list_files_in_directory() should be able to only return images

[cvondrick]

Since this is a computer vision toolkit, list_files_in_directory() should be able to only return images. This commit introduces an optional parameter that:

• if it is a cell array, only return files with extensions in this arra
• if it is the string 'images', only return images
• if it is the string 'videos', only return videos
• if it is a string, only return files with this extension
• if it is not given, return all files

(Also, I wanted to see what 'pull request' did)

[quantombone]

Good idea on using the github system to push changes to submodules.

[quantombone]

I agree with the changes, let me pull it on my end too.

[cvondrick]

Oops, just realized that we both added the same feature here. I guess my submodule copy did not update properly. I'm not sure which solution is better -- regex or a more explicit extension enumeration.

[quantombone]

hmm, let me see what sort of conflicts my local version sees

[quantombone]

I'm not sure how your version is supposed to work...

[quantombone]

I see now, I will update comment.

[quantombone]

I just updated the comment once I figured out how to use it, I was specifying 'jpg' for the extension, but it only works with '.jpg'.

The comment can be seen here: https://github.com/quantombone/exemplarsvm/blob/master/util/list_files_in_directory.m

[cvondrick]

Cool, looks good!