将图像从屏幕抓取到numpy数组，并将其显示为黑白图像 [英] Grab image from screen to numpy array and display it as black and white image

问题描述

我正在尝试从屏幕的特定位置读取图像数据，因此可以以numpy数组的形式对其进行后处理.这是我到目前为止尝试过的:

I am trying to read image data from a certain part of the screen, so I can post-process it in a form of a numpy array. This is what I tried so far:

import numpy as np
from PIL import ImageGrab, Image

img = ImageGrab.grab(bbox=(798, 166, 300, 400))  # (bbox=x,y,width,height)
img_np = np.array(img)

但是当我尝试打印img_np时，它返回:

But when I try to print img_np, it returns:

<PIL.Image.Image image mode=RGB size=0x234 at 0x109F8F0>

它似乎不是一个numpy数组.我还想显示numpy数组中的黑白图像，以验证我的操作正确(并且将来还会显示已处理的numpy数组).我在做错什么吗?

It doesn't seem like it's an numpy array. I also want to display the black and white image from the numpy array to verify what I am doing is right (and also display processed numpy arrays in the future). Is there anything I am doing wrong?

推荐答案

我认为您的

(bbox=798, 166, 300, 400))

x = 798 在您的屏幕上

所以您必须在屏幕上输入(x，y).

so you must make your (x,y) in your screen.

看这张照片: 在此处输入图片描述 结果为无"，因为它无法捕获您的屏幕

look this picture: enter image description here the result is None ,because it cant capture your screen

当我修改x = 100时，它可以工作 在此处输入图片描述

and when I modify the x=100,it works enter image description here

代码:

import numpy as np 
from PIL import ImageGrab,Image 
img=ImageGrab.grab(bbox=(798,166,300,400))  #798
# img=Image.open("Modric.jpg")
print(type(img))
img_np=np.array(img)
print(type(img_np))
print(img_np.shape)

结果:

<class 'PIL.Image.Image'>
<class 'numpy.ndarray'>
()      *******None

在 x = 100 之后:

import numpy as np 
from PIL import ImageGrab,Image 
img=ImageGrab.grab(bbox=(100,166,300,400))  #798
# img=Image.open("Modric.jpg")
print(type(img))
img_np=np.array(img)
print(type(img_np))
print(img_np.shape) code here

结果:

<class 'PIL.Image.Image'>
<class 'numpy.ndarray'>
(234, 200, 3)

右侧的x坐标并在屏幕上可以正常显示

the right x coord and in screen, it can works

对于第一个问题，我很抱歉，右边是这里

I am sorry for the first question,the right is here

import tkinter
win=tkinter.Tk()
width=win.winfo_screenwidth()   #get your screen's width
height=win.winfo_screenheight() #get your screen's height  
print(width,height)                            
img=ImageGrab.grab(bbox=(300,400,width,height)).convert("L")  #798
img_np=np.array(img)
print(img_np.shape)

结果:

1536 864
(464, 1236)

当您使用bbox = {x，y，width，height)时，像素计数方法是width-x和height-y.因此必须将width> x和height> y设置为可用

when you use the bbox=(x,y,width,height) ,the pixel counting method is width-x and height-y . so you must make your width>x and height>y and it works

要转换为灰度图像，可以使用opencv

as for convert to gray image,you can use opencv

import cv2
gray=cv2.cvtColor(img_np,cv2.COLOR_RGB2GRAY)[enter link description here][3]

链接 或者 PIL convert("L")函数

link or the PIL convert("L") function

img=ImageGrab.grab(bbox=(300,400,width,height)).convert("L")  #798

 or

公式:

def rgb2gray(rgb):
"""
gray=0.299*R+0.587*G+0.144*B
"""
return np.uint8(np.dot(rgb[...,:3], [0.299, 0.587, 0.114]))

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