リアルタイムでグラフを描写する

RealTimeGraph.py

from io import BytesIO

from PIL import Image
import matplotlib.pyplot as plt
import numpy as np
import cv2

cap = cv2.VideoCapture(0)

ret, frame = cap.read()

size = 0.4

h1 = int(frame.shape[0]*size)
h2 = int(frame.shape[0]*size*2)
w1 = int(frame.shape[1]*size)
w2 = int(frame.shape[1]*size*2)

x = np.arange(0, 10, 0.1)
def random_img():
    #
    #  random_img
    #  ランダムなグラフの画像データを返します
    #  Returns random graph image data.
    #
    byte = BytesIO()
    y = np.random.randn(100)
    plt.plot(x, y, c='r')
    plt.savefig(byte)
    img = np.array(Image.open(byte))
    img = cv2.cvtColor(img, cv2.COLOR_RGB2BGR)
    img = cv2.resize(img, dsize=(w1, h1))
    byte.close()
    plt.close()
    return img

while True:
    ret, frame = cap.read()

    img = random_img()

    img_comb = cv2.addWeighted(frame[h1:h2, w1:w2], 1, img, 1, 0)

    frame[h1:h2, w1:w2] = img_comb

    cv2.imshow('camera', frame)

    if cv2.waitKey(60) == 27:
        break

cap.release()
cv2.destroyAllWindows()