P1n3/sdg-detector-grpo
178
SDG Detector — GRPO Stage (Merged Checkpoint)

This repository provides the merged full checkpoint of the SDG detector after Stage-2 GRPO. It is already merged with the Stage-1 SFT checkpoint (P1n3/sdg-detector-sft) and can be loaded directly with transformers.
Important: this is not a PEFT/LoRA adapter. Do not load it withPeftModel.from_pretrained, and do not merge it intoQwen/Qwen3-VL-4B-InstructorP1n3/sdg-detector-sft.
Training Summary
Quick Start
from transformers import AutoProcessor, AutoModelForImageTextToText
import torch
ckpt = "P1n3/sdg-detector-grpo" # merged full checkpoint
processor = AutoProcessor.from_pretrained(ckpt)
model = AutoModelForImageTextToText.from_pretrained(
ckpt,
dtype=torch.bfloat16,
device_map="auto",
)
model.eval()For SGLang/OpenAI-compatible serving in BoxFlow-GRPO:
python -m sglang.launch_server \
--model-path P1n3/sdg-detector-grpo \
--served-model-name sdg-detector \
--port 17142 --tp 4 --api-key flowgrpo --trust-remote-codeOutput Format
The detector predicts structured defect sets:
<think>
... reasoning about image quality and caption alignment ...
</think>
<answer>
[
{
"box_2d": [x0, y0, x1, y1],
"label": "artifact" or "misalignment",
"description": "...",
"importance": 1-100
}
]
</answer>License
cc-by-nc-4.0. This checkpoint is derived from P1n3/sdg-detector-sft (itself a derivative of Qwen/Qwen3-VL-4B-Instruct, Apache-2.0). Research and non-commercial use only.
Citation
@article{zhang2026and,
title={Where, What, Why, and Importance: Structured Defect Grounding for Text-to-Image Feedback},
author={Zhang, Huaisong and Yu, Hao and Zhang, Yuxuan and Wang, Jiahe and Chen, Xinrui and Cao, Haoxiang and Lu, Feng and Zhang, Wendong and Yu, Changqian and Yuan, Chun},
journal={arXiv preprint arXiv:2606.06113},
year={2026}
}