Image Gen
Contents
- •Overview
- •When to Use This Skill
- •Workflow
- •Command Reference
- •Prompt Engineering Best Practices
- •Common Patterns
- •Resources
Overview
Generate high-quality images for technical articles using the imagen CLI tool (powered by gemini-2.5-flash-image). This skill provides a systematic workflow for creating two types of images:
- •Cover Images: High-impact, conceptual images that grab attention on LinkedIn/Medium
- •In-Article Images: Technical diagrams and illustrations that explain specific concepts
The skill includes comprehensive prompt engineering guidance and best practices for integrating images with SEO-friendly ALT text.
When to Use This Skill
Invoke this skill when:
- •Creating visual assets for a completed or near-complete article
- •User requests "generate images for this article" or similar
- •Article needs a cover image for publication
- •Technical concepts would benefit from visual explanation
- •Breaking up long text sections with relevant imagery
- •Optimizing article for LinkedIn/Medium with visual appeal
Typical workflow position: After article content is finalized (Phase 8 in the article enhancement workflow), before SEO optimization.
Workflow
Step 1: Analyze Article Content
Before generating any images, analyze the article to identify:
- •Article topic and key themes: What is the main subject?
- •Key concepts needing visualization: Which technical ideas are complex or abstract?
- •Section breaks: Where would images improve readability?
- •Target audience: Developers? DevOps? Beginners or advanced?
Output: List of 2-4 images needed (1 cover + 1-3 in-article)
Example:
Article: "Mastering Alembic for Database Migrations" Images needed: - Cover: Conceptual image representing database evolution/migration - Image 1: Diagram showing migration workflow - Image 2: Visual comparing manual SQL vs Alembic automation
Step 2: Generate Cover Image
Cover images should be high-impact, conceptual, and visually interesting to grab attention. They are often metaphorical rather than literal.
Prompt Engineering for Covers:
- •Style keywords:
digital art,3D render,conceptual art,abstract - •Atmosphere:
cinematic lighting,dramatic,futuristic,professional - •Composition: Specify angle, focus, and elements
- •Structure:
[Style] cover image of [Metaphor/Concept] representing [Article Topic], [Atmosphere/Lighting], [Composition]
Command:
imagen generate "DETAILED PROMPT" --output work/images/[article_name]_cover.png
Example Prompts:
For a Vertex AI article:
imagen generate "A stunning digital art cover image showing three glowing pathways converging into a central AI cloud platform. Each pathway is a different color (green, blue, gold) representing different AI models flowing into Google Cloud infrastructure. The scene has dramatic cinematic lighting with a futuristic tech aesthetic. Style: conceptual, 3D render, high-detail, professional." --output work/images/vertex_ai_cover.png
For an Alembic article:
imagen generate "A dramatic 3D render showing a database schema transforming like evolving architecture, with migration files as glowing blueprints guiding the transformation. Dark background with cinematic lighting highlighting the evolution process. Style: conceptual art, digital art, high-detail, professional." --output work/images/alembic_cover.png
Tips:
- •Be specific and detailed (100+ words is fine)
- •Use metaphors that resonate with the topic
- •Specify lighting/atmosphere for mood
- •Include "professional" or "high-detail" for quality
Step 3: Generate In-Article Images (1-3)
In-article images should explain or reinforce specific concepts from the text. They are more direct and educational than cover images.
Prompt Engineering for In-Article Images:
- •Style keywords:
technical diagram,blueprint,minimalist illustration,clean - •Clarity:
clear labels,connecting arrows,color-coded,organized - •Purpose: Focus on explaining one specific concept
- •Structure:
[Style] showing [Specific Concept], [Visual Elements], [Labels/Clarity]
Command:
imagen generate "CONCEPT-SPECIFIC PROMPT" --output work/images/[article_name]_[concept].png
Example Prompts:
For a technical diagram:
imagen generate "A clean technical diagram showing three distinct client libraries connecting to a central Vertex AI platform. Use color-coded arrows: green for native Google SDK, blue for partner Anthropic SDK, and gold for OpenAI-compatible SDK. Include clear labels for each connection path. Style: blueprint, technical diagram, clear labels, professional." --output work/images/vertex_ai_three_patterns.png
For a comparison illustration:
imagen generate "A minimalist side-by-side comparison showing traditional infrastructure (left) with tangled wires and manual configuration versus modern infrastructure-as-code (right) with clean, organized flow. Use contrasting colors and simple icons. Style: clean, minimalist illustration, symbolic." --output work/images/traditional_vs_iac.png
For a workflow diagram:
imagen generate "A flowchart-style diagram showing the Alembic migration workflow: 1) Model changes → 2) Auto-generate migration → 3) Review migration → 4) Apply to database. Use arrows connecting each step with clear labels. Style: blueprint, technical flowchart, organized, clean." --output work/images/alembic_workflow.png
Tips:
- •Focus on one concept per image
- •Use color-coding to distinguish elements
- •Request "clear labels" or "connecting arrows" for clarity
- •Simpler is often better for technical diagrams
Step 4a: Integrate Images
CRITICAL: Integrate generated images into the article at strategic locations.
Integration Checklist:
- •Create
work/images/directory if needed - •Verify all images generated successfully (cover + in-article)
- •Add cover image immediately after H1 title
- •Add in-article images at strategic section breaks
- •Save updated article as new version (e.g.,
v8_with_images.md)
Markdown Integration Format:
# Article Title  ## Introduction Text introducing the problem... 
Step 4b: Write ALT Text
Write descriptive ALT text (50-125 characters) for each image to ensure accessibility and SEO.
Good ALT Text (descriptive, specific):
- •"Architecture diagram showing Cloud Run connecting through VPC Connector to AlloyDB in private subnet"
- •"Comparison showing manual infrastructure with tangled wires versus automated infrastructure-as-code"
- •"Flowchart illustrating Alembic migration workflow from model changes to database update"
Bad ALT Text (vague, non-descriptive):
- •"diagram" or "image"
- •"architecture" (too vague)
- •"image1.png" or "screenshot"
Step 5: Verify and Save
Final checks:
- •All images generated successfully (check file paths)
- •Images linked correctly in markdown
- •ALT text is descriptive and SEO-friendly (50-125 chars)
- •Cover image placed after H1 title
- •In-article images at logical section breaks
- •New version saved (e.g.,
work/draft/article_v8_with_images.md)
Typical outputs:
- •1 cover image (
*_cover.png) - •1-3 in-article images (
*_concept.png,*_workflow.png, etc.) - •Updated article with integrated images and ALT text
Command Reference
Basic Usage:
imagen generate "PROMPT" --output FILENAME.png
Directory Setup:
mkdir -p work/images
Batch Generation Example:
# Cover imagen generate "COVER PROMPT" --output work/images/article_cover.png # In-article images imagen generate "DIAGRAM PROMPT" --output work/images/article_diagram.png imagen generate "COMPARISON PROMPT" --output work/images/article_comparison.png
Prompt Engineering Best Practices
For comprehensive prompt engineering guidance, refer to references/prompting_guide.md.
Core Principles:
- •Be Specific: Detailed descriptions produce better results
- •Define Style: Always specify artistic style (
digital art,blueprint, etc.) - •Set Atmosphere: Use lighting and mood keywords
- •Use Photography Terms:
wide-angle,close-up,depth of field, etc.
Cover vs In-Article Summary:
| Aspect | Cover Images | In-Article Images |
|---|---|---|
| Goal | Grab attention, create "wow" factor | Explain concepts, reinforce learning |
| Style | digital art, 3D render, conceptual art | technical diagram, blueprint, minimalist |
| Approach | Metaphorical, abstract | Direct, educational |
| Keywords | cinematic, dramatic, futuristic | clean, clear labels, organized |
Common Patterns
Pattern 1: Simple Article (1-2 images)
- •Cover image only
- •OR Cover + 1 key diagram
Pattern 2: Standard Article (2-3 images)
- •Cover image (conceptual)
- •1-2 in-article images (technical diagrams)
Pattern 3: Complex Tutorial (3-4 images)
- •Cover image (conceptual)
- •Workflow/architecture diagram
- •Comparison illustration
- •Example/output visualization
Resources
references/prompting_guide.md
Complete guide to prompt engineering for the imagen CLI, including:
- •Detailed prompt crafting principles
- •Style and medium keywords
- •Lighting and atmosphere techniques
- •Photography/cinematography terms
- •Extensive examples for different image types
Load this reference when crafting complex prompts or needing inspiration for visual concepts.