/media-image — Image Generation & Management

Generate contextual images for your post and resize them for each platform.

Uses excalidraw-skill for diagrams and illustrations (hand-drawn Excalidraw style). Optionally uses DALL-E for photo-style hero images.

Prerequisites

Before starting, read these shared library files:

• Read lib/image-processing.md for resizing commands and platform sizes
• Read lib/manifest-ops.md for updating the manifest
• Read lib/adapter-discovery.md for platform image size requirements

Step 1: Locate the Post

If the user specifies a post path, use it. Otherwise, find the most recent post:

ls -dt content/posts/*/ 2>/dev/null | head -1

Read source.md to understand the content. Read manifest.yaml for existing state.

Step 2: Check Dependencies

echo "=== Image Dependencies ==="

# Check ImageMagick (for resizing)
which convert >/dev/null 2>&1 && echo "[OK] ImageMagick" || echo "[MISSING] ImageMagick — needed for resizing (brew install imagemagick)"

# Check excalidraw-skill (for diagrams)
EXCALIDRAW_SKILL=""
[ -f ".claude/skills/excalidraw-skill/skill/SKILL.md" ] && EXCALIDRAW_SKILL="local"
[ -f "$HOME/.claude/skills/excalidraw-skill/skill/SKILL.md" ] && EXCALIDRAW_SKILL="global"
[ -n "$EXCALIDRAW_SKILL" ] && echo "[OK] excalidraw-skill ($EXCALIDRAW_SKILL)" || echo "[MISSING] excalidraw-skill — install from https://github.com/Minara-AI/excalidraw-skill"

# Check OpenAI API key (optional, for photo-style hero images)
grep -q "^OPENAI_API_KEY=." .env 2>/dev/null && echo "[OK] DALL-E (photo hero images)" || echo "[OPTIONAL] No OPENAI_API_KEY — DALL-E unavailable, using excalidraw only"

Step 3: Plan Images

Analyze source.md and identify where images would add value:

1. Hero/cover image: A cover image that captures the article's theme
2. In-article diagrams: Architecture diagrams, flowcharts, concept maps
3. In-article illustrations: Visual explanations for complex concepts

Use AskUserQuestion to present the image plan: "Here are the images I'd generate for this post. Approve or modify?"

For each image, show:

• Description of what it depicts
• Where it appears in the article
• Generation method: /excalidraw (diagram) or DALL-E (photo-style)

Options:

• A) Generate all
• B) Select specific images
• C) I'll provide my own images (skip to Step 6)
• D) Skip images entirely

Step 4: Generate Images

Diagrams and illustrations (excalidraw-skill)

For each diagram/illustration, use the /excalidraw skill:

/excalidraw Draw <description> — output to <post_dir>/assets/<filename>.png

The excalidraw-skill generates hand-drawn style diagrams with Virgil font, hachure fills, and clean monochrome aesthetics. It's ideal for:

• Architecture diagrams
• Flowcharts and workflows
• Concept maps
• System component diagrams
• Before/after comparisons

If excalidraw-skill is not installed, tell the user: "excalidraw-skill not found. Install it for diagram generation: bash /path/to/excalidraw-skill/install.sh Or provide your own images in the assets/ directory."

Photo-style hero images (DALL-E, optional)

If the user wants a photo-style hero image AND OPENAI_API_KEY is configured:

source .env
URL=$(curl -s https://api.openai.com/v1/images/generations \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d "{\"model\":\"dall-e-3\",\"prompt\":\"<prompt>\",\"n\":1,\"size\":\"1792x1024\",\"quality\":\"standard\"}" \
  | python3 -c "import sys,json; print(json.load(sys.stdin)['data'][0]['url'])")

curl -s -o "<post_dir>/assets/hero.png" "$URL"

If DALL-E is unavailable, use excalidraw for the hero image too, or skip it.

Step 5: Resize for Platforms

For each configured adapter, read adapter.yaml to get image sizes. Resize using ImageMagick:

# Example for Dev.to cover (1000x420)
convert "<post_dir>/assets/hero.png" \
  -resize 1000x420^ -gravity center -extent 1000x420 \
  "<post_dir>/assets/hero-devto.png"

Generate all platform-specific sizes as listed in lib/image-processing.md.

If ImageMagick is not installed, warn the user and skip resizing. The original images will be used (platforms may crop them differently).

Step 6: Update Manifest

Add generated images to the manifest's assets list:

assets:
  - name: hero.png
    type: photo
    prompt: "<prompt used>"
    generator: dall-e-3
    generated: <ISO 8601 timestamp>
    sizes:
      devto: assets/hero-devto.png
      hashnode: assets/hero-hashnode.png
      github-pages: assets/hero-blog.png
  - name: architecture-diagram.png
    type: diagram
    prompt: "<description>"
    generator: excalidraw
    generated: <ISO 8601 timestamp>

Use the atomic write pattern from lib/manifest-ops.md.

Step 7: Update Variant Image References

For each variant file in variants/, update image paths to reference the platform-specific resized version. For example, in variants/devto.md, change cover_image to point to hero-devto.png.

Step 8: Summary

Images generated for "<title>":

  [OK] hero.png — cover image via DALL-E (1792x1024)
       → hero-devto.png (1000x420)
       → hero-hashnode.png (1600x840)
       → hero-blog.png (1200x630)
  [OK] architecture-diagram.png — via excalidraw-skill
  [OK] workflow.png — via excalidraw-skill

Manifest updated. Next: run /media-publish to publish.