Gemini 3.1 Flash Image Preview - Starrise AI

Gemini 3.1 Flash Image Preview is Google’s image generation model, available through Starrise AI via the native Gemini API. It supports text-to-image generation and image editing with reference images.

Key Capabilities

Text-to-image — Generate images from text descriptions
Image editing — Pass a reference image via inline_data combined with text instructions for editing
Aspect ratio control — 1:1, 4:3, 3:4, 16:9, 9:16
Resolution control — 512 (512px), 1K (~1024px), 2K (~2048px), 4K (~4096px, by longest side)
Multimodal output — Return both image and text description via responseModalities: ["TEXT", "IMAGE"]

Text-to-Image Example

curl "https://ai.alad.com/v1beta/models/gemini-3.1-flash-image-preview:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          { "text": "Generate an image of a mountain sunset" }
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["TEXT", "IMAGE"],
      "imageConfig": {
        "aspectRatio": "16:9",
        "imageSize": "1K"
      }
    }
  }'

import requests, base64

url = "https://ai.alad.com/v1beta/models/gemini-3.1-flash-image-preview:generateContent"
response = requests.post(url, params={"key": "YOUR_API_KEY"}, json={
    "contents": [
        {
            "role": "user",
            "parts": [{"text": "Generate an image of a mountain sunset"}]
        }
    ],
    "generationConfig": {
        "responseModalities": ["TEXT", "IMAGE"],
        "imageConfig": {"aspectRatio": "16:9", "imageSize": "1K"}
    }
})

for part in response.json()["candidates"][0]["content"]["parts"]:
    if "inline_data" in part:
        with open("output.jpg", "wb") as f:
            f.write(base64.b64decode(part["inline_data"]["data"]))
        print("Image saved to output.jpg")
    elif "text" in part:
        print("Caption:", part["text"])

import google.genai as genai

client = genai.Client(api_key="YOUR_API_KEY")

response = client.models.generate_content(
    model="gemini-3.1-flash-image-preview",
    contents="Generate an image of a mountain sunset",
    config={
        "responseModalities": ["TEXT", "IMAGE"],
        "imageConfig": {
            "aspectRatio": "16:9",
            "imageSize": "1K"
        }
    }
)

for candidate in response.candidates:
    for part in candidate.content.parts:
        if part.inline_data:
            with open("output.jpg", "wb") as f:
                f.write(part.inline_data.data)
            print("Image saved to output.jpg")
        elif part.text:
            print("Caption:", part.text)

Image Editing Example (with Reference Image)

Pass both a text instruction and an inline_data reference image in the same parts array.

# First convert image to base64:
# BASE64=$(base64 -i your_photo.jpg)
#
# Then send the request:
curl "https://ai.alad.com/v1beta/models/gemini-3.1-flash-image-preview:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "This is a photo of me, please add an alpaca beside me"
          },
          {
            "inline_data": {
              "mime_type": "image/jpeg",
              "data": "<YOUR_BASE64_ENCODED_IMAGE>"
            }
          }
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["TEXT", "IMAGE"],
      "imageConfig": {
        "aspectRatio": "1:1",
        "imageSize": "1K"
      }
    }
  }'

import requests, base64

# Read and encode the reference image
with open("your_photo.jpg", "rb") as f:
    image_b64 = base64.b64encode(f.read()).decode("utf-8")

url = "https://ai.alad.com/v1beta/models/gemini-3.1-flash-image-preview:generateContent"
response = requests.post(url, params={"key": "YOUR_API_KEY"}, json={
    "contents": [
        {
            "role": "user",
            "parts": [
                {
                    "text": "This is a photo of me, please add an alpaca beside me"
                },
                {
                    "inline_data": {
                        "mime_type": "image/jpeg",
                        "data": image_b64          # ← paste base64 string here
                    }
                }
            ]
        }
    ],
    "generationConfig": {
        "responseModalities": ["TEXT", "IMAGE"],
        "imageConfig": {"aspectRatio": "1:1", "imageSize": "1K"}
    }
})

for part in response.json()["candidates"][0]["content"]["parts"]:
    if "inline_data" in part:
        with open("output.jpg", "wb") as f:
            f.write(base64.b64decode(part["inline_data"]["data"]))
        print("Image saved to output.jpg")
    elif "text" in part:
        print("Caption:", part["text"])

import google.genai as genai
from google.genai import types

client = genai.Client(api_key="YOUR_API_KEY")

# Read the image
with open("your_photo.jpg", "rb") as f:
    image_bytes = f.read()

response = client.models.generate_content(
    model="gemini-3.1-flash-image-preview",
    contents=[
        "This is a photo of me, please add an alpaca beside me",
        types.Part.from_bytes(data=image_bytes, mime_type="image/jpeg")
    ],
    config={
        "responseModalities": ["TEXT", "IMAGE"],
        "imageConfig": {
            "aspectRatio": "1:1",
            "imageSize": "1K"
        }
    }
)

for candidate in response.candidates:
    for part in candidate.content.parts:
        if part.inline_data:
            with open("output.jpg", "wb") as f:
                f.write(part.inline_data.data)
            print("Image saved to output.jpg")
        elif part.text:
            print("Caption:", part.text)

Parameters

Parameter	Type	Required	Description
`key`	string	Yes	API key (query parameter)
`contents[].parts[].text`	string	Yes	Text prompt or instruction
`contents[].parts[].inline_data.mime_type`	string	No	Reference image type: `image/jpeg`, `image/png`, `image/webp`
`contents[].parts[].inline_data.data`	string	No	Base64-encoded reference image data
`generationConfig.responseModalities`	array	Yes	`["IMAGE"]` or `["TEXT", "IMAGE"]`
`generationConfig.imageConfig.aspectRatio`	string	No	`1:1` / `4:3` / `3:4` / `16:9` / `9:16`
`generationConfig.imageConfig.imageSize`	string	No	`512` / `1K` / `2K` / `4K` (default `1K`)

API Reference

View the interactive API Playground for Gemini 3.1 Flash Image Preview.