My first filter - please comment

Hi,
I have just finished my first filter (attached). I wonder of some of the experts would be willing to look it over to see it is good enough to submit and that it does what I think it does.
Here is what I think it does – I call it ‘Lab Enhance’:

This filter uses the Lab color space so the contrast and color can be manipulated separately to avoid unwanted color shifts. First the L channel is extracted and blended with the external image using the multiply blend mode for purposes of contrast enhancement by stretching the midtones and compressing the highlights and shadows – the opacity of this blend is broke out for user manipulation. Second the image is blended back with itself using the overlay blend mode for purposes of detail enhancement – the opacity of this blend is also accessible to the user. Third the a and b color channels are extracted for purposes of saturation manipulation – this takes the form of a saturation slider for the user. Fourth all the channels are reassembled into result. This filter will work either with an image or a selection so it can be used just to enhance a sky or the leaves of a tree or even the entire image.

Any comments on how to correct improve or modify this filter to make it more useful or useable would be very much appreciated. Thanks for taking the time to look it over. Also if anyone know how the saturation slider can be reversed so it increases left to right rather than right to left that would be helpful also.


Thanks,
Ron

Lab Enhance.ffxml

I modified your filter to illustrate different "selector" ideas...


P.S. If you totally get rid of the selector component in your filter, the filter will only effect the selected areas if you have a selection selected (similar to my #2 selector effect) -- which makes intuitive sense to me (where I haven't found much use for that component yet).

Lab EnhanceSelector_.ffxml

Here are is an example of before and after using the filter with one of the presets.

http://picasaweb.google.com/ronviers/...5826645202

http://picasaweb.google.com/ronviers/...8193378498

Nice job, ronviers. I like the brightness addition (as the multiply alone may darken things too much).


Just on a note of personal taste, I've always disliked how overlay seems to "orange" things up. So I usually always end up putting a color blend layer (from the original image) on top of any overlay layer, and this seems to rectify the results more to my liking. (So when I use a color layer above a layer that used your filter, I like it even more. Very nice filter!)