📏 LiveRuler — High-Precision Calibration Dashboard

🔗 Try the Live Web Version

LiveRuler is a professional-grade microscope calibration suite designed by Precisometer. It automates the tedious process of calculating the pixel-to-micron scale (µm/px) for optical microscopy and material science imaging.

By combining traditional computer vision with frequency-domain analysis, LiveRuler provides robust, sub-pixel accuracy that resists lighting noise and sample tilt.

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✨ Key Features

• 🎯 Automated Alignment: Uses Hough Transform and FFT power maximization to automatically detect and correct sample rotation.
• 🔬 Precise Calibration Engine: Employs Autocorrelation (ACF) for stable period detection, significantly reducing errors from harmonics.
• 📊 Power Spectrum Visualization: Real-time FFT preview allows users to visually verify the detected frequency peaks.
• 🧪 Dual Mode Support: Pre-configured profiles for 10µm Stage Micrometers and 100µm Grids.
• 🌐 Live Web Version: Available at aliazadbakht.github.io/LiveRuler—runs entirely in the browser via WebAssembly (PyScript).
• 📅 History Tracking: Built-in persistence to track calibration records across sessions.

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🧠 The Science of Precision

LiveRuler doesn't just "count pixels." It uses a multi-stage signal processing pipeline to ensure consistency:

1. Orientation Estimation: A global scan using Canny edges and HoughLines provides a rough tilt angle.
2. Rotation Refinement: The image is iteratively rotated in 0.1° increments to maximize the density of the FFT power spectrum peaks.
3. Artifact Removal: High-pass filtering suppresses uneven illumination and surface reflections.
4. Autocorrelation Analysis: Unlike raw FFT which can be sensitive to noise, autocorrelation identifies the fundamental physical spacing of your ruler markings, making it immune to DC bias and local defects.

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🚀 Getting Started (Local Desktop)

For laboratory environments requiring local image storage.

1. Clone & Prepare:

   git clone https://github.com/Precisometer/LiveRuler.git
   cd LiveRuler

2. Install Dependencies:

   pip install -r requirements.txt

3. Launch:

   python app.py

   The dashboard will automatically open at http://127.0.0.1:5001.

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🛠 Tech Stack

• Backend Logic: OpenCV, NumPy, SciPy, Matplotlib
• Web Interface: Vanilla JS, Glassmorphism CSS, HTML5
• Server: Flask (Desktop) / PyScript (Web)

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🏢 About Precisometer

Precisometer specializes in high-accuracy measurement solutions for microscopy and micro-fabrication. We bridge the gap between academic research and industrial reliability.

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Released under the MIT License • Built with ❤️ by Precisometer