使用Python+Pillow批量裁剪图片的三种常见场景与解决方法

from PIL import Image
import os

def crop_fixed_size(input_dir, output_dir, width, height):
    os.makedirs(output_dir, exist_ok=True)
    
    for filename in os.listdir(input_dir):
        if not filename.lower().endswith(('.jpg', '.jpeg', '.png', '.bmp', '.webp')):
            continue
        
        img_path = os.path.join(input_dir, filename)
        img = Image.open(img_path)
        
        # 左上角裁剪
        cropped = img.crop((0, 0, width, height))
        cropped.save(os.path.join(output_dir, filename))
        print(f"{filename} → {width}x{height}")

# 使用：裁成 800x600
crop_fixed_size(r'D:\原图', r'D:\裁剪后', 800, 600)

from PIL import Image
import os

def crop_center_square(input_dir, output_dir, size):
    os.makedirs(output_dir, exist_ok=True)
    
    for filename in os.listdir(input_dir):
        if not filename.lower().endswith(('.jpg', '.jpeg', '.png', '.bmp', '.webp')):
            continue
        
        img_path = os.path.join(input_dir, filename)
        img = Image.open(img_path)
        
        # 取最小边作为裁剪尺寸，保证不会切掉内容
        min_side = min(img.width, img.height)
        left = (img.width - min_side) // 2
        top = (img.height - min_side) // 2
        right = left + min_side
        bottom = top + min_side
        
        cropped = img.crop((left, top, right, bottom))
        
        # 再缩放到目标尺寸（可选）
        cropped = cropped.resize((size, size), Image.LANCZOS)
        
        cropped.save(os.path.join(output_dir, filename))
        print(f"{filename} → {size}x{size}")

# 使用：裁成 500x500 正方形
crop_center_square(r'D:\照片', r'D:\头像', 500)

from PIL import Image
import os

def crop_by_coordinates(input_dir, output_dir, coords):
    """
    coords: (left, top, right, bottom)
    例如：(100, 50, 400, 400) 表示从(100,50)到(400,400)的矩形区域
    """
    os.makedirs(output_dir, exist_ok=True)
    
    left, top, right, bottom = coords
    crop_width = right - left
    crop_height = bottom - top
    
    for filename in os.listdir(input_dir):
        if not filename.lower().endswith(('.jpg', '.jpeg', '.png', '.bmp', '.webp')):
            continue
        
        img_path = os.path.join(input_dir, filename)
        img = Image.open(img_path)
        
        # 判断原图是否够大
        if img.width < right or img.height < bottom:
            print(f"⚠️ {filename} 尺寸不足，跳过")
            continue
        
        cropped = img.crop((left, top, right, bottom))
        cropped.save(os.path.join(output_dir, filename))
        print(f"{filename} → 裁剪区域 {coords}")

# 使用：裁剪左上角 (100, 50) 到 (600, 550) 的区域
crop_by_coordinates(r'D:\截图', r'D:\裁剪后', (100, 50, 600, 550))

from PIL import Image, ImageDraw, ImageFont
import os

def crop_and_watermark(input_dir, output_dir, size, watermark_text):
    os.makedirs(output_dir, exist_ok=True)
    
    for filename in os.listdir(input_dir):
        if not filename.lower().endswith(('.jpg', '.jpeg', '.png')):
            continue
        
        img_path = os.path.join(input_dir, filename)
        img = Image.open(img_path)
        
        # 居中裁剪
        min_side = min(img.width, img.height)
        left = (img.width - min_side) // 2
        top = (img.height - min_side) // 2
        cropped = img.crop((left, top, left + min_side, top + min_side))
        cropped = cropped.resize((size, size), Image.LANCZOS)
        
        # 加水印
        draw = ImageDraw.Draw(cropped)
        font = ImageFont.truetype("simhei.ttf", int(size * 0.08))  # Windows自带黑体
        
        text_bbox = draw.textbbox((0, 0), watermark_text, font=font)
        text_width = text_bbox[2] - text_bbox[0]
        x = (size - text_width) // 2
        y = size - int(size * 0.1)
        
        draw.text((x, y), watermark_text, fill=(255, 255, 255, 128), font=font)
        
        cropped.save(os.path.join(output_dir, filename), quality=95)
        print(f"{filename} → 裁剪+水印完成")

# 使用
crop_and_watermark(r'D:\商品图', r'D:\成品', 800, '店铺名称')