您可以要求 Gemini 模型分析您提供的內嵌 (base64 編碼) 或透過網址提供的圖片檔案。使用 Firebase AI Logic 時,您可以直接透過應用程式提出這項要求。
這項功能可讓您執行下列操作:
- 建立圖片說明或回答圖片相關問題
- 寫一篇關於圖片的短篇故事或詩
- 偵測圖片中的物件,並傳回物件的定界框座標
- 根據情緒、風格或其他特徵,為一組圖片加上標籤或分類
參閱其他指南,瞭解處理圖片的其他選項 產生結構化輸出內容 多回合聊天 在裝置上分析圖片 產生圖片 |
事前準備
按一下您的 Gemini API 供應商,即可在本頁查看供應商專屬內容和程式碼。 |
如果您尚未完成,請參閱入門指南,瞭解如何設定 Firebase 專案、將應用程式連結至 Firebase、新增 SDK、為所選 Gemini API 供應器初始化後端服務,以及建立 GenerativeModel
例項。
如要測試並重複提示,甚至取得產生的程式碼片段,建議您使用 Google AI Studio。
從圖片檔案 (以 Base64 編碼) 生成文字
在嘗試這個範例前,請先完成本指南的「開始前」一節,設定專案和應用程式。 在該部分,您也需要點選所選Gemini API供應商的按鈕,才能在本頁面上看到供應商專屬內容。 |
您可以要求 Gemini 模型使用文字和圖片進行提示,藉此生成文字,方法是提供每個輸入檔案的 mimeType
和檔案本身。請參閱本頁後續的輸入檔案相關規定和建議。
Swift
您可以呼叫 generateContent()
,根據多模態輸入的文字和圖片生成文字。
單一檔案輸入
import FirebaseAI
// Initialize the Gemini Developer API backend service
let ai = FirebaseAI.firebaseAI(backend: .googleAI())
// Create a `GenerativeModel` instance with a model that supports your use case
let model = ai.generativeModel(modelName: "gemini-2.0-flash")
guard let image = UIImage(systemName: "bicycle") else { fatalError() }
// Provide a text prompt to include with the image
let prompt = "What's in this picture?"
// To generate text output, call generateContent and pass in the prompt
let response = try await model.generateContent(image, prompt)
print(response.text ?? "No text in response.")
多個檔案輸入
import FirebaseAI
// Initialize the Gemini Developer API backend service
let ai = FirebaseAI.firebaseAI(backend: .googleAI())
// Create a `GenerativeModel` instance with a model that supports your use case
let model = ai.generativeModel(modelName: "gemini-2.0-flash")
guard let image1 = UIImage(systemName: "car") else { fatalError() }
guard let image2 = UIImage(systemName: "car.2") else { fatalError() }
// Provide a text prompt to include with the images
let prompt = "What's different between these pictures?"
// To generate text output, call generateContent and pass in the prompt
let response = try await model.generateContent(image1, image2, prompt)
print(response.text ?? "No text in response.")
Kotlin
您可以呼叫 generateContent()
,根據多模態輸入的文字和圖片生成文字。
單一檔案輸入
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
val model = Firebase.ai(backend = GenerativeBackend.googleAI())
.generativeModel("gemini-2.0-flash")
// Loads an image from the app/res/drawable/ directory
val bitmap: Bitmap = BitmapFactory.decodeResource(resources, R.drawable.sparky)
// Provide a prompt that includes the image specified above and text
val prompt = content {
image(bitmap)
text("What developer tool is this mascot from?")
}
// To generate text output, call generateContent with the prompt
val response = generativeModel.generateContent(prompt)
print(response.text)
多個檔案輸入
對於 Kotlin,這個 SDK 中的函式為暫停函式,需要從 協同程式範圍中呼叫。
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
val model = Firebase.ai(backend = GenerativeBackend.googleAI())
.generativeModel("gemini-2.0-flash")
// Loads an image from the app/res/drawable/ directory
val bitmap1: Bitmap = BitmapFactory.decodeResource(resources, R.drawable.sparky)
val bitmap2: Bitmap = BitmapFactory.decodeResource(resources, R.drawable.sparky_eats_pizza)
// Provide a prompt that includes the images specified above and text
val prompt = content {
image(bitmap1)
image(bitmap2)
text("What is different between these pictures?")
}
// To generate text output, call generateContent with the prompt
val response = generativeModel.generateContent(prompt)
print(response.text)
Java
您可以呼叫 generateContent()
,根據多模態輸入的文字和圖片生成文字。
ListenableFuture
。單一檔案輸入
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI())
.generativeModel("gemini-2.0-flash");
// Use the GenerativeModelFutures Java compatibility layer which offers
// support for ListenableFuture and Publisher APIs
GenerativeModelFutures model = GenerativeModelFutures.from(ai);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.sparky);
// Provide a prompt that includes the image specified above and text
Content content = new Content.Builder()
.addImage(bitmap)
.addText("What developer tool is this mascot from?")
.build();
// To generate text output, call generateContent with the prompt
ListenableFuture<GenerateContentResponse> response = model.generateContent(content);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
@Override
public void onSuccess(GenerateContentResponse result) {
String resultText = result.getText();
System.out.println(resultText);
}
@Override
public void onFailure(Throwable t) {
t.printStackTrace();
}
}, executor);
多個檔案輸入
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI())
.generativeModel("gemini-2.0-flash");
// Use the GenerativeModelFutures Java compatibility layer which offers
// support for ListenableFuture and Publisher APIs
GenerativeModelFutures model = GenerativeModelFutures.from(ai);
Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.sparky);
Bitmap bitmap2 = BitmapFactory.decodeResource(getResources(), R.drawable.sparky_eats_pizza);
// Provide a prompt that includes the images specified above and text
Content prompt = new Content.Builder()
.addImage(bitmap1)
.addImage(bitmap2)
.addText("What's different between these pictures?")
.build();
// To generate text output, call generateContent with the prompt
ListenableFuture<GenerateContentResponse> response = model.generateContent(prompt);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
@Override
public void onSuccess(GenerateContentResponse result) {
String resultText = result.getText();
System.out.println(resultText);
}
@Override
public void onFailure(Throwable t) {
t.printStackTrace();
}
}, executor);
Web
您可以呼叫 generateContent()
,根據多模態輸入的文字和圖片生成文字。
單一檔案輸入
import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend } 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-2.0-flash" });
// 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 to include with the image
const prompt = "What do you see?";
const fileInputEl = document.querySelector("input[type=file]");
const imagePart = await fileToGenerativePart(fileInputEl.files[0]);
// To generate text output, call generateContent with the text and image
const result = await model.generateContent([prompt, imagePart]);
const response = result.response;
const text = response.text();
console.log(text);
}
run();
多個檔案輸入
import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend } 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-2.0-flash" });
// 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 to include with the images
const prompt = "What's different between these pictures?";
// Prepare images for input
const fileInputEl = document.querySelector("input[type=file]");
const imageParts = await Promise.all(
[...fileInputEl.files].map(fileToGenerativePart)
);
// To generate text output, call generateContent with the text and images
const result = await model.generateContent([prompt, ...imageParts]);
const response = result.response;
const text = response.text();
console.log(text);
}
run();
Dart
您可以呼叫 generateContent()
,根據文字和圖片的多模態輸入內容生成文字。
單一檔案輸入
import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';
// Initialize FirebaseApp
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
final model =
FirebaseAI.googleAI().generativeModel(model: 'gemini-2.0-flash');
// Provide a text prompt to include with the image
final prompt = TextPart("What's in the picture?");
// Prepare images for input
final image = await File('image0.jpg').readAsBytes();
final imagePart = InlineDataPart('image/jpeg', image);
// To generate text output, call generateContent with the text and image
final response = await model.generateContent([
Content.multi([prompt,imagePart])
]);
print(response.text);
多個檔案輸入
import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';
// Initialize FirebaseApp
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
final model =
FirebaseAI.googleAI().generativeModel(model: 'gemini-2.0-flash');
final (firstImage, secondImage) = await (
File('image0.jpg').readAsBytes(),
File('image1.jpg').readAsBytes()
).wait;
// Provide a text prompt to include with the images
final prompt = TextPart("What's different between these pictures?");
// Prepare images for input
final imageParts = [
InlineDataPart('image/jpeg', firstImage),
InlineDataPart('image/jpeg', secondImage),
];
// To generate text output, call generateContent with the text and images
final response = await model.generateContent([
Content.multi([prompt, ...imageParts])
]);
print(response.text);
Unity
您可以呼叫 GenerateContentAsync()
,根據多模態輸入的文字和圖片生成文字。
單一檔案輸入
using Firebase;
using Firebase.AI;
// Initialize the Gemini Developer API backend service
var ai = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI());
// Create a `GenerativeModel` instance with a model that supports your use case
var model = ai.GetGenerativeModel(modelName: "gemini-2.0-flash");
// Convert a Texture2D into InlineDataParts
var grayImage = ModelContent.InlineData("image/png",
UnityEngine.ImageConversion.EncodeToPNG(UnityEngine.Texture2D.grayTexture));
// Provide a text prompt to include with the image
var prompt = ModelContent.Text("What's in this picture?");
// To generate text output, call GenerateContentAsync and pass in the prompt
var response = await model.GenerateContentAsync(new [] { grayImage, prompt });
UnityEngine.Debug.Log(response.Text ?? "No text in response.");
多個檔案輸入
using Firebase;
using Firebase.AI;
// Initialize the Gemini Developer API backend service
var ai = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI());
// Create a `GenerativeModel` instance with a model that supports your use case
var model = ai.GetGenerativeModel(modelName: "gemini-2.0-flash");
// Convert Texture2Ds into InlineDataParts
var blackImage = ModelContent.InlineData("image/png",
UnityEngine.ImageConversion.EncodeToPNG(UnityEngine.Texture2D.blackTexture));
var whiteImage = ModelContent.InlineData("image/png",
UnityEngine.ImageConversion.EncodeToPNG(UnityEngine.Texture2D.whiteTexture));
// Provide a text prompt to include with the images
var prompt = ModelContent.Text("What's different between these pictures?");
// To generate text output, call GenerateContentAsync and pass in the prompt
var response = await model.GenerateContentAsync(new [] { blackImage, whiteImage, prompt });
UnityEngine.Debug.Log(response.Text ?? "No text in response.");
瞭解如何選擇適合用途和應用程式的模型。
逐句顯示回應
在嘗試這個範例前,請先完成本指南的「開始前」一節,設定專案和應用程式。 在該部分,您也需要點選所選Gemini API供應商的按鈕,才能在本頁面上看到供應商專屬內容。 |
您可以不等待模型產生的完整結果,改用串流處理部分結果,以便加快互動速度。如要串流回應,請呼叫 generateContentStream
。
輸入圖片檔案的規定和建議
請注意,以內嵌資料形式提供的檔案會在傳輸過程中編碼為 base64,因此會增加要求的大小。如果要求過大,您會收到 HTTP 413 錯誤。
請參閱「支援的 Vertex AI Gemini API 輸入檔案和相關規定」一文,瞭解下列項目的詳細資訊:
- 在要求中提供檔案的不同選項 (內嵌或使用檔案網址)
- 圖片檔案的相關規定和最佳做法
支援的圖片 MIME 類型
Gemini 多模態模型支援下列圖片 MIME 類型:
圖片 MIME 類型 | Gemini 2.0 Flash | Gemini 2.0 Flash‑Lite |
---|---|---|
PNG - image/png |
||
JPEG - image/jpeg |
||
WebP - image/webp |
每項要求的限制
圖片的像素數量沒有特定限制。不過,較大的圖片會縮小並填滿,以便符合 3072 x 3072 的最大解析度,同時保留原始顯示比例。
以下是提示要求中允許的圖片檔案數量上限:
- Gemini 2.0 Flash 和 Gemini 2.0 Flash‑Lite:3,000 張圖片
你還可以做些什麼?
- 瞭解如何計算符號,再將長提示傳送至模型。
- 設定 Cloud Storage for Firebase,這樣您就能在多模態要求中加入大型檔案,並透過更妥善的解決方案在提示中提供檔案。檔案可包含圖片、PDF、影片和音訊。
-
開始著手準備正式版 (請參閱正式版檢查清單),包括:
- 設定 Firebase App Check,以免 Gemini API 遭到未經授權的用戶端濫用。
- 整合 Firebase Remote Config,無須發布新版應用程式,即可更新應用程式中的值 (例如型號名稱)。
試用其他功能
- 建構多輪對話 (聊天)。
- 使用文字提示來生成文字。
- 從文字和多模態提示產生結構化輸出內容 (例如 JSON)。
- 使用文字提示生成圖片。
- 使用函式呼叫,將生成模型連結至外部系統和資訊。
瞭解如何控管內容產生作業
- 瞭解提示設計,包括最佳做法、策略和提示範例。
- 設定模型參數,例如溫度參數和輸出符記數量上限 (適用於 Gemini),或顯示比例和人物生成 (適用於 Imagen)。
- 使用安全性設定,調整可能會收到有害回應的機率。
進一步瞭解支援的型號
瞭解可用於各種用途的模型,以及相關配額和價格。針對使用 Firebase AI Logic 的體驗提供意見回饋