使用 Gemini Nano Banana 生成及編輯圖像


您可以要求 Gemini Nano Banana 模型使用純文字和文字加檔案提示,生成及編輯圖片。使用 Firebase AI Logic 時,您可以直接從應用程式提出這項要求。

這項功能可讓您執行下列操作:

  • 透過自然語言對話,逐步生成圖像,並在調整圖像時維持一致性和情境。

  • 生成圖像,並以高畫質呈現文字,包括長字串。

  • 生成文字和圖片夾雜的輸出內容。例如,在單一回合中,網誌文章包含文字和圖片。過去,這需要串連多個模型。

  • 運用 Gemini 的全球知識和推論功能生成圖像。

您可以設定要求的回覆模態,讓模型只生成圖片,或同時生成圖片和文字。如需支援功能的完整清單 (以及提示範例),請參閱本頁後續章節。


跳至文字轉圖片的程式碼 跳至影片轉圖片的程式碼 跳至交錯文字和圖片的程式碼

跳至圖片編輯程式碼 跳至反覆編輯圖片程式碼


查看其他指南,瞭解更多處理圖片的選項
分析圖片 在裝置端分析圖片 生成結構化輸出內容

事前準備

按一下您的Gemini API供應商,即可在這個頁面查看供應商專屬內容和程式碼。

如果尚未完成入門指南,請先完成。該指南說明如何設定 Firebase 專案、將應用程式連結至 Firebase、新增 SDK、為所選 Gemini API 供應商初始化後端服務,以及建立 GenerativeModel 執行個體。

如要測試及反覆調整提示,建議使用 Google AI Studio。

支援這項功能的模型

  • gemini-nano-banana-2.1 (Nano Banana 2.1)
  • gemini-3.1-flash-image (Nano Banana 2)
  • gemini-3.1-flash-lite-image (Nano Banana 2 Lite)
  • gemini-3-pro-image (Nano Banana Pro)

gemini-2.5-flash-image 模型支援這項功能,但已淘汰。

生成及編輯圖像

您可以使用 Gemini Nano Banana 模型生成及編輯圖片。

生成圖片 (僅限文字輸入)

嘗試這個範例前,請先完成本指南的「事前準備」一節,設定專案和應用程式。
在該節中,您也需要點選所選Gemini API供應商的按鈕,這樣這個頁面才會顯示供應商專屬內容。

您可以透過文字提示,要求 Gemini Nano Banana 模型生成圖片。

建立 GenerativeModel 執行個體,在模型設定中加入 IMAGE 回覆模態,然後呼叫 generateContent。

Swift


import FirebaseAILogic

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
let model = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [.image])
)

// Provide a text prompt instructing the model to generate an image
let prompt = "Generate an image of the Eiffel tower with fireworks in the background."

// To generate an image, call `generateContent` with the text input
let response = try await model.generateContent(prompt)

// Handle the generated image
guard let inlineDataPart = response.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let uiImage = UIImage(data: inlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

Kotlin


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.IMAGE) }
)

// Provide a text prompt instructing the model to generate an image
val prompt = "Generate an image of the Eiffel tower with fireworks in the background."

// To generate image output, call `generateContent` with the text input
val generatedImageAsBitmap = model.generateContent(prompt)
    // Handle the generated image
    .candidates.first().content.parts.filterIsInstance<ImagePart>().firstOrNull()?.image

Java


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

// Provide a text prompt instructing the model to generate an image
Content prompt = new Content.Builder()
        .addText("Generate an image of the Eiffel Tower with fireworks in the background.")
        .build();

// To generate an image, call `generateContent` with the text input
ListenableFuture<GenerateContentResponse> response = model.generateContent(prompt);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) { 
        // iterate over all the parts in the first candidate in the result object
        for (Part part : result.getCandidates().get(0).getContent().getParts()) {
            if (part instanceof ImagePart) {
                ImagePart imagePart = (ImagePart) part;
                // The returned image as a bitmap
                Bitmap generatedImageAsBitmap = imagePart.getImage();
                break;
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer): Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service.
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: {
    responseModalities: [ResponseModality.IMAGE],
  },
});

// Provide a text prompt instructing the model to generate an image
const prompt = 'Generate an image of the Eiffel Tower with fireworks in the background.';

// To generate an image, call `generateContent` with the text input
const result = model.generateContent(prompt);

// Handle the generated image
try {
  const inlineDataParts = result.response.inlineDataParts();
  if (inlineDataParts?.[0]) {
    const image = inlineDataParts[0].inlineData;
    console.log(image.mimeType, image.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

Dart


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-nano-banana-2.1',
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [ResponseModalities.image]),
);

// Provide a text prompt instructing the model to generate an image
final prompt = [Content.text('Generate an image of the Eiffel Tower with fireworks in the background.')];

// To generate an image, call `generateContent` with the text input
final response = await model.generateContent(prompt);
if (response.inlineDataParts.isNotEmpty) {
  final imageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

Unity


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Image })
);

// Provide a text prompt instructing the model to generate an image
var prompt = "Generate an image of the Eiffel Tower with fireworks in the background.";

// To generate an image, call `GenerateContentAsync` with the text input
var response = await model.GenerateContentAsync(prompt);

// Handle the generated image
var imageParts = response.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
foreach (var imagePart in imageParts) {
  // Load the Image into a Unity Texture2D object
  UnityEngine.Texture2D texture2D = new(2, 2);
  if (texture2D.LoadImage(imagePart.Data.ToArray())) {
    // Do something with the image
  }
}

編輯圖像 (文字和圖像輸入)

嘗試這個範例前,請先完成本指南的「事前準備」一節,設定專案和應用程式。
在該節中,您也需要點選所選Gemini API供應商的按鈕,這樣這個頁面才會顯示供應商專屬內容。

您可以使用文字和一或多張圖片,提示 Gemini Nano Banana 模型編輯圖片。

建立 GenerativeModel 執行個體,在模型設定中加入 IMAGE 回覆模態,然後呼叫 generateContent。

Swift


import FirebaseAILogic

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
let model = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [.image])
)

// Provide an image for the model to edit
guard let image = UIImage(named: "scones") else { fatalError("Image file not found.") }

// Provide a text prompt instructing the model to edit the image
let prompt = "Edit this image to make it look like a cartoon"

// To edit the image, call `generateContent` with the image and text input
let response = try await model.generateContent(image, prompt)

// Handle the generated image
guard let inlineDataPart = response.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let uiImage = UIImage(data: inlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

Kotlin


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.IMAGE) }
)

// Provide an image for the model to edit
val bitmap = BitmapFactory.decodeResource(context.resources, R.drawable.scones)

// Provide a text prompt instructing the model to edit the image
val prompt = content {
    image(bitmap)
    text("Edit this image to make it look like a cartoon")
}

// To edit the image, call `generateContent` with the prompt (image and text input)
val generatedImageAsBitmap = model.generateContent(prompt)
    // Handle the generated text and image
    .candidates.first().content.parts.filterIsInstance<ImagePart>().firstOrNull()?.image

Java


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

// Provide an image for the model to edit
Bitmap bitmap = BitmapFactory.decodeResource(resources, R.drawable.scones);

// Provide a text prompt instructing the model to edit the image
Content promptcontent = new Content.Builder()
        .addImage(bitmap)
        .addText("Edit this image to make it look like a cartoon")
        .build();

// To edit the image, call `generateContent` with the prompt (image and text input)
ListenableFuture<GenerateContentResponse> response = model.generateContent(promptcontent);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        // iterate over all the parts in the first candidate in the result object
        for (Part part : result.getCandidates().get(0).getContent().getParts()) {
            if (part instanceof ImagePart) {
                ImagePart imagePart = (ImagePart) part;
                Bitmap generatedImageAsBitmap = imagePart.getImage();
                break;
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer): Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service.
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: {
    responseModalities: [ResponseModality.IMAGE],
  },
});

// Prepare an image for the model to edit
async function fileToGenerativePart(file) {
  const base64EncodedDataPromise = new Promise((resolve) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.readAsDataURL(file);
  });
  return {
    type: "inlineData",
    inlineData: { data: await base64EncodedDataPromise, mimeType: file.type },
  };
}

// Provide a text prompt instructing the model to edit the image
const prompt = "Edit this image to make it look like a cartoon";

const fileInputEl = document.querySelector("input[type=file]");
const imagePart = await fileToGenerativePart(fileInputEl.files[0]);

// To edit the image, call `generateContent` with the image and text input
const result = await model.generateContent([prompt, imagePart]);

// Handle the generated image
try {
  const inlineDataParts = result.response.inlineDataParts();
  if (inlineDataParts?.[0]) {
    const image = inlineDataParts[0].inlineData;
    console.log(image.mimeType, image.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

Dart


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-nano-banana-2.1',
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [ResponseModalities.image]),
);

// Prepare an image for the model to edit
final image = await File('scones.jpg').readAsBytes();
final imagePart = InlineDataPart('image/jpeg', image);

// Provide a text prompt instructing the model to edit the image
final prompt = TextPart("Edit this image to make it look like a cartoon");

// To edit the image, call `generateContent` with the image and text input
final response = await model.generateContent([
  Content.multi([prompt,imagePart])
]);

// Handle the generated image
if (response.inlineDataParts.isNotEmpty) {
  final imageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

Unity


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Image })
);

// Prepare an image for the model to edit
var imageFile = System.IO.File.ReadAllBytes(System.IO.Path.Combine(
  UnityEngine.Application.streamingAssetsPath, "scones.jpg"));
var image = ModelContent.InlineData("image/jpeg", imageFile);

// Provide a text prompt instructing the model to edit the image
var prompt = ModelContent.Text("Edit this image to make it look like a cartoon.");

// To edit the image, call `GenerateContent` with the image and text input
var response = await model.GenerateContentAsync(new [] { prompt, image });

// Handle the generated image
var imageParts = response.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
foreach (var imagePart in imageParts) {
  // Load the Image into a Unity Texture2D object
  Texture2D texture2D = new Texture2D(2, 2);
  if (texture2D.LoadImage(imagePart.Data.ToArray())) {
    // Do something with the image
  }
}

根據輸入的影片生成圖片 (文字和影片輸入)

嘗試這個範例前,請先完成本指南的「事前準備」一節,設定專案和應用程式。
在該節中,您也需要點選所選Gemini API供應商的按鈕,這樣這個頁面才會顯示供應商專屬內容。

您可以使用文字和影片提示,要求 Gemini Nano Banana 模型生成圖像。

建立 GenerativeModel 執行個體,在模型設定中加入 IMAGE 回覆模態,然後呼叫 generateContent。

Swift


import FirebaseAILogic

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
let model = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [.image])
)

// Provide the video as `Data` with the appropriate MIME type.
let video = InlineDataPart(data: try Data(contentsOf: videoURL), mimeType: "video/mp4")

// Provide a text prompt instructing the model to generate an image.
let prompt = "Generate a poster image that captures the key themes of this video."

// To generate an image, call `generateContent` with the video and text input.
let response = try await model.generateContent(video, prompt)

// Handle the generated image.
guard let inlineDataPart = response.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let uiImage = UIImage(data: inlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

Kotlin


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.IMAGE) }
)

val contentResolver = applicationContext.contentResolver
contentResolver.openInputStream(videoUri).use { stream ->
  stream?.let {
    val bytes = stream.readBytes()

    // Provide a prompt that includes the video specified above and text.
    val prompt = content {
        inlineData(bytes, "video/mp4")
        text("Generate a poster image that captures the key themes of this video.")
    }

    // Call generateContent with the prompt (video and text input).
    val response = model.generateContent(prompt)

    // Handle the generated image.
    val generatedImageAsBitmap = response.candidates.first().content.parts
        .filterIsInstance<ImagePart>().firstOrNull()?.image
  }
}

Java


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

ContentResolver resolver = getApplicationContext().getContentResolver();
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
try (java.io.InputStream inputStream = resolver.openInputStream(videoUri)) {
    if (inputStream != null) {
        int bytesRead;
        byte[] buffer = new byte[16384];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, bytesRead);
        }
    }
} catch (IOException e) {
    e.printStackTrace();
}

// Provide a prompt that includes the video specified above and text.
Content promptContent = new Content.Builder()
        .addInlineData(byteArrayOutputStream.toByteArray(), "video/mp4")
        .addText("Generate a poster image that captures the key themes of this video.")
        .build();

// Call generateContent with the prompt (video and text input).
ListenableFuture<GenerateContentResponse> response = model.generateContent(promptContent);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        // We didn't get any images back from the model.
        if (result.getCandidates().isEmpty()) {
            return;
        }
        // Handle the generated image.
        for (Part part : result.getCandidates().get(0).getContent().getParts()) {
            if (part instanceof ImagePart) {
                ImagePart imagePart = (ImagePart) part;
                Bitmap generatedImageAsBitmap = imagePart.getImage();
                break;
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer): Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service.
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: {
    responseModalities: [ResponseModality.IMAGE],
  },
});

// Converts a File object to a Part object.
async function fileToGenerativePart(file) {
  const base64EncodedDataPromise = new Promise((resolve) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.readAsDataURL(file);
  });
  return {
    inlineData: { data: await base64EncodedDataPromise, mimeType: file.type },
  };
}

async function run() {
  // Provide a text prompt instructing the model to generate an image.
  const prompt = "Generate a poster image that captures the key themes of this video.";

  const fileInputEl = document.querySelector("input[type=file]");
  const videoPart = await fileToGenerativePart(fileInputEl.files[0]);

  // Call generateContent with the video and text input.
  const result = await model.generateContent([prompt, videoPart]);

  // Handle the generated image.
  try {
    const inlineDataParts = result.response.inlineDataParts();
    if (inlineDataParts?.[0]) {
      const image = inlineDataParts[0].inlineData;
      console.log(image.mimeType, image.data);
    }
  } catch (err) {
    console.error('Prompt or candidate was blocked:', err);
  }
}

run();

Dart


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-nano-banana-2.1',
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [ResponseModalities.image]),
);

// Prepare video for input.
final video = await File('video0.mp4').readAsBytes();
final videoPart = InlineDataPart('video/mp4', video);

// Provide a text prompt instructing the model to generate an image.
final prompt = TextPart("Generate a poster image that captures the key themes of this video.");

// Call generateContent with the video and text input.
final response = await model.generateContent([
  Content.multi([prompt, videoPart])
]);

// Handle the generated image.
if (response.inlineDataParts.isNotEmpty) {
  final imageBytes = response.inlineDataParts.first.bytes;
  // Process the image.
} else {
  // Handle the case where no images were generated.
  print('Error: No images were generated.');
}

Unity


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Image })
);

// Prepare a video for input.
var videoFile = System.IO.File.ReadAllBytes(System.IO.Path.Combine(
  UnityEngine.Application.streamingAssetsPath, "yourVideo.mp4"));
var video = ModelContent.InlineData("video/mp4", videoFile);

// Provide a text prompt instructing the model to generate an image.
var prompt = ModelContent.Text("Generate a poster image that captures the key themes of this video.");

// Call GenerateContentAsync with the video and text input.
var response = await model.GenerateContentAsync(new [] { prompt, video });

// Handle the generated image.
var imageParts = response.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
foreach (var imagePart in imageParts) {
  // Load the Image into a Unity Texture2D object.
  Texture2D texture2D = new Texture2D(2, 2);
  if (texture2D.LoadImage(imagePart.Data.ToArray())) {
    // Do something with the image.
  }
}

生成圖文交錯的內容

嘗試這個範例前,請先完成本指南的「事前準備」一節,設定專案和應用程式。
在該節中,您也需要點選所選Gemini API供應商的按鈕,這樣這個頁面才會顯示供應商專屬內容。

您可以要求 Gemini Nano Banana 模型生成圖文交錯圖像和文字回覆。舉例來說,您可以生成圖片,呈現生成食譜中每個步驟的可能樣貌,並附上步驟說明,不必向模型或不同模型個別提出要求。

建立 GenerativeModel 執行個體,在模型設定中加入 TEXT 和 IMAGE 的回覆模態,然後呼叫 generateContent。

Swift


import FirebaseAILogic

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
let model = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with text and images.
  generationConfig: GenerationConfig(responseModalities: [.text, .image])
)

// Provide a text prompt instructing the model to generate interleaved text and images
let prompt = """
Generate an illustrated recipe for a paella.
Create images to go alongside the text as you generate the recipe
"""

// To generate interleaved text and images, call `generateContent` with the text input
let response = try await model.generateContent(prompt)

// Handle the generated text and image
guard let candidate = response.candidates.first else {
  fatalError("No candidates in response.")
}
for part in candidate.content.parts {
  switch part {
  case let textPart as TextPart:
    // Do something with the generated text
    let text = textPart.text
  case let inlineDataPart as InlineDataPart:
    // Do something with the generated image
    guard let uiImage = UIImage(data: inlineDataPart.data) else {
      fatalError("Failed to convert data to UIImage.")
    }
  default:
    fatalError("Unsupported part type: \(part)")
  }
}

Kotlin


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-nano-banana-2.1",
    // Configure the model to respond with text and images.
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE) }
)

// Provide a text prompt instructing the model to generate interleaved text and images
val prompt = """
    Generate an illustrated recipe for a paella.
    Create images to go alongside the text as you generate the recipe
    """.trimIndent()

// To generate interleaved text and images, call `generateContent` with the text input
val responseContent = model.generateContent(prompt).candidates.first().content

// The response will contain image and text parts interleaved
for (part in responseContent.parts) {
    when (part) {
        is ImagePart -> {
            // ImagePart as a bitmap
            val generatedImageAsBitmap: Bitmap? = part.asImageOrNull()
        }
        is TextPart -> {
            // Text content from the TextPart
            val text = part.text
        }
    }
}

Java


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-nano-banana-2.1",
    // Configure the model to respond with text and images.
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.TEXT, ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

// Provide a text prompt instructing the model to generate interleaved text and images
Content prompt = new Content.Builder()
        .addText("Generate an illustrated recipe for a paella.\n" +
                 "Create images to go alongside the text as you generate the recipe")
        .build();

// To generate interleaved text and images, call `generateContent` with the text input
ListenableFuture<GenerateContentResponse> response = model.generateContent(prompt);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        Content responseContent = result.getCandidates().get(0).getContent();
        // The response will contain image and text parts interleaved
        for (Part part : responseContent.getParts()) {
            if (part instanceof ImagePart) {
                // ImagePart as a bitmap
                Bitmap generatedImageAsBitmap = ((ImagePart) part).getImage();
            } else if (part instanceof TextPart){
                // Text content from the TextPart
                String text = ((TextPart) part).getText();
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        System.err.println(t);
    }
}, executor);

Web


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer): Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service.
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  // Configure the model to respond with text and images.
  generationConfig: {
    responseModalities: [ResponseModality.TEXT, ResponseModality.IMAGE],
  },
});

// Provide a text prompt instructing the model to generate interleaved text and images
const prompt = 'Generate an illustrated recipe for a paella.\n.' +
  'Create images to go alongside the text as you generate the recipe';

// To generate interleaved text and images, call `generateContent` with the text input
const result = await model.generateContent(prompt);

// Handle the generated text and image
try {
  const response = result.response;
  if (response.candidates?.[0].content?.parts) {
    for (const part of response.candidates?.[0].content?.parts) {
      if (part.type === "text") {
        // Do something with the text
        console.log(part.text);
      }
      if (part.type === "inlineData") {
        // Do something with the image
        const image = part.inlineData;
        console.log(image.mimeType, image.data);
      }
    }
  }

} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

Dart


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-nano-banana-2.1',
  // Configure the model to respond with text and images.
  generationConfig: GenerationConfig(responseModalities: [ResponseModalities.text, ResponseModalities.image]),
);

// Provide a text prompt instructing the model to generate interleaved text and images
final prompt = [Content.text(
  'Generate an illustrated recipe for a paella\n ' +
  'Create images to go alongside the text as you generate the recipe'
)];

// To generate interleaved text and images, call `generateContent` with the text input
final response = await model.generateContent(prompt);

// Handle the generated text and image
final parts = response.candidates.firstOrNull?.content.parts;
if (parts != null && parts.isNotEmpty) {
  for (final part in parts) {
    if (part is TextPart) {
      // Do something with text part
      final text = part.text;
    }
    if (part is InlineDataPart) {
      // Process image
      final imageBytes = part.bytes;
    }
  }
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

Unity


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with text and images.
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Text, ResponseModality.Image })
);

// Provide a text prompt instructing the model to generate interleaved text and images
var prompt = "Generate an illustrated recipe for a paella \n" +
  "Create images to go alongside the text as you generate the recipe";

// To generate interleaved text and images, call `GenerateContentAsync` with the text input
var response = await model.GenerateContentAsync(prompt);

// Handle the generated text and image
foreach (var part in response.Candidates.First().Content.Parts) {
  if (part is ModelContent.TextPart textPart) {
    if (!string.IsNullOrWhiteSpace(textPart.Text)) {
      // Do something with the text
    }
  } else if (part is ModelContent.InlineDataPart dataPart) {
    if (dataPart.MimeType == "image/png") {
      // Load the Image into a Unity Texture2D object
      UnityEngine.Texture2D texture2D = new(2, 2);
      if (texture2D.LoadImage(dataPart.Data.ToArray())) {
        // Do something with the image
      }
    }
  }
}

透過多輪對話調整及編輯圖片

嘗試這個範例前,請先完成本指南的「事前準備」一節,設定專案和應用程式。
在該節中,您也需要點選所選Gemini API供應商的按鈕,這樣這個頁面才會顯示供應商專屬內容。

您可以使用多輪對話,與 Gemini Nano Banana 模型反覆調整模型生成或您提供的圖片。

建立 GenerativeModel 執行個體,在模型設定中加入 IMAGE 回覆模態,然後呼叫 startChat() 和 sendMessage() 傳送新的使用者訊息。

Swift


import FirebaseAILogic

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
let model = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [.image])
)

// Initialize the chat
let chat = model.startChat()

guard let image = UIImage(named: "scones") else { fatalError("Image file not found.") }

// Provide an initial text prompt instructing the model to edit the image
let prompt = "Edit this image to make it look like a cartoon"

// To generate an initial response, send a user message with the image and text prompt
let response = try await chat.sendMessage(image, prompt)

// Inspect the generated image
guard let inlineDataPart = response.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let uiImage = UIImage(data: inlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

// Follow up requests do not need to specify the image again
let followUpResponse = try await chat.sendMessage("But make it old-school line drawing style")

// Inspect the edited image after the follow up request
guard let followUpInlineDataPart = followUpResponse.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let followUpUIImage = UIImage(data: followUpInlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

Kotlin


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.IMAGE) }
)

// Provide an image for the model to edit
val bitmap = BitmapFactory.decodeResource(context.resources, R.drawable.scones)

// Create the initial prompt instructing the model to edit the image
val prompt = content {
    image(bitmap)
    text("Edit this image to make it look like a cartoon")
}

// Initialize the chat
val chat = model.startChat()

// To generate an initial response, send a user message with the image and text prompt
var response = chat.sendMessage(prompt)
// Inspect the returned image
var generatedImageAsBitmap = response
    .candidates.first().content.parts.filterIsInstance<ImagePart>().firstOrNull()?.image

// Follow up requests do not need to specify the image again
response = chat.sendMessage("But make it old-school line drawing style")
generatedImageAsBitmap = response
    .candidates.first().content.parts.filterIsInstance<ImagePart>().firstOrNull()?.image

Java


// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-nano-banana-2.1",
    // Configure the model to respond with images only.
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

// Provide an image for the model to edit
Bitmap bitmap = BitmapFactory.decodeResource(resources, R.drawable.scones);

// Initialize the chat
ChatFutures chat = model.startChat();

// Create the initial prompt instructing the model to edit the image
Content prompt = new Content.Builder()
        .setRole("user")
        .addImage(bitmap)
        .addText("Edit this image to make it look like a cartoon")
        .build();

// To generate an initial response, send a user message with the image and text prompt
ListenableFuture<GenerateContentResponse> response = chat.sendMessage(prompt);
// Extract the image from the initial response
ListenableFuture<@Nullable Bitmap> initialRequest = Futures.transform(response, result -> {
    for (Part part : result.getCandidates().get(0).getContent().getParts()) {
        if (part instanceof ImagePart) {
            ImagePart imagePart = (ImagePart) part;
            return imagePart.getImage();
        }
    }
    return null;
}, executor);

// Follow up requests do not need to specify the image again
ListenableFuture<GenerateContentResponse> modelResponseFuture = Futures.transformAsync(
        initialRequest,
        generatedImage -> {
            Content followUpPrompt = new Content.Builder()
                    .addText("But make it old-school line drawing style")
                    .build();
            return chat.sendMessage(followUpPrompt);
        },
        executor);

// Add a final callback to check the reworked image
Futures.addCallback(modelResponseFuture, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        for (Part part : result.getCandidates().get(0).getContent().getParts()) {
            if (part instanceof ImagePart) {
                ImagePart imagePart = (ImagePart) part;
                Bitmap generatedImageAsBitmap = imagePart.getImage();
                break;
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer): Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service.
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: {
    responseModalities: [ResponseModality.IMAGE],
  },
});

// Prepare an image for the model to edit
async function fileToGenerativePart(file) {
  const base64EncodedDataPromise = new Promise((resolve) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.readAsDataURL(file);
  });
  return {
    type: "inlineData",
    inlineData: { data: await base64EncodedDataPromise, mimeType: file.type },
  };
}

const fileInputEl = document.querySelector("input[type=file]");
const imagePart = await fileToGenerativePart(fileInputEl.files[0]);

// Provide an initial text prompt instructing the model to edit the image
const prompt = "Edit this image to make it look like a cartoon";

// Initialize the chat
const chat = model.startChat();

// To generate an initial response, send a user message with the image and text prompt
const result = await chat.sendMessage([prompt, imagePart]);

// Request and inspect the generated image
try {
  const inlineDataParts = result.response.inlineDataParts();
  if (inlineDataParts?.[0]) {
    // Inspect the generated image
    const image = inlineDataParts[0].inlineData;
    console.log(image.mimeType, image.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

// Follow up requests do not need to specify the image again
const followUpResult = await chat.sendMessage("But make it old-school line drawing style");

// Request and inspect the returned image
try {
  const followUpInlineDataParts = followUpResult.response.inlineDataParts();
  if (followUpInlineDataParts?.[0]) {
    // Inspect the generated image
    const followUpImage = followUpInlineDataParts[0].inlineData;
    console.log(followUpImage.mimeType, followUpImage.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

Dart


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-nano-banana-2.1',
  // Configure the model to respond with images only.
  generationConfig: GenerationConfig(responseModalities: [ResponseModalities.image]),
);

// Prepare an image for the model to edit
final image = await File('scones.jpg').readAsBytes();
final imagePart = InlineDataPart('image/jpeg', image);

// Provide an initial text prompt instructing the model to edit the image
final prompt = TextPart("Edit this image to make it look like a cartoon");

// Initialize the chat
final chat = model.startChat();

// To generate an initial response, send a user message with the image and text prompt
final response = await chat.sendMessage([
  Content.multi([prompt,imagePart])
]);

// Inspect the returned image
if (response.inlineDataParts.isNotEmpty) {
  final imageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

// Follow up requests do not need to specify the image again
final followUpResponse = await chat.sendMessage([
  Content.text("But make it old-school line drawing style")
]);

// Inspect the returned image
if (followUpResponse.inlineDataParts.isNotEmpty) {
  final followUpImageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

Unity


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service.
// Create a `GenerativeModel` instance with a Gemini model that supports image output.
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  // Configure the model to respond with images only.
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Image })
);

// Prepare an image for the model to edit
var imageFile = System.IO.File.ReadAllBytes(System.IO.Path.Combine(
  UnityEngine.Application.streamingAssetsPath, "scones.jpg"));
var image = ModelContent.InlineData("image/jpeg", imageFile);

// Provide an initial text prompt instructing the model to edit the image
var prompt = ModelContent.Text("Edit this image to make it look like a cartoon.");

// Initialize the chat
var chat = model.StartChat();

// To generate an initial response, send a user message with the image and text prompt
var response = await chat.SendMessageAsync(new [] { prompt, image });

// Inspect the returned image
var imageParts = response.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
// Load the image into a Unity Texture2D object
UnityEngine.Texture2D texture2D = new(2, 2);
if (texture2D.LoadImage(imageParts.First().Data.ToArray())) {
  // Do something with the image
}

// Follow up requests do not need to specify the image again
var followUpResponse = await chat.SendMessageAsync("But make it old-school line drawing style");

// Inspect the returned image
var followUpImageParts = followUpResponse.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
// Load the image into a Unity Texture2D object
UnityEngine.Texture2D followUpTexture2D = new(2, 2);
if (followUpTexture2D.LoadImage(followUpImageParts.First().Data.ToArray())) {
  // Do something with the image
}



提供參考圖像

Gemini Nano Banana 模型可讓您在提示中提供參考圖像。這類映像檔包括:

  • Gemini Nano Banana 2.1 (gemini-nano-banana-2.1):

    • 最多 10 張高保真物件圖片,可加入最終圖片
    • 最多 4 張角色圖片,用於維持角色一致性
  • Gemini Nano Banana 2 (gemini-3.1-flash-image):

    • 最多 10 張高保真物件圖片,可加入最終圖片
    • 最多 4 張角色圖片,用於維持角色一致性
  • Gemini Nano Banana 2 Lite (gemini-3.1-flash-lite-image):

    • 最多 10 張高保真物件圖片,可加入最終圖片
    • 最多 4 張角色圖片,用於維持角色一致性
  • Gemini Nano Banana Pro (gemini-3-pro-image)

    • 最多 6 張高保真物件圖片,可加入最終圖片
    • 最多 5 張角色圖片,用於維持角色一致性
    • 最多 3 張圖片,做為風格參考

請注意,gemini-2.5-flash-image 模型最多只能支援 3 張圖片。

設定圖像生成

根據預設,Gemini Nano Banana 模型會生成正方形圖片 (顯示比例 1:1),解析度為 1024x1024。您可以使用 generationConfig 中的 imageConfig 屬性,自訂生成圖像的輸出內容。

舉例來說,您可以使用顯示比例和圖片大小列舉,設定輸出圖片 (例如 16:9 顯示比例和 2K 解析度,產生 2752x1536 圖片),如下所示:

Swift

// ...

// Specify aspect ratio and image size (both optional) in an image config.
let imageConfig = ImageConfig(aspectRatio: .landscape16x9, imageSize: .size2K)

let generationConfig = GenerationConfig(
  // Configure the model to respond with text (optional) and images (required).
  // Include the text modality only if you want interleaved text and images in the response.
  responseModalities: [.text, .image],
  imageConfig: imageConfig
)

// Make sure you initialize your chosen Gemini API backend service
let model = FirebaseAI.firebaseAI().generativeModel(
  modelName: "gemini-nano-banana-2.1",
  generationConfig: generationConfig
)

// ...

Kotlin

// ...

val config = generationConfig {
    // Configure the model to respond with text (optional) and images (required).
    // Include the text modality only if you want interleaved text and images in the response.
    responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE)
    // Specify aspect ratio and image size (both optional) in an image config.
    imageConfig = imageConfig {
        aspectRatio = AspectRatio.LANDSCAPE_16x9
        imageSize = ImageSize.SIZE_2K
    }
}

// Make sure you initialize your chosen Gemini API backend service
val model = Firebase.ai.generativeModel(
    modelName = "gemini-nano-banana-2.1",
    generationConfig = config
)

// ...

Java

// ...

GenerationConfig config = new GenerationConfig.Builder()
    // Configure the model to respond with text (optional) and images (required).
    // Include the text modality only if you want interleaved text and images in the response.
    .setResponseModalities(Arrays.asList(ResponseModality.TEXT, ResponseModality.IMAGE))
    // Specify aspect ratio and image size (both optional) in an image config.
    .setImageConfig(
        ImageConfig.builder()
            .setAspectRatio(AspectRatio.LANDSCAPE_16x9)
            .setImageSize(ImageSize.SIZE_2K)
            .build()
    )
    .build();

// Make sure you initialize your chosen Gemini API backend service
GenerativeModel model = FirebaseAI.getInstance().generativeModel(
    "gemini-nano-banana-2.1",
    config
);

// ...

Web

import {
  getGenerativeModel,
  ResponseModality,
  ImageConfigAspectRatio,
  ImageConfigImageSize
} from "firebase/ai";

// ...

const generationConfig = {
  // Configure the model to respond with text (optional) and images (required).
  // Include the text modality only if you want interleaved text and images in the response.
  responseModalities: [ResponseModality.TEXT, ResponseModality.IMAGE],
  // Specify aspect ratio and image size (both optional) in an image config.
  imageConfig: {
    aspectRatio: ImageConfigAspectRatio.LANDSCAPE_16x9,
    imageSize: ImageConfigImageSize.SIZE_2K
  }
};

// Make sure you initialize your chosen Gemini API backend service
const model = getGenerativeModel(ai, {
  model: "gemini-nano-banana-2.1",
  generationConfig
});

// ...

Dart

// ...

final generationConfig = GenerationConfig(
  // Configure the model to respond with text (optional) and images (required).
  // Include the text modality only if you want interleaved text and images in the response.
  responseModalities: [ResponseModalities.text, ResponseModalities.image],
  // Specify aspect ratio and image size (both optional) in an image config.
  imageConfig: ImageConfig(
    aspectRatio: ImageAspectRatio.landscape16x9,
    imageSize: ImageSize.size2K,
  ),
);

// Make sure you initialize your chosen Gemini API backend service
final model = FirebaseAI.instance.generativeModel(
  model: 'gemini-nano-banana-2.1,
  generationConfig: generationConfig,
);

// ...

Unity

// ...

var generationConfig = new GenerationConfig(
  // Configure the model to respond with text (optional) and images (required).
  // Include the text modality only if you want interleaved text and images in the response.
  responseModalities: new[] { ResponseModality.Text, ResponseModality.Image },
  // Specify aspect ratio and image size (both optional) in an image config.
  imageConfig: new ImageConfig(
    aspectRatio: ImageConfig.AspectRatio.Landscape16x9,
    imageSize: ImageConfig.ImageSize.Size2K)
);

// Make sure you initialize your chosen Gemini API backend service.
var model = FirebaseAI.GetInstance().GetGenerativeModel(
  modelName: "gemini-nano-banana-2.1",
  generationConfig: generationConfig
);

// ...

支援的顯示比例

所有 Gemini Nano Banana 模型都支援下列顯示比例:

預設值:1:1 (正方形)

1:1、1:4、1:8、2:3、3:2、3:4、4:1、4:3、4:5、5:4、8:1、9:16、16:9、21:9

支援的圖片大小 (解析度)

支援的圖片大小 (解析度) 取決於使用的模型。

Gemini Nano Banana 個模型 支援的大小 (解析度)
Gemini Nano Banana 2.1
gemini-nano-banana-2.1
預設:1K (1024)
1K (1024)、2K (2048)、4K (4096)
Gemini Nano Banana 2
gemini-3.1-flash-image
預設值:1K (1024)
512、1K (1024)、2K (2048)、4K (4096)
Gemini Nano Banana 2 Lite
gemini-3.1-flash-lite-image
預設:1K (1024)
512 (僅限 Gemini Developer API),1K (1024)
Gemini Nano Banana Pro
gemini-3-pro-image
預設:1K (1024)
1K (1024)、2K (2048)、4K (4096)

您必須使用大寫 K 後置字元 (即 1K、2K、4K)。512 值不使用 K 後置字元。如果使用小寫 k 後置字串 (例如 1k),系統會拒絕。

請注意,gemini-2.5-flash-image 模型固定為 1K (1024)。



支援功能

以下是支援的功能,例如模態、工具、輸入和語言。

如要瞭解各模型支援的顯示比例和解析度,請參閱本指南前述的「設定圖像生成」一節。

支援的多模態

Gemini Nano Banana 模型支援下列「模態」。您不必在要求中明確設定這些「模態」,比較像是常見用途的建議模式。本指南先前章節中,已提供這份清單中每種模態的提示範例和程式碼範例。

  • 文字 圖片 (純文字轉圖片)

    • 生成艾菲爾鐵塔的圖片,背景有煙火。
  • 文字 圖片 (圖片中的文字呈現)

    • 生成一張電影動態效果相片,呈現一棟大型建築,正面投影著這段巨大文字。
  • 圖像編輯 (文字和圖像轉圖像)

    • [司康圖片] + 編輯這張圖片,讓它看起來像卡通

    • [貓咪圖片] + [枕頭圖片] + 在這個枕頭上製作貓咪的十字繡。

  • 影片和文字 圖片 (文字和影片轉圖片)

    • [公園的影片/網址] + 生成海報圖片,呈現這部影片的主要主題。
  • 文字 圖片和文字 (交錯)

    • 生成西班牙海鮮燉飯的食譜插圖。生成食譜時,系統會同時建立圖片和文字。

    • 生成一則關於狗的故事,呈現 3D 卡通動畫風格。 為每個場景生成圖片。

  • 圖片和文字 圖片和文字 (交錯)

    • [擺設家具的房間圖片] + 我的房間還適合擺放什麼顏色的沙發?可以更新圖片嗎?
  • 多輪圖像編輯 (對話)

    • [藍色汽車的圖片] + 將這輛車變成敞篷車。,然後現在將顏色改成黃色。

支援的工具

支援使用Google Search建立基準:

  • Gemini Nano Banana 2.1 (gemini-nano-banana-2.1)

  • Gemini Nano Banana 2 (gemini-3.1-flash-image)

  • Gemini Nano Banana Pro (gemini-3-pro-image)

其他支援的功能

  • 支援的多模態輸入內容:

    • 圖片輸入:所有 Nano Banana 模型。

    • 影片輸入:

      • Gemini Nano Banana 2.1 (gemini-nano-banana-2.1)
      • Gemini Nano Banana 2 (gemini-3.1-flash-image)
      • Gemini Nano Banana 2 Lite (gemini-3.1-flash-lite-image)
    • 音訊輸入:不適用於任何 Nano Banana 模型。

  • 所有 Nano Banana 模型都支援下列功能:

    • 生成 PNG 圖片。
    • 生成及編輯人物圖像。
    • 使用安全篩選器,提供彈性且限制較少的使用者體驗。
  • 支援生成結構化輸出內容 (例如 JSON):

    • Gemini Nano Banana Pro (gemini-3-pro-image)

支援的語言

雖然 Gemini Nano Banana 模型可接受多種語言的文字提示詞,但使用本節列出的語言可獲得最佳成效。

以下是文字提示詞和生成圖像內文字支援的語言:

ar-EG、de-DE、EN、es-MX、fr-FR、hi-IN、id-ID、it-IT、ja-JP、ko-KR、pt-BR、ru-RU、uk-UA、vi-VN、zh-CN

如要在生成圖像中使用特定語言 (即使沒有語言代碼),只要在提示中要求模型即可 (例如「將這張資訊圖表更新為西班牙文。請勿變更圖片的其他元素。」)。

請注意,gemini-2.5-flash-image 模型僅支援文字提示詞中的 EN、es-MX、ja-JP、zh-CN、hi-IN,且只能在圖片中生成英文。



最佳做法

以下是 Gemini Nano Banana 模型的最佳做法。

  • 生成含有文字的圖片時,請先生成文字,再生成含有該文字的圖片。

  • 不一定每次都會觸發圖像生成功能。此外,在下列情況下,圖片或文字生成功能可能無法正常運作:

    • 模型可能只會生成文字,不會生成圖片 (尤其是提示不明確時)。如果發生這種情況,FinishReason 為 NO_IMAGE。
      請試著明確要求輸出圖像。例如「生成圖片」、「邊進行邊提供圖片」、「更新圖片」。

    • 模型可能會在生成過程中停止。
      請再試一次或改用其他提示詞。

    • 模型可能會生成文字做為圖片。
      請試著明確要求輸出文字。例如「生成敘述文字和插圖」。

    • 如果提示可能不安全,模型可能不會處理要求,而是傳回回應,指出無法建立不安全的圖片。在這種情況下,FinishReason 為 STOP。