AI商业海报设计：从提示词到可交付稿的工程化实践

import os, io, requests
from openai import OpenAI
from PIL import Image, ImageDraw, ImageFont

client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

def generate_bg(prompt):
    resp = client.images.generate(
        model="dall-e-3",
        prompt=prompt,
        size="1024x1792",   # 竖版，接近 9:16
        quality="hd",
        n=1
    )
    url = resp.data[0].url
    return Image.open(io.BytesIO(requests.get(url).content)).convert("RGB")

prompt = ("商业护肤海报背景，产品位于画面下方三分之一，上方大面积留白，"
          "极简高级，柔和自然光，浅灰与香槟金，影棚质感，"
          "无文字，无水印，超清，4k")
bg = generate_bg(prompt).resize((1080, 1920))

def draw_poster(bg, title, subtitle, cta, brand,
                font_path="SourceHanSansCN-Bold.otf"):
    img = bg.copy()
    draw = ImageDraw.Draw(img)
    W, H = img.size
    title_font = ImageFont.truetype(font_path, 88)
    sub_font = ImageFont.truetype(font_path, 42)
    cta_font = ImageFont.truetype(font_path, 38)
    brand_font = ImageFont.truetype(font_path, 32)

    # 安全区：左右 8%，顶部 10%，底部 12%
    margin = int(W * 0.08)
    y = int(H * 0.12)

    def wrap(text, font, max_w):
        lines, cur = [], ""
        for ch in text:
            if draw.textlength(cur + ch, font=font) <= max_w:
                cur += ch
            else:
                lines.append(cur); cur = ch
        if cur: lines.append(cur)
        return lines

    for line in wrap(title, title_font, W - margin * 2):
        draw.text((margin, y), line, font=title_font, fill="#1A1A1A")
        y += 110
    y += 20
    for line in wrap(subtitle, sub_font, W - margin * 2):
        draw.text((margin, y), line, font=sub_font, fill="#555555")
        y += 60

    # CTA 按钮
    btn_w, btn_h = 360, 96
    btn_x, btn_y = margin, H - int(H * 0.18)
    draw.rounded_rectangle([btn_x, btn_y, btn_x + btn_w, btn_y + btn_h],
                           radius=48, fill="#C9A96A")
    draw.text((btn_x + 48, btn_y + 28), cta, font=cta_font, fill="#FFFFFF")

    draw.text((margin, H - int(H * 0.08)), brand,
              font=brand_font, fill="#1A1A1A")
    return img

poster = draw_poster(bg, "焕活新肌", "28天见证透亮光感",
                     "立即体验", "AURORA")
poster.save("poster_9x16.jpg", quality=95)

# 多尺寸导出
for ratio, size in {"1:1": (1080, 1080), "16:9": (1920, 1080)}.items():
    poster.resize(size).save(f"poster_{ratio.replace(':','x')}.jpg",
                             quality=95)