MatPlotlib를 이용한 히스토그램 그리기

import matplotlib.pyplot as plt
def  histoImage() :
    global window, canvas, paper, filename, inImage, outImage, inH, inW, outH, outW
    incountList = [0] * 256
    outcountList = [0] * 256
 
    for i in range(inH):
        for k in range(inW):
            incountList[inImage[i][k]] += 1
 
    for i in range(outH):
        for k in range(outW):
            outcountList[outImage[i][k]] += 1
 
 
    plt.plot(incountList)
    plt.plot(outcountList)
    plt.show()