How to count objects

Here is the code related to counting objects for YOLOv4

In the main while True: loop:

if FLAGS.count:
    # count objects found
    counted_classes = utils.count_objects(
        pred_bbox, by_class=True, allowed_classes=allowed_classes)

    # draw bounding boxes and output count
    image = utils.draw_bbox(
        frame, pred_bbox, FLAGS.info, counted_classes, allowed_classes=allowed_classes)
else:
    # just draw the bounding boxes
    image = utils.draw_bbox(
        frame, pred_bbox, FLAGS.info, allowed_classes=allowed_classes)

Here is utils.count_objects():

# function to count objects, can return total classes or count per class
def count_objects(data, by_class=False, allowed_classes=list(read_class_names(cfg.YOLO.CLASSES).values())):
    boxes, scores, classes, num_objects = data

    #create dictionary to hold count of objects
    counts = dict()

    # if by_class = True then count objects per class
    if by_class:
        class_names = read_class_names(cfg.YOLO.CLASSES)
        # loop through total number of objects found
        for i in range(num_objects):
            # grab class index and convert into corresponding class name
            class_index = int(classes[i])
            class_name = class_names[class_index]
            if class_name in allowed_classes:
                counts[class_name] = counts.get(class_name, 0) + 1
            else:
                continue
    # else count total objects found
    else:
        counts['total object'] = num_objects
    return counts

In the draw_bbox function:

if counted_classes != None:
    for key, value in counted_classes.items():
        if key == "bench" or key == "bus" or key == "wine glass" or key == "sandwich" or key == "toothbrush":
            cv2.putText(image, "{}es detected: {}".format(key, value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, red, font_thickness)
        elif key == "sheep" or key == "skis" or key == "scissors":
            cv2.putText(image, "{} detected: {}".format(key, value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, red, font_thickness)
        elif key == "knife":
            cv2.putText(image, "knives detected: {}".format(value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, red, font_thickness)
        elif key == "mouse":
            cv2.putText(image, "mice detected: {}".format(value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, red, font_thickness)
        elif key == "person":
            cv2.putText(image, "people detected: {}".format(value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, blue, font_thickness)
        else:
            cv2.putText(image, "{}s detected: {}".format(key, value), (indent, offset),
                        cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, red, font_thickness)
        offset += 40

return image