odysseus-dev/odysseus · error · HTTPException

Pillow not installed on server

Error message

Pillow not installed on server

What it means

Error "Pillow not installed on server" thrown in odysseus-dev/odysseus.

Source

Thrown at routes/gallery/gallery_routes.py:1321

        if not base.endswith("/v1"):
            base += "/v1"

        is_openai = _is_openai_api_base(base)

        if is_openai:
            # OpenAI path: /v1/images/edits with gpt-image-1.
            # Mask convention differs from Stable Diffusion:
            #   SD:     white pixels = regenerate, black = keep
            #   OpenAI: transparent alpha = regenerate, opaque = keep
            # So we convert the incoming PNG mask into an alpha-channel PNG.
            if not api_key:
                raise HTTPException(400, "OpenAI endpoint has no api_key stored — edit it in Endpoints settings.")
            import base64, io
            try:
                from PIL import Image
            except ImportError:
                raise HTTPException(500, "Pillow not installed on server")

            try:
                img_bytes = base64.b64decode(body["image"])
                mask_bytes = base64.b64decode(body["mask"])
                source_png = Image.open(io.BytesIO(img_bytes)).convert("RGBA")
                mask_png = Image.open(io.BytesIO(mask_bytes)).convert("L")  # luminance
                # Build OpenAI mask: RGBA where alpha=255 means keep, 0 means regenerate.
                # SD mask: white (255) = regenerate → alpha 0.  Black (0) = keep → alpha 255.
                # RGB must be white for keep areas; start from fully-white opaque and
                # overwrite alpha so visual contents match the expected semantic.
                alpha = mask_png.point(lambda p: 255 - p)
                oa_mask = Image.new("RGBA", source_png.size, (255, 255, 255, 255))
                oa_mask.putalpha(alpha)

                src_buf = io.BytesIO()
                source_png.save(src_buf, format="PNG")
                src_buf.seek(0)
                mask_buf = io.BytesIO()

View on GitHub (pinned to f9235ebbf1)

Solutions

1. Install Pillow into the server Python environment: pip install Pillow.
2. Install the image dependencies from the project requirements and restart.

When it happens

Trigger: Triggered when the corresponding server-side validation or runtime check at the recorded location rejects the request or operation and returns this error message to the caller.

Common situations: See trigger scenarios.

AI-assisted analysis of odysseus-dev/odysseus@f9235ebbf1 (2026-08-14). Data as JSON: /api/errors/127236c7aaa03807. Report an issue: GitHub.