Python script to resize images via Cloud Function

gcp_cloud_function_image_resize.py

import functions_framework
from flask import Request, Response
from google.cloud import storage
from PIL import Image
import io
import mimetypes

# Set your bucket name here
BUCKET_NAME = 'my-resize-bucket-poc'

@functions_framework.http
def resize_image(request: Request) -> Response:
    # Parse query parameters
    image_path = request.args.get('image')
    size_str = request.args.get('size')

    if not image_path or not size_str:
        return Response("Missing 'image' or 'size' query parameter", status=400)

    # Parse size
    try:
        width, height = map(int, size_str.lower().split('x'))
    except ValueError:
        return Response("Invalid size format. Use WIDTHxHEIGHT, e.g., 300x200", status=400)

    # Download image from GCS
    client = storage.Client()
    bucket = client.bucket(BUCKET_NAME)
    blob = bucket.blob(image_path)

    if not blob.exists():
        return Response(f"Image not found: {image_path}", status=404)

    image_data = blob.download_as_bytes()

    # Resize image using Pillow
    try:
        with Image.open(io.BytesIO(image_data)) as img:
            img = img.convert("RGBA") if img.mode in ("P", "LA") else img
            resized_img = img.resize((width, height), Image.Resampling.LANCZOS)


            buffer = io.BytesIO()
            mime_type, _ = mimetypes.guess_type(image_path)
            image_format = mime_type.split("/")[-1].upper() if mime_type else "PNG"

            resized_img.save(buffer, format=image_format)
            buffer.seek(0)

            return Response(
                response=buffer.read(),
                status=200,
                content_type=mime_type or "image/png",
                headers={"Cache-Control": "public, max-age=3600"}
            )
    except Exception as e:
        return Response(f"Error processing image: {e}", status=500)