Function _resize_to_envelope

src/utils/image_processor.py:221–235

Resize ``img`` to fit within ``max_w × max_h`` preserving aspect ratio. Returns ``(resized_img, new_w, new_h)``. No-op when image already fits. Matches sharp's ``fit: 'inside', withoutEnlargement: true``.

(img: Any, max_w: int, max_h: int)

def _resize_to_envelope(img: Any, max_w: int, max_h: int) -> tuple[Any, int, int]:
    """Resize ``img`` to fit within ``max_w × max_h`` preserving aspect ratio.

    Returns ``(resized_img, new_w, new_h)``. No-op when image already fits.
    Matches sharp's ``fit: 'inside', withoutEnlargement: true``.
    """
    Image, _ = _pil()
    w, h = img.size
    if w <= max_w and h <= max_h:
        return img, w, h
    scale = min(max_w / w, max_h / h)
    new_w = max(1, int(w * scale))
    new_h = max(1, int(h * scale))
    resized = img.resize((new_w, new_h), Image.LANCZOS)
    return resized, new_w, new_h


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