TypLens V1.1

TypLens V1.1 converts an image of a printed mathematical formula directly into Typst math source. Its 29.2-million-parameter model can run locally in a browser using the supplied full-precision or compact ONNX graphs.

Repository name: TypLens. Model version: V1.1. Release tag: v1.1.

Hugging Face model repository · GitHub repository

What changed from V1

• A newly trained single-channel grayscale model replaces V1's RGB encoder input. Training ran for eight epochs (33,544 updates) on the original 268,346 training pairs, starting from the upstream-derived native-vocabulary initializer rather than continuing the released V1 checkpoint.
• Training and inference use the same luminance conversion, background polarity normalization, content bounding box, 2% margin and 384×384 bicubic resize.
• Full FP32 and compact dynamic INT8 ONNX exports come from the final checkpoint. The vocabulary and native Typst output format remain unchanged.

Integration change: V1.1 requires [1, 1, 384, 384] tensors and the custom preprocessing described in INFERENCE.md. Replace the preprocessing and both model graphs together. V1's RGB input pipeline is incompatible.

Files and sizes

Format	Files in the Hugging Face pack	Weight bytes	Download size, decimal MB
Native FP32	model.safetensors	116,870,000	116.9
Browser FP32	onnx/fp32/encoder.onnx + decoder.onnx	117,177,351	117.2
Browser compact	onnx/int8/encoder.onnx + decoder.onnx	33,120,766	33.1

The compact ONNX weights are 71.7% smaller than the FP32 ONNX weights. These numbers exclude tokenizer metadata and the application's runtime. Compact means dynamic INT8 linear weights; some operations and the caches remain FP32. The GitHub release provides a separate ZIP for each ONNX variant.

This distribution contains weights, tokenizer/configuration, documentation and license notices. It contains no training code, optimizer state, training images or inference runtime binaries. See release-manifest.json for file hashes and INFERENCE.md for integration.

Recorded evaluation

The final server FP32 checkpoint was reviewed on 135 reused IBEM development images with greedy generation and a maximum of 1,023 new tokens:

Measure	Result
Natural end of generation	135/135
Typst compilation	135/135
Content accepted by source-image review	127/135 (94.1%)
Exact match to one reference source string	76/135 (56.3%)
Accepted despite a different reference source string	51

Equivalent Typst spellings and nonessential spacing differences were accepted; visible symbols, indices, accents and matrix structure still had to match. The reviewer was an AI assistant, without an independent second annotator. 38 cases were reviewed anew; 97 judgments were inherited only when both the source image hash and complete prediction matched the earlier source review. This reused development set also informed checkpoint selection, so 94.1% is not an independent test accuracy. It is a server FP32 result, not a measured compact-model accuracy. No controlled V1 versus V1.1 accuracy comparison is claimed.

Both ONNX variants completed three real desktop Edge/WASM smoke-test images each. Input tensors matched the training preprocessing and generated tokens matched their CPU ONNX references; on these three images both variants also matched server FP32 outputs. One image retained a known accent error. These checks establish basic execution/parity, not full accuracy or absence of quantization loss. See evaluation-summary.json.

Intended use and limitations

Use one printed formula crop from a PDF, paper or screenshot per request. This model does not convert full documents. Handwriting, mobile inference and WebGPU performance have not been evaluated for this release. Small accents, similar symbols, missing indices and complex block matrices remain failure cases. Inspect the generated formula before use. Applications can show partial or validation-failed output with a warning so that it remains editable.

Provenance and license

The model derives from Pix2Text-MFR-1.5 (pinned revision 1cef9f0bdcd6a4c63df7de1311fb0894593340cc), with a native Typst vocabulary and a one-channel image projection. It has 29,206,656 parameters and uses 1,199 tokens. Source checkpoint SHA-256: d42cfd2da242a11ecdb1fe8727ee01e6896a116cd46f74357c4fdce90eebe788.

The release retains MIT for project contributions, with the Pix2Text and Microsoft MIT notices. Training data came from UniMER and IBEM. Dataset attribution and component-level provenance limits are retained in NOTICE.md. The model license does not relicense those datasets. Keep LICENSE, NOTICE.md and licenses/ when redistributing the weights.