如何在不首先将文件保存为png或jpeg的情况下将numpy数组传递给openCV？

Question

我正在尝试截图，然后将其转换为numpy数组。然后我想使用屏幕截图运行cv2.matchTemplate。到目前为止，我唯一的方法是保存图像：cv2.imwrite（'temp.png'，imcv），然后在cv2.matchTemplate中使用该图像。这似乎大错特错。如何正确转换numpy数组以避免保存并直接传递给cv2.matchTemplate函数？

我在Ubuntu btw做这个项目

import pyscreenshot as ImageGrab
import PIL
import cv2
import numpy as np
from matplotlib import pyplot as plt

# part of the screen
im=ImageGrab.grab(bbox=(65,50,835,725)) # X1,Y1,X2,Y2

#convert to numpy array
im=im.convert('RGB')
imcv = np.array(im) 
imcv = imcv[:, :, ::-1].copy() 
cv2.imwrite('temp.png',imcv)

img = cv2.imread('temp.png',0)
template = cv2.imread('fight.png',0)
w, h = template.shape[::-1]

# Apply template Matching
res = cv2.matchTemplate(img,template,cv2.TM_CCOEFF)
min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(res)
print(min_val)
print(max_val)
print(min_loc)
print(max_loc)
if(max_loc == (484,125)):
    print("True!")

top_left = max_loc
bottom_right = (top_left[0] + w, top_left[1] + h)

cv2.rectangle(img,top_left, bottom_right, 255, 2)

plt.subplot(121),plt.imshow(res,cmap = 'gray')
plt.title('Matching Result'), plt.xticks([]), plt.yticks([])
plt.subplot(122),plt.imshow(img,cmap = 'gray')
plt.title('Detected Point'), plt.xticks([]), plt.yticks([])
plt.suptitle(cv2.TM_CCOEFF)

plt.show()

这也是最简单的方法：我还将在代码后发布错误消息。

import pyscreenshot as ImageGrab
import PIL
import cv2
import numpy

im=ImageGrab.grab(bbox=(65,50,835,725)) # X1,Y1,X2,Y2
print type(im)
im=im.convert('RGB')
print type(im)
im = numpy.array(im)
print type(im)
im = im[:, :, ::-1].copy() 
print type(im)
cv2.cv.fromarray(im)
print type(im) 

template = cv2.imread('fight.png',0)

templateTest = cv2.matchTemplate(im,template,cv2.TM_CCOEFF)
min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(res)
print(min_val)
print(max_val)
print(min_loc)
print(max_loc)

<type 'instance'>
<type 'instance'>
<type 'numpy.ndarray'>
<type 'numpy.ndarray'>
<type 'numpy.ndarray'>
OpenCV Error: Assertion failed ((img.depth() == CV_8U || img.depth() == CV_32F) && img.type() == templ.type()) in matchTemplate, file /home/kninja/Downloads/opencv-2.4.9/modules/imgproc/src/templmatch.cpp, line 249
Traceback (most recent call last):
  File "StartOVer.py", line 32, in <module>
    res = cv2.matchTemplate(im,template,cv2.TM_CCOEFF)
cv2.error: /home/kninja/Downloads/opencv-2.4.9/modules/imgproc/src/templmatch.cpp:249: error: (-215) (img.depth() == CV_8U || img.depth() == CV_32F) && img.type() == templ.type() in function matchTemplate

Answer 1

import pyscreenshot as ImageGrab
import PIL
import cv2
import numpy

im=ImageGrab.grab(bbox=(65,50,835,725)) # X1,Y1,X2,Y2
print type(im)
im=im.convert('RGB')
print type(im)
im = numpy.array(im)
print type(im) 

cv_img = im.astype(np.uint8)
cv_gray = cv2.cvtColor(cv_img, cv2.COLOR_RGB2GRAY)

template = cv2.imread("filename.png", cv2.IMREAD_GRAYSCALE)