Generare immagini con Gemini

I seguenti modelli Gemini supportano la possibilità di generare immagini oltre al testo:

  • Gemini 2.5 Flash Image, noto anche come Gemini 2.5 Flash (con Nano Banana)

  • Gemini 3 Pro Image (anteprima), altrimenti noto come Gemini 3 Pro (con Nano Banana)

Per saperne di più sulle funzionalità dei modelli Gemini, consulta Modelli Gemini.

Genera immagini

Di seguito viene mostrato come generare immagini utilizzando Vertex AI Studio o l'API.

Per saperne di più sulle best practice per i prompt, consulta la sezione Progettare prompt multimodali.

Console

Per generare immagini con Gemini:

  1. Apri Vertex AI Studio > Crea prompt.
  2. Fai clic su Cambia modello e seleziona uno dei seguenti modelli dal menu:
    • gemini-2.5-flash-image
    • gemini-3-pro-image-preview
  3. Nel riquadro Output, seleziona Immagine e testo dal menu a discesa.
  4. Scrivi una descrizione dell'immagine che vuoi generare nell'area di testo dell'area di testo Scrivi un prompt.
  5. Fai clic sul pulsante Prompt ().

Gemini genera un'immagine in base alla tua descrizione. Questa operazione richiede alcuni secondi, ma può essere relativamente più lenta a seconda della capacità.

Python

Installa

pip install --upgrade google-genai

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

import os
from io import BytesIO

from google import genai
from google.genai.types import GenerateContentConfig, Modality
from PIL import Image

client = genai.Client()

response = client.models.generate_content(
    model="gemini-3-pro-image-preview",
    contents=("Generate an image of the Eiffel tower with fireworks in the background."),
    config=GenerateContentConfig(
        response_modalities=[Modality.TEXT, Modality.IMAGE],
    ),
)
for part in response.candidates[0].content.parts:
    if part.text:
        print(part.text)
    elif part.inline_data:
        image = Image.open(BytesIO((part.inline_data.data)))
        # Ensure the output directory exists
        output_dir = "output_folder"
        os.makedirs(output_dir, exist_ok=True)
        image.save(os.path.join(output_dir, "example-image-eiffel-tower.png"))

Go

Scopri come installare o aggiornare Go.

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

import (
	"context"
	"fmt"
	"io"
	"os"

	"google.golang.org/genai"
)

// generateMMFlashWithText demonstrates how to generate both text and image outputs.
func generateMMFlashWithText(w io.Writer) error {
	ctx := context.Background()

	client, err := genai.NewClient(ctx, &genai.ClientConfig{
		HTTPOptions: genai.HTTPOptions{APIVersion: "v1"},
	})
	if err != nil {
		return fmt.Errorf("failed to create genai client: %w", err)
	}

	modelName := "gemini-2.5-flash-image"
	contents := []*genai.Content{
		{
			Parts: []*genai.Part{
				{Text: "Generate an image of the Eiffel tower with fireworks in the background."},
			},
			Role: genai.RoleUser,
		},
	}

	resp, err := client.Models.GenerateContent(ctx,
		modelName,
		contents,
		&genai.GenerateContentConfig{
			ResponseModalities: []string{
				string(genai.ModalityText),
				string(genai.ModalityImage),
			},
			CandidateCount: int32(1),
			SafetySettings: []*genai.SafetySetting{
				{Method: genai.HarmBlockMethodProbability},
				{Category: genai.HarmCategoryDangerousContent},
				{Threshold: genai.HarmBlockThresholdBlockMediumAndAbove},
			},
		},
	)
	if err != nil {
		return fmt.Errorf("failed to generate content: %w", err)
	}

	if len(resp.Candidates) == 0 || resp.Candidates[0].Content == nil {
		return fmt.Errorf("no candidates returned")
	}
	var fileName string
	for _, part := range resp.Candidates[0].Content.Parts {
		if part.Text != "" {
			fmt.Fprintln(w, part.Text)
		} else if part.InlineData != nil {
			fileName = "example-image-eiffel-tower.png"
			if err := os.WriteFile(fileName, part.InlineData.Data, 0o644); err != nil {
				return fmt.Errorf("failed to save image: %w", err)
			}
		}
	}
	fmt.Fprintln(w, fileName)

	// Example response:
	// I will generate an image of the Eiffel Tower at night, with a vibrant display of
	// colorful fireworks exploding in the dark sky behind it.
	// ....
	return nil
}

Node.js

Installa

npm install @google/genai

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

const fs = require('fs');
const {GoogleGenAI, Modality} = require('@google/genai');

const GOOGLE_CLOUD_PROJECT = process.env.GOOGLE_CLOUD_PROJECT;
const GOOGLE_CLOUD_LOCATION =
  process.env.GOOGLE_CLOUD_LOCATION || 'us-central1';

async function generateImage(
  projectId = GOOGLE_CLOUD_PROJECT,
  location = GOOGLE_CLOUD_LOCATION
) {
  const client = new GoogleGenAI({
    vertexai: true,
    project: projectId,
    location: location,
  });

  const response = await client.models.generateContentStream({
    model: 'gemini-2.5-flash-image',
    contents:
      'Generate an image of the Eiffel tower with fireworks in the background.',
    config: {
      responseModalities: [Modality.TEXT, Modality.IMAGE],
    },
  });

  const generatedFileNames = [];
  let imageIndex = 0;

  for await (const chunk of response) {
    const text = chunk.text;
    const data = chunk.data;
    if (text) {
      console.debug(text);
    } else if (data) {
      const outputDir = 'output-folder';
      if (!fs.existsSync(outputDir)) {
        fs.mkdirSync(outputDir, {recursive: true});
      }
      const fileName = `${outputDir}/generate_content_streaming_image_${imageIndex++}.png`;
      console.debug(`Writing response image to file: ${fileName}.`);
      try {
        fs.writeFileSync(fileName, data);
        generatedFileNames.push(fileName);
      } catch (error) {
        console.error(`Failed to write image file ${fileName}:`, error);
      }
    }
  }

  // Example response:
  //  I will generate an image of the Eiffel Tower at night, with a vibrant display of
  //  colorful fireworks exploding in the dark sky behind it. The tower will be
  //  illuminated, standing tall as the focal point of the scene, with the bursts of
  //  light from the fireworks creating a festive atmosphere.

  return generatedFileNames;
}

Java

Scopri come installare o aggiornare Java.

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True


import com.google.genai.Client;
import com.google.genai.types.Blob;
import com.google.genai.types.Candidate;
import com.google.genai.types.Content;
import com.google.genai.types.GenerateContentConfig;
import com.google.genai.types.GenerateContentResponse;
import com.google.genai.types.Part;
import com.google.genai.types.SafetySetting;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;

public class ImageGenMmFlashWithText {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String modelId = "gemini-2.5-flash-image";
    String outputFile = "resources/output/example-image-eiffel-tower.png";
    generateContent(modelId, outputFile);
  }

  // Generates an image with text input
  public static void generateContent(String modelId, String outputFile) throws IOException {
    // Client Initialization. Once created, it can be reused for multiple requests.
    try (Client client = Client.builder().location("global").vertexAI(true).build()) {

      GenerateContentConfig contentConfig =
          GenerateContentConfig.builder()
              .responseModalities("TEXT", "IMAGE")
              .candidateCount(1)
              .safetySettings(
                  SafetySetting.builder()
                      .method("PROBABILITY")
                      .category("HARM_CATEGORY_DANGEROUS_CONTENT")
                      .threshold("BLOCK_MEDIUM_AND_ABOVE")
                      .build())
              .build();

      GenerateContentResponse response =
          client.models.generateContent(
              modelId,
              "Generate an image of the Eiffel tower with fireworks in the background.",
              contentConfig);

      // Get parts of the response
      List<Part> parts =
          response
              .candidates()
              .flatMap(candidates -> candidates.stream().findFirst())
              .flatMap(Candidate::content)
              .flatMap(Content::parts)
              .orElse(new ArrayList<>());

      // For each part print text if present, otherwise read image data if present and
      // write it to the output file
      for (Part part : parts) {
        if (part.text().isPresent()) {
          System.out.println(part.text().get());
        } else if (part.inlineData().flatMap(Blob::data).isPresent()) {
          BufferedImage image =
              ImageIO.read(new ByteArrayInputStream(part.inlineData().flatMap(Blob::data).get()));
          ImageIO.write(image, "png", new File(outputFile));
        }
      }

      System.out.println("Content written to: " + outputFile);
      // Example response:
      // Here is the Eiffel Tower with fireworks in the background...
      //
      // Content written to: resources/output/example-image-eiffel-tower.png
    }
  }
}

REST

Esegui questo comando nel terminale per creare o sovrascrivere questo file nella directory corrente:

curl -X POST \
  -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  -H "Content-Type: application/json" \
  https://${API_ENDPOINT}:generateContent \
  -d '{
    "contents": {
      "role": "USER",
      "parts": [
        {
          "text": "Create a tutorial explaining how to make a peanut butter and jelly sandwich in three easy steps."
        }
      ]
    },
    "generationConfig": {
      "responseModalities": ["TEXT", "IMAGE"],
      "imageConfig": {
        "aspectRatio": "16:9",
      },
     },
     "safetySettings": {
      "method": "PROBABILITY",
      "category": "HARM_CATEGORY_DANGEROUS_CONTENT",
      "threshold": "BLOCK_MEDIUM_AND_ABOVE"
    },
  }' 2>/dev/null >response.json

Gemini genera un'immagine in base alla tua descrizione. Questa procedura richiede alcuni secondi, ma può essere relativamente più lenta a seconda della capacità.

Genera testo e immagini interleaving

Gemini 2.5 Flash Image supporta la generazione di immagini interleaving con risposte di testo. Ad esempio, Gemini 2.5 Flash Image ti consente di generare immagini per ogni passaggio di una ricetta generata senza dover inviare richieste separate al modello.

Console

Per generare immagini interleaving con risposte di testo:

  1. Apri Vertex AI Studio > Crea prompt.
  2. Fai clic su Cambia modello e seleziona uno dei seguenti modelli dal menu:
    • gemini-2.5-flash-image
    • gemini-3-pro-image-preview
  3. Nel riquadro Output, seleziona Immagine e testo dal menu a discesa.
  4. Scrivi una descrizione dell'immagine che vuoi generare nell'area di testo dell'area di testo Scrivi un prompt. Ad esempio, "Crea un tutorial che spieghi come preparare un panino con burro di arachidi e marmellata in tre semplici passaggi. Per ogni passaggio, fornisci un titolo con il numero del passaggio, una spiegazione e genera anche un'immagine, genera ogni immagine con un formato 1:1".
  5. Fai clic sul pulsante Prompt ().

Gemini genera una risposta in base alla tua descrizione. Questa procedura richiede alcuni secondi, ma può essere relativamente più lenta a seconda della capacità.

Python

Installa

pip install --upgrade google-genai

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

from google import genai
from google.genai.types import GenerateContentConfig, Modality
from PIL import Image
from io import BytesIO

client = genai.Client()

response = client.models.generate_content(
    model="gemini-3-pro-image-preview",
    contents=(
        "Generate an illustrated recipe for a paella."
        "Create images to go alongside the text as you generate the recipe"
    ),
    config=GenerateContentConfig(response_modalities=[Modality.TEXT, Modality.IMAGE]),
)
with open("output_folder/paella-recipe.md", "w") as fp:
    for i, part in enumerate(response.candidates[0].content.parts):
        if part.text is not None:
            fp.write(part.text)
        elif part.inline_data is not None:
            image = Image.open(BytesIO((part.inline_data.data)))
            image.save(f"output_folder/example-image-{i+1}.png")
            fp.write(f"![image](example-image-{i+1}.png)")

Java

Scopri come installare o aggiornare Java.

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True


import com.google.genai.Client;
import com.google.genai.types.Blob;
import com.google.genai.types.Candidate;
import com.google.genai.types.Content;
import com.google.genai.types.GenerateContentConfig;
import com.google.genai.types.GenerateContentResponse;
import com.google.genai.types.Part;
import java.awt.image.BufferedImage;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;

public class ImageGenMmFlashTextAndImageWithText {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String modelId = "gemini-2.5-flash-image";
    String outputFile = "resources/output/paella-recipe.md";
    generateContent(modelId, outputFile);
  }

  // Generates text and image with text input
  public static void generateContent(String modelId, String outputFile) throws IOException {
    // Client Initialization. Once created, it can be reused for multiple requests.
    try (Client client = Client.builder().location("global").vertexAI(true).build()) {

      GenerateContentResponse response =
          client.models.generateContent(
              modelId,
              Content.fromParts(
                  Part.fromText("Generate an illustrated recipe for a paella."),
                  Part.fromText(
                      "Create images to go alongside the text as you generate the recipe.")),
              GenerateContentConfig.builder().responseModalities("TEXT", "IMAGE").build());

      try (BufferedWriter writer = new BufferedWriter(new FileWriter(outputFile))) {

        // Get parts of the response
        List<Part> parts =
            response
                .candidates()
                .flatMap(candidates -> candidates.stream().findFirst())
                .flatMap(Candidate::content)
                .flatMap(Content::parts)
                .orElse(new ArrayList<>());

        int index = 1;
        // For each part print text if present, otherwise read image data if present and
        // write it to the output file
        for (Part part : parts) {
          if (part.text().isPresent()) {
            writer.write(part.text().get());
          } else if (part.inlineData().flatMap(Blob::data).isPresent()) {
            BufferedImage image =
                ImageIO.read(new ByteArrayInputStream(part.inlineData().flatMap(Blob::data).get()));
            ImageIO.write(
                image, "png", new File("resources/output/example-image-" + index + ".png"));
            writer.write("![image](example-image-" + index + ".png)");
          }
          index++;
        }

        System.out.println("Content written to: " + outputFile);

        // Example response:
        // A markdown page for a Paella recipe(`paella-recipe.md`) has been generated.
        // It includes detailed steps and several images illustrating the cooking process.
        //
        // Content written to:  resources/output/paella-recipe.md
      }
    }
  }
}

Go

Scopri come installare o aggiornare Go.

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

import (
	"context"
	"fmt"
	"io"
	"os"
	"path/filepath"

	"google.golang.org/genai"
)

// generateMMFlashTxtImgWithText demonstrates how to generate an illustrated recipe
// combining text and image outputs into a markdown file.
func generateMMFlashTxtImgWithText(w io.Writer) error {
	ctx := context.Background()

	client, err := genai.NewClient(ctx, &genai.ClientConfig{
		HTTPOptions: genai.HTTPOptions{APIVersion: "v1"},
	})
	if err != nil {
		return fmt.Errorf("failed to create genai client: %w", err)
	}

	modelName := "gemini-2.5-flash-image"
	contents := []*genai.Content{
		{
			Parts: []*genai.Part{
				{Text: "Generate an illustrated recipe for a paella. " +
					"Create images to go alongside the text as you generate the recipe."},
			},
			Role: genai.RoleUser,
		},
	}

	resp, err := client.Models.GenerateContent(ctx,
		modelName,
		contents,
		&genai.GenerateContentConfig{
			ResponseModalities: []string{
				string(genai.ModalityText),
				string(genai.ModalityImage),
			},
			CandidateCount: int32(1),
		},
	)
	if err != nil {
		return fmt.Errorf("failed to generate content: %w", err)
	}

	if len(resp.Candidates) == 0 || resp.Candidates[0].Content == nil {
		return fmt.Errorf("no candidates returned")
	}

	outputFolder := ""

	// Create the markdown file
	mdFile := filepath.Join(outputFolder, "paella-recipe.md")
	fp, err := os.Create(mdFile)
	if err != nil {
		return fmt.Errorf("failed to create markdown file: %w", err)
	}
	defer fp.Close()

	for i, part := range resp.Candidates[0].Content.Parts {
		if part.Text != "" {
			if _, err := fp.WriteString(part.Text); err != nil {
				return fmt.Errorf("failed to write text: %w", err)
			}
		} else if part.InlineData != nil {
			imgFile := filepath.Join(outputFolder, fmt.Sprintf("example-image-%d.png", i+1))
			if err := os.WriteFile(imgFile, part.InlineData.Data, 0644); err != nil {
				return fmt.Errorf("failed to save image: %w", err)
			}
			if _, err := fp.WriteString(fmt.Sprintf("![image](%s)", filepath.Base(imgFile))); err != nil {
				return fmt.Errorf("failed to write image reference: %w", err)
			}
		}
	}

	fmt.Fprintln(w, mdFile)

	// Example response:
	//  A markdown page for a Paella recipe (`paella-recipe.md`) has been generated.
	//  It includes detailed steps and several images illustrating the cooking process.
	return nil
}

Node.js

Installa

npm install @google/genai

Per saperne di più, consulta la documentazione di riferimento dell'SDK.

Imposta le variabili di ambiente per utilizzare l'SDK Gen AI con Vertex AI:

# Replace the `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION` values
# with appropriate values for your project.
export GOOGLE_CLOUD_PROJECT=GOOGLE_CLOUD_PROJECT
export GOOGLE_CLOUD_LOCATION=global
export GOOGLE_GENAI_USE_VERTEXAI=True

const fs = require('fs');
const {GoogleGenAI, Modality} = require('@google/genai');

const GOOGLE_CLOUD_PROJECT = process.env.GOOGLE_CLOUD_PROJECT;
const GOOGLE_CLOUD_LOCATION =
  process.env.GOOGLE_CLOUD_LOCATION || 'us-central1';

async function savePaellaRecipe(response) {
  const parts = response.candidates[0].content.parts;

  let mdText = '';
  const outputDir = 'output-folder';

  for (let i = 0; i < parts.length; i++) {
    const part = parts[i];

    if (part.text) {
      mdText += part.text + '\n';
    } else if (part.inlineData) {
      if (!fs.existsSync(outputDir)) {
        fs.mkdirSync(outputDir, {recursive: true});
      }
      const imageBytes = Buffer.from(part.inlineData.data, 'base64');
      const imagePath = `example-image-${i + 1}.png`;
      const saveImagePath = `${outputDir}/${imagePath}`;

      fs.writeFileSync(saveImagePath, imageBytes);
      mdText += `![image](./${imagePath})\n`;
    }
  }
  const mdFile = `${outputDir}/paella-recipe.md`;

  fs.writeFileSync(mdFile, mdText);
  console.log(`Saved recipe to: ${mdFile}`);
}

async function generateImage(
  projectId = GOOGLE_CLOUD_PROJECT,
  location = GOOGLE_CLOUD_LOCATION
) {
  const client = new GoogleGenAI({
    vertexai: true,
    project: projectId,
    location: location,
  });

  const response = await client.models.generateContent({
    model: 'gemini-2.5-flash-image',
    contents:
      'Generate an illustrated recipe for a paella. Create images to go alongside the text as you generate the recipe',
    config: {
      responseModalities: [Modality.TEXT, Modality.IMAGE],
    },
  });
  console.log(response);

  await savePaellaRecipe(response);

  return response;
}
// Example response:
//  A markdown page for a Paella recipe(`paella-recipe.md`) has been generated.
//  It includes detailed steps and several images illustrating the cooking process.

REST

Esegui questo comando nel terminale per creare o sovrascrivere questo file nella directory corrente:

curl -X POST \
  -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  -H "Content-Type: application/json" \
  https://${API_ENDPOINT}:generateContent \
  -d '{
    "contents": {
      "role": "USER",
      "parts": [
        {
          "text": "Create a tutorial explaining how to make a peanut butter and jelly sandwich in three easy steps. For each step, provide a title with the number of the step, an explanation, and also generate an image, generate each image in a 1:1 aspect ratio."
        }
      ]
    },
    "generationConfig": {
      "responseModalities": ["TEXT", "IMAGE"],
      "imageConfig": {
        "aspectRatio": "16:9",
      },
    },
    "safetySettings": {
      "method": "PROBABILITY",
      "category": "HARM_CATEGORY_DANGEROUS_CONTENT",
      "threshold": "BLOCK_MEDIUM_AND_ABOVE"
    },
  }' 2>/dev/null >response.json

Gemini genera un'immagine in base alla tua descrizione. Questa procedura richiede alcuni secondi, ma può essere relativamente più lenta a seconda della capacità.

Passaggi successivi

Per saperne di più sulla generazione di immagini con Gemini, consulta i seguenti link: