# Comic Compressor
A high-performance Rust application for compressing comic book files (CBR/CBZ/PDF) with parallel processing. Converts images to WebP format for optimal file size reduction while maintaining visual quality.
## Features
- ✅ **Cross-platform compatibility** - Works on Mac, Windows, and Linux
- ✅ **Parallel processing** - Processes multiple files and images simultaneously
- ✅ **Multiple format support** - Handles CBR (RAR), CBZ (ZIP), and PDF files with automatic format detection
- ✅ **Advanced PDF support** - Direct image extraction from PDFs (JPEG, PNG, CMYK, Grayscale)
- ✅ **Automatic folder processing** - Processes all comic files in a directory by default
- ✅ **Progress visualization** - Docker-style layered progress display
- ✅ **Smart compression** - Skips images that don't benefit from compression
- ✅ **CBR output format** - Always outputs .cbr files regardless of input format
- ✅ **Standalone binary** - No external dependencies required
## Installation
### From Source
```bash
git clone <repository>
cd compress_comics_rust
cargo build --release
```
The compiled binary will be available at `target/release/compress_comics`
## Usage
### Process a single file
```bash
./compress_comics comic.cbz --quality 85
./compress_comics comic.cbr --quality 85
./compress_comics comic.pdf --quality 85
```
### Process all comic files in current directory (default behavior)
```bash
./compress_comics
```
### Process all comic files in a specific directory
```bash
./compress_comics /path/to/comics/
```
### Custom settings
```bash
./compress_comics comics/ --quality 75 --target-height 1600
```
### Rename original files (convenient workflow)
```bash
./compress_comics comics/ --rename-original --quality 85
# Result: Original files become *_original.ext, compressed files get clean names
```
## Options
- `--quality` / `-q`: WebP quality (1-100, default: 90)
- 85-95: High quality, moderate compression
- 65-80: Balanced quality and size
- 40-60: Small files, lower quality
- `--target-height` / `-H`: Target height for images in pixels (default: 1800)
- `--max-dimension` / `-m`: Maximum dimension fallback (default: 1200)
- `--rename-original` / `-r`: Rename original file to `<name>_original.<ext>` and give compressed file the original name
## Output
### Default Behavior
The tool creates new files with the suffix ` optimized_webp_q{quality}.cbr`:
- Input: `MyComic.cbz` → Output: `MyComic optimized_webp_q90.cbr`
- Input: `MyComic.cbr` → Output: `MyComic optimized_webp_q90.cbr`
- Input: `MyComic.pdf` → Output: `MyComic optimized_webp_q90.cbr`
### With `--rename-original` Option
When using `--rename-original`, the compressed file takes the original name:
- `MyComic.cbz` → `MyComic_original.cbz` (backup) + `MyComic.cbr` (compressed)
- `MyComic.cbr` → `MyComic_original.cbr` (backup) + `MyComic.cbr` (compressed)
- `MyComic.pdf` → `MyComic_original.pdf` (backup) + `MyComic.cbr` (compressed)
## Performance Features
### Parallel Processing
- Files are processed in parallel using all available CPU cores
- Images within each file are also processed in parallel
- Progress is displayed for each file simultaneously
### Smart Compression
- Only compresses images when WebP provides size benefits
- Automatically detects two-page spreads and adjusts processing
- Skips already well-compressed images
### Memory Efficient
- Uses temporary directories for processing
- Automatic cleanup after completion
- Streaming archive processing
## Progress Display
The tool shows progress similar to Docker image downloads:
```
🚀 Found 3 comic file(s) to process
Settings: Quality=90, Target Height=1800px
-----------------------------------------------------
⠋ [00:01:23] [████████████████████████████████████████] 2/3 files (00:00:45)
📖 Comic1.cbz [████████████████████████████████] 100%
📖 Comic2.cbz [████████████████░░░░░░░░░░░░░░░░] 65%
📖 Comic3.cbz [████░░░░░░░░░░░░░░░░░░░░░░░░░░░░] 15%
```
## Summary Report
After processing, the tool provides a detailed summary:
```
📊 Processing Summary:
-----------------------------------------------------
📖 Comic1.cbz: 45.2% savings (23 images processed, 2 skipped)
📖 Comic2.cbz: 38.7% savings (18 images processed, 1 skipped)
🎯 Overall Results:
Total files processed: 2
Total images processed: 41
Total images skipped: 3
Overall size reduction: 42.1%
Original size: 125.43 MB
Compressed size: 72.65 MB
💡 1 file(s) were already well-compressed and showed minimal improvement.
```
## Real-World Results
### CBR/CBZ Files
```
📖 Amber Blake - 01.cbr: 61.1% savings (104 images processed, 0 skipped)
📖 Auschwitz - 01.cbr: 67.9% savings (84 images processed, 0 skipped)
Original: 237.83 MB → Compressed: 85.05 MB (64.3% total savings)
```
### PDF Files
```
📖 Brocéliande - Tome 67.pdf: 76.3% savings (55 images processed, 0 skipped)
Original: 119.41 MB → Compressed: 28.29 MB (76.3% savings)
```
### With `--rename-original` Option
```
📖 comic1.cbr: 76.4% savings (84 images processed, 0 skipped)
📖 comic2.pdf: 81.1% savings (55 images processed, 0 skipped)
Before: comic1.cbr (115.75 MB), comic2.pdf (125.21 MB)
After: comic1_original.cbr (backup), comic2_original.pdf (backup)
comic1.cbr (27.35 MB), comic2.cbr (23.71 MB)
Total: 229.80 MB → 48.69 MB (78.8% savings)
```
### Why These Results?
- **PDF files often have the highest compression ratios** because they typically contain uncompressed or lightly compressed images
- **CBR/CBZ files vary** depending on original compression - some modern files are already well-optimized
- **WebP format** provides excellent quality-to-size ratio, especially for comic book artwork
- **--rename-original** makes workflow seamless - no manual file management needed
## Technical Details
- **Language**: Rust (standalone binary, no runtime dependencies)
- **Image Processing**: High-quality Lanczos3 resampling
- **Compression**: WebP lossy compression with configurable quality
- **Archive Format**: ZIP-based CBR files (universal comic reader compatibility)
- **Extraction**:
- **CBR files**: Native RAR support with ZIP fallback for compatibility
- **CBZ files**: Native ZIP extraction
- **PDF files**: Direct embedded image extraction (JPEG, PNG, CMYK, Grayscale)
- **Threading**: Rayon for work-stealing parallelism
## PDF Support Details
The tool provides comprehensive PDF support for comic books:
### ✅ Supported PDF Image Formats
- **JPEG (DCTDecode)**: Direct extraction with no quality loss
- **PNG/Compressed (FlateDecode)**: Decompression and reconstruction
- **Raw RGB/Grayscale**: Uncompressed pixel data extraction
- **CMYK Images**: Automatic conversion to RGB color space
### ⚠️ Unsupported PDF Formats
- **CCITT Fax compression**: Skipped with informative message
- **Complex vector graphics**: Only embedded raster images are extracted
- **Text-only PDFs**: No images to extract
## Limitations
- Output uses ZIP compression for CBR files (not RAR compression, but maintains .cbr extension for compatibility)
- WebP format may not be supported by very old comic readers
- PDF vector graphics are not rasterized (only embedded images are extracted)
## Building for Distribution
To build optimized binaries for distribution:
```bash
cargo build --release
strip target/release/compress_comics # Optional: reduce binary size
```
The resulting binary is self-contained and can be distributed without any dependencies.