imagen-generator

# Gemini Image Generator (Nano Banana) Generate or edit images using Gemini 3 Pro Image (gemini-3-pro-image) on Vertex AI, save to CC Pages, and share. Two modes: - **Text-to-image** — pure prompt, model invents from scratch - **Image-to-image (修图)** — pass `--image <path>` one or more times; model treats them as visual baselines and the text prompt as the editing instruction (preserve / add / remove / restyle) ## Usage Call the generation script directly: ```bash ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "your prompt here" ``` ### Options ```bash # Basic generation (1 image, 1:1 aspect ratio, 1K resolution) ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "a cute cat sitting on a GPU server" # Custom aspect ratio: 1:1, 3:4, 4:3, 16:9, 9:16, 3:2, 2:3, 4:5, 5:4, 21:9, 4:1, 1:4, 8:1, 1:8 ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "TPU pod in a datacenter" --aspect 16:9 # Multiple images (1-4, generated sequentially) ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "neural network visualization" --count 2 # Resolution: 1K (default), 2K, 4K ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "landscape photo" --resolution 2K # Custom output filename ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "logo design" --output my-logo # Override model (default: gemini-3-pro-image) ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "photo" --model gemini-3.1-flash-image # Combine options ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "B200 GPU rack in datacenter, photorealistic" --aspect 16:9 --resolution 2K --count 2 ``` ### Image-to-Image (修图) Pass `--image <path>` to provide a visual baseline. The text prompt becomes the editing instruction (what to keep, what to add, what to change). Repeat `--image` for multiple references — first one is the primary baseline. ```bash # 在一张图上加元素，保持原风格 ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh \ "Keep the cyberpunk style unchanged. Add a glowing holographic dashboard in the upper-left corner showing 4 floating cards." \ --image ~/CloseCrab/crab-with-claude-code-inside.png \ --aspect 4:5 --resolution 2K --output poster-with-cards # 多参考图：第一张是主 baseline，后面是风格/元素参考 ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh \ "Combine subject of first image with the lighting and color palette of second image" \ --image subject.png --image style_ref.png \ --aspect 16:9 --resolution 2K # 改 aspect 重构图（recompose）— 模型会保留主体，重新构图填满目标比例 ~/.claude/skills/imagen-generator/scripts/imagen-generate.sh \ "Same subject, recompose for vertical poster, keep cinematic mood" \ --image hero.png --aspect 9:16 --resolution 2K ``` **Prompt 写法建议（修图）**： - 明确写"KEEP UNCHANGED:"列出要保留的元素（风格、材质、灯光、构图） - 明确写"ADD:" / "CHANGE:" / "REMOVE:" 列出要修改的元素 - 最后强调"this must still look like the same artwork"，否则模型可能跑偏成纯文生图 - 改 aspect 时加"recompose for ... aspect, keep [subject] as dominant element" 支持的图片格式：`.png`, `.jpg`, `.jpeg`, `.webp`, `.gif` ### Output - Images saved to `$CC_PAGES_WEB_ROOT/assets/imagen/` as PNG - Returns the public URL: `$CC_PAGES_URL_PREFIX/assets/imagen/{filename}.png` - When called from Discord context, send the URL using `send-to-discord.sh --plain` ### Workflow for Discord ```bash # 1. Generate image URL=$(~/.claude/skills/imagen-generator/scripts/imagen-generate.sh "your prompt" --aspect 16:9) # 2. Send to Discord ~/.claude/scripts/send-to-discord.sh --plain "$URL" ``` ## Model - **`gemini-3-pro-image`** (default) — Gemini 3 Pro Image, best quality, supports text+image generation - **`gemini-3.1-flash-image`** — Nano Banana 2, faster, good price-performance ## Supported Aspect Ratios `1:1`, `3:4`, `4:3`, `16:9`, `9:16`, `3:2`, `2:3`, `4:5`, `5:4`, `21:9`, `4:1`, `1:4`, `8:1`, `1:8` ## Supported Resolutions `1K` (default), `2K`, `4K`　（`512` 不被模型支持，会返回 400） ## Prompt Tips - Be specific and descriptive: "a red sports car on a mountain road at sunset, photorealistic" > "car" - Supports Chinese prompts natively (simplified & traditional) - For technical diagrams, add style keywords: "technical illustration", "blueprint style", "infographic" - Gemini models can also generate text within images (e.g., signs, labels, infographics) ## Prerequisites - `google-genai` Python SDK (`pip install google-genai`) - Application Default Credentials configured (`gcloud auth application-default login`) - Vertex AI API enabled on the GCP project - CC Pages (GCS-backed via `$CC_PAGES_WEB_ROOT`) ## Files ``` ~/.claude/skills/imagen-generator/scripts/ ├── imagen-generate.sh # Entry point (exec wrapper) └── imagen-generate.py # Core logic (google-genai SDK) $CC_PAGES_WEB_ROOT/assets/imagen/ # Generated images (web-accessible) ```