def natural_sort_key(s):
    """自然排序：確保 1.jpg, 2.jpg, 10.jpg 按數(shù)字順序排列"""
    return [int(text) if text.isdigit() else text.lower()
            for text in re.split('([0-9]+)', s)]

# ? 核心：按行切分
rows = []
for i in range(0, len(group_images), COLS):
    rows.append(group_images[i:i + COLS])

for row_idx, row_images in enumerate(rows):
    y = row_idx * img_height
    num_in_row = len(row_images)

    # ? 核心：最后一行居中
    if num_in_row == COLS:
        offset_x = 0  # 滿行，左對齊
    else:
        # 不滿行，計算居中偏移量
        total_width = num_in_row * img_width
        offset_x = (canvas_width - total_width) // 2

with Image.open(img_path) as img:
    # 尺寸統(tǒng)一：如果不一致，用LANCZOS算法高質(zhì)量重采樣
    if img.size != (img_width, img_height):
        print(f"警告: {os.path.basename(img_path)} 尺寸不一致，已調(diào)整")
        img = img.resize((img_width, img_height), Image.Resampling.LANCZOS)

    # 模式統(tǒng)一：比如有的是RGB，有的是RGBA，統(tǒng)一成基準圖的模式
    if img.mode != img_mode:
        img = img.convert(img_mode)

    canvas.paste(img, (x, y))

save_params = {}

# 如果是JPG/JPEG，設(shè)置最高質(zhì)量，禁用色度子采樣
if input_extension.lower() in ['.jpg', '.jpeg']:
    save_params['quality'] = 100
    save_params['subsampling'] = 0

# 如果原圖有DPI信息，繼承下來
if img_dpi:
    save_params['dpi'] = img_dpi

canvas.save(save_path, **save_params)

import re
from PIL import Image
import os

# ==================== 手動配置區(qū) ====================
TARGET_PATH = r'你的圖片文件夾路徑'  # 請修改此處
IMAGES_PER_GROUP = 3   # 每組幾張圖
ROWS = 2               # 行數(shù)
COLS = 2               # 列數(shù)
BOTTOM_PADDING = 0     # 底部留白（像素）
# ===================================================


def natural_sort_key(s):
    """自然排序：確保 1.jpg, 2.jpg, 10.jpg 按數(shù)字順序排列"""
    return [int(text) if text.isdigit() else text.lower()
            for text in re.split('([0-9]+)', s)]


def create_collage(folder_path):
    # 1. 讀取并篩選圖片
    valid_extensions = ('.jpg', '.jpeg', '.png', '.bmp', '.webp', '.tiff')
    raw_files = [
        f for f in os.listdir(folder_path)
        if f.lower().endswith(valid_extensions)
    ]

    # 排除之前生成的拼圖，防止重復(fù)處理
    raw_files = [f for f in raw_files if "collage_final" not in f]

    # 按自然順序排序并拼接完整路徑
    image_files = sorted(
        [os.path.join(folder_path, f) for f in raw_files],
        key=natural_sort_key
    )

    if not image_files:
        print("未找到圖片，請檢查路徑。")
        return

    # 2. 讀取第一張圖作為基準，獲取尺寸、模式、DPI等信息
    with Image.open(image_files[0]) as first_img:
        img_width, img_height = first_img.size
        input_extension = os.path.splitext(image_files[0])[1]
        img_mode = first_img.mode
        img_dpi = first_img.info.get('dpi')

        print(f"\n--- 原始分辨率識別 ---")
        print(f"單圖尺寸: {img_width} x {img_height}")
        print(f"色彩模式: {img_mode}")
        print(f"輸出格式: {input_extension}")
        if img_dpi:
            print(f"DPI: {img_dpi}")

    # 3. 計算畫布總尺寸
    canvas_width = COLS * img_width
    canvas_height = ROWS * img_height + BOTTOM_PADDING

    # 4. 分組（如果圖片很多，可以分成多張拼圖）
    groups = [
        image_files[i:i + IMAGES_PER_GROUP]
        for i in range(0, len(image_files), IMAGES_PER_GROUP)
    ]

    for group_num, group_images in enumerate(groups):
        # 創(chuàng)建白色背景畫布
        canvas = Image.new(img_mode, (canvas_width, canvas_height), color='white')

        # ? 核心邏輯：將當前組的圖片按行切分
        rows = []
        for i in range(0, len(group_images), COLS):
            rows.append(group_images[i:i + COLS])

        # 逐行粘貼圖片
        for row_idx, row_images in enumerate(rows):
            y = row_idx * img_height
            num_in_row = len(row_images)

            # ? 核心邏輯：計算當前行的X偏移量（實現(xiàn)居中）
            if num_in_row == COLS:
                offset_x = 0
            else:
                total_width = num_in_row * img_width
                offset_x = (canvas_width - total_width) // 2

            # 逐列粘貼圖片
            for col_idx, img_path in enumerate(row_images):
                x = offset_x + col_idx * img_width

                try:
                    with Image.open(img_path) as img:
                        # 統(tǒng)一尺寸
                        if img.size != (img_width, img_height):
                            print(f"警告: {os.path.basename(img_path)} 尺寸不一致，已調(diào)整")
                            img = img.resize((img_width, img_height), Image.Resampling.LANCZOS)
                        
                        # 統(tǒng)一色彩模式
                        if img.mode != img_mode:
                            img = img.convert(img_mode)

                        canvas.paste(img, (x, y))

                except Exception as e:
                    print(f"處理出錯: {img_path}, 原因: {e}")

        # 5. 保存文件
        suffix = f"_{group_num + 1}" if len(groups) > 1 else ""
        save_name = f"collage_final{suffix}{input_extension}"
        save_path = os.path.join(folder_path, save_name)

        save_params = {}
        # JPG特殊處理：最高質(zhì)量
        if input_extension.lower() in ['.jpg', '.jpeg']:
            save_params['quality'] = 100
            save_params['subsampling'] = 0
        # 繼承DPI
        if img_dpi:
            save_params['dpi'] = img_dpi

        canvas.save(save_path, **save_params)
        print(f"? 成功生成: {save_name}")


if __name__ == "__main__":
    create_collage(TARGET_PATH)

pip install pillow

python image_collage.py