前言

QT+Python是非常经典的窗体编程组合，功能完善，可视化界面美观易维护，这篇博客针对相片更换背景颜色方面编写代码，代码整洁，规则，易读，对学习与使用Python有较好的帮助。

文章目录

一、所需工具软件

二、使用步骤

1. 引入库

2. 导入相片

3. 颜色选择

4. 运行结果

三、在线协助

一、所需工具软件

1. Python3.6以上

2. Pycharm代码编辑器

3. PyQT, OpenCV库

二、使用步骤

1.引入库

代码如下（示例）：

# -*- coding: utf-8 -*-
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5 import QtWidgets
from PyQt5.QtWidgets import *
import cv2 as cv
import numpy as np
import os

2.导入相片

代码如下（示例）：

def on_loadImage_clicked(self):
    """
    Slot documentation goes here.
    """
    # TODO: not implemented yet
    
    self.file_name, self.file_type = QFileDialog.getOpenFileName(self,"打开文件","D:/","All Files (*);")

    if (img.shape[2] == 3):#bgr到rgb转换的显示
        qimg = cv.cvtColor(img, cv.COLOR_BGR2RGB)
        qimg = QImage(qimg.data, qimg.shape[1], qimg.shape[0], qimg.shape[1]*qimg.shape[2],QImage.Format_RGB888)
        self.before.setPixmap(QPixmap.fromImage(qimg))
    else:
        qimg = QImage(img.data, img.shape[1], img.shape[0],QImage.Format_Grayscale8)
        self.before.setPixmap(QPixmap.fromImage(qimg))

该处使用的url网络请求的数据。

3.颜色选择：

代码如下（示例）：

def on_colorchoose_currentIndexChanged(self, p0):
    current = self.colorchoose.currentText()
    if self.target:
        if current=="红色":
            self.color =[0, 0, 255]
            self.newname= '_red'
        elif current=="白色":
            self.color =[255, 255, 255]
            self.newname= '_white'
        elif current=="蓝色":
            self.color =[255, 0, 0]
            self.newname= '_blue'
        elif current=="绿色":
            self.color =[0, 255, 0]
            self.newname= '_green'
        elif current=="黄色":
            self.color=[0, 255, 255]
            self.newname= '_yellow'
        elif current=="紫色":
            self.color=[255, 0, 255]
            self.newname= '_violet'
        elif current=="灰色":
            self.color=[96, 96, 96]
            self.newname= '_gray'

@pyqtSlot()
def on_change_clicked(self):
    """
    Slot documentation goes here.
    """
    # TODO: not implemented yet
    if self.red.text()!="":
        self.newname='_define'
        print(self.color)
        self.target = False
    img =cv.imread(self.file_name, -1)

    if (img is None):
        print(1)
        self.textBrowser.setText("打开图片失败，请重新加载")
    else:
        # 准备数据
        wide = img.shape[1]
        height = img.shape[0]
        dims = img.shape[2]
        sampleCount = wide * height
        clusterCount = 4
        points = np.zeros([sampleCount, dims], np.float32)
        centers = np.zeros([clusterCount, 1], np.float32)
        index = 0
        for i in range(height):
            for j in range(wide):
                index = i * wide + j
                for n in range(dims):
                    points[index][n] = img[i][j][n]
        criteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 10, 0.1)
        ret, label, center = cv.kmeans(points, clusterCount, None, criteria, 10, cv.KMEANS_PP_CENTERS)
        mask = np.zeros((img.shape[0], img.shape[1]), np.uint8)
        index = wide * 2 + 4
        img2 = img.copy()
        cindex = label[index]
        for i in range(height):
            for j in range(wide):
                index = i * wide + j
                label1 = label[index]
                if cindex == label1:
                    for n in range(dims):
                        img2[i][j][n] = 0;
                    mask[i][j] = 0;
                else:
                    mask[i][j] = 255
        structuting = cv.getStructuringElement(cv.MORPH_RECT, (13, 13))
        mask =cv.dilate(mask,structuting)
        mask = cv.erode(mask, structuting)
        structuting2 = cv.getStructuringElement(cv.MORPH_RECT, (9, 9))
        mask = cv.erode(mask, structuting2)
        cv.waitKey(10)

        img2 = cv.GaussianBlur(img2, (3, 3), 0, 0)
        if (img2.shape[2] == 3):
            qimg = cv.cvtColor(img2, cv.COLOR_BGR2RGB)
            qimg = QImage(qimg.data, qimg.shape[1], qimg.shape[0], qimg.shape[1] * qimg.shape[2],
                          QImage.Format_RGB888)
            self.after.setPixmap(QPixmap.fromImage(qimg))
        else:
            qimg = QImage(img.data, img.shape[1], img.shape[0], QImage.Format_Grayscale8)
            self.after.setPixmap(QPixmap.fromImage(qimg))
        name=fathername+"/"+name+self.newname+type
        print(name)
        cv.imwrite(name,img2)
        write = "the image has been saved in:"+name
        self.textBrowser.setText(write)