CoW/common/utils.py

import io
import os

from PIL import Image


def fsize(file):
    if isinstance(file, io.BytesIO):
        return file.getbuffer().nbytes
    elif isinstance(file, str):
        return os.path.getsize(file)
    elif hasattr(file, "seek") and hasattr(file, "tell"):
        pos = file.tell()
        file.seek(0, os.SEEK_END)
        size = file.tell()
        file.seek(pos)
        return size
    else:
        raise TypeError("Unsupported type")


def compress_imgfile(file, max_size):
    if fsize(file) <= max_size:
        return file
    file.seek(0)
    img = Image.open(file)
    rgb_image = img.convert("RGB")
    quality = 95
    while True:
        out_buf = io.BytesIO()
        rgb_image.save(out_buf, "JPEG", quality=quality)
        if fsize(out_buf) <= max_size:
            return out_buf
        quality -= 5