Image Model Overview

Image generation and editing using Google Vertex AI Imagen models (v1, v2, v3). Implements LangChain4j ImageModel.

Class

public class VertexAiImageModel implements ImageModel {
    public Response<Image> generate(String prompt);
    public Response<List<Image>> generate(String prompt, int n);
    public Response<Image> edit(Image image, String prompt);
    public Response<Image> edit(Image image, Image mask, String prompt);
    public static Builder builder();
}

Imports

import dev.langchain4j.model.vertexai.VertexAiImageModel;
import dev.langchain4j.model.vertexai.VertexAiImageModel.AspectRatio;
import dev.langchain4j.model.vertexai.VertexAiImageModel.ImageStyle;
import dev.langchain4j.model.vertexai.VertexAiImageModel.MimeType;
import dev.langchain4j.model.vertexai.VertexAiImageModel.PersonGeneration;
import dev.langchain4j.data.image.Image;
import dev.langchain4j.model.output.Response;

Minimal Example

VertexAiImageModel model = VertexAiImageModel.builder()
    .endpoint("https://us-central1-aiplatform.googleapis.com/v1/")
    .project("your-project-id")
    .location("us-central1")
    .publisher("google")
    .modelName("imagegeneration@006")
    .build();

Response<Image> response = model.generate("A serene mountain landscape at sunset");
Image image = response.content();
byte[] imageData = image.bytes();

Supported Models

• imagegeneration@006 - Imagen 3 (latest, highest quality)
• imagegeneration@005 - Imagen 2 (good quality)
• imagegeneration@002 - Imagen 1 (basic quality)

Configuration Parameters

Required

• endpoint - API endpoint URL
• project - Google Cloud Project ID
• location - GCP region
• publisher - Model publisher ("google")
• modelName - Model name/version

Optional

• seed (Long) - Random seed for reproducibility (0-4,294,967,295)
• language (String) - Language code (e.g., "en", "es")
• guidanceScale (Integer) - Edit strength (0-21+)
• negativePrompt (String) - What to avoid
• aspectRatio (AspectRatio) - Image aspect ratio
• mimeType (MimeType) - PNG or JPEG
• compressionQuality (Integer) - JPEG quality (1-100)
• personGeneration (PersonGeneration) - Person generation policy
• watermark (Boolean) - Add watermark
• sampleImageStyle (ImageStyle) - Style (Imagen v1 only)
• sampleImageSize (Integer) - Output size in pixels
• maxRetries (Integer) - Retry attempts (default: 3)
• persistToCloudStorage (String) - GCS URI for saving
• withPersisting - Enable local persistence
• persistTo (Path) - Local save directory
• logRequests (Boolean) - Log requests
• logResponses (Boolean) - Log responses

Enums

AspectRatio

SQUARE (1:1), PORTRAIT (9:16), LANDSCAPE (16:9), THREE_FOURTHS (3:4), FOUR_THIRDS (4:3)

MimeType

PNG, JPEG

PersonGeneration

DONT_ALLOW, ALLOW_ADULT, ALLOW_ALL

ImageStyle (Imagen v1 only)

PHOTOGRAPH, DIGITAL_ART, LANDSCAPE, SKETCH, WATERCOLOR, CYBERPUNK, POP_ART

Use Cases

• AI art generation
• Product visualization
• Marketing content creation
• Image editing and enhancement
• Concept prototyping

See Also

• Examples - Detailed usage examples
• API Reference - Complete API documentation