---
license: apache-2.0
language:
  - en
tags:
  - image-quality-assessment
  - document-quality
  - mplug-owl2
  - vision-language
  - document-analysis
  - IQA
pipeline_tag: image-to-text
library_name: transformers
---

# DeQA-Doc-Overall: Document Image Quality Assessment

**DeQA-Doc-Overall** is a vision-language model for assessing the **overall quality** of document images. It provides a quality score from 1 (bad) to 5 (excellent) that reflects the general visual quality of scanned or photographed documents.

## Model Family

This model is part of the **DeQA-Doc** family, which includes three specialized models:

| Model | Description | HuggingFace |
|-------|-------------|-------------|
| **DeQA-Doc-Overall** | Overall document quality (this model) | [mapo80/DeQA-Doc-Overall](https://huggingface.co/mapo80/DeQA-Doc-Overall) |
| **DeQA-Doc-Color** | Color quality assessment | [mapo80/DeQA-Doc-Color](https://huggingface.co/mapo80/DeQA-Doc-Color) |
| **DeQA-Doc-Sharpness** | Sharpness/clarity assessment | [mapo80/DeQA-Doc-Sharpness](https://huggingface.co/mapo80/DeQA-Doc-Sharpness) |

## Quick Start

```python
import torch
from transformers import AutoModelForCausalLM
from PIL import Image

# Load the model
model = AutoModelForCausalLM.from_pretrained(
    "mapo80/DeQA-Doc-Overall",
    trust_remote_code=True,
    torch_dtype=torch.float16,
    device_map="auto",
)

# Score an image
image = Image.open("document.jpg").convert("RGB")
score = model.score([image])
print(f"Overall Quality Score: {score.item():.2f} / 5.0")
```

## Batch Processing

You can score multiple images at once:

```python
images = [
    Image.open("doc1.jpg").convert("RGB"),
    Image.open("doc2.jpg").convert("RGB"),
    Image.open("doc3.jpg").convert("RGB"),
]

scores = model.score(images)
for i, score in enumerate(scores):
    print(f"Document {i+1}: {score.item():.2f} / 5.0")
```

## Score Interpretation

| Score Range | Quality Level | Description |
|-------------|---------------|-------------|
| 4.5 - 5.0 | **Excellent** | Perfect quality, no visible defects |
| 3.5 - 4.5 | **Good** | Minor imperfections, highly readable |
| 2.5 - 3.5 | **Fair** | Noticeable issues but still usable |
| 1.5 - 2.5 | **Poor** | Significant quality problems |
| 1.0 - 1.5 | **Bad** | Severe degradation, hard to read |

## Model Architecture

- **Base Model**: mPLUG-Owl2 (LLaMA2-7B + ViT-L Vision Encoder)
- **Vision Encoder**: CLIP ViT-L/14 (1024 visual tokens via Visual Abstractor)
- **Language Model**: LLaMA2-7B
- **Training**: Full fine-tuning on document quality datasets
- **Input Resolution**: Images are resized to 448x448 (with aspect ratio preservation)

## Technical Details

| Property | Value |
|----------|-------|
| Model Size | ~16 GB (float16) |
| Parameters | ~7.2B |
| Input | RGB images (any resolution) |
| Output | Quality score (1.0 - 5.0) |
| Inference | ~2-3 seconds per image on A100 |

## Hardware Requirements

| Setup | VRAM Required | Recommended |
|-------|---------------|-------------|
| Full precision (fp32) | ~32 GB | A100, H100 |
| Half precision (fp16) | ~16 GB | A100, A40, RTX 4090 |
| With CPU offload | ~8 GB GPU + RAM | RTX 3090, RTX 4080 |

### GPU Inference (Recommended)

```python
model = AutoModelForCausalLM.from_pretrained(
    "mapo80/DeQA-Doc-Overall",
    trust_remote_code=True,
    torch_dtype=torch.float16,
    device_map="auto",
)
```

### CPU Offload (Lower VRAM)

```python
model = AutoModelForCausalLM.from_pretrained(
    "mapo80/DeQA-Doc-Overall",
    trust_remote_code=True,
    torch_dtype=torch.float16,
    device_map="auto",
    offload_folder="/tmp/offload",
)
```

## Installation

```bash
pip install torch transformers accelerate pillow sentencepiece protobuf
```

**Note**: Use `transformers>=4.36.0` for best compatibility.

## Use Cases

- **Document Scanning QA**: Automatically flag low-quality scans for re-scanning
- **Archive Digitization**: Prioritize documents needing restoration
- **OCR Preprocessing**: Filter images likely to produce poor OCR results
- **Document Management**: Sort and categorize documents by quality
- **Quality Control**: Automated quality checks in document processing pipelines

## Example: Quality-Based Filtering

```python
import torch
from transformers import AutoModelForCausalLM
from PIL import Image
from pathlib import Path

model = AutoModelForCausalLM.from_pretrained(
    "mapo80/DeQA-Doc-Overall",
    trust_remote_code=True,
    torch_dtype=torch.float16,
    device_map="auto",
)

# Filter documents by quality
def filter_by_quality(image_paths, min_score=3.0):
    good_docs = []
    bad_docs = []

    for path in image_paths:
        img = Image.open(path).convert("RGB")
        score = model.score([img]).item()

        if score >= min_score:
            good_docs.append((path, score))
        else:
            bad_docs.append((path, score))

    return good_docs, bad_docs

# Usage
docs = list(Path("documents/").glob("*.jpg"))
good, bad = filter_by_quality(docs, min_score=3.5)

print(f"Good quality: {len(good)} documents")
print(f"Need review: {len(bad)} documents")
```

## Limitations

- Optimized for document images (forms, letters, reports, etc.)
- May not perform well on natural photos or artistic images
- Requires GPU with sufficient VRAM for efficient inference
- Score is subjective and based on training data distribution

## Credits & Attribution

This model is based on the **DeQA-Doc** project by Junjie Gao et al., which won the **Championship** in the VQualA 2025 DIQA (Document Image Quality Assessment) Challenge.

**Original Repository**: [https://github.com/Junjie-Gao19/DeQA-Doc](https://github.com/Junjie-Gao19/DeQA-Doc)

All credit for the research, training methodology, and model architecture goes to the original authors.

## Citation

If you use this model in your research, please cite the original paper:

```bibtex
@inproceedings{deqadoc,
  title={{DeQA-Doc}: Adapting {DeQA-Score} to Document Image Quality Assessment},
  author={Gao, Junjie and Liu, Runze and Peng, Yingzhe and Yang, Shujian and Zhang, Jin and Yang, Kai and You, Zhiyuan},
  booktitle={Proceedings of the IEEE/CVF International Conference on Computer Vision Workshop},
  year={2025},
}
```

**ArXiv**: [https://arxiv.org/abs/2507.12796](https://arxiv.org/abs/2507.12796)

## License

Apache 2.0

## Related Models

- [DeQA-Doc-Color](https://huggingface.co/mapo80/DeQA-Doc-Color) - Color quality assessment
- [DeQA-Doc-Sharpness](https://huggingface.co/mapo80/DeQA-Doc-Sharpness) - Sharpness assessment