image-server.py

#!/usr/bin/env python3
  
import sys

import magic
from PIL import Image

from inky.inky_uc8159 import Inky

from flask import Flask, request, Response

inky = Inky()
saturation = 0.5

app = Flask(__name__)

def validate_image(buffer):
    mime_type = magic.from_buffer(buffer, mime=True)
    
    if mime_type == 'image/png' or mime_type == 'image/jpeg' or mime_type == 'image/webp' or mime_type == 'image/gif':
        return True
    elif mime_type == 'image/heic':
        return False
    else:
        return False

def convert_to_epaper(input_image, epaper_width=640, epaper_height=400):
    # 画像が640x400ピクセルの場合はそのまま出力
    if input_image.size == (epaper_width, epaper_height):
        return input_image

    # アスペクト比を保ったままリサイズ
    width, height = input_image.size
    aspect_ratio = width / height
    target_ratio = epaper_width / epaper_height
    if aspect_ratio > target_ratio:
        # 横長の場合
        new_width = epaper_width
        new_height = int(new_width / aspect_ratio)
    else:
        # 縦長の場合
        new_height = epaper_height
        new_width = int(new_height * aspect_ratio)
    input_image = input_image.resize((new_width, new_height), resample=Image.LANCZOS)

    # 透過PNGの場合、透過部分を白で塗りつぶす
    if input_image.mode == 'RGBA':
        background = Image.new('RGBA', input_image.size, (255, 255, 255, 255))
        background.paste(input_image, mask=input_image)
        input_image = background.convert('RGB')

    # 足りない領域を白で塗りつぶす
    padded_image = Image.new("RGB", (epaper_width, epaper_height), color=(255, 255, 255))
    left = (epaper_width - new_width) // 2
    upper = (epaper_height - new_height) // 2
    padded_image.paste(input_image, (left, upper))
    return padded_image

# @app.before_request
# def log_request_info():
#     app.logger.debug('Headers: %s', request.headers)
#     app.logger.debug('Body: %s', request.get_data())

@app.route('/upload', methods=['POST'])
def upload_file():
    code = 400
    # check if the post request has the file part
    if 'file' not in request.files:
        ret = 'No file part'
    file = request.files['file']
    if file and validate_image(file.read()):
        try:
            image = Image.open(file)
            converted = convert_to_epaper(image)
            inky.set_image(converted, saturation=saturation)
            inky.show()
            ret = 'upload success'
            code = 200
        except ValueError as e:
            print(e)
            ret = str(e)
            code = 400
        except Exception as e:
            print(e)
            code = 500
            ret = str(e)
    return Response(response=ret, status=code)

# app.run(debug=True, host='0.0.0.0', port=7777)
app.run(debug=False, host='0.0.0.0', port=7777)