Myanmar Crnn Ocr

--- license: apache-2.0 language: - my tags: - ocr - crnn - ctc - myanmar - onnx library_name: onnxruntime pipeline_tag: image-to-text --- # Myanmar CRNN OCR Model Lightweight CRNN + CTC model for recognising text lines from scanned Myanmar documents. Used by [mmpdfkit](https://github.com/kaungsithu/mmpdfkit) to convert scanned Myanmar PDFs to Unicode Markdown. ## Model Details | Property | Value | |---|---| | Architecture | CRNN (Conv + BiLSTM + CTC) | | Input | Grayscale line crop, height=32px, variable width | | Output | Myanmar / English Unicode text | | Vocabulary size | 272 classes (Myanmar Unicode U+1000–U+109F, Extended U+AA60–U+AA7F, English, punctuation) | | Format | INT8 quantised ONNX (~8.9 MB) | | Training data | 7.6M synthetic + real scanned Myanmar document line images | | Best val CER | **4.17%** (epoch 50) | ## Files | File | Size | Description | |---|---|---| | `myanmar-crnn-ocr.onnx` | ~8.9 MB | INT8 quantised — production model used by mmpdfkit | ## Usage with mmpdfkit **pip** ```bash pip install mmpdfkit[ocr] mmpdfkit your_scanned_document.pdf ``` **uv** (recommended — faster installs, isolated environment) ```bash uv tool install mmpdfkit[ocr] mmpdfkit your_scanned_document.pdf ``` The model is downloaded automatically on first OCR run and cached at `~/.cache/mmpdfkit/`. ## Direct ONNX Usage ```python import onnxruntime as ort import numpy as np import cv2 # Load model session = ort.InferenceSession("myanmar-crnn-ocr.onnx", providers=["CPUExecutionProvider"]) # Prepare a grayscale line crop (H, W) uint8 crop = cv2.imread("line.png", cv2.IMREAD_GRAYSCALE) h, w = crop.shape if h != 32: crop = cv2.resize(crop, (max(1, round(w * 32 / h)), 32), interpolation=cv2.INTER_LANCZOS4) crop = cv2.resize(crop, (crop.shape[1] * 2, 32), interpolation=cv2.INTER_LANCZOS4) x = (crop.astype(np.float32) / 255.0)[np.newaxis, np.newaxis] # (1, 1, 32, W) logits = session.run(["output"], {"input": x})[0] # (1, W', 272) indices = logits[0].argmax(axis=1).tolist() # Apply greedy CTC decode (collapse repeats, remove blank index 22) ``` ## Preprocessing - Binarise page with Otsu threshold - Deskew up to ~5° using `cv2.minAreaRect` - Horizontal dilation to merge characters within a line - Row projection to segment line bands - Each line crop resized to height=32, then width doubled before inference ## Training Trained with CTC loss on 7.6M Mya...

Source context: 0 downloads · 2 likes · Pipeline image-to-text · Library onnxruntime · Repo ksithu/myanmar-crnn-ocr

Source context: 0 downloads · 1 likes · Pipeline image-to-text · Library onnxruntime · Repo ksithu/myanmar-crnn-ocr