python将jpg转为svg python将png图片转为jpg

jpg格式:是有损图片压缩，可以使用最少的磁盘空间得到质量较好的图片
png格式:不属于压缩性。

png转换成jpg：

from PIL import Image
import cv2 as cv
import os

def PNG_JPG(PngPath):
    img = cv.imread(PngPath, 0)
    w, h = img.shape[::-1]
    infile = PngPath
    outfile = os.path.splitext(infile)[0] + ".jpg"
    img = Image.open(infile)
    img = img.resize((int(w / 2), int(h / 2)), Image.ANTIALIAS)
    try:
        if len(img.split()) == 4:
            # prevent IOError: cannot write mode RGBA as BMP
            r, g, b, a = img.split()
            img = Image.merge("RGB", (r, g, b))
            img.convert('RGB').save(outfile, quality=70)
            os.remove(PngPath)
        else:
            img.convert('RGB').save(outfile, quality=70)
            os.remove(PngPath)
        return outfile
    except Exception as e:
        print("PNG转换JPG 错误", e)

转换一张图片： 

#############转换一张图片#################
import os
img='img.png'
Path='./'
if img.endswith('.png'):
    PngPath= Path + img
    PNG_JPG(PngPath)

转换多张图片：

################转换多张图片#####################
import os
path_root = os.getcwd()
Path='/home/jovyan/work/data/gyx/competition/train_2/'
img_dir = os.listdir(Path)
for img in img_dir:
    if img.endswith('.png'):
        PngPath= Path + img
        PNG_JPG(PngPath)
img_dir = os.listdir(Path)
for img in img_dir:
    print(img)