cv2_capture_pulse_plot_v2.py

import argparse
import cv2
import numpy as np
import matplotlib.pyplot as plt
from scipy.signal import detrend

helpText = "'Esc' to Quit"

def parse_args():
    parser = argparse.ArgumentParser(description="CV2 Video Capture PhotoPlethysmoGram Test")
    parser.add_argument("--vid", dest="video_dev",
                        help="video device # of USB webcam (/dev/video?) [1]",
                        default=1, type=int)
    args_ret = parser.parse_args()
    return args_ret

def line(x0, x1, y0, y1, func):
    isSwap = abs(y1 - y0) > abs(x1 - x0)
    if isSwap:
        x0, y0 = y0, x0
        x1, y1 = y1, x1
    if x0 > x1:
        x0, x1 = x1, x0
        y0, y1 = y1, y0
    deltax = x1 - x0
    deltay = abs(y1 - y0)
    error = deltax / 2
    y = y0
    if y0 < y1:
        ystep = 1
    else:
        ystep = -1
    for x in range(x0, x1):
        if isSwap:
            func(y, x)
        else:
            func(x, y)
        error = error - deltay
        if error < 0:
            y = y + ystep
            error = error + deltax

def plot_r(x, y):
    frame[int(y), int(x)] = [255,0,0]
def plot_g(x, y):
    frame[int(y), int(x)] = [0,255,0]
def plot_b(x, y):
    frame[int(y), int(x)] = [0,0,255]                
def plot_w(x, y):
    frame[int(y), int(x)] = [255,255,255]                

DATA_LENGTH = 64
if __name__ == "__main__":
    # plot init
    xx = np.arange(64)
    yy = np.random.randn(64)
    fig, ax = plt.subplots(3,figsize=(8,8),linewidth=0.1)
    fig.subplots_adjust(hspace=0.5)

    # arg parsing
    args = parse_args()
    print("Called with args:")
    print(args)
    # open video device
    cap = cv2.VideoCapture(args.video_dev)
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, 32)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 32)

    width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    px = int(width /2 )  # float
    py = int(height /2 ) # float
    print(py,px)
    
    redHistoryDataList = np.random.randn(64)
    redOutputDataList = np.random.randn(64)
    greenHistoryDataList = np.random.randn(64)
    greenOutputDataList = np.random.randn(64)
    blueHistoryDataList = np.random.randn(64)
    blueOutputDataList = np.random.randn(64)
    # plots setup
    li1, = ax[0].plot(xx, yy, color='r')
    ax[0].set_xlim(0,DATA_LENGTH)
    ax[0].set_ylim(-255,255)
    li2, = ax[1].plot(xx, yy, color='g')
    ax[1].set_xlim(0,DATA_LENGTH)
    ax[1].set_ylim(-255,255)
    li3, = ax[2].plot(xx, yy, color='b')
    ax[2].set_xlim(0,DATA_LENGTH)
    ax[2].set_ylim(-255,255)

    while(True):
        ret, frame = cap.read()
        if ret:
            cv2.putText(frame, helpText, (11,20), cv2.FONT_HERSHEY_PLAIN, 1.0, (32,32,32), 4, cv2.LINE_AA)
            cv2.putText(frame, helpText, (10,20), cv2.FONT_HERSHEY_PLAIN, 1.0, (240,240,240), 1, cv2.LINE_AA)

            bb, gg, rr = cv2.split(frame)
            one_r = (255-np.mean(rr))
            one_g = (255-np.mean(gg))
            one_b = (255-np.mean(bb))
            redHistoryDataList = np.append(redHistoryDataList,one_r )
            if len(redHistoryDataList) > DATA_LENGTH :
                redHistoryDataList = np.delete(redHistoryDataList,0)
            greenHistoryDataList = np.append(greenHistoryDataList,one_g )
            if len(greenHistoryDataList) > DATA_LENGTH :
                greenHistoryDataList = np.delete(greenHistoryDataList,0)
            blueHistoryDataList = np.append(blueHistoryDataList,one_b )
            if len(blueHistoryDataList) > DATA_LENGTH :
                blueHistoryDataList = np.delete(blueHistoryDataList,0)
            
            redOutputDataList = np.append(redOutputDataList,(one_r - np.mean(redHistoryDataList[-32:])))
            if len(redOutputDataList) > DATA_LENGTH :
                redOutputDataList = np.delete(redOutputDataList,0)
            greenOutputDataList = np.append(greenOutputDataList,(one_g - np.mean(greenHistoryDataList[-32:])))
            if len(greenOutputDataList) > DATA_LENGTH :
                greenOutputDataList = np.delete(greenOutputDataList,0)
            blueOutputDataList = np.append(blueOutputDataList,(one_b - np.mean(blueHistoryDataList[-32:])))
            if len(blueOutputDataList) > DATA_LENGTH :
                blueOutputDataList = np.delete(blueOutputDataList,0)
            
            li1.set_xdata(np.arange(len(redOutputDataList)))
            li1.set_ydata((redOutputDataList)*50)
            li2.set_xdata(np.arange(len(greenOutputDataList)))
            li2.set_ydata((greenOutputDataList)*50)
            li3.set_xdata(np.arange(len(blueOutputDataList)))
            li3.set_ydata((blueOutputDataList)*50)
            #
            now_x = 0
            old_x = 0
            old_ry = 0
            old_gy = 0
            old_by = 0
#            for p in drawDataList:
#                by = int((255-p[0]) * 1.0)
#                gy = int((255-p[1]) * 1.0)
#                ry = int((255-p[2]) * 1.0)
#                
#                if now_x == 0:
#                    frame[old_by, now_x] = [255,0,0]
#                    frame[old_gy, now_x] = [0,255,0]
#                    frame[old_ry, now_x] = [0,0,255]
#                else:
#                    line(old_x, now_x, old_by, by, plot_r)
#                    line(old_x, now_x, old_gy, gy, plot_g)
#                    line(old_x, now_x, old_ry, ry, plot_b)
#                    line(old_x+1, now_x+1, old_ry+1, ry+1, plot_b)
#                    line(old_x+2, now_x+2, old_ry+2, ry+2, plot_w)
#                      
#                old_x = now_x
#                old_by = by
#                old_gy = gy
#                old_ry = ry
#                now_x=now_x+2

            cv2.imshow('frame', frame)
            if cv2.waitKey(1) & 0xFF == 27:
                break
            plt.pause(0.001)
        
    cap.release()
    cv2.destroyAllWindows()
    plt.close()