using grayscale image to blur another image

ive got these two images:

and i need to use the second one as a depth-of-field blur thing to blur the first colour image. ive gone through help and it says you can, but as far as i could tell it didnt tell you how :-?

also searched the forum

any help is appreciated
thanx

hmm...when i fake depth of field i usually use two layers, one blurred and one not, and mask between them. this is different though, and an interesting idea...let me play with it.

question though, how'd you generate the grayscale image?

chris

ok, it looks like this can be done with the "lens blur" filter by applying the grayscale image in an alpha channel...not sure of the settings but give it a shot and post some results

chris

Why not just dupplicate the layer, add a mask, guassian blur and then paste the grayscale into the mask?

Supposedly lens blur works better. It does have the interesting effect of bluring with iris shapes.

ok, ive figured out how to do it. i just copied the grayscale onto a new channel in the colour image, then used the chnnel's selection to do a simple gaussian blur. i prefer this over a lens blur myself... so thanx for the ideas, couldnt have done it without you guys

in reply to how i got the grayscale itself, i used a 3d modeling program to model and render it, and it just so happens that it can render depth of field images too. it makes no sense that it cant use it directly with the render...

modeling program: anim8or ( www.anim8or.com )

thanx guys :D

Rodder, because lens blur will vary the strenght of the blur based on the greyscale map, while a gaussian blur would be uniform, and only be masked by the blur. You could acheive what you want by loading the greyscale, then applying several times a very slight blur, each time increasing the selection area.

well in the end, i applied it to another image i had, i like it better.

used gaussian blur instead of lens blur. also some glow

what do you guys think?