caesium-clt/docs/USAGE.md

CaesiumCLT Usage

Options

Compression (at least one is required)

• -q, --quality <QUALITY>
  Sets compression quality between 0 and 100. Higher the value, better the quality and bigger the file size.
• --lossless
  Perform lossless compression. Some file formats may not support this or result in bigger file sizes.
• --max-size <MAX_SIZE>
  Attempts to compress the image to the nearest size in bytes without exceeding it. If the requested size is too small, it will output the smallest possible result.

Advanced compression

• --jpeg-chroma-subsampling <JPEG_CHROMA_SUBSAMPLING>
  Sets the chroma subsampling for JPEG files. Possible values are:

  • 4:4:4
  • 4:2:2
  • 4:2:0
  • 4:1:1
  • auto

• --jpeg-baseline
  Forces the output to be in baseline JPEG format instead of progressive.

• --png-opt-level <PNG_OPT_LEVEL>
  Sets the optimization level for PNG files. Higher values result in better compression but take longer to complete. Possible values are between 0 and 6. Default is 3.

• --zopfli
  Use zopfli when optimizing PNG files. It may take a very long time to complete, especially if the application is not build in release mode.

Metadata

• -e, --exif
  Keeps EXIF metadata info during compression, if present. This can slightly increase the output file size.
• --keep-dates
  Keeps the original last modified and last accessed date information, if possible.

Resizing

• --width <WIDTH>
  Sets the width of the output image. If height is not set, it will preserve the aspect ratio. Can't be used with --long-edge or --short-edge.
• --height <HEIGHT>
  Sets the height of the output image. If width is not set, it will preserve the aspect ratio. Can't be used with --long-edge or --short-edge.
• --long-edge <LONG_EDGE>
  Sets the size of the longest edge of the image. It is aware of rotation metadata. Can't be used with --width or --height or --short-edge.
• --short-edge <SHORT_EDGE>
  Sets the size of the shortest edge of the image. It is aware of rotation metadata. Can't be used with --width or --height or --long-edge.

Destination

• -o, --output <OUTPUT>
  Sets the output folder. If the folder does not exist, it will be created. Can't be used with --same-folder-as-input.
• --same-folder-as-input
  Sets the output folder to be the same as the input folder. WARNING: this can potentially overwrite the original files if a suffix is not set. Overwritten files CANNOT be recovered.
• --suffix <SUFFIX>
  Adds a suffix to the output filename, before the file extension.
• -S, --keep-structure
  Preserves the folder tree structure of the input files. Can be used only with -R.
• -o, --overwrite <OVERWRITE>
  Sets the overwrite policy if the output file already exists. Possible values are:
  • all: Always overwrite
  • never: Never overwrite
  • bigger: Overwrite only if the file to be overwritten is bigger
• --format <FORMAT>
  Converts the original image to the selected format. Possible values are:
  • jpeg
  • png
  • webp
  • tiff
  • original (default, no changes)

Other

• -R, --recursive
  If the input is a folder, scan its subfolders too.
• -d, --dry-run
  Do not write output files, only simulate the process.
• --threads <THREADS>
  Specify the number of parallel jobs. The maximum is the number of processors available. 0 means that the application will try to guess the maximum number of parallel jobs available. Default is 0.
• -Q, --quiet
  Suppress all output. Overrides --verbose.
• --verbose <VERBOSE>
  Select how much output you want to see. Possible values are:
  • quiet: Suppress all output
  • progress: Show only progress and final results
  • warnings-and-errors: Show also skipped and error messages
  • all: Print all
• -h, --help
  Print help. A summary can be seen with -h.
• -V, --version
  Print version.

Full help

Use --help to see the full list of options.