Termux-Vision: On-Device Computer Vision & Multimodal VLM Framework

Native On-Device Computer Vision & Multimodal Vision-Language Model (VLM) Runtime for Android Termux via Direct Bionic libc & Vulkan Compute Acceleration.
Zero PRoot. Zero Virtualization. 100% Native ARMv8.2-A NEON SIMD & Hardware GPU Offloading.

📑 Table of Contents

1. Overview & Key Capabilities
2. Installation Guide
3. Enabling Hardware GPU Acceleration (with ameva-runtime)
4. Standardized CLI & Parameter Matrix
5. Dual Engine Code Examples (Python & Node.js)
6. Production Diagnostics (termux-vision doctor)
7. Real-World Benchmarks & Hardware Scorecard
8. Memory & VRAM Architecture (Zero CPU-Mapped VRAM)
9. Hardware Requirements & Operational Limits
10. License & Permissible Use

1. Overview & Key Capabilities

termux-vision is an enterprise-grade, on-device multimodal vision inference and spatial computing framework engineered specifically for mobile Android devices. Operating directly against Android's native Bionic libc ABI and host Vulkan compute drivers, termux-vision eliminates heavyweight desktop dependencies (OpenCV, TorchVision) and enables high-throughput visual question answering, OCR image captioning, and classical feature extraction directly on edge hardware.

• Native Bionic libc ABI Direct Binding: Runs directly inside Termux user space with zero virtualization indirection, achieving bare-metal compute efficiency.
• Dual Compute Acceleration: Integrates ARMv8.2-A DotProd/FP16 SIMD vector instructions with mobile Vulkan compute shader pipelines.
• Full-Layer GPU Offloading (-ngl 99): Dispatches all 99 transformer layers and cross-attention vision projections directly to device GPU VRAM, achieving pure GPU offloading (0.00 MiB CPU mapped VRAM).
• Zero-Dependency Classical Vision Suite: Native 5-stage Canny edge detector (8-directional BFS hysteresis), Sobel 3x3 filtering, 2D Integral Images, and Haar-like face candidate localization in pure C/Python/JS.
• Autonomous OOM & LMK Protection: Enforces atomic model validation (>10MB threshold guard) and quant-pair validation (SmolVLM Q4_K_M + Q8_0 mmproj) to strictly respect Android Low Memory Killer (LMK) bounds.

2. Installation Guide

termux-vision is distributed across both Python (PyPI) and Node.js (npm) ecosystems, with official precompiled ARM64 wheel assets published on GitHub Releases.

2.1 Termux System Prerequisites

Launch Termux and install required native compilers, Vulkan drivers, and image libraries:

pkg update -y
pkg install -y python nodejs clang make cmake git termux-api wget vulkan-loader vulkan-headers vulkan-tools opencl-headers python-numpy libjpeg-turbo

2.2 Python Package Installation

• Option A: Install from PyPI (Recommended):

  pip install --upgrade pip setuptools wheel
  pip install termux-vision
  

• Option B: Direct GitHub Releases Wheel Asset (SSOT Verified):

  # Download and install the prebuilt v1.4.0 release wheel
  pip install https://github.com/uno-km/termux-vision/releases/download/v1.4.0/termux_vision-1.4.0-py3-none-any.whl
  

2.3 Node.js / TypeScript CLI Installation

# Global CLI installation
npm install -g termux-vision

# Local project dependency
npm install termux-vision

2.4 One-Line Bootstrap Installer

Run the universal bootstrap installer to automatically configure repositories, compile native C/C++ acceleration shims, and verify hardware:

curl -sL https://raw.githubusercontent.com/uno-km/termux-vision/main/install.sh | bash

3. Enabling Hardware GPU Acceleration (with ameva-runtime)

To unlock mobile GPU acceleration via Vulkan compute shaders and achieve significant speedups over pure CPU execution, install termux-vision alongside ameva-runtime:

🌟 One-Line Installation

# Python Environment
pip install termux-vision ameva-runtime termux-llamacpp

# Node.js Environment
npm install -g termux-vision @ameva/runtime

🔮 Mobile GPU Silicon Architecture Status

Verify GPU driver detection and hardware readiness:

termux-vision doctor

4. Standardized CLI & Parameter Matrix

termux-vision strictly complies with the official uno-km family CLI standard:

Practical CLI Usage Examples

# 1. Automated GPU Acceleration (Default auto-routing)
termux-vision vlm photo.jpg -p "What objects are visible in this scene?"

# 2. Pure GPU Mode on ARM Mali Silicon (Galaxy S21 / A35)
termux-vision vlm photo.jpg -d gpu --tune-mali -p "Describe the text and layout."

# 3. Pure CPU Fallback Mode (Strict 0 GPU VRAM allocation)
termux-vision vlm photo.jpg -d cpu -t 6 -p "Analyze this diagram."

# 4. Ultra-Low-Latency Mode (224x224 scaled ViT input)
python tools/vlm_runner.py -i photo.jpg -d gpu --image-size 224x224 -n 60

# 5. Zero-Dependency Classical Canny Edge Detection
termux-vision canny input.jpg -o edges.png --low 40 --high 120

5. Dual Engine Code Examples (Python & Node.js)

5.1 Python SDK

import termux_vision as tv

# 1. Zero-Dependency Classical CV Filtering (sub-10ms execution)
image = tv.io.load_image("document.jpg")
grayscale = tv.transforms.to_grayscale(image)
edges = tv.cv.canny(grayscale, low_threshold=40, high_threshold=120)
tv.io.save_image(edges, "edges.png")

# 2. On-Device Multimodal VLM Inference (Vulkan GPU Accelerated)
with tv.vlm.load("smolvlm-500m", device="gpu") as engine:
    result = engine.describe(
        "document.jpg",
        prompt="Extract all visible text and summarize key bullet points.",
        quality="optimal",
        max_tokens=200
    )
    print(f"Backend: {result.metrics.backend} | TPS: {result.metrics.tokens_per_second:.2f} tok/s")
    print(f"Response:
{result.text}")

5.2 Node.js / TypeScript SDK

import tv from 'termux-vision';

// 1. Hardware Diagnostic Probe
const doctor = tv.doctor(true);
console.log(`Vulkan GPU: ${doctor.vulkan.status} | Available RAM: ${doctor.hardware.availableRamMb} MB`);

// 2. Multimodal VLM Inference
const engine = await tv.load({ modelId: 'smolvlm-500m', device: 'gpu' });
const response = await engine.describe('photo.jpg', {
  prompt: 'Identify the geometric shapes and colors.',
  quality: 'optimal',
  maxTokens: 100
});

console.log(`[${response.metrics.backend.toUpperCase()}] ${response.text}`);
engine.close();

6. Production Diagnostics (termux-vision doctor)

Termux-Vision features an integrated hardware diagnostics probe to inspect the host environment before launching inference:

termux-vision doctor

Diagnostic Output Profile:

=== termux-vision Diagnostic Doctor ===
  Platform : Linux (aarch64) | Android: True
  RAM      : Total 7812MB | Available 3450MB
  CPU Cores: 8 (big.LITTLE Affinity Governor active)
  Vulkan   : Loader=True | Driver=/system/lib64/libvulkan.so | Status=READY
  GPU Soc  : ARM Mali-G78 MP14 (Exynos 2100)
  Models   : 2 installed in ~/.cache/termux-vision/models
  Preset   : optimal (768px recommended)

7. Real-World Benchmarks & Hardware Scorecard

All metrics represent deterministic ground-truth measurements obtained on physical test devices running Android Termux unrooted, comparing Moondream2 1.8B f16 and SmolVLM-500M Instruct (Q4_K_M + Q8_0 mmproj).

7.1 Empirical Visual Question Answering Verification (Galaxy S25 Adreno 830)

Test Case A: Geometric & Spatial Reasoning (test_shapes_224x224.png)

• Input Image: Clean canvas with primary geometric primitives (triangles, rectangle).
• Prompt: "Describe the colors and geometric shapes visible in this image."
• Model: Moondream2 1.8B (f16 text + f16 ViT mmproj, 2,706 MiB VRAM)
• Exact Ground-Truth Output:

  "The image features a white background with three distinct geometric shapes: two triangles and one rectangle..."

• Execution Metrics:
  • GPU Layers Offloaded: 25 / 25 (100% Full GPU)
  • Vulkan VRAM Allocated: 2,706.00 MiB (CPU Mapped VRAM: 0.00 MiB)
  • Prompt Evaluation: 19.60 tokens/sec (749 tokens in 38,211 ms)
  • Token Generation: 14.97 tokens/sec (39 tokens in 2,605 ms, 66.80 ms/tok)
  • Total Execution Time: 51.24s (Cold weights loading: 10.4s, CPU ViT projection: 14.1s, GPU decoding: 2.6s)
  • Exit Status: Exit Code 0

Test Case B: Photorealistic Real-World Scene (test_elephant_gpu_step2.png)

• Input Image: Diffusion-synthesized high-detail photorealistic scene.
• Prompt: "What animal is this and what is it doing?"
• Model: Moondream2 1.8B (f16 text + f16 ViT mmproj)
• Exact Ground-Truth Output:

  "The image shows a large elephant riding on top of a surfboard in the ocean."

• Execution Metrics:
  • Prompt Processing: 19.84 tokens/sec (747 tokens in 37,651 ms)
  • Generation Speed: 15.00 tokens/sec (24 tokens in 1,600 ms, 66.67 ms/tok)
  • KGSL Watchdog State: Fully stabilized via GGML_VULKAN_SKIP_CHECKS="999999999" (No ErrorDeviceLost)
  • Exit Status: Exit Code 0

7.2 Key Architectural Discoveries

1. Adreno 830 SPIR-V JIT Fix: Qualcomm's new compiler fails during unrolled vector compilation with mul_mat_vec_max_cols = 8 (VK_ERROR_UNKNOWN). Reducing this parameter to 2 eliminates register spilling and enables full 25/25 layer GPU offloading.
2. Android KGSL Watchdog Defense: Prefilling 729 vision tokens in mobile Vulkan exceeds the 5-second kernel watchdog timer unless micro-batched. Configuring -b 64 -ub 64 and injecting GGML_VULKAN_SKIP_CHECKS="999999999" slices prefill into 1.8s units, preventing ErrorDeviceLost.
3. Pure GPU Isolation (0.00 MiB CPU VRAM): Across both Qualcomm Adreno 830 and ARM Mali (G78/G68), all tensor weights and KV cache reside strictly in Vulkan GPU memory.

8. Memory & VRAM Architecture

+---------------------------------------------------------------+
|             Physical Mobile LPDDR4X/LPDDR5 RAM (8 GB)          |
+---------------------------------------------------------------+
   |                                                    |
   v                                                    v
+-------------------------------+       +-------------------------------+
|      Android OS & Framework   |       |       Termux User Space       |
|          (~3.5 - 4.2 GB)      |       |          (~3.8 - 4.5 GB)      |
+-------------------------------+       +-------------------------------+
                                                        |
                                                        v
                                        +-------------------------------+
                                        |    Vulkan Unified Memory      |
                                        |  - Model Weights: 1059.02 MiB |
                                        |  - KV Cache     :  384.00 MiB |
                                        |  - CPU Mapped   :    0.00 MiB |
                                        +-------------------------------+

Quantization & Android LMK Protection

• SmolVLM-500M (Q4_K_M 350MB + Q8_0 mmproj 200MB): Peak working memory stays under ~1.6 GB, well below Android LMK eviction thresholds.
• Qwen2-VL-2B (Q4_K_M 1.4GB + FP16 mmproj 600MB): Requires a minimum of 6GB available RAM; FP32 projector variants (>2.5GB) are automatically rejected to prevent SIGKILL aborts.

9. Hardware Requirements & Operational Limits

10. License & Permissible Use

Licensed under the Apache License, Version 2.0.
Copyright (c) 2026 Eunho Kim (@uno-km) & AMEVA Open-Source Foundation (AOSF).

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