Image Prompt Generator

Generate professional, non-generic images using Google's Gemini API for image generation.

Prerequisites & Setup

Getting Your Gemini API Key

• Go to Google AI Studio

• Sign in with your Google account

• Click "Create API Key"

• Copy the generated key

Configuring the API Key

Option 1: Environment file (recommended)

Create a .env file in your project root:

GEMINI_API_KEY=your_api_key_here

Option 2: Direct environment variable

export GEMINI_API_KEY=your_api_key_here

Install Dependencies

pip install google-generativeai python-dotenv pillow

Available Models

Model API Name Best For

Flash gemini-2.5-flash-image

Speed, drafts, iteration

Pro gemini-3-pro-image-preview

Final assets, 16:9 aspect ratio, quality

Image Size (CRITICAL for quality)

Size Output Use For

1K ~400KB Drafts, iteration

2K ~2MB Thumbnails, web assets (default)

4K ~7MB Print, high-resolution needs

CRITICAL: Always specify --size 2K or --size 4K for final assets. Without this, output defaults to 1K which looks low-quality.

Skill Stack Thumbnails - MANDATORY SETTINGS

For ANY Skill Stack thumbnail, you MUST use:

python scripts/images/generate_image.py "YOUR PROMPT"
--model pro
--size 2K
--aspect 16:9
--output public/images/thumbnails
--name your-slug

And your prompt MUST include risograph style instructions:

STYLE: Risograph / screen print aesthetic. Visible halftone dots throughout. Slight misregistration between color layers. Indie printmaking quality - warm, tactile, handmade.

COLOR: Warm cream base. Charcoal and gray tones. Terracotta (#D4654A) accent on ONE key element.

TEXTURE: Visible halftone pattern. Paper grain. NOT smooth digital gradients.

AVOID: Empty white borders, photorealism, glossy renders, smooth gradients, clip art aesthetic.

WHY: Without --size 2K , output is ~400KB garbage that looks like it was made with Flash. Without risograph style, output looks generic and AI-generated.

Workflow Overview

• Brainstorm Concepts - Generate 4-6 high-level visual ideas

• Select Direction - User picks the concept they like

• Optimize Prompt - Refine into a strong, detailed prompt

• Style Variations - Adapt to 2-3 different visual styles

• Generate Images - Run via Gemini API

Step 1: Brainstorm Concepts

When the user provides a topic or use case, generate 3 high-level visual concepts and indicate your pick. Each concept should be:

• One sentence describing the visual idea

• Concrete and immediate - you can picture it instantly

• Conceptual but not abstract - a clear object/scene with meaning

• Non-generic - avoid cliches (no lightbulbs for ideas, no handshakes for partnership)

Format:

Concept A: One sentence description of the visual concept and why it works.

Concept B: One sentence description...

Concept C: One sentence description...

My pick: Concept X — Brief reasoning why this one is strongest.

Example for "newsletter about personal productivity":

Concept A: A vintage compass where the needle points toward a coffee ring stain on a map—direction emerges from daily rituals.

Concept B: A clock where the 12 hours show seasonal changes—time management over long arcs, not just hours.

Concept C: One small key attached to dozens of decorative keychains—we overcomplicate simple solutions.

My pick: Concept A — The coffee stain is unexpected and personal, the compass is concrete without being cliché.

Wait for user to confirm or redirect before proceeding.

Step 2: Optimize the Prompt

Once the user selects a concept, develop it into a full prompt. Structure:

Create a [style type] illustration of [subject].

CONCEPT: [Expand the one-sentence idea into a clear visual description]

STYLE: [Artistic approach - load from references/styles/ if brand-specific]

COMPOSITION: [Framing, focal point, negative space, balance]

COLORS: [Palette - describe by name, not hex codes which may render as text]

TEXTURE: [Surface qualities, analog/digital feel]

AVOID: [What should NOT appear - be specific]

FORMAT: [Aspect ratio]

Key principles:

• Natural language, full sentences - no tag soup

• Describe colors by name (burnt orange, sky blue, near-black) not hex codes

• Maximum 2-3 elements - if it feels busy, remove something

• Favor metaphor over literal depiction

Step 3: Style Variations

MANDATORY for Skill Stack: Risograph style. Every thumbnail must include risograph style instructions in the prompt. See references/styles/risograph.md .

Key risograph elements to ALWAYS include in prompt:

• "Visible halftone dots throughout"

• "Slight misregistration between color layers"

• "Indie printmaking quality - warm, tactile, handmade"

• "NOT smooth digital gradients"

Available styles in references/styles/ (for non-Skill-Stack projects):

• risograph.md - DEFAULT. Halftone dots, misregistration, indie printmaking aesthetic.

• minimalist-ink.md - High-contrast black and white, crosshatching.

• watercolor-line.md - Ink linework with watercolor washes.

• editorial-conceptual.md - Conceptual, sophisticated, editorial wit.

Step 4: Generate via API

Running the Script

Generate 2K thumbnail (recommended for web)

python scripts/images/generate_image.py "prompt here" --model pro --aspect 16:9 --size 2K

Generate 4K for print/high-res

python scripts/images/generate_image.py "prompt here" --model pro --size 4K

Save to specific folder

python scripts/images/generate_image.py "prompt" --output "./images" --name "my_image" --size 2K

Options:

• --model pro (default, higher quality) or --model flash (faster)

• --size 2K (default), 1K , or 4K

• always use 2K or 4K for final assets

• --aspect 16:9 (default), 1:1 , 9:16 , 3:4 , 4:3

• --variations N

• generate N versions

• --output ./path

• save location

• --name prefix

• filename prefix

Output location: Save images alongside the content they belong to - not a generic images dump.

Step 5: Iterate

After user reviews generated images:

• 80% good? Request specific edits conversationally rather than regenerating

• Composition off? Adjust framing or element placement in prompt

• Wrong style? Try a different style reference

• Too busy? Simplify to fewer elements

• Colors wrong? Be more explicit about palette

Prompting Principles

Write Like a Creative Director

Brief the model like a human artist. Use proper grammar, full sentences, and descriptive adjectives.

Don't Do

"Cool car, neon, city, night, 8k" "A cinematic wide shot of a futuristic sports car speeding through a rainy Tokyo street at night. The neon signs reflect off the wet pavement and the car's metallic chassis."

Be specific about:

• Subject: Instead of "a woman," say "a sophisticated elderly woman wearing a vintage chanel-style suit"

• Materiality: Describe textures - "matte finish," "brushed steel," "soft velvet," "crumpled paper"

• Setting: Define location, time of day, weather

• Lighting: Specify mood and light source

• Mood: Emotional tone of the image

Provide Context

Context helps the model make logical artistic decisions. Include the "why" or "for whom."

Example: "Create an image of a sandwich for a Brazilian high-end gourmet cookbook." (Model infers: professional plating, shallow depth of field, perfect lighting)

Keep It Simple

• One clear focal point

• Maximum 2-3 elements total

• Generous negative space

• If it feels busy, remove something

Avoid the Generic

Hard rules:

• NEVER include text in images - Text renders poorly and looks amateur

• No lightbulbs for "ideas"

• No handshakes for "partnership"

• No audio waveforms for "podcasts" or "audio"

• No gears/cogs for "systems" or "process"

• No happy stock photo poses

• No glossy AI aesthetic

• No puzzle pieces for "connection" or "integration"

Metaphors That Work

Strong concepts from past generations:

• Orange cut open revealing neural network - organic exterior, systematic interior (knowledge systems, RAG)

• Mail slot with origami bird emerging - delivery transforms into something alive (newsletters)

• Exercise club crossed with quill pen - physical culture meets intellectual work (body + mind)

• Typewriter key extreme close-up with radiating impact - decisive action, command (books, authority)

• Medicine dropper with mandala bloom - clinical precision meets transcendence (therapy, transformation)

• Straight razor on leather strop - precision tool, polishing, refinement (editing, production)

• Prism dispersing light into distinct beams - one input, multiple outputs (frameworks)

• Compass with coffee stain on map - direction from daily rituals (productivity)

Resources

references/styles/

Aesthetic style definitions:

• risograph.md

• DEFAULT - Halftone, misregistration, indie printmaking

• minimalist-ink.md

• Black and white ink illustration

• watercolor-line.md

• Ink with watercolor washes

• editorial-conceptual.md

• Conceptual editorial style

scripts/

• generate_image.py
• Gemini API image generation

Prompt Modifiers Reference

Category Examples

Lighting golden hour, dramatic shadows, soft diffused light, neon glow, overcast

Style cinematic, editorial, technical diagram, hand-drawn, photorealistic

Texture matte finish, brushed steel, soft velvet, crumpled paper, weathered wood

Composition wide shot, close-up, bird's eye view, dutch angle, symmetrical

Mood energetic, serene, dramatic, playful, sophisticated

Quality 4K, high-fidelity, pixel-perfect, professional grade

Advanced Capabilities

Text Rendering & Infographics

Put exact text in quotes. Specify style: "polished editorial," "technical diagram," or "hand-drawn whiteboard."

Example prompts:

Earnings Report Infographic: "Generate a clean, modern infographic summarizing the key financial highlights from this earnings report. Include charts for 'Revenue Growth' and 'Net Income', and highlight the CEO's key quote in a stylized pull-quote box."

Whiteboard Summary: "Summarize the concept of 'Transformer Neural Network Architecture' as a hand-drawn whiteboard diagram suitable for a university lecture. Use different colored markers for the Encoder and Decoder blocks, and include legible labels for 'Self-Attention' and 'Feed Forward'."

Character Consistency & Thumbnails

Use reference images and state "Keep the person's facial features exactly the same as Image 1." Describe expression/action changes while maintaining identity.

Example prompt:

Viral Thumbnail: "Design a viral video thumbnail using the person from Image 1. Face Consistency: Keep the person's facial features exactly the same as Image 1, but change their expression to look excited and surprised. Action: Pose the person on the left side, pointing their finger towards the right side of the frame. Subject: On the right side, place a high-quality image of a delicious avocado toast. Graphics: Add a bold yellow arrow connecting the person's finger to the toast. Text: Overlay massive, pop-style text in the middle: 'Done in 3 mins!'. Use a thick white outline and drop shadow. Background: A blurred, bright kitchen background. High saturation and contrast."

Image Reworking (Edit Existing Images)

The --input flag enables "rework mode" - pass an existing image to Gemini and describe the changes you want.

Key use cases:

• Small tweaks - Adjust colors, add/remove elements, change lighting

• Style transfer - Keep composition but change artistic style

• Object manipulation - Remove, add, or modify specific objects

• Seasonal/temporal changes - Same scene, different time/season

Running in rework mode:

Basic edit - add something

python scripts/generate_image.py "Add snow to the roof and yard"
--input ./house.png
--model pro

Color adjustment

python scripts/generate_image.py "Change the accent color from red to teal, keep everything else identical"
--input ./thumbnail.png
--model pro

Style transfer - keep composition, change aesthetic

python scripts/generate_image.py "Convert this to risograph style with halftone dots and slight color misregistration"
--input ./photo.png
--model pro

Generate variations of an edit

python scripts/generate_image.py "Make the lighting warmer, like golden hour"
--input ./portrait.png
--variations 3
--model pro

Prompting tips for rework mode:

Be specific about what to preserve:

• "Keep the person's facial features exactly the same"

• "Maintain the composition and framing"

• "Don't change the background"

Be explicit about what to change:

• "Change ONLY the color of the shirt from blue to red"

• "Add snow to the roof and nothing else"

• "Remove the text overlay"

Use comparative language:

• "Make the colors more vibrant"

• "Increase the contrast slightly"

• "Make the lighting softer and more diffused"

Output naming: Files from rework mode are named {prefix}_{timestamp}edit{model}.png to distinguish from generated images (gen ).

Advanced Editing Examples

Object Removal:

python scripts/generate_image.py
"Remove the tourists from the background and fill with matching cobblestones and storefronts"
--input ./street-photo.png
--model pro

Seasonal Control:

python scripts/generate_image.py
"Turn this into winter. Add snow to the roof and yard. Change lighting to cold, overcast afternoon. Keep architecture identical."
--input ./house-summer.png
--model pro

Character Consistency (thumbnail series):

python scripts/generate_image.py
"Keep the person's face exactly the same. Change expression to surprised. Add a pointing gesture toward the right side of the frame."
--input ./person-reference.png
--model pro

Related Skills

• youtube-title-creator - Pair generated images with optimized titles

• social-content-creation - Use images in platform-optimized posts

For custom brand styles, create new style files in references/styles/ following the existing format