From the CLI there is no magical way to automatically do that. You'd have to write some code to take the bounding boxes, extract the roi, and save them as new images.

sir, what do i have to edit in image.c?

From the CLI there is no magical way to automatically do that. You'd have to write some code to take the bounding boxes, extract the roi, and save them as new images.

What? No, don't edit image.c! You need to learn to use the API. Or save the coordinates in a file (search for -ext_output in the readme) and use whatever language you are familiar with.

Hello Sir,
i found this in image_opencv.cpp
@AlexeyAB I think this is old piece of code which is not updated

// you should create directory: result_img static int copied_frame_id = -1; static IplImage* copy_img = NULL; if (copied_frame_id != frame_id) { copied_frame_id = frame_id; if(copy_img == NULL) copy_img = cvCreateImage(cvSize(show_img->width, show_img->height), show_img->depth, show_img->nChannels); cvCopy(show_img, copy_img, 0); } static int img_id = 0; img_id++; char image_name[1024]; sprintf(image_name, "result_img/img_%d_%d_%d_%s.jpg", frame_id, img_id, class_id, names[class_id]); CvRect rect = cvRect(pt1.x, pt1.y, pt2.x - pt1.x, pt2.y - pt1.y); cvSetImageROI(copy_img, rect); cvSaveImage(image_name, copy_img, 0); cvResetImageROI(copy_img);

if i compile after un commenting these lines

i get following error

/src/image_opencv.cpp:986:84: error: ‘class cv::Mat’ has no member named ‘width’
if(copy_img == NULL) copy_img = cvCreateImage(cvSize(show_img->width, show_img->height), show_img->depth, show_img->nChannels);
^~~~~
compilation terminated due to -Wfatal-errors.
Makefile:182: recipe for target 'obj/image_opencv.o' failed
make: *** [obj/image_opencv.o] Error 1

@AlexeyAB I Finally found the solution. I think after the update , "show_img" has been changed from type "Iplimage" to "cv::Mat" and the commented code wasn't updated based on the new conversion so to make the coomented lines work, we need to convert show_img to iplimage type by adding this line

IplImage* imggf = new IplImage(*show_img);

and change the line if(copy_img == NULL) copy_img = cvCreateImage(cvSize(show_img->width, show_img->height), show_img->depth, show_img->nChannels);

To
if(copy_img == NULL) copy_img = cvCreateImage(cvSize(imggf->width,imggf->height), imggf->depth, imggf->nChannels);

and cvCopy(show_img, copy_img, 0);

to
cvCopy(imggf, copy_img, 0);

I'll put up a pull request as well including some other topic related changes

#7282

Here is my pull request where I've addressed the above problem.

Hi, can you try following code
in file src/image_opencv.cpp, show_img is Mat pointer.
Just crop desired portion out of Mat.

// you should create directory: result_img static int copied_frame_id = -1; // static IplImage* copy_img = NULL; if (copied_frame_id != frame_id) { copied_frame_id = frame_id; // if(copy_img == NULL) copy_img = cvCreateImage(cvSize(show_img->width, show_img->height), show_img->depth, show_img->nChannels); // cvCopy(show_img, copy_img, 0); } static int img_id = 0; img_id++; char image_name[1024]; sprintf(image_name, "result_img/img_%d_%d_%d_%s.jpg", frame_id, img_id, class_id, names[class_id]); CvRect rect = cvRect(pt1.x, pt1.y, pt2.x - pt1.x, pt2.y - pt1.y); cv::Mat copy_image = (*show_img)(rect); cv::imwrite(image_name, copy_image); // cvSetImageROI(copy_img, rect); // cvSaveImage(image_name, copy_img, 0); // cvResetImageROI(copy_img);

pull request created for the same
#8197