caesiumclt Share Help

Lossy/lossless image compression tool

Category

Image

License

Apache 2

Platforms

Windows macOS Linux

Released

2017

Path

c:\caesiumclt\caesiumclt.exe

Benefits

Can target specific file sizes; resize based on width, height, long/short edge. Supports WebP. EXIF metadata preservation.

Examples

caesiumclt.exe -q 85 --suffix _compressed --keep-dates --same-folder-as-input d:\images\image.jpg

caesiumclt.exe --max-size 200000 -o d:\imageout d:\imagein\large-image.jpg

# caesiumclt - Help

Source: https://saerasoft.com/caesiumclt/

```
A fast and efficient lossy and/or lossless image compression tool

Usage: caesiumclt.exe [OPTIONS] <--quality <QUALITY>|--lossless|--max-size <MAX_SIZE>> <--output <OUTPUT>|--same-folder-as-input> [FILES]...

Arguments:
  [FILES]...
          Input files or directories to process

Options:
  -q, --quality <QUALITY>
          Compression quality [0-100], higher values mean better quality

      --lossless
          Use lossless compression (may increase file size for some formats)

      --max-size <MAX_SIZE>
          Target maximum file size in bytes or human-readable format (e.g., 100KB, 0.5MB)

      --width <WIDTH>
          Output image width in pixels (preserves the aspect ratio if height not set)

      --height <HEIGHT>
          Output image height in pixels (preserves the aspect ratio if width not set)

      --long-edge <LONG_EDGE>
          Size in pixels for the longest edge of the image

      --short-edge <SHORT_EDGE>
          Size in pixels for the shortest edge of the image

      --no-upscale
          Prevents upscaling of the image when resizing

  -o, --output <OUTPUT>
          Output directory path

      --same-folder-as-input
          Use input file's directory as output (WARNING: may overwrite originals)

      --format <FORMAT>
          Convert to the selected output format or keep the original
          
          [default: original]
          [possible values: jpeg, png, gif, webp, tiff, original]

      --png-opt-level <PNG_OPT_LEVEL>
          PNG optimization level [0-6], higher values provide better compression
          
          [default: 3]

      --jpeg-chroma-subsampling <JPEG_CHROMA_SUBSAMPLING>
          Chroma subsampling for JPEG files
          
          [default: auto]
          [possible values: 4:4:4, 4:2:2, 4:2:0, 4:1:1, auto]

      --jpeg-baseline
          Output baseline JPEG instead of progressive (default)

      --zopfli
          Use zopfli for PNG optimization (significantly slower but better compression)

  -e, --exif
          Keep EXIF metadata during compression

      --keep-dates
          Preserve original file timestamps

      --strip-icc
          Strips ICC profile info on JPG files, ignoring the -e flag

      --suffix <SUFFIX>
          Add suffix to output filenames

  -R, --recursive
          Scan subfolders recursively when input is a directory

  -S, --keep-structure
          Preserve directory structure (requires -R/--recursive)

  -d, --dry-run
          Simulate compression without writing files

      --threads <THREADS>
          Number of parallel jobs (0 = auto-detect, max = available processors)
          
          [default: 0]

      --check-extension-only
          Trust file extensions instead of reading magic bytes (significantly faster on large directories)

  -O, --overwrite <OVERWRITE>
          Policy for handling existing output files

          Possible values:
          - all:    Always overwrite existing files
          - never:  Never overwrite existing files
          - bigger: Overwrite only if the existing file is bigger
          
          [default: all]

      --min-savings <MIN_SAVINGS>
          Minimum compression savings required to write an output file. Use percentage (e.g., '10%', '1.5%'), absolute size (e.g., '100KB', '1MB'), or plain number as bytes

  -Q, --quiet
          Suppress all output

      --verbose <VERBOSE>
          Verbosity level: 0 = quiet, 1 = progress only, 2 = errors only, 3 = all
          
          [default: 1]

  -h, --help
          Print help (see a summary with '-h')

  -V, --version
          Print version
```