bat_img

Fast, multithreaded batch image processor — available as a standalone command-line tool installable via pip.

The binary is a native Rust executable (no Python overhead at runtime). The Python package is simply a convenient delivery mechanism so you can install bat_img the same way you install any other command-line tool.

Installation

pip install bat_img

brew install libheif  # for HEIC/HEIF support

Pre-built binaries are provided for:

After installation, the bat_img command is available in your terminal.

Quick start

# Strip GPS location from all iPhone photos (in-place)
bat_img -i ~/Pictures/iPhone --strip-gps

# Resize all JPEGs to 1920 px wide, save to ./web/
bat_img -i ./photos -r 1920x0 -o ./web

# Convert HEIC → WebP at quality 85, resize to 2048 px wide
bat_img -i ./iphone_photos -r 2048x0 -f webp -q 85 -o ./web

# Strip ALL metadata, sharpen — 8 threads, recurse
bat_img -i ./raw -R --strip-all --sharpen -t 8 -o ./export

Features

Usage

bat_img [OPTIONS] --input <INPUT>...

All options

  -i, --input <INPUT>...       File, glob pattern, or directory
  -o, --output <DIR>           Output directory.
                               Omit to process files in-place.
  -R, --recursive              Recurse into subdirectories
  -t, --threads <N>            Thread count [default: CPU core count]
  -q, --quality <1-100>        JPEG/WebP quality (HEIC preserves original
                               quality when omitted)
  -f, --format <FORMAT>        Output format:
                               heic | heif | jpeg | png | webp | tiff | bmp | gif
      --strip-gps              Remove GPS location from EXIF
      --strip-all              Remove all metadata
  -r, --resize <WxH>           Resize (use 0 for auto: 1920x0 or 0x1080)
      --filter <FILTER>        Resize filter [default: lanczos3]
                               nearest|triangle|catmull-rom|gaussian|lanczos3
      --no-upscale             Never upscale smaller images
      --border <PIXELS>        Add border N pixels wide on all sides
      --border-color <COLOR>   Border color: name or #rrggbb [default: white]
      --rotate <DEG>           Rotate clockwise: 90 | 180 | 270
      --flip-h                 Flip horizontally
      --flip-v                 Flip vertically
      --brightness <VALUE>     Brightness delta (-100..+100)
      --contrast <VALUE>       Contrast delta (-100..+100)
      --sharpen                Apply unsharp mask
      --grayscale              Convert to grayscale
      --prefix <PREFIX>        Prepend string to output filename
      --suffix <SUFFIX>        Append string to output filename
      --overwrite              Overwrite existing output files
      --dry-run                Preview without writing files
      --quiet                  Suppress output except errors
  -h, --help                   Print help
  -V, --version                Print version

In-place mode

Omitting --output overwrites each original file in place. A temp file is written first and then atomically renamed over the original, so the source is never corrupted if something goes wrong.

# Strip GPS from every HEIC file recursively — no copies made
bat_img -i ~/Pictures -R --strip-gps

# Resize all JPEGs to 2048 px wide, in-place
bat_img -i ./photos -r 2048x0

Note: in-place mode cannot change the file format (e.g. HEIC → WebP). Use --output when changing formats.

Examples

# Add a 20 px black border to all PNGs
bat_img -i ./screenshots --border 20 --border-color black -o ./bordered

# Rotate scans 90° clockwise and convert to grayscale
bat_img -i ./scans --rotate 90 --grayscale -o ./processed

# Convert HEIC → JPEG at quality 90, resize to fit 1920×1080
bat_img -i ./iphone_photos -f jpeg -q 90 -r 1920x1080 -o ./jpegs

# Dry-run — see what would happen without writing anything
bat_img -i ./photos -r 800x600 --strip-gps --dry-run

HEIC support

bat_img can read and write HEIC/HEIF files natively, including:

• Decoding HEIC photos from iPhone / iPad
• Re-encoding back to HEIC while preserving the original codec (HEVC / AV1) and file size (unless --quality is specified)
• Converting HEIC to any other supported format with -f jpeg, -f webp, etc.

License

bat_img is distributed under MIT License. Please see details in LICENSE.