show count on top left

[deimsdeutsch]

In demo.c -> detect_in_thread method...

Are the objects being draw in separate threads ? I am looking to count the number of persons in the video and show them on top left ... please point me in right direction..

Thanks .

[AlexeyAB]

There are 3 threads:

1. main - shows image (with drawed boxes) on the screen: https://github.com/AlexeyAB/darknet/blob/4403e71b330b42d3cda1e0721fb645cf41bac14f/src/demo.c#L235

2. fetch_in_thread - gets frames from the Video-stream: https://github.com/AlexeyAB/darknet/blob/4403e71b330b42d3cda1e0721fb645cf41bac14f/src/demo.c#L63

3. detect_in_thread - Yolo v3 detection + draws boxes on the image: https://github.com/AlexeyAB/darknet/blob/4403e71b330b42d3cda1e0721fb645cf41bac14f/src/demo.c#L115

[deimsdeutsch]

Thanks for replying.

Changed the method for total count and person count on top left:

void draw_detections_cv_v3(IplImage* show_img, detection *dets, int num, float thresh, char **names, image **alphabet, int classes)
{
    int i, j;
    if (!show_img) return;

    int count = 0, person_counter=0;
    char scount[5];
    char sperson_counter[5];

    for (i = 0; i < num; ++i) {
        char labelstr[4096] = { 0 };
        int class_id = -1;
        for (j = 0; j < classes; ++j) {
            if (dets[i].prob[j] > thresh) {
                if (class_id < 0) {
                    strcat(labelstr, names[j]);
                    class_id = j;
                }
                else {
                    strcat(labelstr, ", ");
                    strcat(labelstr, names[j]);
                }
                printf("%s: %.0f%%\n", names[j], dets[i].prob[j] * 100);
            }
        }
        if (class_id >= 0) {
            int width = show_img->height * .006;

            /*
            if(0){
            width = pow(prob, 1./2.)*10+1;
            alphabet = 0;
            }
            */

            //printf("%d %s: %.0f%%\n", i, names[class_id], prob*100);
            int offset = class_id * 123457 % classes;
            float red = get_color(2, offset, classes);
            float green = get_color(1, offset, classes);
            float blue = get_color(0, offset, classes);
            float rgb[3];

            //width = prob*20+2;

            rgb[0] = red;
            rgb[1] = green;
            rgb[2] = blue;
            box b = dets[i].bbox;
            //printf("%f %f %f %f\n", b.x, b.y, b.w, b.h);

            int left = (b.x - b.w / 2.)*show_img->width;
            int right = (b.x + b.w / 2.)*show_img->width;
            int top = (b.y - b.h / 2.)*show_img->height;
            int bot = (b.y + b.h / 2.)*show_img->height;

            if (left < 0) left = 0;
            if (right > show_img->width - 1) right = show_img->width - 1;
            if (top < 0) top = 0;
            if (bot > show_img->height - 1) bot = show_img->height - 1;

            //int b_x_center = (left + right) / 2;
            //int b_y_center = (top + bot) / 2;
            //int b_width = right - left;
            //int b_height = bot - top;
            //sprintf(labelstr, "%d x %d - w: %d, h: %d", b_x_center, b_y_center, b_width, b_height);

            float const font_size = show_img->height / 1000.F;
            CvPoint pt1, pt2, pt_text, pt_text_bg1, pt_text_bg2;
            pt1.x = left;
            pt1.y = top;
            pt2.x = right;
            pt2.y = bot;
            pt_text.x = left;
            pt_text.y = top - 12;
            pt_text_bg1.x = left;
            pt_text_bg1.y = top - (10 + 25 * font_size);
            pt_text_bg2.x = right;
            pt_text_bg2.y = top;
            CvScalar color;
            color.val[0] = red * 256;
            color.val[1] = green * 256;
            color.val[2] = blue * 256;

            cvRectangle(show_img, pt1, pt2, color, width, 8, 0);
            //printf("left=%d, right=%d, top=%d, bottom=%d, obj_id=%d, obj=%s \n", left, right, top, bot, class_id, names[class_id]);
            cvRectangle(show_img, pt_text_bg1, pt_text_bg2, color, width, 8, 0);
            cvRectangle(show_img, pt_text_bg1, pt_text_bg2, color, CV_FILLED, 8, 0);    // filled
            CvScalar black_color;
            black_color.val[0] = 0;
            CvFont font;
            cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, font_size, font_size, 0, font_size * 3, 8);
            cvPutText(show_img, labelstr, pt_text, &font, black_color);
            count += 1;

            if (strcmp(labelstr, "person") == 0)
                person_counter += 1;
        }
    }

    float const font_size = show_img->height / 1000.F;
    CvPoint top_left, top_left2;
    top_left.x = 10;
    top_left.y = 15;

    top_left2.x = 10;
    top_left2.y = 35;

    CvScalar black_color;
    black_color.val[0] = 0;
    CvFont font;
    cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, font_size, font_size, 0, font_size * 3, 8);
    cvPutText(show_img, _itoa(count,scount,10), top_left, &font, black_color);
    cvPutText(show_img, _itoa(person_counter, sperson_counter, 10), top_left2, &font, black_color);
}