Pre-fill description, title, alt text and caption of a media

Hello,

I’m not sure I’m posting this in the correct section, sorry if that’s the case.

I have a wordpress blog hosted on wordpress.com and I’am using regularly the post by email option but I also create post directly on the web interface sometimes.

I would like to know if it is possible to prefill the “title”, “alt text”, “description” and “caption” of a media (a picture most of the time) so they are all set when I upload the picture (by email and/or directly on the web interface). For example by setting some specific tag when posting by email or through the creation of a specific exif (or any over metadata) tag.

I tried to find this information in the media and in the “post by email” section of the help but didn’t find anything.

Any help appreciated.

Thanks in adavance.