Amazing-Python-Scripts

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import numpy as np
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from matplotlib import pyplot as plt
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import cv2
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import io
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import time
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# Camera stream
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cap = cv2.VideoCapture(0)
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cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
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cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1280)
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cap.set(cv2.CAP_PROP_FPS, 30)
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# Video stream (optional, not tested)
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# cap = cv2.VideoCapture("video.mp4")
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# Image crop
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x, y, w, h = 800, 500, 100, 100
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x, y, w, h = 950, 300, 100, 100
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heartbeat_count = 128
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heartbeat_values = [0]*heartbeat_count
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heartbeat_times = [time.time()]*heartbeat_count
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# Matplotlib graph surface
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fig = plt.figure()
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ax = fig.add_subplot(111)
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while True:
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    # Capture frame-by-frame
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    ret, frame = cap.read()
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    img = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
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    crop_img = img[y:y + h, x:x + w]
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    # Update the data
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    heartbeat_values = heartbeat_values[1:] + [np.average(crop_img)]
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    heartbeat_times = heartbeat_times[1:] + [time.time()]
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    # Draw matplotlib graph to numpy array
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    ax.plot(heartbeat_times, heartbeat_values)
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    fig.canvas.draw()
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    plot_img_np = np.fromstring(fig.canvas.tostring_rgb(),
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                                dtype=np.uint8, sep='')
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    plot_img_np = plot_img_np.reshape(
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        fig.canvas.get_width_height()[::-1] + (3,))
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    plt.cla()
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    # Display the frames
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    cv2.imshow('Crop', crop_img)
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    cv2.imshow('Graph', plot_img_np)
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    if cv2.waitKey(1) & 0xFF == ord('q'):
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        break
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cap.release()
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cv2.destroyAllWindows()
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