Question

我正在从相机捕捉图像并在Tkinter的画布上显示图像。但是，看起来很奇怪的现象是画布将使用下面的代码闪烁

def get_image_cam() :
    global cam,cam_flag,cam_image, cam_imageTk, canvas_img
    print '[THREAD CREATE]get image camera'
    print cam_flag
    while cam_flag :
        image = cam.get_image()
        pygame.image.save(image,'capture.bmp')
        cam_image = Image.open('capture.bmp') 
        cam_imageTk = ImageTk.PhotoImage(cam_image)
        canvas_img.create_image(0, 0, anchor = NW ,image = cam_imageTk)

    print '[THREAD EXIT] get image camera'
    thread.exit_thread()

我已经搜索了很多来解决这个问题。下面是一些代码 http://codingmess.blogspot.com/2008/07/showing-webcam-image-in-desktop-window_08.html，它确实有帮助

def showimage(image):
    '''Loads given image and puts it into the window'''
    img = Image.open(image)
    photo = ImageTk.PhotoImage(img)
    container.canvas.create_image(container.width/2+2, container.height/2,  image=photo)
    container.obr = photo # why is this line necessary?

作为帖子的作者说，他不知道为什么这个'container.obr = photo'有帮助。我对我的代码做了同样的事情。它改变如下：

def get_image_cam() :
    global cam,cam_flag,cam_image, cam_imageTk, canvas_img
    print '[THREAD CREATE]get image camera'
    print cam_flag
    while cam_flag :
        image = cam.get_image()
        pygame.image.save(image,'capture.bmp')
        cam_image = Image.open('capture.bmp') 
        cam_imageTk = ImageTk.PhotoImage(cam_image)
        canvas_img.create_image(0, 0, anchor = NW ,image = cam_imageTk)
        obr = cam_imageTk # variable 'obr' is not neccessary, you can change it to anything you want 

    print '[THREAD EXIT] get image camera'
    thread.exit_thread()

有没有人可以帮我解释一下？提前谢谢。

Answer 1

PhotoImage创建本地对象（在函数中）当您离开函数时被垃圾收集器删除（并且您丢失了图像以便闪烁）。

您必须将此分配给现有的全局变量或现有对象。

python Tkinter在画布上显示图像，它总是闪烁

1 个答案: