mb_detect_encoding detects ASCII as UTF-8?

Question

I\'m trying to automatically convert imported IPTC metadata from images to UTF-8 for storage in a database based on the PHP mb_ functions.

Currently

Answer 1

If you do not want to worry about what encodings you will allow, you can add them all

$encoding = mb_detect_encoding($val, implode(',', mb_list_encodings()));

Answer 2

Specifying a custom order, where ASCII is detected first, works.

mb_detect_encoding($val, 'ASCII,UTF-8,ISO-8859-15');

For completeness, the list of available encodings is at http://www.php.net/manual/en/mbstring.supported-encodings.php

Answer 3

You can specified explicitly

$val = mb_convert_encoding($val, 'UTF-8', 'ASCII');

EDIT:

$val = mb_convert_encoding($val, 'UTF-8', 'auto');