WeChat Cover Generator（公众号封面生成）

Overview

Generate production-ready WeChat Official Account article covers from an article file or a topic description. The workflow handles the entire pipeline: reading the article's publish info block (title candidates / summary / cover suggestion), choosing a visual style, generating a 1:1 master image, applying Chinese title overlay with system fonts, producing all three required formats, and running programmatic QA.

The critical rule this skill encodes: WeChat's backend accepts only ONE cover image, but automatically crops two displays — the headline card shows the full 2.35:1 image, while the share thumbnail shows the CENTER 1:1 region. Therefore key content must live in the central safe zone. See references/wechat-cover-rules.md §1.

Workflow

Step 1 · Read the article

Read the article file. Extract the publish-info block at the top (usually quoted lines starting with >):

• 标题（候选列表，选最贴合的一个，可浓缩为 4-8 字主标题 + 副标题）
• 摘要（80 字内）
• 封面建议（若有，作为风格参考；用户可要求自由发挥）
• 文章类型（科普/叙事/行业洞察 → 决定风格，见风格库）

Step 2 · Choose a style and industry imagery

Consult the style library in references/wechat-cover-rules.md §3. Quick guide:

Choose industry-specific imagery（references/wechat-cover-rules.md §3.5）— the most important step for cover quality:

• Follow the 意象选择三步法: list 3-5 candidate symbols for the topic's field, verify each is field-exclusive (reject generic symbols like yin-yang, hearts, stars, gears), then prefer material contrast against the counterpart.
• Use the 行业意象速查表 for common fields (中医/金融/教育/科技/西医/电商/农业/法律/建筑/历史), and search references for any niche/unfamiliar symbol before prompting.
• General rule: generic symbols dilute professionalism; field-exclusive tools and artifacts (针灸铜人, 算盘, 芯片, 化验单...) read instantly.

Step 3 · Generate the 1:1 master image

Use the image generation tool (ImageGen / equivalent) with size 1024x1024. Follow the prompt template in references/wechat-cover-rules.md §4.

Mandatory prompt requirements:

• square 1:1 composition, subject fills the lower two thirds, centered horizontally
• upper third reserved as clean empty background for title overlay
• generous safe margins, full subject visible, no crop
• For short labels (2-5 chars) that the image model renders: list ALL labels with explicit positions and add ALL N ... MUST appear, no exceptions, no omissions（多标签防漏技巧，§4）

Never ask the image model to render titles longer than ~6 characters — overlay them with PIL instead (§4, §5).

Step 4 · Run the post-processing script

Run scripts/make_cover.py with the generated 1:1 master image:

python scripts/make_cover.py <input_1x1_image> \
  --title "主标题" \
  --subtitle "副标题" \
  -o <output_dir>

The script produces (default modes square,wide,dual):

1. cover_1x1_*.png — 1080×1080 square share cover
2. cover_900x383_*.png — wide headline cover (crops the 2.35:1 band from center; --crop-center adjusts, default 0.52)
3. cover_单图双用.png — single-image dual-use cover: central 383×383 safe zone (subject + title) with blurred ambiance extension on both sides. This is the recommended upload.

Use --modes square or --modes wide to generate only specific formats.

Step 5 · Verify with built-in QA

The script runs automatic pixel-sampling QA after each render (title-region pixel counts). Check the output:

• [QA] ... ✅ for every mode. If a mode shows ⚠️ 偏低, inspect the title region or re-run with adjusted parameters.
• For extra verification (no image-viewing capability), follow the QA table in references/wechat-cover-rules.md §6: background sampling, warm-pixel grid for subject location, title pixel count.

Step 6 · Deliver

• Present the cover_单图双用.png first (recommended upload), then the wide and square versions.
• Also write a short 封面说明 markdown next to the covers recording: design rationale, title scheme, and QA results.
• File placement convention: if the article lives in a platform-organized folder structure (e.g. docs/软文/公众号/02_科普_.../ where each article has its own subfolder holding copy + images), save all generated covers and the 封面说明 into that article's subfolder — never scatter them at the platform root. Platform-level files (e.g. _发布须知.md) stay at the platform root.

Concrete Example

User: "给这篇文章做一个封面" (attaching an article .md)

1. Read article → extract title candidates & cover suggestion.
2. Pick style (article-type → style library) and pick industry imagery (§3.5 意象三步法 + 速查表).
3. ImageGen 1024×1024 with prompt template (subject centered, upper third empty).
4. python make_cover.py master.png --title "最难的不是技术" --subtitle "做灵素AI 这一年" -o <article_dir>
5. Confirm 3 QA ✅ lines.
6. Present dual-use + wide + square, write 封面说明.md.

Resources

• scripts/make_cover.py — PIL post-processing: title/subtitle overlay (auto light/dark text color by background), 900×383 crop, 1080×1080 square, 383×383 central safe-zone dual-use layout, programmatic QA. Auto-detects Chinese fonts (Windows 微软雅黑 / macOS 苹方 / Linux Noto).
• references/wechat-cover-rules.md — WeChat cover crop mechanics, full workflow, style library (with prompt elements per style), industry-specific imagery library with 意象三步法 + 10-domain quick-reference table (中医/金融/教育/科技/西医/电商/农业/法律/建筑/历史), ImageGen prompt templates, multi-label anti-dropout tricks, PIL title spec, QA table, delivery checklist.