一、读写图片和添加logo

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本文链接： https://blog.csdn.net/s294878304/article/details/102742143

OpenCV  (4.1.1)

1、读取和保存图片

import numpy as np
import cv2
from matplotlib import pyplot as plt

# img = cv2.imread("test.jpg",0) # 灰度图
img = cv2.imread("opencv_test_picture/read.jpg")
# cv2.imshow('image',img) 显示不出来
# plt.imshow(img)
plt.imshow(img, cmap = 'gray', interpolation = 'bicubic')
plt.xticks([]), plt.yticks([]) # to hide tick values on X and Y axis
plt.show()


cv2.imwrite("opencv_test_picture/write.jpg", img)
print(img.shape)
print(img.size) # 返回图像的像素数目
print(img.dtype)# 图像的数据类型

2、添加logo

# encoding: utf-8

"""
@author: sunxianpeng
@file: operation.py
@time: 2019/10/25 15:22
"""
import numpy as np
import cv2
from matplotlib import pyplot as plt
class Main():
    def __init__(self):
        pass
    def read_pic(self,path):
        # img = cv2.imread("test.jpg",0) # 灰度图
        img = cv2.imread(path)
        return img

    def show_pic(self,img):
        # cv2.imshow('image',img) 显示不出来
        # plt.imshow(img)
        plt.imshow(img, cmap='gray', interpolation='bicubic')
        #     plt.xticks([]), plt.yticks([]) # to hide tick values on X and Y axis
        plt.show()

    def write_pic(self,img, path):
        cv2.imwrite(path, img)

    def add_logo(self):
        # 加载图像
        img1 = m.read_pic(path1)
        img2 = m.read_pic(path2)

        # I want to put logo on top-left corner, So I create a ROI
        rows, cols, channels = img2.shape
        roi = img1[0:rows, 0:cols]
        # Now create a mask of logo and create its inverse mask also
        img2gray = cv2.cvtColor(img2, cv2.COLOR_BGR2GRAY)

        ret, mask = cv2.threshold(img2gray, 175, 255, cv2.THRESH_BINARY)
        mask_inv = cv2.bitwise_not(mask)

        # Now black-out the area of logo in ROI
        # 取 roi 中与 mask 中不为零的值对应的像素的值，其他值为 0
        # 注意这里必须有 mask=mask 或者 mask=mask_inv, 其中的 mask= 不能忽略
        print(roi.dtype)
        print(mask.dtype)
        print(mask.shape)
        print(roi.shape)
        img1_bg = cv2.bitwise_and(roi, roi, mask=mask)
        # img1_bg = cv2.bitwise_and(roi, roi)
        # # 取 roi 中与 mask_inv 中不为零的值对应的像素的值，其他值为 0。
        # # Take only region of logo from logo image.
        img2_fg = cv2.bitwise_and(img2, img2, mask=mask_inv)
        # img2_fg = cv2.bitwise_and(img2, img2)
        # # Put logo in ROI and modify the main image
        dst = cv2.add(img1_bg, img2_fg)
        img1[0:rows, 0:cols] = dst
        m.show_pic(img1)


if __name__ == '__main__':
    m = Main()
    path1 = r"F:\PythonProjects\python_study\xiaohulu\image_process\data\ball.jpg"
    path2 = r"F:\PythonProjects\python_study\xiaohulu\image_process\data\opencv_logo3.jpg"
    m.add_logo()

问题

error: OpenCV(4.1.1) /io/opencv/modules/core/src/arithm.cpp:663: error: (-209:Sizes of input arguments do not match) The operation is neither 'array op array' (where arrays have the same size and the same number of channels), nor 'array op scalar', nor 'scalar op array' in function 'arithm_op'

解决办法：

logo图片的行和列数必须小于非logo图片

1、查看图像大小是否一致

2、查看图像数据类型是否一致（.dtype查看出具类型。uint8等类型是否一致）

3、查看mask图像是否符合要求（需灰度模式图像）