compress_comics 1.0.0

High-performance comic book compression tool with WebP conversion supporting CBR, CBZ, and PDF formats
compress_comics-1.0.0 is not a library.

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

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

./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)

./compress_comics

Process all comic files in a specific directory

./compress_comics /path/to/comics/

Custom settings

./compress_comics comics/ --quality 75 --target-height 1600

Rename original files (convenient workflow)

./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:

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.