Python Pillow库批量为图片添加文字水印或图片水印

pip install pillow

from pil import image, imagedraw, imagefont, imageenhance
import os
from pathlib import path

# ==================== 方案 1：文字水印 ====================
def add_text_watermark(input_image, output_image, text="内部资料",
                       position="center", font_size=40, color=(255, 255, 255, 128),
                       angle=0):
    """
    为图片添加文字水印

    参数:
        input_image: 输入图片路径
        output_image: 输出图片路径
        text: 水印文字
        position: 位置 'center'/'bottom-right'/'bottom-left'/'top-right'/'top-left'
        font_size: 字体大小
        color: 字体颜色 (r, g, b, a)
        angle: 旋转角度（0=水平，-30=左倾斜）
    """
    # 打开图片
    img = image.open(input_image).convert('rgba')

    # 创建透明图层
    txt_layer = image.new('rgba', img.size, (255, 255, 255, 0))
    draw = imagedraw.draw(txt_layer)

    # 获取字体
    try:
        font = imagefont.truetype("c:/windows/fonts/msyh.ttc", font_size)  # 微软雅黑
    except:
        font = imagefont.load_default()

    # 计算文字大小和位置
    bbox = draw.textbbox((0, 0), text, font=font)
    text_width = bbox[2] - bbox[0]
    text_height = bbox[3] - bbox[1]

    img_width, img_height = img.size

    positions = {
        'center': ((img_width - text_width) // 2, (img_height - text_height) // 2),
        'bottom-right': (img_width - text_width - 20, img_height - text_height - 20),
        'bottom-left': (20, img_height - text_height - 20),
        'top-right': (img_width - text_width - 20, 20),
        'top-left': (20, 20),
    }

    x, y = positions.get(position, positions['center'])

    # 如果需要旋转
    if angle != 0:
        # 创建更大的图层以容纳旋转后的文字
        big_layer = image.new('rgba', (img_width * 2, img_height * 2), (255, 255, 255, 0))
        big_draw = imagedraw.draw(big_layer)
        big_draw.text((img_width // 2, img_height // 2), text, font=font, fill=color)
        big_layer = big_layer.rotate(angle, expand=0)
        txt_layer = big_layer.crop((img_width // 2, img_height // 2,
                                     img_width // 2 + img_width,
                                     img_height // 2 + img_height))
    else:
        draw.text((x, y), text, font=font, fill=color)

    # 叠加
    result = image.alpha_composite(img, txt_layer)

    # 保存（转回 rgb 以便保存为 jpeg）
    result = result.convert('rgb')
    result.save(output_image, quality=95)
    print(f"文字水印: {os.path.basename(input_image)}")


# ==================== 方案 2：图片水印（logo） ====================
def add_image_watermark(input_image, output_image, logo_path,
                       position="bottom-right", opacity=0.5, scale=0.15):
    """
    为图片添加 logo 水印

    参数:
        input_image: 输入图片
        output_image: 输出图片
        logo_path: logo 图片路径（建议 png 透明背景）
        position: 位置
        opacity: 透明度（0-1，1=完全不透明）
        scale: logo 相对原图大小的比例（0.15=15%）
    """
    img = image.open(input_image).convert('rgba')

    # 打开 logo
    logo = image.open(logo_path).convert('rgba')

    # 缩放 logo
    new_logo_size = (int(img.width * scale), int(img.height * scale * logo.height / logo.width))
    logo = logo.resize(new_logo_size, image.lanczos)

    # 设置 logo 透明度
    if opacity < 1:
        # 调整 alpha 通道
        r, g, b, a = logo.split()
        a = a.point(lambda x: int(x * opacity))
        logo = image.merge('rgba', (r, g, b, a))

    # 计算位置
    positions = {
        'center': ((img.width - logo.width) // 2, (img.height - logo.height) // 2),
        'bottom-right': (img.width - logo.width - 20, img.height - logo.height - 20),
        'bottom-left': (20, img.height - logo.height - 20),
        'top-right': (img.width - logo.width - 20, 20),
        'top-left': (20, 20),
    }

    x, y = positions.get(position, positions['bottom-right'])

    # 创建透明图层并粘贴 logo
    watermark_layer = image.new('rgba', img.size, (0, 0, 0, 0))
    watermark_layer.paste(logo, (x, y))

    # 叠加
    result = image.alpha_composite(img, watermark_layer)
    result = result.convert('rgb')
    result.save(output_image, quality=95)
    print(f"logo水印: {os.path.basename(input_image)}")


# ==================== 方案 3：平铺水印（全屏重复） ====================
def add_tiled_watermark(input_image, output_image, text="内部资料",
                        font_size=30, color=(255, 255, 255, 50), angle=-30, spacing=150):
    """
    添加平铺水印（全屏重复文字）
    """
    img = image.open(input_image).convert('rgba')
    txt_layer = image.new('rgba', img.size, (255, 255, 255, 0))
    draw = imagedraw.draw(txt_layer)

    try:
        font = imagefont.truetype("c:/windows/fonts/msyh.ttc", font_size)
    except:
        font = imagefont.load_default()

    # 计算文字大小
    bbox = draw.textbbox((0, 0), text, font=font)
    text_width = bbox[2] - bbox[0]
    text_height = bbox[3] - bbox[1]

    # 平铺
    y = 0
    while y < img.height:
        x = 0
        row_offset = (y // spacing) % 2 * (spacing // 2)  # 错行排列
        while x < img.width:
            draw.text((x + row_offset, y), text, font=font, fill=color)
            x += text_width + spacing
        y += text_height + spacing

    result = image.alpha_composite(img, txt_layer)
    result = result.convert('rgb')
    result.save(output_image, quality=95)
    print(f"平铺水印: {os.path.basename(input_image)}")


# ==================== 批量处理 ====================
def batch_add_watermark(input_dir, output_dir, watermark_func, **kwargs):
    """
    批量为文件夹中的所有图片添加水印
    """
    input_path = path(input_dir)
    output_path = path(output_dir)
    output_path.mkdir(parents=true, exist_ok=true)

    image_extensions = {'.jpg', '.jpeg', '.png', '.bmp', '.webp', '.tiff'}
    count = 0

    for file_path in input_path.iterdir():
        if file_path.is_file() and file_path.suffix.lower() in image_extensions:
            output_file = output_path / file_path.name
            watermark_func(str(file_path), str(output_file), **kwargs)
            count += 1

    print(f"\n批量水印完成: {count} 张图片")


# ==================== 使用示例 ====================
if __name__ == "__main__":
    # 单个文件
    # add_text_watermark("工牌照片.jpg", "工牌_水印.jpg", text="内部资料", position="center", font_size=50)

    # 批量文字水印
    batch_add_watermark(
        input_dir="原始工牌照片",
        output_dir="已加水印",
        watermark_func=add_text_watermark,
        text="仅限内部使用",
        position="center",
        font_size=40,
    )

    # 批量 logo 水印
    # batch_add_watermark(
    #     input_dir="产品图片",
    #     output_dir="已加logo",
    #     watermark_func=add_image_watermark,
    #     logo_path="company_logo.png",
    #     position="bottom-right",
    #     opacity=0.7,
    #     scale=0.1
    # )

    # 平铺水印（防截图）
    # batch_add_watermark(
    #     input_dir="机密文档截图",
    #     output_dir="平铺水印",
    #     watermark_func=add_tiled_watermark,
    #     text="机密文件",
    #     font_size=25,
    #     angle=-30,
    # )

font = imagefont.truetype("c:/windows/fonts/msyh.ttc", font_size)  # 微软雅黑
# 或
font = imagefont.truetype("c:/windows/fonts/simsun.ttc", font_size)  # 宋体

color=(255, 255, 255, 50)  # alpha=50，更透明

result.save(output_image, 'png')