1. libheif library

This library is an ISO/IEC 23008-12:2017 HEIF file format decoder and encoder.

Site : https://github.com/strukturag/libheif

It is available in the RPM Fusion repository which provides good quality package, following the same rules than Fedora, for software which are compatib le with official repository but are not distribuable byFedora  / Red Hat (patent encumbered or non free algorithm).

2. ImageMagick

Site : https://imagemagick.org/

This tool supports this format, it is available in the optional package ImageMagick7-heic (or ImageMagick6-heic)

Example, using my repository and RPM Fusion :

$ sudo dnf install ImageMagick7 ImageMagick7-heic
$ convert Example1.heic Example1.jpg
$ eog Example1.jpg

3. libvips

Site : https://libvips.github.io/libvips/

This tools supports this format since version 8.8.0 released yesterday.

The vips-heif package adds this support (extension of vips).

Exemple :

$ sudo dnf install vips-tools vips-heif
$ vips pngsave Example2.heic Example2.png

4. PHP with imagick extension

Site : https://pecl.php.net/package/imagick

Using the php-pecl-imagick-im7 and ImageMagick7-heif packages (or php-pecl-imagick-im6 and ImageMagick6-heic)

$imagick = new Imagick();

5. PHP with vips extension

Using the php-pecl-vips and vips-heif packages

$x = vips_image_new_from_file('Example4.heic');
vips_image_write_to_file($x['out'], 'Example4.jpg');

6. Conclusion

This widely used format is now perfectly supported, and easy to install for users of my repository.