函数 'cv::cvtColor' 中的 !_src.empty()

Question

from skimage.measure import compare_ssim

import argparse

import imutils

import cv2

first = ("original_02.png")

second = ("modified_02.png")

imageA = cv2.imread("first")

imageB = cv2.imread("second")

grayA = cv2.cvtColor(imageA, cv2.COLOR_BGR2GRAY)

grayB = cv2.cvtColor(imageB, cv2.COLOR_BGR2GRAY)

(score, diff) = compare_ssim(grayA, grayB, full=True)

diff = (diff * 255).astype("uint8")

print("SSIM: {}".format(score))

thresh = cv2.threshold(diff, 0, 255, cv2.THRESH_BINARY_INV | cv2.THRESH_OTSU)[1]

cnts = cv2.findContours(thresh.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

cnts = imutils.grab_contours(cnts)

for c in cnts:

    (x, y, w, h) = cv2.boundingRect(c)

    cv2.rectangle(imageA, (x, y), (x + w, y + h), (0, 0, 255), 2)

    cv2.rectangle(imageB, (x, y), (x + w, y + h), (0, 0, 255), 2)

cv2.imshow("Original", imageA)

cv2.imshow("Modified", imageB)

cv2.imshow("Diff", diff)

cv2.imshow("Thresh", thresh)

cv2.waitKey(0)

这是我的代码，我遇到了标题中提到的错误。我将代码和必要的文件保存在同一个文件夹中

greyA = cv2.cvtColor(imageA, cv2.COLOR_BGR2GRAY) cv2.error: OpenCV(4.4.0) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-j8nxabm_\opencv\modules\imgproc \src\color.cpp:182: 错误: (-215:断言失败) !_src.empty() 在函数“cv::cvtColor”中

上面是我收到的错误

Answer 1

您不是在读取图像，而是将字符串读取到 imread 中。imread()将此解释为路径并可能返回，None因为它找不到路径。相反尝试：first = ("original_02.png")second = ("modified_02.png")imageA = cv2.imread(first)imageB = cv2.imread(second)

Answer 2

错误消息告诉您您的图像是空的。这是为什么？— 因为您的代码正在尝试读取名称为'first'且'second'. 实际上，您想要读取这些名称的变量。因此删除引号。此外，没有理由将变量名称放在括号中 - 也删除它们。目前看来您打算将这些变量定义为元组（但您没有）：first = "original_02.png"second = "modified_02.png"imageA = cv2.imread(first)imageB = cv2.imread(second)接下来，您应该检查这是否真的有效。如果无法读取图像（...），该函数将返回一个空矩阵