從影象上拾取一個點，並水平向右顯示以該點為起點的30個畫素的光譜曲線

import cv2
import matplotlib.pyplot as plt
from matplotlib.pyplot import MultipleLocator
#人機互動拾取影象上一個點，並顯示水平方向上30個畫素的光譜曲線圖



def mouse(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN:
        xy = "%d,%d" % (x, y)
        cv2.circle(img, (x, y), 
 
3, (250, 55, 250), thickness=-1)
        cv2.putText(img, xy, (x, y), cv2.FONT_HERSHEY_PLAIN,
                    1.0, (50, 200, 255), thickness=1)
        cv2.imshow("image", img)
        column,line=xy.split(',')
        l,c=int(line), int(column)
        print(line, column)
        X=[]
        Y1=[]
        Y2
 
=[]
        Y3=[]
        n=40
        for i in range(n):
            X.append(c+i)
            Y1.append(a[l,c+ i, 0])
            Y2.append(a[l,c + i, 1])
            Y3.append(a[l,c+ i, 2])

        cv2.line(img, ( c,l), (X[-1],l ), color=(0, 0, 255), thickness=2)
        #顯示中文
        plt.rcParams['
 
font.sans-serif'] = ['SimHei']
        plt.figure(figsize=(8, 4))

        x_major_locator = MultipleLocator(2)
        ax = plt.gca()
        # ax為兩條座標軸的例項
        ax.xaxis.set_major_locator(x_major_locator)
        plt.plot(X, Y1, label="R", color="red", linewidth=2)
        plt.plot(X, Y2, label="G", color="green", linewidth=2)
        plt.plot(X, Y3, label="B", color="blue", linewidth=2)
        plt.xlabel("Time(s)")
        plt.ylabel("Value值")
        plt.title("RGB光譜曲線")

        plt.show()
        cv2.imshow("image", img)


if __name__ == '__main__':

    img = cv2.imread('mountain.jpg')
    print(img.shape)
    cv2.namedWindow("image")
    cv2.imshow("image", img)
    a=img.copy()

    cv2.setMouseCallback("image", mouse)

    cv2.waitKey(0)
    cv2.destroyAllWindows()

效果圖