccnt+1);
c=(a+b)*0.707;
d=(a-b)*0.707;
int _ccnt=ccnt/2;
im5.at<float>(rcnt,_ccnt)=c;
im6.at<float>(rcnt,_ccnt)=d;
}
}
imr=Mat::zeros(256,256,CV_32F);
imd=Mat::zeros(256,256,CV_32F);
im3.copyTo(imd(Rect(0,0,128,128)));
im4.copyTo(imd(Rect(0,127,128,128)));
im5.copyTo(imd(Rect(127,0,128,128)));
im6.copyTo(imd(Rect(127,127,128,128)));
//---------------------------------Reconstruction-------------------------------------
im11=Mat::zeros(im.rows/2,im.cols,CV_32F);
im12=Mat::zeros(im.rows/2,im.cols,CV_32F);
im13=Mat::zeros(im.rows/2,im.cols,CV_32F);
im14=Mat::zeros(im.rows/2,im.cols,CV_32F);
for(int rcnt=0;rcnt<im.rows/2;rcnt++)
{
for(int ccnt=0;ccnt<im.cols/2;ccnt++)
{
int _ccnt=ccnt*2;
im11.at<float>(rcnt,_ccnt)=im3.at<float>(rcnt,ccnt); //Upsampling of stage I
im12.at<float>(rcnt,_ccnt)=im4.at<float>(rcnt,ccnt);
im13.at<float>(rcnt,_ccnt)=im5.at<float>(rcnt,ccnt);
im14.at<float>(rcnt,_ccnt)=im6.at<float>(rcnt,ccnt);
}
}
for(int rcnt=0;rcnt<im.rows/2;rcnt++)
{
for(int ccnt=0;ccnt<im.cols;ccnt+=2)
{
a=im11.at<float>(rcnt,ccnt);
b=im12.at<float>(rcnt,ccnt);
c=(a+b)*0.707;
im11.at<float>(rcnt,ccnt)=c;
d=(a-b)*0.707; //Filtering at Stage I
im11.at<float>(rcnt,ccnt+1)=d;
a=im13.at<float>(rcnt,ccnt);
b=im14.at<float>(rcnt,ccnt);
c=(a+b)*0.707;
im13.at<float>(rcnt,ccnt)=c;
d=(a-b)*0.707;
im13.at<float>(rcnt,ccnt+1)=d;
}
}
temp=Mat::zeros(im.rows,im.cols,CV_32F);
for(int rcnt=0;rcnt<im.rows/2;rcnt++)
{
for(int ccnt=0;ccnt<im.cols;ccnt++)
{
int _rcnt=rcnt*2;
imr.at<float>(_rcnt,ccnt)=im11.at<float>(rcnt,ccnt); //Upsampling at stage II
temp.at<float>(_rcnt,ccnt)=im13.at<float>(rcnt,ccnt);
}
}
for(int rcnt=0;rcnt<im.rows;rcnt+=2)
{
for(int ccnt=0;ccnt<im.cols;ccnt++)
{
a=imr.at<float>(rcnt,ccnt);
b=temp.at<float>(rcnt,ccnt);
c=(a+b)*0.707;
imr.at<float>(rcnt,ccnt)=c; //Filtering at Stage II
d=(a-b)*0.707;
imr.at<float>(rcnt+1,ccnt)=d;
}
}
imd.convertTo(imd,CV_8U);
namedWindow("Input Image",1);
imshow("Input Image",imi);
namedWindow("Wavelet Decomposition",1);
imshow("Wavelet Decomposition",imd);
imr.convertTo(imr,CV_8U);
namedWindow("Wavelet Reconstruction",1);
imshow("Wavelet Reconstruction",imr);
waitKey(0);
return 0;
}
int main()
{
image my;
my.getim();
return 0;
}
J'espère que quelqu'un le trouvera utile!
6
répondu
la lluvia
2014-10-07 07:07:37
je vois qu'il y a très peu d'exemples de code pour wavelet en java, surtout si vous utilisez openCV. J'ai dû utiliser wavelet en java avec openCV et j'ai utilisé le code C de @la luvia et converti en java.
il y a eu beaucoup de problèmes lors de la traduction du code, parce qu'il y avait beaucoup de différences dans les méthodes openCV et les façons de l'utiliser. Ce livre m'a beaucoup aidé dans le processus trop.
j'espère que ce code et le livre donnent une certaine perspective sur la façon d'utiliser la lib et quelques différences entre le C et Java.
Voici le code:
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
public class Wavelet {
//Imperative in java
static{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}
String pathname = "C:/Users/user/img096";
public static void main(String[] args) {
Wavelet wavelet = new Wavelet();
wavelet.applyHaarFoward();
wavelet.applyHaarReverse();
Imgcodecs.imwrite(wavelet.pathname+"imi.jpg", wavelet.imi);
Imgcodecs.imwrite(wavelet.pathname+"imd.jpg", wavelet.imd);
Imgcodecs.imwrite(wavelet.pathname+"imr.jpg", wavelet.imr);
}
Mat im,im1,im2,im3,im4,im5,im6,temp,im11,im12,im13,im14,imi,imd,imr;
float a,b,c,d;
private void applyHaarFoward(){
try{
im = Imgcodecs.imread(pathname+".jpg", 0);
imi = new Mat(im.rows(), im.cols(), CvType.CV_8U);
im.copyTo(imi);
//in CvType. If the number of channels is omitted, it evaluates to 1.
im.convertTo(im, CvType.CV_32F, 1.0, 0.0);
im1 = new Mat(im.rows()/2, im.cols(), CvType.CV_32F);
im2 = new Mat(im.rows()/2, im.cols(), CvType.CV_32F);
im3 = new Mat(im.rows()/2, im.cols()/2, CvType.CV_32F);
im4 = new Mat(im.rows()/2, im.cols()/2, CvType.CV_32F);
im5 = new Mat(im.rows()/2, im.cols()/2, CvType.CV_32F);
im6 = new Mat(im.rows()/2, im.cols()/2, CvType.CV_32F);
// ------------------- Decomposition -------------------
for (int rcnt = 0; rcnt < im.rows(); rcnt+=2) {
for (int ccnt = 0; ccnt < im.cols(); ccnt++) {
//even though the CvType is float with only one channel
//the method Mat.get() return a double array
//with only one position, [0].
a = (float) im.get(rcnt, ccnt)[0];
b = (float) im.get(rcnt+1, ccnt)[0];
c = (float) ((a+b)*0.707);
d = (float) ((a-b)*0.707);
int _rcnt= rcnt/2;
im1.put(_rcnt, ccnt, c);
im2.put(_rcnt, ccnt, d);
}
}
for (int rcnt = 0; rcnt < im.rows()/2; rcnt++) {
for (int ccnt = 0; ccnt < im.cols() - 2; ccnt+=2) {
a = (float) im1.get(rcnt, ccnt)[0];
b = (float) im1.get(rcnt, ccnt+1)[0];
c = (float) ((a+b)*0.707);
d = (float) ((a-b)*0.707);
int _ccnt = ccnt/2;
im3.put(rcnt, _ccnt, c);
im4.put(rcnt, _ccnt, d);
}
}
for (int rcnt = 0; rcnt < im.rows()/2; rcnt++) {
for (int ccnt = 0; ccnt < im.cols() - 2; ccnt+=2) {
a = (float) im2.get(rcnt, ccnt)[0];
b = (float) im2.get(rcnt, ccnt+1)[0];
c = (float) ((a+b)*0.707);
d = (float) ((a-b)*0.707);
int _ccnt = ccnt/2;
im5.put(rcnt, _ccnt, c);
im6.put(rcnt, _ccnt, d);
}
}
imr = Mat.zeros(im.rows(), im.cols(), CvType.CV_32F);//imr = Mat.zeros(512, 512, CvType.CV_32F);
imd = Mat.zeros(512, 512, CvType.CV_32F);
im3.copyTo(imd.adjustROI(0, 0, 256, 256));
im4.copyTo(imd.adjustROI(0, 255, 256, 256));
im5.copyTo(imd.adjustROI(255, 0, 256, 256));
im6.copyTo(imd.adjustROI(255, 255, 256, 256));
}catch(Exception ex){
System.err.println(ex.getLocalizedMessage());
ex.printStackTrace();
}
}
private void applyHaarReverse(){
// ------------------- Reconstruction -------------------
im11 = Mat.zeros(im.rows()/2, im.cols(), CvType.CV_32F);
im12 = Mat.zeros(im.rows()/2, im.cols(), CvType.CV_32F);
im13 = Mat.zeros(im.rows()/2, im.cols(), CvType.CV_32F);
im14 = Mat.zeros(im.rows()/2, im.cols(), CvType.CV_32F);
for (int rcnt = 0; rcnt < im.rows()/2; rcnt++) {
for (int ccnt = 0; ccnt < im.cols()/2; ccnt++) {
int _ccnt = ccnt*2;
im11.put(rcnt, _ccnt, im3.get(rcnt, ccnt));
im12.put(rcnt, _ccnt, im4.get(rcnt, ccnt));
im13.put(rcnt, _ccnt, im5.get(rcnt, ccnt));
im14.put(rcnt, _ccnt, im6.get(rcnt, ccnt));
}
}
for (int rcnt = 0; rcnt < im.rows()/2; rcnt++) {
for (int ccnt = 0; ccnt < im.cols() - 2; ccnt+=2) {
a = (float) im11.get(rcnt, ccnt)[0];
b = (float) im12.get(rcnt, ccnt)[0];
c = (float) ((a+b)*0.707);
im11.put(rcnt, ccnt, c);
d = (float) ((a-b)*0.707);
im11.put(rcnt, ccnt+1, d);
a = (float) im13.get(rcnt, ccnt)[0];
b = (float) im14.get(rcnt, ccnt)[0];
c = (float) ((a+b)*0.707);
im13.put(rcnt, ccnt, c);
d = (float) ((a-b)*0.707);
im13.put(rcnt, ccnt+1, d);
}
}
temp = Mat.zeros(im.rows(), im.cols(), CvType.CV_32F);
for (int rcnt = 0; rcnt < im.rows()/2; rcnt++) {
for (int ccnt = 0; ccnt < im.cols(); ccnt++) {
int _rcnt = rcnt*2;
imr.put(_rcnt, ccnt, im11.get(rcnt, ccnt));
temp.put(_rcnt, ccnt, im13.get(rcnt, ccnt));
}
}
for (int rcnt = 0; rcnt < im.rows()-2; rcnt+=2) {
for (int ccnt = 0; ccnt < im.cols(); ccnt++) {
a = (float) imr.get(rcnt, ccnt)[0];
b = (float) temp.get(rcnt, ccnt)[0];
c = (float) ((a+b)*0.707);
imr.put(rcnt, ccnt, c);
d = (float) ((a-b)*0.707);
imr.put(rcnt+1, ccnt, d);
}
}
}
}
j'Espère que c'est utile.
1
répondu
RochaRF
2016-06-22 22:20:56