[アップデート] Amazon Nova Canvas で virtual try-on と style options がサポートされました

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
"""
Shows how to generate an image from a text prompt with the Amazon Nova Canvas model (on demand).
"""
import base64
import io
import json
import logging
import boto3
from PIL import Image
from botocore.config import Config

from botocore.exceptions import ClientError


class ImageError(Exception):
    "Custom exception for errors returned by Amazon Nova Canvas"

    def __init__(self, message):
        self.message = message


logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)


def generate_image(model_id, body):
    """
    Generate an image using Amazon Nova Canvas model on demand.
    Args:
        model_id (str): The model ID to use.
        body (str) : The request body to use.
    Returns:
        image_bytes (bytes): The image generated by the model.
    """

    logger.info(
        "Generating image with Amazon Nova Canvas model %s", model_id)

    bedrock = boto3.client(
        service_name='bedrock-runtime',
        config=Config(read_timeout=300)
    )

    accept = "application/json"
    content_type = "application/json"

    response = bedrock.invoke_model(
        body=body, modelId=model_id, accept=accept, contentType=content_type
    )
    response_body = json.loads(response.get("body").read())

    base64_image = response_body.get("images")[0]
    base64_bytes = base64_image.encode('ascii')
    image_bytes = base64.b64decode(base64_bytes)

    finish_reason = response_body.get("error")

    if finish_reason is not None:
        raise ImageError(f"Image generation error. Error is {finish_reason}")

    logger.info(
        "Successfully generated image with Amazon Nova Canvas model %s", model_id)

    return image_bytes


def main():
    """
    Entrypoint for Amazon Nova Canvas  example.
    """

    logging.basicConfig(level=logging.INFO,
                        format="%(levelname)s: %(message)s")

    model_id = 'amazon.nova-canvas-v1:0'

    prompt = """オフィスの窓側から見える東京タワーの風景"""

    styles = [
        "3D_ANIMATED_FAMILY_FILM",
        "DESIGN_SKETCH",
        "FLAT_VECTOR_ILLUSTRATION",
        "GRAPHIC_NOVEL_ILLUSTRATION",
        "MAXIMALISM",
        "MIDCENTURY_RETRO",
        "PHOTOREALISM",
        "SOFT_DIGITAL_PAINTING"
    ]

    for style in styles:
        logger.info(f"Generating image with style: {style}")
        
        body = json.dumps({
            "taskType": "TEXT_IMAGE",
            "textToImageParams": {
                "text": prompt,
                "style": style
            },
            "imageGenerationConfig": {
                "numberOfImages": 1,
                "height": 1024,
                "width": 1024,
                "cfgScale": 8.0,
                "seed": 0
            }
        })

        try:
            image_bytes = generate_image(
                model_id=model_id,
                body=body
            )
            image = Image.open(io.BytesIO(image_bytes))
            
            # Save image with style-based filename
            filename = f"{style}.png"
            image.save(filename)
            logger.info(f"Saved image as {filename}")

        except ClientError as err:
            message = err.response["Error"]["Message"]
            logger.error(f"A client error occurred for style {style}:", message)
            print(f"A client error occured for style {style}: " + format(message))
        except ImageError as err:
            logger.error(f"Error for style {style}: {err.message}")
            print(f"Error for style {style}: {err.message}")

        else:
            print(
                f"Finished generating image with style {style} using model {model_id}.")


if __name__ == "__main__":
    main()