webcam.py

import cv2
import numpy as np
import time


net = cv2.dnn.readNet("../include/yolov3-tiny-head_final.weights", "../include/yolov3-tiny-head.cfg")
layer_names = net.getLayerNames()
output_layers = [layer_names[i[0] - 1] for i in net.getUnconnectedOutLayers()]

scale = 0.00392
conf_threshold = 0.5
nms_threshold = 0.4

# define the frame properties
colors = [tuple(255 * np.random.rand(3)) for _ in range(10)]
capture = cv2.VideoCapture('/dev/video0')
capture.set(cv2.CAP_PROP_FRAME_WIDTH, 416)
capture.set(cv2.CAP_PROP_FRAME_HEIGHT, 416)


while True:
    ret, frame = capture.read()
    if ret: 
        height, width, channels = frame.shape
        image = cv2.resize(frame, (416,416))
        blob = cv2.dnn.blobFromImage(image, scale, (416,416), (0, 0, 0), True)
        net.setInput(blob)
        outs=net.forward(output_layers)

        confidences = []
        boxes = []
           
        for out in outs:
            for detection in out:
                confidence = detection[5]
                if confidence > 0.35:
                    
                    center_x = int(detection[0]*width)
                    center_y = int(detection[1]*height)
                    w = int(detection[2]*width)
                    h = int(detection[3]*height)
                    x = center_x - w/2
                    y = center_y - h/2
                    confidences.append(float(confidence))
                    boxes.append([x, y, w, h])

        # apply non-max suppression
        indices = cv2.dnn.NMSBoxes(boxes, confidences, conf_threshold, nms_threshold)
        # go through the detections remaining
        # after nms and draw bounding box

        for i in indices:
            i = i[0]
            x,y,w,h = boxes[i]
            confidence = confidences[i]       
            color = colors[1]
            cv2.rectangle(frame,(x,y),(x+w,y+h),color,2)
            cv2.putText(frame,str(round(confidence,2)),(x,y-10), cv2.FONT_HERSHEY_COMPLEX, 1, (0, 0, 0), 2)

    cv2.imshow('frame', frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

capture.release()
cv2.destroyAllWindows()