Thanks to J. Ogden who has responded to our "Creating Grids" tutorial with his own spin on the technique. We thought it was worthy of its own page...
"My method is a combination of several other's that have aready posted their answers."
Open the photo that you wish to apply the mosaic effect to.
Open a new image with the number of horizontal and vertical boxes you wish to have on the photo for example: New -> 8pix X 12pix.
In this new VERY small image: fill with white and add noise,
create a new layer, set layer mode to Multipy, fill with white, add noise
repeat 4-8 times
Merge the layers down together to create a very small white-gray-black image
Now we need to expand our small image to fit the larger photo:
go Image -> Image Size and under pixel demensions type in the height and width you are shooting for. you might need to turn OFF constrain proportions and VERY IMPORTANT!! set Resample Image to-> Nearest Neighbor!! If you don't the new larger black-gray-white will look like a topo map of hills (if you want to create that effect for a displacetment map this would do the job ;)
We now have two images, one the original photo and two our large black-gray-white mosaic squares.
If you want to "play" with the Mosaic now is the time to do so...
Some interesting effects can added to our squares: Noise, Glowing Edges, halftone pattern, any of the Sketch or stylize filters or my personal favorite Unsharp Mask.
I used unsharp Mask with these settings
* Amount = 400%-500%
* Radius = 20-40
* Threshold = 20 (a light effect) 160 for a heavy effect.
After Playing with the squares or simply leaving them alone for their sharp edges, we need to combine the images together. I also found many ways to do this.
1. create a pattern from the mosaic image and "fill" to a white layer over the photo.
2. create a white layer over the photo, add a layer mask to this layer and apply the mosaic to this mask.
3. copy and past the mosaic to a layer over the photo.
Now that the mosaic and photo layers are together in the same image, play with the layer mode, (Darken,Lighten, Pinlight,...) the opacity, and fill to get the right amount of mosaic into your photo.
I have also found the need to edit the Levels on the mosaic layer to get the right amount of black-darkgray-lightgray-white. To do this simply
select the mosaic layer then go
IMAGE -> ADJUSTMENTS -> LEVELS...
Enjoy your new Photos and Art Work !!