所以在堆栈溢出成员的帮助下,我有以下代码：

data = "needle's (which is a png image) base64 code goes here"
decoded = data.decode('base64')
f = cStringIO.StringIO(decoded)
image = Image.open(f)
needle = image.load()

while True:
    screenshot = ImageGrab.grab()
    haystack = screenshot.load()
    if detectImage(haystack, needle):
        break
    else:
        time.sleep(5)

我写了下面的代码来检查针是否在大海捞针：

def detectImage(haystack, needle):
    counter = 0
    for hayrow in haystack:
        for haypix in hayrow:
            for needlerow in needle:
                for needlepix in needlerow:
                    if haypix == needlepix:
                        counter += 1

    if counter == 980: #the needle has 980 pixels
        return True
    else:
        return False

问题是我在第3行遇到了这个错误：’PixelAccess’对象不可迭代

有人告诉我,将针和干草堆复制成numpy / scipy阵列会更容易.然后我可以使用一个函数来检查2D阵列针是否在2D数组haystack中.

我需要帮助：

1)将这些数组转换为numpy数组.

2)检查2D阵列针是否在2D阵列干草堆内的功能.我的功能不起作用.

这些是图像：
针：

草垛：

解决方法:

您可以在opencv中使用matchTemplate来检测位置：

import cv2
import numpy as np
import pylab as pl

needle = cv2.imread("needle.png")
haystack = cv2.imread("haystack.jpg")

diff = cv2.matchTemplate(haystack, needle, cv2.TM_CCORR_NORMED)
x, y = np.unravel_index(np.argmax(diff), diff.shape)

pl.figure(figsize=(12, 8))
im = pl.imshow(haystack[:,:, ::-1])
ax = pl.gca()
ax.add_artist(pl.Rectangle((y, x), needle.shape[1], needle.shape[0],  transform=ax.transData, alpha=0.6))

这是输出：