image_codec.py

"""Conversions between on-disk/base64 image representations and PIL images."""
import base64
import json
import os
from io import BytesIO

from PIL import Image
from PIL.Image import Image as PILImage

from logging_utils import print_decode_error, print_encode_error, print_thumbnail_error

LANCZOS = getattr(Image, "Resampling", Image).LANCZOS


def make_thumb_b64(path: str, max_dim: int = 220) -> str:
    if not os.path.exists(path):
        return ""
    try:
        img = Image.open(path).convert("RGB")
        img.thumbnail((max_dim, max_dim), LANCZOS)
        buf = BytesIO()
        img.save(buf, format="JPEG", quality=65)
        return f"data:image/jpeg;base64,{base64.b64encode(buf.getvalue()).decode()}"
    except Exception as e:
        print_thumbnail_error(path, e)
        return ""


def encode_full_image(path: str) -> str:
    if not os.path.exists(path):
        return ""
    try:
        with open(path, "rb") as f:
            data = f.read()
        ext = path.rsplit(".", 1)[-1].lower()
        mime = {"jpg": "image/jpeg", "jpeg": "image/jpeg", "png": "image/png", "webp": "image/webp"}.get(ext, "image/jpeg")
        return f"data:{mime};base64,{base64.b64encode(data).decode()}"
    except Exception as e:
        print_encode_error(path, e)
        return ""


def b64_to_pil_list(b64_json_str: str) -> list[PILImage]:
    if not b64_json_str or b64_json_str.strip() in ("", "[]"):
        return []
    try:
        b64_list = json.loads(b64_json_str)
    except Exception:
        return []
    pil_images: list[PILImage] = []
    for b64_str in b64_list:
        if not b64_str or not isinstance(b64_str, str):
            continue
        try:
            if b64_str.startswith("data:image"):
                _, data = b64_str.split(",", 1)
            else:
                data = b64_str
            image_data = base64.b64decode(data)
            pil_images.append(Image.open(BytesIO(image_data)).convert("RGB"))
        except Exception as e:
            print_decode_error(e)
    return pil_images