Gemini 画像生成エラー完全解決ガイド — 429 エラーから安全フィルター問題まで

import google.generativeai as genai
from google.generativeai.types import generation_types
import time
 
genai.configure(api_key="YOUR_API_KEY")
 
def get_quota_info():
    """APIの現在のクォータ情報を取得"""
    try:
        # Quota API で残りリソースを確認
        # 注: 日本の API では直接 quota エンドポイントがない場合、
        # リトライ戦略で対応
        return {"status": "check_needed"}
    except Exception as e:
        print(f"Quota info error: {e}")
        return None
 
def generate_image_with_retry(prompt, max_retries=3):
    """指数バックオフを用いたリトライロジック"""
    model = genai.GenerativeModel("gemini-2.0-flash-exp")
 
    for attempt in range(max_retries):
        try:
            # 画像生成リクエスト
            response = model.generate_images(
                prompt=prompt,
                number_of_images=1,
                safety_filter_level="block_none"  # 初回は安全フィルター設定を確認
            )
            return response
 
        except genai.types.BlockedPromptException as e:
            # 安全フィルター により ブロック
            print(f"Content policy violation: {e}")
            return None
 
        except genai.types.RequestLimitExceeded as e:
            # 429 エラー
            if attempt < max_retries - 1:
                wait_time = 2 ** attempt + 1  # 1秒、3秒、7秒...
                print(f"Rate limited (429). Retrying in {wait_time}s...")
                time.sleep(wait_time)
            else:
                print("Max retries exceeded. Upgrade to paid tier or wait.")
                return None
 
        except Exception as e:
            print(f"Unexpected error: {type(e).__name__}: {e}")
            return None
 
    return None
 
# 使用例
result = generate_image_with_retry("A serene mountain landscape at sunset")
if result:
    print(f"Image URL: {result.candidates[0].image.uri}")

def generate_with_safety_options(
    prompt,
    safety_level="default"  # "none", "default", "strict"
):
    """複数の安全レベルでトライ"""
    model = genai.GenerativeModel("gemini-2.0-flash-exp")
 
    safety_configs = {
        "none": generation_types.SafetyFilterLevel.BLOCK_NONE,
        "default": generation_types.SafetyFilterLevel.BLOCK_SOME,
        "strict": generation_types.SafetyFilterLevel.BLOCK_MOST
    }
 
    try:
        response = model.generate_images(
            prompt=prompt,
            number_of_images=1,
            safety_filter_level=safety_configs.get(safety_level, "default")
        )
        return response, "success"
    except genai.types.BlockedPromptException:
        return None, "blocked"
 
# 正当なプロンプトを言い換える例
original = "医師が患者の X 線画像を説明している"
rephrased = "Medical professional reviewing radiography images in clinical setting"
 
result, status = generate_with_safety_options(rephrased, safety_level="default")
if status == "blocked":
    print("If legitimate, consider:")
    print("1. Use English prompts (sometimes less filtered)")
    print("2. Use abstract/illustrated style")
    print("3. Add context: 'Educational medical illustration for textbook'")

import base64
import io
from PIL import Image
 
def save_generated_image_safely(response, output_path):
    """破損対策を含めた画像保存"""
    try:
        if hasattr(response.candidates[0], 'image'):
            # URI形式の場合
            image_data = response.candidates[0].image
            if hasattr(image_data, 'uri'):
                print(f"Image URL: {image_data.uri}")
                # ウェブサービスの場合は直接 URL を使用
                return image_data.uri
 
            # Base64形式の場合
            if hasattr(image_data, 'data'):
                try:
                    image_bytes = base64.b64decode(image_data.data)
                    img = Image.open(io.BytesIO(image_bytes))
                    img.verify()  # 破損チェック
                    img.save(output_path)
                    print(f"Saved to {output_path}")
                    return output_path
                except Exception as decode_error:
                    print(f"Decode error: {decode_error}")
                    return None
 
    except AttributeError as e:
        print(f"Unexpected response format: {e}")
        return None
 
# 使用例
model = genai.GenerativeModel("gemini-2.0-flash-exp")
response = model.generate_images(
    prompt="A cat wearing a space suit",
    number_of_images=1
)
save_generated_image_safely(response, "output.png")

# ✅ 画像生成対応のモデル
IMAGE_GENERATION_MODEL = "gemini-2.0-flash-exp"
IMAGEN_MODEL = "imagen-3"  # 別ブランドの Imagen API
 
def list_available_models():
    """利用可能なモデルを一覧表示"""
    models = genai.list_models()
    for model in models:
        if 'generateImage' in str(model.supported_generation_methods):
            print(f"✓ Image generation: {model.name}")
        else:
            print(f"- Text only: {model.name}")
 
list_available_models()

import threading
 
def generate_with_timeout(prompt, timeout_seconds=60):
    """タイムアウト付きの画像生成"""
    model = genai.GenerativeModel("gemini-2.0-flash-exp")
    result = [None]
    exception = [None]
 
    def generate():
        try:
            result[0] = model.generate_images(
                prompt=prompt,
                number_of_images=1
            )
        except Exception as e:
            exception[0] = e
 
    thread = threading.Thread(target=generate)
    thread.daemon = True
    thread.start()
    thread.join(timeout=timeout_seconds)
 
    if thread.is_alive():
        print(f"Timeout after {timeout_seconds}s. Try:")
        print("1. Reduce image size")
        print("2. Simplify prompt")
        print("3. Use streaming instead")
        return None
 
    if exception[0]:
        raise exception[0]
 
    return result[0]
 
# 使用例
image = generate_with_timeout(
    "Complex 3D scene with many details",
    timeout_seconds=90
)