I am looking for a way to project one image I have onto the surface of another image I have.  Confused yet?  hehe.  Here is the deal, I have a pic of a wall.  I would like to place another image on top of it and make it look like it is being projected onto the wall.  I still want to be able to see the details of the wall of course.  I have found some tuts on how to place text on a wall and get the effect I am looking for but nothing involving doing it with another image.  Any ideas?

Use any one of the layer blending options to taste -- Multiply and Soft Light might work best, but try them all and see which ones you like.

If the image is dark use Darken blend mode, if image is light use Lighten blend mode. After tweak with levels or even better with curves to get semitransparent areas off and increase the contrast :)

Tihomir

Try using the displace filter.  Here is a link to a tutorial that explains how to use it for what you want to achieve.

Displace Filter Tutorial

Shane

Great tute...thanx

Double click on the layer thumbnail to bring up the blending options dialogue box (is that what it's called?)  Play with the sliders that say "This layer" "Underlying Layer"  These sliders make parts of the respective layers 'disappear'  or 'appear' through each other.

If the wall is not parallel to the viewer... may need to use transformation tools... such as "distort" to pull the ends to match the wall... frame, or whatever... as well as what has already been said.

Or if you have time and image is not too complex, make a mask in channels palette. First duplicate the channel with most contrast (usually its blue). Use curves to increase contrast even more and make masking easyer. If its on white bacground use multiply blend mode for the brush, the advantage of that is that you can freely mask the edges with black without afecting the white background. After you finish, CTRL+LMB on mask channel to select it, in layers palette click on top layer and finally click on add layer mask in the bottom of the palette :)

Tihomir