MegawizCo/typhoon-ocr-7b-mlx-q4

Typhoon-OCR-7B — MLX q4

MLX-quantized port of typhoon-ai/typhoon-ocr-7b for native Apple Silicon inference. Larger sibling of the 3b variant — same model family, more parameters → more robust on tricky handwriting at the cost of latency.

Quantization: 4-bit affine, group size 64. Effective rate 5.439 bits/weight (vision-projector + layer-norm stay full precision). Size on disk: 5.3 GB.

⚠️ Note: config.json patched

The upstream typhoon-ai/typhoon-ocr-7b config.json is missing the vision_config fields that mlx-vlm's Qwen2.5-VL loader requires (out_hidden_size, depth, intermediate_size, num_heads, patch_size, spatial_merge_size, window_size, fullatt_block_indexes, temporal_patch_size). The conversion fails with a shape mismatch otherwise. We patched the config by copying those fields verbatim from the upstream Qwen/Qwen2.5-VL-7B-Instruct config — the base vision tower is identical, only the fields were omitted from the upstream serialization.

The patched config.json ships with this repo. If you re-run the conversion command below on the upstream model, you need to apply the same patch first (see end of this README).

Benchmark

7-image internal smoke set (2 synthetic printed Thai/English + 5 synthetic mixed-Thai handwriting). Same prompt (Extract all text from this image.) on Mac mini Apple Silicon, 2026-05-13:

Backend	HW CER median	HW CER max	Wall median	Generation TPS	Peak RAM
3b MLX q4	0.009	0.081	1.95 s	~107	~3.5 GB
3b MLX q8	0.000	0.081	2.34 s	~65	~5 GB
7b MLX q4 (this)	0.012	0.037	3.55 s	~56	~6 GB
7b MLX q8	0.012	0.028	4.66 s	~32	~9 GB

Read: the 7b's median CER (0.012) is slightly worse than 3b q8 (0.000) on this synthetic set — but the CER ceiling is meaningfully lower (0.037 vs 0.081). 7b is the right pick when you care about worst-case behaviour on hard handwriting; 3b q4 is the right pick when you care about throughput and have a fallback.

The test set is synthetic — generated Thai medical-style text rendered with handwriting-style fonts — not real PHI. Real photographed handwriting is harder; expect higher CER until partner-hospital evaluation lands.

Usage

uv pip install mlx-vlm

from mlx_vlm import generate, load
from mlx_vlm.prompt_utils import apply_chat_template
from mlx_vlm.utils import load_config

model, processor = load("MegawizCo/typhoon-ocr-7b-mlx-q4")
config = load_config("MegawizCo/typhoon-ocr-7b-mlx-q4")

prompt = apply_chat_template(processor, config, "Extract all text from this image.", num_images=1)
out = generate(model, processor, prompt, image=["prescription.png"], max_tokens=512)
print(out.text)  # 7b wraps in {"natural_text": "..."} (3b uses {"text": "..."})

⚠️ Output shape differs from 3b: 7b wraps in {"natural_text": "..."} (3b uses {"text": "..."}). Parse with both keys in a fallback.

CLI:

mlx_vlm.generate \
  --model MegawizCo/typhoon-ocr-7b-mlx-q4 \
  --image prescription.png \
  --prompt "Extract all text from this image." \
  --max-tokens 512

Reproduce the conversion

The upstream config patch + conversion in three commands:

# 1) Pull upstream
hf download typhoon-ai/typhoon-ocr-7b --local-dir typhoon-ocr-7b

# 2) Patch vision_config (copy missing fields from Qwen2.5-VL-7B-Instruct)
python3 -c "
import json
with open('typhoon-ocr-7b/config.json') as f: cfg = json.load(f)
cfg['vision_config'].update({
    'depth': 32, 'hidden_act': 'silu', 'hidden_size': 1280,
    'intermediate_size': 3420, 'num_heads': 16, 'in_chans': 3,
    'out_hidden_size': 3584, 'patch_size': 14, 'spatial_merge_size': 2,
    'spatial_patch_size': 14, 'window_size': 112,
    'fullatt_block_indexes': [7, 15, 23, 31],
    'tokens_per_second': 2, 'temporal_patch_size': 2,
})
with open('typhoon-ocr-7b/config.json', 'w') as f: json.dump(cfg, f, indent=2)
"

# 3) Convert
mlx_vlm.convert --hf-path ./typhoon-ocr-7b -q --q-bits 4 --mlx-path typhoon-ocr-7b-mlx-q4

License & attribution

• License: Apache 2.0 — inherited from upstream typhoon-ai/typhoon-ocr-7b.
• Base model: SCB 10X / Typhoon AI.
• Vision architecture: Qwen2.5-VL.
• Config patch + quantization + repackaging: MegawizCo (2026-05-13).

Related

• MegawizCo/typhoon-ocr-7b-mlx-q8 — higher-fidelity 7b variant
• MegawizCo/typhoon-ocr-3b-mlx-q4 — faster, smaller, throughput-default
• MegawizCo/typhoon-ocr-3b-mlx-q8 — 3b high-fidelity