slimg

AI-powered image generator CLI using Google Imagen 4 with Gemini prompt enhancement.

Short theme text is automatically expanded into a detailed image generation prompt by Gemini, then passed to Imagen 4 for high-quality image output.

Installation

# Run directly with npx (no install needed)
npx @miyakoh/slimg "your prompt" -o output.png

# Install globally
npm install -g @miyakoh/slimg

# Use as a Claude Code skill
npx skills add miyakoh/slimg

Setup

Set your Google API key as an environment variable:

export GOOGLE_API_KEY="your-api-key"
# or
export GEMINI_API_KEY="your-api-key"

Get your API key from Google AI Studio.

Usage

slimg "<prompt>" -t <style> -a <ratio> -o <output-path>

Examples

# Slide background (flat style, 16:9)
slimg "abstract geometric pattern, navy and teal gradients" \
  -t flat -a 16:9 -o images/bg.png

# Concept illustration
slimg "cloud architecture diagram, modern and clean" \
  -t illustration -a 16:9 -o images/concept.png

# Icon
slimg "security shield icon, teal accent" \
  -t minimal -a 1:1 -o images/icon.png

# Fast generation
slimg "team collaboration" \
  -t corporate -a 16:9 -e imagen4-fast -o images/team.png

# Skip prompt enhancement
slimg "a detailed prompt you wrote yourself" \
  --no-enhance -o images/raw.png

Options

| Option | Values | Default | |--------|--------|---------| | -t, --style | realistic, illustration, flat, anime, watercolor, oil-painting, pixel-art, sketch, 3d-render, corporate, minimal, pop-art | flat | | -a, --aspect-ratio | 16:9, 4:3, 1:1, 9:16, 3:4 | 16:9 | | -o, --output | Output file path | required | | -e, --engine | imagen4, imagen4-fast, imagen4-ultra | imagen4 | | -f, --format | png, jpg, jpeg | auto-detected from output path | | --no-enhance | Skip Gemini prompt enhancement | false | | --dry-run | Show config without API calls | false | | --debug | Print enhanced prompt | false |

Style Guide

| Use Case | Style (-t) | Aspect Ratio (-a) | |----------|-------------|-------------------| | Product photos, landscapes | realistic | 16:9, 4:3 | | Characters, mascots | anime, illustration | 1:1, 3:4 | | Icons, logos | flat, minimal | 1:1 | | Art, posters | watercolor, oil-painting, pop-art | any | | Game assets | pixel-art, 3d-render | 1:1 | | Business, presentations | corporate | 16:9 | | Concept sketches | sketch | any |

Engines

| Engine | Description | |--------|-------------| | imagen4 | Standard quality (default) | | imagen4-fast | Faster generation, slightly lower quality | | imagen4-ultra | Highest quality, slower |

How It Works

1. Prompt Enhancement - Your short theme is expanded by Gemini into a detailed image generation prompt with style, lighting, composition, and color descriptions
2. Image Generation - The enhanced prompt is sent to Google Imagen 4 API
3. Output - The generated image is saved to the specified path

Programmatic Usage

import { createClient, enhancePrompt, generateImage, resolveApiKey } from "@miyakoh/slimg";

const apiKey = resolveApiKey();
const client = createClient(apiKey);

const prompt = await enhancePrompt(client, "sunset over mountains", "realistic");
const imageBuffer = await generateImage(client, prompt, {
  engine: "imagen4",
  aspectRatio: "16:9",
  format: "png",
});

License

MIT