compress-pptx

compress-pptx

Compress a PPTX or POTX file, converting all PNG/TIFF images to lossy JPEGs.

What it does

When copy-pasting images to PowerPoint presentations, these sometimes get inserted as lossless versions, blowing up the size of the presentation.

This script takes all PNG or TIFF images part of the presentation which are larger than a given threshold (1 MiB by default), converts them to a lossy JPEG variant, and creates a new PPTX file.

:warning: This is not the same as compressing images with PowerPoint's own functionality. You may still need to do this to reduce the size of your presentation!

PNGs containing transparency can be skipped to prevent graphics issues. Normally their transparent parts are replaced with white (although you can choose another color).

Requirements

• Operating system: macOS or Linux
  • Note: Under Linux, you need LibreOffice installed to convert embedded EMF files
• Python 3.8 or higher
• ImageMagick's magick commands (magick convert and magick identify)
• Optionally: ffmpeg for media files, and

Under Ubuntu, get ImageMagick via:

apt install imagemagick

Under macOS, install it with Homebrew:

brew install imagemagick

For ffmpeg, use the static builds from ffmpeg.org.

Installation

Via pip:

pip3 install --user compress-pptx

Usage

Call compress-pptx and point it to a PPTX or POTX file. It'll compress the images and output another compressed file next to it.

For more options, see the -h output:

usage: compress-pptx [-h] [-o OUTPUT] [-s SIZE] [-q QUALITY] [-t TRANSPARENCY]
                     [-k] [-v] [-f] [-m] [-j] [-l] [--num-cpus NUM_CPUS]
                     input

positional arguments:
  input

options:
  -h, --help            show this help message and exit
  -o OUTPUT, --output OUTPUT
                        Output file (default: None)
  -s SIZE, --size SIZE  Minimum size threshold in bytes. Also accepts the
                        suffixes k/M/G or KiB/MiB/GiB (default: 1MiB)
  -q QUALITY, --quality QUALITY
                        JPEG output quality (0-100) (default: 85)
  -t TRANSPARENCY, --transparency TRANSPARENCY
                        Replace transparency with color (default: white)
  -k, --skip-transparent-images
                        Skip converting transparent images at all (default:
                        False)
  -v, --verbose         Show additional info (default: False)
  -f, --force           Force overwriting output file (default: False)
  -m, --compress-media  Compress other media types such as audio and video
                        (requires ffmpeg) (default: False)
  -j, --recompress-jpeg
                        Recompress jpeg images (default: False)
  -l, --use-libreoffice
                        Use LibreOffice to compress EMF files (only way to
                        compress EMF files under Linux) (default: False)
  --num-cpus NUM_CPUS   Number of CPUs to use (default: all available CPUs)

Bash Version

There's an unmaintained Bash version under bash/compress-pptx.sh.

Contributors

caydey 💻

License

MIT License

Copyright (c) 2021-2023 Werner Robitza

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Changelog

v0.8.3 (2023-10-02)

• Migrate to magick commands.

v0.8.2 (2023-10-02)

• Add CLI option for num_cpus.

v0.8.1 (2023-10-02)

• Formatting and fix path handling.

v0.8.0 (2023-03-13)

• Bump requirement to python 3.8.

• Docs: add @caydey as a contributor.

• Update README and minor code changes.

• Added '-l' to compress emf files using libreoffice.

• Fixed bug for when file compression fails.

• Fixed bug with clashing variable names.

• Refractored "image" to "file"

• Media file compression and recompress jpeg files.

v0.7.2 (2023-01-30)

• Remove manifest.in.

v0.7.1 (2022-08-02)

• Update python requirements.

v0.7.0 (2022-08-02)

• Update python requirements.

v0.6.0 (2021-10-28)

• Add feature to skip transparent images completely, add EMF.

v0.5.0 (2021-08-06)

• Allow POTX files, fixes #4.

• Fallback to 'convert' and 'identify', fixes #3.

v0.4.0 (2021-05-25)

• Add handling of transparency and TIFFs.

v0.3.0 (2021-05-14)

• Auto-formatting.

• Add -f/--force parameter.

• Update gitignore.

v0.2.1 (2021-03-29)

• Add defaults to CLI options.

• Update badge link.

v0.2.0 (2021-03-10)

• Change executable name for harmonization purposes.

v0.1.3 (2021-03-10)

• Improve setup.py.

• Remove release script.

v0.1.2 (2021-03-06)

• Format setup.py and switch to markdown.

• Add warning.

• Update badge URL.

v0.1.1 (2021-02-08)

• Better error handling; check for magick command.

• Add badge to readme.

v0.1.0 (2021-02-07)

• Fix README.

• Add changelog.

• Switch to python package.

• Various updates, v0.2.

• Add TODO notice.

• Handle input errors.

• Update instructions, add script.

• Add script and README.

• Initial commit.