Method: Gets dimensions of image.

Method: Returns first matched extension from Mime-type, as mapped from wp_get_mime_types()

Method: Returns first matched mime-type from extension, as mapped from wp_get_mime_types()

Method: Either calls editor’s save function or handles file as a stream.

Method: Builds and returns proper suffix for file based on height and width.

Method: Builds an output filename based on current file, and adding proper suffix

Method: Returns preferred mime-type and extension based on provided file’s extension and mime, or current file’s extension and mime.