How to convert Apple iOS HEIC image format to JPG in a batch in terminal

Moving from Google Pixel on Android to Apple iPhone on iOS brought new challenges for the photos stored on the Google Photos cloud. The format of the iOS photos is HEIC being a perfect container format for storing individual images and image sequences, but with low out-of-the box system support. Imagine sending a HEIC photo to your automotive technician / mechanic still sitting on Windows 7 desktop. The obvious way is converting them from HEIC to JPEG in a batch.

1. Install libheif an HEIF and AVIF file format decoder and encoder

   sudo apt install libheif-examples
   

2. Resize all HEIC images ending with .HEIC¹ in a downloads folder to JPG with 75% image quality

   cd ~/downloads
   for file in *.HEIC; do heif-convert -q 75 "$file" "${file/%.HEIC/.jpg}"; done