PyQt4 解决jpg图片不能正常显示问题

#-*- coding:utf-8 -*-
import sys
import requests
import urllib2
import base64
import io
from io import BytesIO
from PIL import Image
try:
    from PyQt4.QtCore import *
    from PyQt4.QtGui import  *
except:     
    from PyQt5.QtWidgets import QApplication
    from PyQt5.QtWidgets import (QWidget,  QLabel, QVBoxLayout)
 
    from PyQt5.QtGui import  QPixmap



class graphicsView(QLabel):
    def __init__(self,parent=None):
        super(graphicsView,self).__init__(parent)
        self._parent=parent
        

class MyLineEdit(QWidget):
    def __init__( self, parent=None ):
            super(MyLineEdit, self).__init__(parent)
            self.initui()
    def initui(self):
            headers = {
                    "User-Agent":"Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Mobile Safari/537.36",
                    'Referer':'https://www.tujigu.com/bigimg.html'}

            url='https://lns.hywly.com/a/1/33144/11.jpg'
            
            req = requests.get(url,headers)
            html=req.content
            html= self.image_to_byte_array(html)
            with open("1.png", "wb") as f:
                f.write(html)



            photo = QPixmap(self)
            photo.scaled(0.5, Qt.KeepAspectRatio)
         
            photo.loadFromData(html)
            
             
            label= graphicsView(self)

            
            label.setPixmap(photo)
   
            layout =QVBoxLayout()
            layout.addWidget(label)
            self.setLayout(layout)
            
            self.resize(500,505)
             
            self.show()
    def image_to_byte_array(self,html):#将jpg字节转换为png字节
        byte_stream = BytesIO(html)  # 把请求到的数据转换为Bytes字节流
        roiImg = Image.open(byte_stream)   # Image打开Byte字节流数据
        #roiImg.show()   #显示图片
        imgByteArr = io.BytesIO()     
        roiImg.save(imgByteArr, format='PNG') 
        imgByteArr = imgByteArr.getvalue()
        return imgByteArr

if __name__ == '__main__': 
 
    
    app = QApplication(sys.argv)

    ap=MyLineEdit()
    ap.show()
 
    sys.exit(app.exec_())

思路 ：因为jpg图片大多情况无法在Qt正常显示，故将jpg字节流转为png字节流，之后即可正常显示。

本地图片

img = cv2.imread(filepath)  # 读取图像
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)  # 转换图像通道
#img = cv2.imdecode(np.fromfile(im_name,dtype=np.uint8),-1)#中文路径时，替换上一行
x = img.shape[1]  # 获取图像大小
y = img.shape[0]
frame = QImage(img, x, y, QImage.Format_RGB888)
self.image=QPixmap(frame)

一般来说这样也可以正常显示，不过可能个别图片显示异常。

with open(filepath, 'rb') as f:
     text = f.read()
frame = self.image_to_byte_array(text)
self.image=QPixmap()
self.image.loadFromData(frame)

同理也可以读取本地jpg图片字节流装换为png，之后进行操作。