Python3.4图片转换素描详解编程语言

    from PIL import Image, ImageFilter, ImageOps   
    img = Image.open('C://Users//hengli//Pictures//lovewallpaper//214926-106.jpg')   
    def dodge(a, b, alpha):   
        return min(int(a*255/(256-b*alpha)), 255)   
    def draw(img, blur=25, alpha=1.0):   
        img1 = img.convert('L')        #图片转换成灰色   
        img2 = img1.copy()   
        img2 = ImageOps.invert(img2)   
        for i in range(blur):          #模糊度   
            img2 = img2.filter(ImageFilter.BLUR)   
        width, height = img1.size   
        for x in range(width):   
            for y in range(height):   
                a = img1.getpixel((x, y))   
                b = img2.getpixel((x, y))   
                img1.putpixel((x, y), dodge(a, b, alpha))   
        img1.show()   
        #img1.save('C://Users//hengli//Pictures//CameraMan//照片1.png')   
    draw(img)