🖼️ Image Converter GUI

A modern Python GUI application built with PySide6 for converting and resizing images with advanced features including drag & drop support, clipboard paste, URL fetching, unit conversion, comprehensive preview system, and optimized multi-threading.

📸 Screenshots

Main Interface

Main application window showing the intuitive drag & drop interface, format options, and size selection controls

Preview System

Comprehensive preview dialog showing detailed conversion information before saving

🚀 Quick Start

1. 📥 Download the latest release - Get the ready-to-use executable
2. 🖱️ Drag & drop an image into the application
3. ⚙️ Choose your desired format and size options
4. 👁️ Preview your conversion settings
5. 💾 Convert and save your images!

No Python installation required with the pre-built executable!

✨ Features

🎯 Input Methods

• Drag & Drop: Direct image dropping with visual feedback
• File Browser: Traditional file selection dialog
• URL Fetching: Download images directly from web URLs
• Clipboard Support: Paste images with Ctrl+V

📐 Advanced Unit System

• Multiple Units: Pixels, Centimeters, Inches
• Real-time Conversion: Dynamic unit switching with DPI calculation
• Smart Labels: Size options update based on selected unit
• DPI Integration: Proper physical size calculations
• Quality Integration: DPI and quality settings synchronized

🔄 Format Support

• Input: PNG, JPG, JPEG, BMP, WebP, GIF, ICO, TIFF, HEIC
• Output: PNG, JPEG, JPG, WebP, ICO
• Format-Specific Optimization:
  • WebP: Fast compression with quality capping
  • PNG: Compression levels based on quality settings
  • ICO: Automatic size optimization (max 256x256)
  • JPEG: Full quality and DPI support

🎨 Intelligent Resizing

• Original Size: Keep source dimensions
• Predefined Sizes: 16x16, 32x32, 48x48, 128x128, 150x150, 192x192, 512x512
• Custom Dimensions: User-defined sizes with unit support
• Batch Processing: Multiple sizes simultaneously
• Aspect Ratio Control: Lock/unlock with resize modes (Stretch, Crop, Fit)

👁️ Comprehensive Preview System

• Real-time Preview: See exactly what you'll get before saving
• Batch Preview: Preview multiple sizes at once
• Detailed Information: File size, dimensions, format, DPI, quality
• Format-Specific Details: Compression info, limitations, recommendations
• Actual Conversion: Preview uses real conversion settings for accurate results

⚡ Performance & Threading

• Non-blocking UI: Multi-threaded conversion prevents freezing
• Cancellable Operations: Stop conversions mid-process
• Progress Tracking: Real-time status updates
• Optimized WebP: Fast compression settings for responsive UI

🎛️ Advanced Settings

• Quality Control: 1-100% quality settings with format-specific handling
• DPI Settings: 72-600 DPI with metadata support
• Compression Modes: Format-specific optimization
• Resize Modes: Stretch, Crop, Fit with aspect ratio control

🚀 Installation

Option 1: Download Pre-built Executable (Recommended)

📥 Download Latest Release

1. Go to Releases · bibekchandsah/image-converter
2. Download the latest ImageConverter.exe file
3. Run the executable directly - no installation required!

The pre-built executable includes all dependencies and works on Windows 10/11 without requiring Python installation.

Option 2: Run from Source

1. Install Python 3.8+

2. Install required dependencies:

pip install PySide6 Pillow requests

3. Run the application:

python main.py

📁 Project Structure

ImageConverter/
├── main.py                    # Application entry point
├── ui_mainwindow.py          # Main GUI window and logic
├── converter.py              # Image conversion functionality
├── downloader.py             # URL image fetching
├── utils/
│   ├── file_utils.py         # File handling utilities
│   └── resize_options.py     # Size validation and presets
├── assets/
│   └── style.qss            # Modern UI stylesheet
└── README.md

🎯 Usage

Basic Workflow

1. Load an Image:

   • Drag & drop an image file into the drop area
   • Click the drop area to browse files
   • Enter an image URL and click "Fetch"
   • Paste from clipboard with Ctrl+V

2. Configure Settings:

   • Format: Choose PNG, JPEG, JPG, WebP, or ICO
   • Quality: Set 1-100% (affects lossy formats)
   • DPI: Set 72-600 DPI (for print quality)
   • Aspect Ratio: Lock/unlock with resize mode selection

3. Select Units & Sizes:

   • Unit: Choose Pixels, Centimeters, or Inches
   • Sizes: Check one or more size options
   • Custom: Enter specific dimensions in chosen unit

4. Preview Before Saving:

   • Click "Preview" to see exact results
   • Review file sizes, dimensions, and format details
   • Cancel to adjust settings or proceed to save

5. Convert & Save:

   • Click "Convert Image(s)" after preview confirmation
   • Monitor progress with real-time status updates
   • Cancel conversion if needed

Advanced Features

Unit Conversion

• Switch between Pixels, Centimeters, and Inches
• Size labels automatically update based on DPI settings
• Custom size dialog supports decimal values for precise measurements

Preview System

• Comprehensive Details: See file size, dimensions, DPI, quality, and format-specific info
• Actual Conversion: Preview performs real conversion for accurate file sizes
• Format Guidance: Get recommendations and limitations for each format

Quality & DPI Control

• Format-Specific: Quality affects JPEG/WebP, compression level for PNG
• DPI Metadata: Properly set for PNG/JPEG, noted as unsupported for WebP/ICO
• Smart Defaults: 300 DPI for print quality, 90% quality for good balance

🔧 Technical Details

• Framework: PySide6 (Qt for Python)
• Image Processing: Pillow (PIL)
• HTTP Requests: requests library
• Threading: QThread for non-blocking operations
• File Handling: pathlib for cross-platform compatibility

📝 Output File Naming

Converted files follow this pattern:

original_filename_WIDTHxHEIGHT.format

Examples:

• sunset_128x128.webp
• photo_512x512.png
• icon_32x32.ico

🎯 Unit Conversion Examples

Pixel Mode (Default)

• Direct pixel dimensions: 512x512, 256x256, etc.

Centimeter Mode (300 DPI)

• 1.0 cm = 118 pixels
• 2.5 cm = 295 pixels
• 5.0 cm = 590 pixels

Inch Mode (300 DPI)

• 0.5 inches = 150 pixels
• 1.0 inch = 300 pixels
• 2.0 inches = 600 pixels

Note: Conversions depend on DPI setting. Higher DPI = more pixels per physical unit.

🔍 Preview System Details

What You See in Preview

• File Name: Exact output filename
• Dimensions: Final pixel dimensions (with unit conversion if applicable)
• Format: Output format with specific notes
• DPI: Resolution setting (where supported)
• Quality: Compression quality with format-specific details
• File Size: Actual file size after conversion
• Format Notes: Optimization details and limitations

Preview Accuracy

• Uses real conversion process for accurate file sizes
• Shows actual compression results
• Displays format-specific optimizations
• Provides cancellation option before saving

🛠️ Advanced Features

📐 Unit System

• Pixel Mode: Direct pixel dimensions (default)
• Centimeter Mode: Physical measurements with DPI calculation
• Inch Mode: Imperial measurements with DPI conversion
• Dynamic Updates: Size labels change based on selected unit and DPI

👁️ Preview System

• Real Conversion: Uses actual conversion settings for accurate previews
• Detailed Info: Shows file size, dimensions, DPI, quality, compression type
• Format-Specific Guidance:
  • PNG: Shows compression level (Low/Medium/High)
  • JPEG: Shows quality percentage and DPI
  • WebP: Shows optimized quality and fast compression note
  • ICO: Shows size limitations and compatibility notes

⚡ Performance Optimizations

• Multi-threading: Non-blocking UI during conversions
• WebP Optimization: Fast compression (method 1, quality capped at 85%)
• PNG Compression: Quality-based compression levels (1-9)
• Memory Management: Size limits prevent memory issues
• Cancellation: Stop long-running conversions

🎨 Resize Modes

• Stretch: Resize to exact dimensions (may distort)
• Crop: Fill target size completely, crop excess
• Fit: Fit completely inside target size with background

🔧 Format-Specific Features

• ICO Optimization: Automatic size reduction to 256x256 for compatibility
• WebP Fast Mode: Optimized for speed with quality capping
• PNG Compression: Quality setting controls compression level
• JPEG Quality: Full 1-100% quality range with DPI support

🖱️ User Interface

• Drag & Drop: Visual feedback and validation
• Clipboard Support: Paste images and URLs
• Progress Tracking: Real-time conversion status
• Error Handling: Graceful error recovery and user feedback
• Responsive Design: Adapts to window resizing

🎨 UI Features

• Modern, clean design
• Responsive layout
• Real-time image preview
• Progress indicators
• Status messages
• Intuitive controls

🔍 Format Support & Optimization

Input Formats

• PNG (Portable Network Graphics) - Lossless with transparency
• JPEG/JPG (Joint Photographic Experts Group) - Compressed photos
• BMP (Bitmap) - Uncompressed raster format
• WebP (Web Picture format) - Modern web format
• GIF (Graphics Interchange Format) - Animated/simple graphics
• ICO (Icon format) - Windows icons
• TIFF (Tagged Image File Format) - High-quality archival
• HEIC (High Efficiency Image Container) - Apple's modern format

Output Formats with Smart Optimization

PNG - Lossless Compression

• Quality Setting: Controls compression level (1-9)
• DPI Support: Full metadata support
• Transparency: Preserved from source
• Best For: Graphics, logos, images with transparency

JPEG/JPG - Lossy Compression

• Quality Range: 1-100% with visual quality control
• DPI Support: Full metadata and print quality support
• Optimization: Automatic optimization enabled
• Best For: Photographs, complex images

WebP - Modern Web Format

• Fast Compression: Optimized method 1 for speed
• Quality Capping: Automatically capped at 85% for performance
• No DPI: Format doesn't support DPI metadata
• Best For: Web images, modern browsers

ICO - Windows Icons

• Size Limitation: Automatically optimized to 256x256 max (PIL limitation)
• Multiple Sizes: Can contain multiple icon sizes
• No Quality/DPI: Lossless format without metadata support
• Best For: Windows application icons, favicons

Format-Specific Intelligence

• Automatic Optimization: Each format uses optimal settings
• Size Warnings: Clear indication of format limitations
• Quality Guidance: Format-appropriate quality recommendations
• Compatibility Notes: Information about format support and limitations

🚨 Requirements & Performance

System Requirements

• Python: 3.8 or higher
• Operating System: Windows 10/11, macOS, or Linux
• Memory: 4GB RAM recommended for large image processing
• Storage: Minimal disk space (temporary files cleaned automatically)

Dependencies

pip install PySide6 Pillow requests

Performance Notes

• Large Images: >10MB images may take longer to process
• ICO Format: Limited to 256x256 pixels (PIL limitation)
• WebP: Optimized for speed with quality capping at 85%
• Multi-threading: UI remains responsive during conversion
• Memory Management: Automatic size limits prevent memory issues

📄 License

This project is open source and available under the MIT License.

� Recentt Improvements

Version 2.0 Features

• ✅ Unit System: Pixels, Centimeters, Inches with real-time conversion
• ✅ Advanced Preview: Real conversion preview with detailed information
• ✅ Multi-threading: Non-blocking UI with cancellation support
• ✅ Format Optimization: WebP fast mode, PNG compression levels, ICO size limits
• ✅ Clipboard Support: Paste images and URLs with Ctrl+V
• ✅ Quality Control: Format-specific quality and DPI settings
• ✅ Resize Modes: Stretch, Crop, Fit with aspect ratio control
• ✅ Smart UI: Dynamic labels, progress tracking, error handling

Performance Enhancements

• 🚀 WebP Speed: 3x faster conversion with optimized settings
• 🚀 UI Responsiveness: Multi-threaded processing prevents freezing
• 🚀 Memory Management: Automatic size limits and cleanup
• 🚀 Preview Speed: Efficient temporary file handling

👨‍💻 Author

Bibek
Date: 30 Oct 2025 (Updated: 2 Nov 2025)
Project: Image Converter GUI v2.0
Language: Python 3 (PySide6)
Features: Advanced unit conversion, preview system, multi-threading

📦 Latest builds available at: Releases · bibekchandsah/image-converter

🤝 Contributing

Feel free to submit issues, feature requests, or pull requests to improve this application.

Development Focus Areas

• Additional output formats (AVIF, JPEG XL)
• Batch file processing
• Image editing features (rotate, flip, filters)
• Plugin system for custom formats
• Command-line interface