Python进行图片压缩的六种方法全解

pip install Pillow

from PIL import Image

img = Image.open("photo.jpg")

# ① 降质量（最常用）
img.save("small.jpg", quality=85, optimize=True)

# ② 缩尺寸
img_resized = img.resize((1920, 1080), Image.LANCZOS)
img_resized.save("resized.jpg", quality=85)

# ③ 换格式（PNG → JPEG，体积常减50%+）
if img.mode == 'RGBA':
    img = img.convert('RGB')
img.save("converted.jpg", "JPEG", quality=85)

pip install tinify

import tinify
tinify.key = "YOUR_API_KEY"

source = tinify.from_file("input.png")
source.to_file("output.png")  # 自动选最优参数

from PIL import Image

img = Image.open("photo.jpg")
img.save("photo.webp", "WEBP", quality=80)

pip install pyvips

import pyvips

img = pyvips.Image.thumbnail("huge.jpg", 1920)
img.write_to_file("small.jpg", Q=85)

import cv2

img = cv2.imread("photo.jpg")
cv2.imwrite("small.jpg", img, [cv2.IMWRITE_JPEG_QUALITY, 85])

import numpy as np
from sklearn.cluster import KMeans
from PIL import Image

img = Image.open("photo.jpg")
pixels = np.array(img).reshape(-1, 3)

kmeans = KMeans(n_clusters=64)  # 只保留64种颜色
kmeans.fit(pixels)
new_pixels = kmeans.cluster_centers_[kmeans.labels_]

new_img = Image.fromarray(new_pixels.reshape(img.size[1], img.size[0], 3).astype('uint8'))
new_img.save("kmeans.jpg")

需要压缩图片？
│
├─ 几张图，临时用 → 在线工具（tinypng.com），别写代码
│
├─ 批量 + 离线 → Pillow（本文方法1），够用
│
├─ 压缩率优先 → TinyPNG API
│
├─ 网站配图 → WebP格式
│
├─ 图片>50MB / 批量>1000张 → PyVips
│
├─ 视频帧处理 → OpenCV
│
└─ 玩算法 / 艺术化 → K-means

import os
from PIL import Image

def compress_batch(input_dir, output_dir, quality=85, max_width=1920):
    os.makedirs(output_dir, exist_ok=True)
    
    for f in os.listdir(input_dir):
        if not f.lower().endswith(('.jpg', '.jpeg', '.png', '.bmp')):
            continue
        
        in_path = os.path.join(input_dir, f)
        out_path = os.path.join(output_dir, f)
        
        with Image.open(in_path) as img:
            if img.mode in ('RGBA', 'P'):
                img = img.convert('RGB')
            
            if img.width > max_width:
                ratio = max_width / img.width
                img = img.resize((max_width, int(img.height * ratio)), Image.LANCZOS)
            
            img.save(out_path, 'JPEG', quality=quality, optimize=True)
            
            orig = os.path.getsize(in_path) / 1024
            new = os.path.getsize(out_path) / 1024
            print(f"{f}: {orig:.0f}KB → {new:.0f}KB ({1-new/orig:.0%})")

compress_batch("./原图", "./压缩", quality=85)