import gradio as gr from PIL import Image import io import zipfile import random def random_black_or_white(): """返回 RGBA (黑 或 白)，50% 概率""" return (0, 0, 0, 255) if random.random() < 0.5 else (255, 255, 255, 255) def random_non_black_white(): """ 返回 (r,g,b,a)，且不是纯黑(0,0,0)也不是纯白(255,255,255)。 用于最后不足4张时的空格颜色填充。 """ while True: r = random.randint(0, 255) g = random.randint(0, 255) b = random.randint(0, 255) if not (r == g == b == 0 or r == g == b == 255): return (r, g, b, 255) def limit_2048(img: Image.Image): """若宽或高大于2048，则等比例缩小到不超过2048。""" w, h = img.size if w > 2048 or h > 2048: scale = min(2048 / w, 2048 / h) new_w = int(w * scale) new_h = int(h * scale) img = img.resize((new_w, new_h), Image.Resampling.LANCZOS) return img def resize_to_64_multiple(img: Image.Image): """ 将图像就近缩放到(w', h')，其中 w'、h'均为64倍数（至少64）。 空余区域随机黑/白填充，保留透明度。 """ w, h = img.size w64 = max(64, round(w / 64) * 64) h64 = max(64, round(h / 64) * 64) scale = min(w64 / w, h64 / h) nw = int(w * scale) nh = int(h * scale) bg_color = random_black_or_white() background = Image.new("RGBA", (w64, h64), bg_color) scaled = img.resize((nw, nh), Image.Resampling.LANCZOS) ox = (w64 - nw) // 2 oy = (h64 - nh) // 2 background.paste(scaled, (ox, oy), scaled) return background def make_collage_2x2(images_4): """传入4张同尺寸RGBA，以2×2拼接，并限制在2048以内。""" w, h = images_4[0].size collage = Image.new("RGBA", (2*w, 2*h), (0, 0, 0, 255)) collage.paste(images_4[0], (0, 0), images_4[0]) collage.paste(images_4[1], (w, 0), images_4[1]) collage.paste(images_4[2], (0, h), images_4[2]) collage.paste(images_4[3], (w, h), images_4[3]) return limit_2048(collage) def make_collage_leftover(images_leftover): """ 针对不足4张(1~3)的情况，随机布局(1x1,1x2,2x1,2x2等)容纳这些图片， 其余空格以“非黑非白”的纯色填充，并最终限制2048以内。 """ n = len(images_leftover) if n < 1 or n > 3: return None # 先做“64倍数随机黑/白填充”缩放 resized_list = [resize_to_64_multiple(img) for img in images_leftover] # 找最大宽、高，统一尺寸 max_w = max(im.size[0] for im in resized_list) max_h = max(im.size[1] for im in resized_list) # 再居中贴到背景 (max_w, max_h) 保证每张图一致 uniformed = [] for rimg in resized_list: w, h = rimg.size if (w, h) == (max_w, max_h): uniformed.append(rimg) else: # 用本身的背景色(左上像素)来填充 bg_color = rimg.getpixel((0,0)) bg = Image.new("RGBA", (max_w, max_h), bg_color) offx = (max_w - w) // 2 offy = (max_h - h) // 2 bg.paste(rimg, (offx, offy), rimg) uniformed.append(bg) # 选定随机布局 # n=1: (1x1),(1x2),(2x1),(2x2) # n=2: (1x2),(2x1),(2x2) # n=3: (2x2) possible_layouts = [] if n == 1: possible_layouts = [(1,1), (1,2), (2,1), (2,2)] elif n == 2: possible_layouts = [(1,2), (2,1), (2,2)] else: # n == 3 possible_layouts = [(2,2)] rows, cols = random.choice(possible_layouts) big_w = cols * max_w big_h = rows * max_h collage = Image.new("RGBA", (big_w, big_h), (0,0,0,255)) # 网格坐标 cells = [(r, c) for r in range(rows) for c in range(cols)] random.shuffle(cells) # 把uniformed中的图贴到前n个格子 for i, img_ in enumerate(uniformed): r, c = cells[i] offset_x = c * max_w offset_y = r * max_h collage.paste(img_, (offset_x, offset_y), img_) # 剩余格子(空格)用“非黑非白”的随机色填充 leftover_cells = cells[n:] for (r, c) in leftover_cells: color_ = random_non_black_white() rect = Image.new("RGBA", (max_w, max_h), color_) collage.paste(rect, (c*max_w, r*max_h), rect) return limit_2048(collage) def process_images(uploaded_files): """ 1) 分成若干4张组 => each 2x2； 2) 对最后剩余(1~3张)，make_collage_leftover 处理。 3) 返回所有结果图 """ pil_images = [] for f in uploaded_files: if f is not None: # 保留透明 img = Image.open(f.name).convert("RGBA") pil_images.append(img) results = [] total = len(pil_images) groups_4 = total // 4 leftover = total % 4 idx = 0 # 先拼满4张的组 for _ in range(groups_4): group_4 = pil_images[idx:idx+4] idx += 4 # 每张先resize resized_4 = [resize_to_64_multiple(im) for im in group_4] # 再统一max_w, max_h max_w = max(im.size[0] for im in resized_4) max_h = max(im.size[1] for im in resized_4) final_4 = [] for rimg in resized_4: w, h = rimg.size if (w, h) == (max_w, max_h): final_4.append(rimg) else: # 补背景居中 bg_color = rimg.getpixel((0,0)) bg = Image.new("RGBA", (max_w, max_h), bg_color) offx = (max_w - w)//2 offy = (max_h - h)//2 bg.paste(rimg, (offx, offy), rimg) final_4.append(bg) collage_2x2 = make_collage_2x2(final_4) results.append(collage_2x2) # 再拼 leftover 1~3张 if leftover > 0: leftover_images = pil_images[idx:] collage_left = make_collage_leftover(leftover_images) if collage_left is not None: results.append(collage_left) return results def make_zip(uploaded_files): """把所有拼接结果打包成zip并返回给Gradio的File组件。""" collages = process_images(uploaded_files) # 若无生成任何拼图 if not collages: # 返回 None 说明无法下载；会显示“无可下载内容”提示 return None buf = io.BytesIO() with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as zf: for i, img in enumerate(collages, start=1): img_bytes = io.BytesIO() img.save(img_bytes, format="PNG") img_bytes.seek(0) zf.writestr(f"collage_{i}.png", img_bytes.read()) buf.seek(0) return buf def on_zip_click(files): """ 用来返回 (zip_file_obj, message_str) 两个输出： 1) zip_file_obj 要么是zip流，要么是None； 2) message_str 用于提示结果或错误。 """ z = make_zip(files) if z is None: return (None, "无可下载内容 - 请检查是否上传了图片或剩余不足4张且无法拼图") else: return (z, "打包完成！可点击上方链接下载。") with gr.Blocks() as demo: gr.Markdown("## 2×2 拼接小工具（支持最后不足4张、随机填充、保留透明）") with gr.Row(): with gr.Column(): file_input = gr.Files(label="上传多张图片", file_types=["image"]) preview_btn = gr.Button("生成预览") zip_btn = gr.Button("打包下载 ZIP") with gr.Column(): # 不使用 .style() 以兼容老Gradio gallery_out = gr.Gallery(label="拼接结果预览", columns=2) # 一开始就 visible=True，这样点击按钮后能马上显示下载链接 zip_file_out = gr.File(label="点击下载打包结果", visible=True, interactive=False) msg_output = gr.Textbox(label="处理信息", interactive=False) # 生成预览 preview_btn.click( fn=process_images, inputs=[file_input], outputs=[gallery_out] ) # 打包下载ZIP，额外给一个文本提示 zip_btn.click( fn=on_zip_click, inputs=[file_input], outputs=[zip_file_out, msg_output] ) demo.launch()