python-opencv限制图片长宽实现图片压缩

1.业务背景

图片压缩前的预处理，适配手机端图片大小显示且尽可能的减少图片存储空间的占用。通过限制图片的最大宽度和最大高度来减少图片的大小。

2.核心代码

import cv2
import os
import shutil
import math

def img_compress_by_openCV(img_path_local,img_size_thresh = 300,max_height=2560,max_width=1440):
    # 压缩前图片大小
    img_src_size = os.path.getsize(img_path_local)/1024
    
    # 压缩后图片保存地址
    img_path_compress = "./images/opencvs_"+img_path_local.split("/")[-1]
    
    # 若压缩前图片大小已经大小阈值img_size_thresh则跳过压缩
    if(img_src_size<img_size_thresh):
        print("图片大小小于"+str(img_size_thresh)+"KB,跳过压缩");
        shutil.copyfile(img_path_local,img_path_compress)
    else:
        print("openCV压缩前图片大小:"+str(int(img_src_size))+"KB")
        # 计算压缩比
        img = cv2.imread(img_path_local)
        heigh, width = img.shape[:2]
        print("openCV压缩前图片尺寸(heigh, width)=:("+str(int(heigh))+","+str(int(width))+")")
        
        compress_rate = min(max_height/heigh,max_width/width,1)
        
         # 调用openCV进行图片压缩
        img_compress = cv2.resize(img, (int(heigh*compress_rate), int(width*compress_rate)),interpolation=cv2.INTER_AREA) # 双三次插值
        cv2.imwrite(img_path_compress, img_compress)
        # 压缩后图片大小
        img_compress_size = os.path.getsize(img_path_compress)/1024
        print("openCV压缩后图片大小:"+str(int(img_compress_size))+"KB")
        print("openCV压缩前图片尺寸(heigh, width)=:("+str(heigh*compress_rate)+","+str(int(width*compress_rate))+")")
    
    return img_path_compress

img_path_local = "./images/1684155324391.jpg"
img_path_compress = img_compress_by_openCV(img_path_local)

• 运行结果

openCV压缩前图片大小:2219KB
openCV压缩前图片尺寸(heigh, width)=:(4000,3000)
openCV压缩后图片大小:469KB
openCV压缩前图片尺寸(heigh, width)=:(1920.0,1440)