Query Supported Image Formats

[olivervogel]

Is there a way to list or query the supported image formats at runtime? Something along the lines of Imagick::queryFormats() at Imagick.

At the moment I get by by creating a temporary 1x1 image and trying to encode it into the format to check. However, this does not seem to be very resource-friendly.

Also see Intervention/image-driver-vips#17

[jcupitt]

Hello @olivervogel,

The libvips way is to use gobject introspection to find this. You walk the class hierarchy below VipsForeignLoad and find all the non-abstract classes, or perhaps the set of defined suffixes.

You can do this at the CLI with eg.:

$ vips -l load
      VipsForeignLoad (load), loaders, priority=0
        VipsForeignLoadCsv (csvload_base), load csv, priority=0, untrusted
          VipsForeignLoadCsvFile (csvload), load csv (.csv), priority=0, untrusted, get_flags, get_flags_filename, header, load
          VipsForeignLoadCsvSource (csvload_source), load csv, priority=0, untrusted, is_a_source, get_flags, header, load
        VipsForeignLoadMatrix (matrixload_base), load matrix, priority=0
          VipsForeignLoadMatrixFile (matrixload), load matrix (.mat), priority=0, is_a, get_flags, get_flags_filename, header, load
          VipsForeignLoadMatrixSource (matrixload_source), load matrix, priority=0, is_a_source, get_flags, header, load
        VipsForeignLoadRaw (rawload), load raw data from a file, priority=0, untrusted, get_flags, get_flags_filename, header
... etc.

In php-vips, you'd call vips_type_map(), though it'd need a bit of FFI calling. I'll try to make an example.

[olivervogel]

Thanks @jcupitt

Could you show me some more details. I can't currently figure out how to get results with vips_type_map() and calling FFI. Many thanks in advance.

[jcupitt]

Sorry, not found the time to make some example code yet.