The raw screenshot images from an Android phone usually come in with a filename in the following naming format, is fairly compressed and contain metadata about the phone itself.
$ du -sh -- *
309K Screenshot_20250108_144158_Thunderbird.jpg
373K Screenshot_20250108_144212_Thunderbird.jpg
185K Screenshot_20250108_144506_Thunderbird.jpg
Renaming screenshots from Android.
I prefer to rename them, so they begin with ISO date and time and use system friendly characters.
$ for file in Screenshot_*; do mv "$file" "$(echo "$file" | sed -E 's/Screenshot_([0-9]{4})([0-9]{2})([0-9]{2})_([0-9]{2})([0-9]{2})([0-9]{2}).*/\1-\2-\3-\4-\5-\6-screenshot.jpg/')"; done
$ du -sh -- *
309K 2025-01-08-14-41-58-screenshot.jpg
373K 2025-01-08-14-42-12-screenshot.jpg
185K 2025-01-08-14-45-06-screenshot.jpg
Resizing screenshots from Android with ImageMagick.
The default size is the size of the display, which is usually fine, but they can be optionally resized with ImageMagick to save space. The change in size and quality has no significant impact on the screenshot image quality, while the reduction in file size is huge as it schrinks to about 15% of the original size.
$ magick mogrify -resize 900x900 -quality 75 *-screenshot.jpg
$ du -sh -- *
33K 2025-01-08-14-41-58-screenshot.jpg
45K 2025-01-08-14-42-12-screenshot.jpg
25K 2025-01-08-14-45-06-screenshot.jpg
Reducing screenshots from Android with JPEGOPTIM.
The filesize can be lossless optimized even further, and metadata removed for added privacy, with JPEGOPTIM.
$ jpegoptim --strip-all --all-progressive *-screenshot.jpg
$ du -sh -- *
33K 2025-01-08-14-41-58-screenshot.jpg
41K 2025-01-08-14-42-12-screenshot.jpg
25K 2025-01-08-14-45-06-screenshot.jpg
Final screenshot images.
The original screenshots have now been renamed, resized and reduced, so they use a minimum of storage space and no longer contains metadata for added privacy. The proces has overwritten the original ones, so the storage space has been freed. The screenshots are ready for archiving and publishing on Internet.
