将一张图像贴到另一张图像指定区域

import cv2
import numpy as np


def mergeImg(inputImg, maskImg, contourData, drawPosition):
    '''
    :param inputImg: 输入的图像
    :param maskImg: 输入的模板图像
    :param contourData: 输入的模板中轮廓数据 numpy 形式如[(x1,y1),(x2,y2),...,]
    :param drawPosition: （x,y） 大图中要绘制模板的位置,以maskImg左上角为起始点
    :return: outPutImg：输出融合后的图像
             outContourData: 输出轮廓在inputImg的坐标数据
             outRectData: 输出轮廓的矩形框在inputImg的坐标数据
    '''
    # 通道需要相等
    if (inputImg.shape[2] != maskImg.shape[2]):
        print("inputImg shape != maskImg shape")
        return
    inputImg_h = inputImg.shape[0]
    inputImg_w = inputImg.shape[1]
    maskImg_h = maskImg.shape[0]
    maskImg_w = maskImg.shape[1]
    # inputImg图像尺寸不能小于maskImg
    if (inputImg_h < maskImg_h or inputImg_w < maskImg_w):
        print("inputImg size < maskImg size")
        return
    # 画图的位置不能超过原始图像
    if (((drawPosition[0] + maskImg_w) > inputImg_w) or ((drawPosition[1] + maskImg_h) > inputImg_h)):
        print("drawPosition + maskImg > inputImg range")
        return
    outPutImg = inputImg.copy()
    input_roi = outPutImg[drawPosition[1]:drawPosition[1] + maskImg_h, drawPosition[0]:drawPosition[0] + maskImg_w]
    imgMask_array = np.zeros((maskImg_h, maskImg_w, maskImg.shape[2]), dtype=np.uint8)
    triangles_list = [contourData]

    cv2.fillPoly(imgMask_array, triangles_list, color=(1, 1, 1))
    cv2.fillPoly(input_roi, triangles_list, color=(0, 0, 0))
    # cv2.imshow('imgMask_array', imgMask_array)
    imgMask_array = imgMask_array * maskImg
    output_ori = input_roi + imgMask_array
    outPutImg[drawPosition[1]:drawPosition[1] + maskImg_h, drawPosition[0]:drawPosition[0] + maskImg_w] = output_ori

    return outPutImg


if (__name__ == "__main__"):
    #原图
    imgStr = r'img/1634081248.020272.jpg'
    #篡改后的车牌图像
    imgMaskStr = r'plate.png'
    img = cv2.imread(imgStr)
    maskImg = cv2.imread(imgMaskStr)
    # w,h裁剪下来的原车牌size
    w=189
    h=66
    maskImg=cv2.resize(maskImg,(w,h))
    print(maskImg.shape[1])
    contourData = np.array([(0,0),(maskImg.shape[1],0),(maskImg.shape[1],maskImg.shape[0]),(0,maskImg.shape[0])])
    #贴图的起始点，原车牌图像目标框的左上角点
    x1=1668
    y1=1360
    outPutImg= mergeImg(img, maskImg, contourData, (x1,y1))
    cv2.imwrite('result.png', outPutImg)