Python 批量拼接图片合成竖长长图教程

用 Pillow 把多张截图竖向或横向拼接成一张长图，自动对齐宽度、留间距、支持加底色，适合聊天记录、海报组图、代码截图批量合成。

场景痛点

做教程时要把十几张截图拼成一张长图发朋友圈或写文档，用截图工具一张张拖，对齐宽度、调间距都得手动，长图导出还经常被压缩。用 Python 把一个文件夹里的图按文件名顺序自动竖向拼接，统一宽度、自动留缝、背景填白，一秒出图。

用到的库

pip install Pillow

完整代码

# -*- coding: utf-8 -*-
# 把文件夹里的图片按文件名顺序竖向拼接成一张长图
import os
from PIL import Image

IMG_EXTS = {".jpg", ".jpeg", ".png", ".bmp", ".webp"}

def vconcat_images(input_dir, out_path, target_width=1080,
gap=20, bg_color=(255, 255, 255)):
"""竖向拼接：统一缩放到 target_width，图之间留 gap 像素白缝"""
files = [f for f in sorted(os.listdir(input_dir))
if os.path.splitext(f)[1].lower() in IMG_EXTS]
if not files:
print("没有找到图片")
return

frames = []
for name in files:
with Image.open(os.path.join(input_dir, name)) as im:
im = im.convert("RGB")
# 按目标宽度等比缩放
ratio = target_width / im.width
new_h = int(im.height * ratio)
im = im.resize((target_width, new_h), Image.LANCZOS)
frames.append(im)
print(f"加载 {name} -> {target_width}x{new_h}")

total_h = sum(f.height for f in frames) + gap * (len(frames) - 1)
canvas = Image.new("RGB", (target_width, total_h), bg_color)

y = 0
for f in frames:
canvas.paste(f, (0, y))
y += f.height + gap

canvas.save(out_path, quality=92)
print(f"完成：{out_path}  尺寸 {target_width}x{total_h}")

def hconcat_images(input_dir, out_path, target_height=1080,
gap=20, bg_color=(255, 255, 255)):
"""横向拼接：统一高度，从左到右排"""
files = [f for f in sorted(os.listdir(input_dir))
if os.path.splitext(f)[1].lower() in IMG_EXTS]
frames = []
for name in files:
with Image.open(os.path.join(input_dir, name)) as im:
im = im.convert("RGB")
ratio = target_height / im.height
new_w = int(im.width * ratio)
frames.append(im.resize((new_w, target_height), Image.LANCZOS))

total_w = sum(f.width for f in frames) + gap * (len(frames) - 1)
canvas = Image.new("RGB", (total_w, target_height), bg_color)
x = 0
for f in frames:
canvas.paste(f, (x, 0))
x += f.width + gap
canvas.save(out_path, quality=92)
print(f"完成：{out_path}  尺寸 {total_w}x{target_height}")

if __name__ == "__main__":
# 把 ./shots 下的截图竖向拼成 1080 宽的长图
vconcat_images("./shots", "./long_image.jpg",
target_width=1080, gap=20)