python|211115

    gray = image(f, 1)

    img = np.array(gray)
    for i in img:
        for j in range(len(i)):
            if i[j]<=0:
                i[j]=0
            elif i[j]<=0.2:
                i[j]=0.2
            elif i[j]<=0.4:
                i[j] = 0.4
            elif i[j]<=0.6:
                i[j] = 0.6
            elif i[j]<=0.8:
                i[j] = 0.8
            elif i[j]<=1:
                i[j] = 1

    plt.clf()
    sc = plt.imshow(img, cmap = my_cmap)