python - CV2 OpenCL，cv2.UMat 对象不可迭代

Question

我正在使用 pyzbar 库来解码二维码。现在我正在尝试使用 uMat 来加快这个过程。问题是 pyzbar 解码不能接受 umat 变量。

File "C:\Python\lib\site-packages\pyzbar\pyzbar.py", line 175, in decode pixels, width, height = image TypeError: 'cv2.UMat' object is not iterable

这是我的代码示例

import cv2
import numpy as np
from pyzbar.pyzbar import decode 
import matplotlib.pyplot as plt

cv2.ocl.setUseOpenCL(True)

for subdir, dirs, files in os.walk("Images"):
    for file in sorted(files):
        filepath = subdir + os.sep + file
        if filepath.endswith(".JPG"):

            image = cv2.imread(filepath, cv2.IMREAD_GRAYSCALE)
            image = cv2.UMat(image)

            symbols = decode(image)

            if symbols:
                plt.title(symbols[0][0])
                plt.imshow(image)
                plt.show()

Answer 1

我猜这个错误的原因可以在 decode from pyzbar 的文档中找到:

def decode(image, symbols=None, scan_locations=False):
"""Decodes datamatrix barcodes in `image`.
Args:
    image: `numpy.ndarray`, `PIL.Image` or tuple (pixels, width, height)
    symbols (ZBarSymbol): the symbol types to decode; if `None`, uses
        `zbar`'s default behaviour, which is to decode all symbol types.
    scan_locations (bool): If `True`, results will include scan
        locations.

解码需要包含特定顺序数据的图像或矩阵，由 OpenCV 支持的垫实例填充。 UMat格式不满足这个要求，所以会出现错误。