opencv实现抠图（单一背景），替换背景图

下面简单图片演示一下：

提取mask：

===>

替换背景：

 + =

python的opencv代码如下：

# coding=utf-8

import cv2
import  numpy as np

img=cv2.imread('lp.jpg')
img_back=cv2.imread('back.jpg')
#日常缩放
rows,cols,channels = img_back.shape
img_back=cv2.resize(img_back,None,fx=0.7,fy=0.7)
cv2.imshow('img_back',img_back)

rows,cols,channels = img.shape
img=cv2.resize(img,None,fx=0.4,fy=0.4)
cv2.imshow('img',img)
rows,cols,channels = img.shape#rows，cols最后一定要是前景图片的，后面遍历图片需要用到

#转换hsv
hsv=cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
#获取mask
lower_blue=np.array([78,43,46])
upper_blue=np.array([110,255,255])
mask = cv2.inRange(hsv, lower_blue, upper_blue)
cv2.imshow('Mask', mask)

#腐蚀膨胀
erode=cv2.erode(mask,None,iterations=1)
cv2.imshow('erode',erode)
dilate=cv2.dilate(erode,None,iterations=1)
cv2.imshow('dilate',dilate)

#遍历替换
center=[50,50]#在新背景图片中的位置
for i in range(rows):
    for j in range(cols):
        if dilate[i,j]==0:#0代表黑色的点
            img_back[center[0]+i,center[1]+j]=img[i,j]#此处替换颜色，为BGR通道
cv2.imshow('res',img_back)

cv2.waitKey(0)
cv2.destroyAllWindows()

批量测试代码：

import os
import sys
import cv2
import numpy as np 


# 遍历文件夹
def walk_file(file):
    for root, dirs, files in os.walk(file):

        # root 表示当前正在访问的文件夹路径
        # dirs 表示该文件夹下的子目录名list
        # files 表示该文件夹下的文件list
        img_files = []
        # 遍历文件
        for f in files:
            # print(os.path.join(root, f))
            img_files.append( os.path.join(root, f) )

        # 遍历所有的文件夹
        #for d in dirs:
        #    print(os.path.join(root, d))

        return img_files


def matting(img_file, img_back_file='./back.png'):
    img=cv2.imread( img_file )
    #日常缩放
    # rows,cols,channels = img_back.shape
    # img_back=cv2.resize(img_back,None,fx=0.7,fy=0.7)
    #cv2.imshow('img_back',img_back)
 
    rows,cols,channels = img.shape
    # img=cv2.resize(img,None,fx=0.5,fy=0.5)
    #cv2.imshow('img',img)
    rows,cols,channels = img.shape#rows，cols最后一定要是前景图片的，后面遍历图片需要用到
    print ('>>>>>', rows,cols)
    img_back=np.ones([rows,cols,3]) * 255 #cv2.imread( img_back_file )
 
    #转换hsv
    hsv=cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
    #获取mask
    lower_blue=np.array([0,0,0])
    upper_blue=np.array([50,100,255])
    mask = cv2.inRange(hsv, lower_blue, upper_blue)
    #cv2.imshow('Mask', mask)
 
    #腐蚀膨胀
    erode=cv2.erode(mask,None,iterations=1)
    #cv2.imshow('erode',erode)
    dilate=cv2.dilate(erode,None,iterations=1)
    #cv2.imshow('dilate',dilate)
 
    #遍历替换
    center=[0,0]#在新背景图片中的位置
    for i in range(rows):
        for j in range(cols):
            if dilate[i,j]==0:#0代表黑色的点
                img_back[center[0]+i,center[1]+j]=img[i,j]#此处替换颜色，为BGR通道
    #cv2.imshow('res',img_back)
 
    #cv2.waitKey(0)
    #cv2.destroyAllWindows()
    cv2.imwrite( './res/'+img_file.split('/')[-1], img_back )




def main():
    img_files = walk_file('./imgs/')
    print( '>>>', img_files )
    for per_img in img_files:
        matting( per_img )




if __name__ == '__main__':
    main()