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| 1 |
+
# AssameseOCR
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| 2 |
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| 3 |
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**AssameseOCR** is a vision-language model for Optical Character Recognition (OCR) of printed Assamese text. Built on Microsoft's Florence-2-large foundation model with a custom character-level decoder, it achieves 94.67% character accuracy on the Mozhi dataset.
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+
## Model Details
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| 6 |
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| 7 |
+
### Model Description
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| 8 |
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- **Developed by:** MWire Labs
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- **Model type:** Vision-Language OCR
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- **Language:** Assamese (অসমীয়া)
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- **License:** Apache 2.0
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- **Base Model:** microsoft/Florence-2-large-ft
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- **Architecture:** Florence-2 Vision Encoder + Custom Transformer Decoder
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| 15 |
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| 16 |
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### Model Architecture
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| 17 |
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| 18 |
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```
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+
Image (768×768)
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↓
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Florence-2 Vision Encoder (frozen, 360M params)
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↓
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Vision Projection (1024 → 512 dim)
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↓
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Transformer Decoder (4 layers, 8 heads)
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↓
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Character-level predictions (187 vocab)
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```
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**Key Components:**
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- **Vision Encoder:** Florence-2-large DaViT architecture (frozen)
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- **Decoder:** 4-layer Transformer with 512 hidden dimensions
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- **Tokenizer:** Character-level with 187 tokens (Assamese chars + English + digits + symbols)
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- **Total Parameters:** 378M (361M frozen, 17.5M trainable)
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## Training Details
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### Training Data
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- **Dataset:** [Mozhi Indic OCR Dataset](https://huggingface.co/datasets/darknight054/indic-mozhi-ocr) (Assamese subset)
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- **Training samples:** 79,697 word images
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- **Validation samples:** 9,945 word images
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- **Test samples:** 10,146 word images
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- **Source:** IIT Hyderabad CVIT
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### Training Procedure
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**Hardware:**
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- GPU: NVIDIA A40 (48GB VRAM)
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- Training time: ~8 hours (3 epochs)
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**Hyperparameters:**
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- Epochs: 3
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- Batch size: 16
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- Learning rate: 3e-4
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- Optimizer: AdamW (weight_decay=0.01)
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- Scheduler: CosineAnnealingLR
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- Max sequence length: 128 characters
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- Gradient clipping: 1.0
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**Training Strategy:**
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- Froze Florence-2 vision encoder (leveraging pretrained visual features)
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- Trained only the projection layer and transformer decoder
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- Full fine-tuning (no LoRA) for maximum quality
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## Performance
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### Results
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| Split | Character Accuracy | Loss |
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|-------|-------------------|------|
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| Epoch 1 (Val) | 91.61% | 0.2844 |
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| Epoch 2 (Val) | 94.09% | 0.1548 |
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| Epoch 3 (Val) | **94.67%** | **0.1221** |
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**Character Error Rate (CER):** ~5.33%
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### Comparison
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The model achieves strong performance for a foundation model approach:
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- Mozhi paper (CRNN+CTC specialist): ~99% accuracy
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- AssameseOCR (Florence generalist): 94.67% accuracy
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The 5% gap is expected when adapting a general vision-language model versus training a specialized OCR architecture. However, AssameseOCR offers:
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- Extensibility to vision-language tasks (VQA, captioning, document understanding)
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- Faster training (3 epochs vs typical 10-20 for CRNN)
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- Foundation model benefits (transfer learning, robustness)
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## Usage
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### Installation
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```bash
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pip install torch torchvision transformers pillow
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```
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### Inference
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```python
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import torch
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from PIL import Image
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from transformers import AutoModelForCausalLM, CLIPImageProcessor
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import json
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# Load tokenizer
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class CharTokenizer:
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def __init__(self, vocab):
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self.vocab = vocab
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self.char2id = {c: i for i, c in enumerate(vocab)}
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self.id2char = {i: c for i, c in enumerate(vocab)}
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self.pad_token_id = self.char2id["<pad>"]
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self.bos_token_id = self.char2id["<s>"]
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self.eos_token_id = self.char2id["</s>"]
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def decode(self, ids, skip_special_tokens=True):
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chars = []
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for i in ids:
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ch = self.id2char.get(i, "")
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if skip_special_tokens and ch.startswith("<"):
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continue
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chars.append(ch)
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return "".join(chars)
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@classmethod
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def load(cls, path):
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with open(path, "r", encoding="utf-8") as f:
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vocab = json.load(f)
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return cls(vocab)
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# Load model components
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device = "cuda" if torch.cuda.is_available() else "cpu"
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# Load Florence base model
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florence_model = AutoModelForCausalLM.from_pretrained(
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"microsoft/Florence-2-large-ft",
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trust_remote_code=True
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).to(device)
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# Load image processor
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image_processor = CLIPImageProcessor.from_pretrained("microsoft/Florence-2-large-ft")
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# Load tokenizer
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char_tokenizer = CharTokenizer.load("assamese_char_tokenizer.json")
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# Load AssameseOCR weights
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# (Note: You'll need to define the FlorenceCharOCR class as in training)
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checkpoint = torch.load("assamese_ocr_best.pt", map_location=device)
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# ocr_model.load_state_dict(checkpoint['model_state_dict'])
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# Inference
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image = Image.open("assamese_text.jpg")
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# Process and predict...
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```
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## Vocabulary
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The character-level tokenizer includes:
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- **Assamese characters:** 119 unique chars (consonants, vowels, diacritics, conjuncts)
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- **English:** 52 chars (a-z, A-Z)
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- **Digits:** 30 chars (ASCII 0-9, Assamese ০-৯, Devanagari ०-९)
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- **Symbols:** 33 chars (punctuation, special chars)
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- **Special tokens:** 6 tokens (`<pad>`, `<s>`, `</s>`, `<unk>`, `<OCR>`, `<lang_as>`)
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- **Total vocabulary:** 187 tokens
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## Limitations
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- Trained only on printed text (not handwritten)
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- Word-level images from Mozhi dataset (may not generalize to full-page OCR without line segmentation)
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- Character-level decoder may struggle with very long sequences (>128 chars)
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- Does not handle layout analysis or reading order
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- Performance on degraded/low-quality images not extensively tested
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## Future Work
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- Extend to **MeiteiOCR** for Meitei Mayek script
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- Scale to **NE-OCR** covering all 9+ Northeast Indian languages
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- Add document layout analysis and reading order detection
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- Improve performance with synthetic data augmentation
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- Fine-tune for handwritten text recognition
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- Extend to multimodal tasks (image captioning, VQA for documents)
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## Citation
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If you use AssameseOCR in your research, please cite:
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```bibtex
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@software{assameseocr2026,
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author = {MWire Labs},
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| 189 |
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title = {AssameseOCR: Vision-Language Model for Assamese Text Recognition},
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year = {2026},
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publisher = {Hugging Face},
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url = {https://huggingface.co/MWirelabs/assamese-ocr}
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}
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```
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## Acknowledgments
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- **Dataset:** Mozhi Indic OCR Dataset by IIT Hyderabad CVIT ([Mathew et al., 2022](https://arxiv.org/abs/2205.06740))
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- **Base Model:** Florence-2 by Microsoft Research
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- **Organization:** MWire Labs, Shillong, Meghalaya, India
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## Contact
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| 203 |
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- **Organization:** [MWire Labs](https://huggingface.co/MWirelabs)
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- **Location:** Shillong, Meghalaya, India
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- **Focus:** Language technology for Northeast Indian languages
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---
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**Part of the MWire Labs NLP suite:**
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- [KhasiBERT](https://huggingface.co/MWirelabs/KhasiBERT-110M) - Khasi language model
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- [NE-BERT](https://huggingface.co/MWirelabs/NE-BERT) - 9 Northeast languages
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| 213 |
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- [Kren-M](https://huggingface.co/MWirelabs/Kren-M) - Khasi-English conversational AI
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| 214 |
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- **AssameseOCR** - Assamese text recognition
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