RES_sigma

# GranD RefSeg — RefCOCOg-style Parquet export - records: 537611 - split: `train` - source: automatic retained set after one semantic repair ## Fields The first eight fields follow the local RefCOCOg Parquet schema: `question_id`, `image`, `question`, `answer`, `segmentation`, `bbox`, `iscrowd`, and `file_name`. `question` is the primary referring expression; `answer` retains all approved referring expressions for the same mask. `bbox` is `[x, y, width, height]` on the 512×512 crop. `image` and `mask` embed their original JPEG/PNG bytes. GranD masks can contain disconnected regions and holes, which the flat RefCOCOg polygon field cannot preserve without loss. Therefore `mask` and `mask_rle_*` are authoritative, lossless extensions; `segmentation` is intentionally empty.