On Wed, Oct 17, 2012 at 6:48 PM, Tony Yu <tsyu80@gmail.com> wrote:

I'm not really sure how a utility function would work. Wouldn't you need to provide at least 2 utility functions when converting to LAB:

image, ab = prepare_rgb(image) # ... code to generate `filtered_image` from `image` filtered_image = finalize_rgb(filtered_image, ab)

A utility function would simply take an image and apply the specified filter to all its layers (which are pre-and post-converted in some way), e.g. apply_to_rgb(image, filter)

Basically, that's all to say that I think a decorator makes a lot more sense in this case.

But it does mean introducing a flag. I'm debating which is clearer and more explicit: apply_to_luminance(image, filter) vs filter(image, rgb_behavior='luminance') (with the caveat that rgb_behavior has to be documented in each and every filter function--and that we have to figure out a way of preserving signatures and docstrings with decorators) Stéfan