How can I draw a blurring rectangle on the image? - c++

Question

I find a code which allows you to draw a blurring rectangle on the cam
and I try to change it from draw a blurring rectangle on the cam to an image because I want draw a blurring rectangle on the image.
and this is my code
#include < stdio.h>
#include < iostream>
#include < opencv2\opencv.hpp>
#include < opencv2/core/core.hpp>
#include < opencv2/highgui/highgui.hpp>
#include < opencv2/video/background_segm.hpp>
#include < opencv2\gpu\gpu.hpp>
#include < opencv2\legacy\legacy.hpp>
using namespace std;
using namespace cv;
bool selectObject = false;
Rect selection;
Point origin;
int trackObject = 0;
Mat image;
static void onMouse(int event, int x, int y, int, void*)
{
if (selectObject)
{
selection.x = MIN(x, origin.x);
selection.y = MIN(y, origin.y);
selection.width = std::abs(x - origin.x);
selection.height = std::abs(y - origin.y);
selection &= Rect(0, 0, image.cols, image.rows);
}
switch (event)
{
case CV_EVENT_LBUTTONDOWN:
origin = Point(x, y);
selection = Rect(x, y, 0, 0);
selectObject = true;
break;
case CV_EVENT_LBUTTONUP:
selectObject = false;
if (selection.width > 0 && selection.height > 0)
trackObject = -1;
break;
}
}
int main(void)
{
Mat img;
img = imread("C:/Users/faho0odywbas/Desktop/test.jpg");
Mat frame;
namedWindow("Demo");
setMouseCallback("Demo", onMouse);
for (;;)
{
frame.copyTo(image);
if (selectObject && selection.width > 0 && selection.height > 0)
{
Mat roi(image, selection);
bitwise_not(roi, roi);
printf("%d %d %d %d\n", selection.x, selection.y, selection.width, selection.height);
}
while (1){
imshow("Demo", img);
if (waitKey(10) > 10)
break;
}
}
return 0;
}
and the code shows the image, but I can't draw the rectangle on it !!
What I miss ?
Thanks

Answer 1

i have made some modification on your source. almost done all you want!
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
using namespace std;
using namespace cv;
bool selectObject = false;
Rect selection;
Point origin;
int msize = 5;
Mat image,blurredImage;
vector<Rect> blurredAreas;
static bool doMosaic( Mat img, int msize)
{
for (int i = 0; i < img.cols-msize; i+=msize)
for(int j = 0; j < img.rows-msize; j+=msize)
{
Rect r = Rect(i,j,msize,msize);
Mat mosaic = img( r );
mosaic.setTo(mean(mosaic));
}
return true;
}
static bool doBlur()
{
for(size_t i = 0; i< blurredAreas.size(); i++)
{
Mat roi = blurredImage(selection);
//GaussianBlur(roi,roi,Size(),5,5);
doMosaic(roi,msize);
}
imshow("Demo", blurredImage);
return true;
}
static void onMouse(int event, int x, int y, int, void*)
{
switch (event)
{
case CV_EVENT_LBUTTONDOWN:
origin = Point(x, y);
selectObject = true;
break;
case CV_EVENT_LBUTTONUP:
{
selectObject = false;
blurredAreas.push_back(selection);
doBlur();
break;
}
}
if (selectObject)
{
selection.x = MIN(x, origin.x);
selection.y = MIN(y, origin.y);
selection.width = std::abs(x - origin.x)+1;
selection.height = std::abs(y - origin.y)+1;
selection &= Rect(0, 0, image.cols, image.rows);
if ( selection.width > 0 && selection.height > 0)
{
Mat blurredImagecopy;
blurredImage.copyTo(blurredImagecopy);
Mat roi = blurredImagecopy(selection);
bitwise_not(roi, roi);
imshow("Demo", blurredImagecopy);
}
}
}
int main(void)
{
image = imread("test.jpg");
image.copyTo(blurredImage);
namedWindow("Demo");
setMouseCallback("Demo", onMouse );
imshow("Demo", image);
while( true )
{
int key = waitKey(0);
if( key == 27 )
break;
if( key == 's' ) // saves result image
{
imwrite("result.jpg",blurredImage);
}
if( key == 'i' ) // space key for clear blurred areas
{
msize +=5;
image.copyTo(blurredImage);
doBlur();
}
if( key == 'd' ) // space key for clear blurred areas
{
msize = msize == 5 ? 5 : msize - 5;
image.copyTo(blurredImage);
doBlur();
}
if( key == 32 ) // space key for clear blurred areas
{
blurredAreas.clear();
image.copyTo(blurredImage);
doBlur();
}
}
return 0;
}