OpenAI GPT Image generation and editing (gpt-image-2, 1.5, 1, mini). Text-to-image, mask-based inpainting, multi-reference composition, multi-turn conversational editing via Responses API, streaming with partial images. This skill should be used when generating or editing images via OpenAI's image models, when near-perfect text rendering in images is needed, when mask-based region-aware editing is required, when multi-turn conversational image editing is desired, or when streaming progressive image delivery is needed. Complements nano-banana-pro (Gemini) as a parallel image generation backend.
OpenAI GPT Image generation and editing (gpt-image-2, 1.5, 1, mini). Text-to-image, mask-based inpainting, multi-reference composition, multi-turn conversational editing via Responses API, streaming with partial images. This skill should be used when generating or editing images via OpenAI's image models, when near-perfect text rendering in images is needed, when mask-based region-aware editing is required, when multi-turn conversational image editing is desired, or when streaming progressive image delivery is needed. Complements nano-banana-pro (Gemini) as a parallel image generation backend.
GPT Atelier
OpenAI GPT Image generation and editing. Wraps both the Image API (one-shot) and Responses API (multi-turn conversational) with 6 scripts covering generate, edit, compose, converse, stream, and test workflows.
Prerequisite:OPENAI_API_KEY environment variable.
Models
Flag
Model
Strengths
(default)
gpt-image-2
Reasoning-based, ~99% text rendering, up to 8 consistent images, 4K, streaming
--fast
gpt-image-1.5
Region-aware editing, 4x faster, cheaper
--mini
gpt-image-1-mini
Cheapest ($0.006/image low quality)
Quick Start
# Test connectivity
python3 scripts/test_connection.py --check-models
# Generate an image
python3 scripts/generate_image.py "A Minoan bull-leaper under golden light"# Compare models side-by-side (HTML page)
python3 scripts/compare_models.py --all --open
python3 scripts/edit_image.py photo.png --mask sky_mask.png
python3 scripts/compose_images.py item1.png item2.png item3.png
python3 scripts/converse_image.py
python3 scripts/stream_image.py --partials 3
"A bronze seal stamp in Minoan style"
# Edit with mask
"Replace the sky with a dramatic sunset"
# Compose from references
"Create a gift basket containing these items"
# Multi-turn editing session
# Streaming with partial images
"An ancient fresco being restored"
Image API scripts share: --output DIR, --filename NAME, --quality low|medium|high, --format png|jpeg|webp, --fast, --mini. converse_image.py uses --orchestrator instead of --fast/--mini.
Auto-converts B&W masks to RGBA (requires Pillow: pip install Pillow).
# Region-aware edit with mask
python3 scripts/edit_image.py "Add a flamingo to the pool" lounge.png --mask pool_mask.png
# Full-image restyle
python3 scripts/edit_image.py "Convert to watercolor painting style" photo.jpg
# Edit with reference images
python3 scripts/edit_image.py "Replace the car with this bicycle" street.png --images bicycle.png
Without a prompt, enters interactive REPL. Maintains conversation state via previous_response_id.
# Interactive session
python3 scripts/converse_image.py --auto-save
> A cyberpunk street scene at night
> Now add neon signs with Japanese text
> Make it rain and add reflections
> /save final_scene
# Single-shot
python3 scripts/converse_image.py "Design a coffee brand logo" --output ./logos
Generates the same prompt across multiple models and outputs a dark-themed HTML comparison page. See references/compare-models-reference.md for full options.
6. Streaming with Partial Images
python3 scripts/stream_image.py "prompt" --partials N [options]
Outputs partial images as they generate, then the final image.
# Stream with 3 progressively sharper partials
python3 scripts/stream_image.py "A detailed architectural drawing" --partials 3 --save-partials
Additional option: --save-partials to save intermediate images.
Prompting Quick-Hits
Lead with scene/style, not subject. First words carry highest visual weight. Specify intended use (ad, UI mockup, editorial) so the model picks the right polish level.
Always double-quote literal text."HELLO WORLD" engages the high-accuracy text rendering engine.
Pixel dimensions in prompt. For custom aspect ratios, append "Output in exactly WxH (R:R ratio) resolution" — the API size param alone is unreliable. Done automatically by inject_size_hint() for gpt-image-2.
Use --thinking for complex scenes. The orchestrator model matters — Thinking models produce significantly better multi-element compositions.
Generate fresh, don't edit. Reference-image editing on gpt-image-2 produces yellow tint and poor prompt adherence. For design-final work, generate from scratch.
See references/prompting-guide.md for full details.
When to Use GPT Atelier vs Nano Banana Pro
Task
GPT Atelier
Nano Banana Pro
Text rendering (complex, non-Latin)
Best
Good
Mask-based inpainting
Native, low drift
Higher drift (~40%)
Reference-image editing
Yellow tint risk — use --fast
Better fidelity
Multi-turn editing with state
Responses API
Multi-turn chat
Photorealism
Excellent
Excellent
Cinematic digital painting
Good
Best
UI mockups / screenshots
Best
Good
Multi-image consistency
Up to 8/prompt
Up to 14 references
Streaming partial delivery
Native
Not available
Dark/artistic themes
Stricter policy
More permissive
Budget/volume
$0.006/img (mini low)
Gemini pricing
Arbitrary aspect ratios
Any (16px multiples)
10 presets
Cost Control
Start with --quality low ($0.006/image) for ideation. Graduate to medium ($0.05) for review, high ($0.21) for final assets. Use --fast for cheaper generation, --mini for maximum cost savings. Use --format jpeg for faster response times.
Script Reference
Script
Purpose
API
generate_image.py
Text-to-image
Image API
edit_image.py
Edit with mask/references
Image API
compose_images.py
Multi-reference composition
Image API
converse_image.py
Multi-turn editing
Responses API
compare_models.py
Side-by-side model comparison (HTML)
Image API
stream_image.py
Streaming with partials
Image API
test_connection.py
Connectivity check
Models API
Reference Documentation
File
Contents
references/api-reference.md
Full parameter reference, pricing, size constraints
references/compare-models-reference.md
Model comparison script: options, examples, HTML output
references/prompting-guide.md
Prompt engineering patterns, text rendering, style keywords
