Ordy

A React Native mobile application that analyzes your photo gallery to detect monochromatic images and find similar/duplicate photos using advanced image processing algorithms.

Technical Architecture

Core Components

• PhotoGrid: Renders photo collection in a customizable grid with efficient memory management
• ScanTab: Manages scanning workflows and result visualization
• BatchProcessor: Handles concurrent image analysis operations

Key Technologies

• React Native + TypeScript
• Expo Media Library for asset access
• SHA-256 perceptual hashing for image similarity detection
• Parallel processing architecture for analyzing large photo libraries

Features

Gallery Management

• Paginated loading of device media
• Responsive grid display with date metadata
• Modal view for photo inspection
• Pull-to-refresh and infinite scroll implementations

Photo Analysis

• Monochrome Detection: Identifies images with color uniformity above 92%
• Similarity Detection: Finds similar photos with >87% hash similarity
• Duplicate Detection: Identifies near-identical photos with >98% hash similarity
• Real-time progress tracking with dual-phase progress display

Performance Optimizations

• Batch processing with configurable chunk sizes
• In-memory caching of analysis results
• Limited parallel operations to prevent device overload
• Progressive asset loading for large libraries

Implementation Details

Image Analysis Pipeline

1. Asset Retrieval: Efficiently loads photo metadata in configurable batches
2. Perceptual Hashing: Generates compact signatures for similarity comparison
   • Images are resized to 16×16px
   • Color data is transformed into cryptographic hash
3. Color Analysis: Identifies monochromatic images
   • Samples color distribution in 32×32px downsamples
   • Calculates variance across color spectrum
   • Applies 92% uniformity threshold for classification
4. Similarity Comparison: Compares hash signatures using Hamming distance algorithm

Configuration Constants

• HASH_SIZE: 16px (hash generation dimensions)
• COLOR_ANALYSIS_SIZE: 32px (color analysis dimensions)
• MONOCHROME_THRESHOLD: 0.92 (92% color uniformity)
• SIMILARITY_THRESHOLD: 0.87 (87% hash similarity)
• BATCH_SIZE: 100 (photos processed per batch)
• MAX_PARALLEL_OPERATIONS: 25 (concurrent operations)

Getting Started

Prerequisites

• Node.js 12+
• React Native environment
• Expo CLI

Installation

# Clone the repository
git clone https://github.com/yourusername/ordy.git

# Install dependencies
cd ordy
npm install

# Start development server
expo start

Performance Considerations

The application implements several optimizations for processing large photo libraries:

• Memory-efficient processing: Photos are processed in configurable batches
• Operation throttling: Parallel operations are limited to prevent device lockup
• Progressive loading: Two-phase loading strategy for improved UX
• Hash caching: Previously processed images are cached to avoid redundant processing