Introduction to Styles and Quality Modifiers in Java

Introduction to Styles and Quality Modifiers

Welcome back! In the previous lesson, you learned how to craft effective prompts by focusing on the key components: subject, context, and style . This lesson builds on that foundation by introducing you to styles and quality modifiers, which are essential for enhancing the quality and artistic expression of your generated images. By the end of this lesson, you will understand how to combine these elements to create visually stunning and high-quality images using Google's Gemini API and the gemini-3.1-flash-image model.

Understanding Quality Modifiers

Quality modifiers are keywords that enhance the detail and clarity of the generated images. They help the model understand that you are aiming for a high-quality asset. For instance, general modifiers like high-quality, beautiful, and stylized can be used to improve the overall aesthetic of an image. When generating photos, you might use specific modifiers such as 4K, HDR, or Studio Photo to achieve a more realistic and detailed output. Similarly, for art and illustration, modifiers like by a professional or detailed can add depth and intricacy to the artwork. To illustrate the impact of quality modifiers, consider the following example. A prompt without quality modifiers, such as a photo of a corn stalk, might produce a basic image. However, by adding quality modifiers like 4K HDR beautiful photo of a corn stalk taken by a professional photographer, the resulting image will be more vibrant and detailed.

Exploring Artistic Styles

Artistic styles define the visual approach of the generated image. In this lesson, we will explore two main styles: photography and art/illustration . For photography, you can use prompts that start with A photo of... to generate photorealistic images. For example, A photo of coffee beans in a kitchen on a wooden surface will produce an image that resembles a real photograph. In contrast, art and illustration styles allow for more creative expression. You can use prompts like A painting of... or A sketch of... to create images in various artistic styles. For instance, A technical pencil drawing of an angular sporty electric sedan with skyscrapers in the background will generate a detailed pencil sketch, while Digital art of an angular sporty electric sedan with skyscrapers in the background will produce a vibrant digital artwork.

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Combining Styles with Quality Modifiers: Code Example

Let's dive into a code example to see how you can combine artistic styles with quality modifiers to generate high-quality images:

Java

package com.example.imagegenerator;

import com.google.genai.Client;
import com.google.genai.types.HttpOptions;
import com.google.genai.types.GenerateContentConfig;
import com.google.genai.types.GenerateContentResponse;
import com.google.genai.types.Part;

import java.io.FileOutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.List;

public class ImageGenerator {
    public static void main(String[] args) throws Exception {
        String apiKey = System.getenv("GEMINI_API_KEY");
        String baseUrl = System.getenv("GEMINI_BASE_URL");
        
        Client client = new Client.Builder()
                .apiKey(apiKey)
                .httpOptions(HttpOptions.builder().baseUrl(baseUrl).apiVersion("v1beta").build())
                .build();

        // Define prompts combining artistic styles with quality modifiers
        List<String> styleQualityPrompts = List.of(
            "A beautiful landscape, photorealistic style, 4K resolution",
            "A portrait of a woman, oil painting style, high definition",
            "A futuristic cityscape, cyberpunk style, ultra-realistic, 8K resolution",
            "A serene beach scene, watercolor painting, high-quality details"
        );

        String outputDir = "public/images";
        Files.createDirectories(Paths.get(outputDir));

        for (String prompt : styleQualityPrompts) {
            GenerateContentResponse response = client.models.generateContent(
                "gemini-3.1-flash-image",
                prompt,
                GenerateContentConfig.builder()
                    .responseModalities(List.of("IMAGE"))
                    .build()
            );

            for (Part part : response.candidates().get().get(0).content().get().parts().get()) {
                if (part.inlineData().isPresent()) {
                    byte[] imageBytes = Base64.getDecoder().decode(part.inlineData().get().data().orElseThrow(() -> new RuntimeException("No data found")));
                    long timestamp = System.currentTimeMillis();
                    String outputPath = outputDir + "/image_" + timestamp + ".png";
                    try (FileOutputStream fos = new FileOutputStream(outputPath)) {
                        fos.write(imageBytes);
                    }
                    System.out.println("Image written to: " + outputPath);
                }
            }
        }
    }
}

package com.example.imagegenerator;

import com.google.genai.Client;
import com.google.genai.types.HttpOptions;
import com.google.genai.types.GenerateContentConfig;
import com.google.genai.types.GenerateContentResponse;
import com.google.genai.types.Part;

import java.io.FileOutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.List;

public class ImageGenerator {
    public static void main(String[] args) throws Exception {
        String apiKey = System.getenv("GEMINI_API_KEY");
        String baseUrl = System.getenv("GEMINI_BASE_URL");
        
        Client client = new Client.Builder()
                .apiKey(apiKey)
                .httpOptions(HttpOptions.builder().baseUrl(baseUrl).apiVersion("v1beta").build())
                .build();

        // Define prompts combining artistic styles with quality modifiers
        List<String> styleQualityPrompts = List.of(
            "A beautiful landscape, photorealistic style, 4K resolution",
            "A portrait of a woman, oil painting style, high definition",
            "A futuristic cityscape, cyberpunk style, ultra-realistic, 8K resolution",
            "A serene beach scene, watercolor painting, high-quality details"
        );

        String outputDir = "public/images";
        Files.createDirectories(Paths.get(outputDir));

        for (String prompt : styleQualityPrompts) {
            GenerateContentResponse response = client.models.generateContent(
                "gemini-3.1-flash-image",
                prompt,
                GenerateContentConfig.builder()
                    .responseModalities(List.of("IMAGE"))
                    .build()
            );

            for (Part part : response.candidates().get().get(0).content().get().parts().get()) {
                if (part.inlineData().isPresent()) {
                    byte[] imageBytes = Base64.getDecoder().decode(part.inlineData().get().data().orElseThrow(() -> new RuntimeException("No data found")));
                    long timestamp = System.currentTimeMillis();
                    String outputPath = outputDir + "/image_" + timestamp + ".png";
                    try (FileOutputStream fos = new FileOutputStream(outputPath)) {
                        fos.write(imageBytes);
                    }
                    System.out.println("Image written to: " + outputPath);
                }
            }
        }
    }
}

In this example, we define a list of prompts that combine artistic styles with quality modifiers. Each prompt specifies a style, such as photorealistic or oil painting, along with quality modifiers like 4K resolution or high definition.

The code uses the official Gemini Java SDK to call generateContent on the gemini-3.1-flash-image model with responseModalities set to IMAGE. The generated image bytes are extracted directly from the inline data of the response parts and saved to the specified directory.

Introduction to Styles and Quality Modifiers in Java