What this technique does is take an image and add pixel detail to it without additional data (like overlaying more images). This is achieved by overlaying an inverted copy of the image on top of itself and offsetting it in 4 multiple directions.The effect will make the image crisper, great for those hardcore close-up shots.
This is a random texture from CGTextures that I used for this demo. Clck for full (medium) res.
I cropped a part of the above photo (flipped it, even) and aligned it as my starting point. The horizontal thing is measured at 25% of the image from the top.
Even at 100% view, it is clear that it lacks pixel detail, little edges and definition. One way to deal with it is apply a lot of unsharpen masks but it usually ends up looking "burned" and overkilled. While unsharpen is beneficial in smaller dosages (like many other things...) we want to avoid using it too much.
Step I: Inverted overlay
Duplicate your background layer, set it to Overlay and invert it (ctrl-I). Reduce the opacity to 50%. Make sure 'Lock Position' is off.
Step II: 4 versions
Duplicate your image (Ctrl-J) x3, so you have 4 inverted Overlays on top of each other (see image below).
Step III: Shake it Baby
Select your first overlay and Nudge it 1 pixel LEFT. Now Nudge your 2nd overlay 1 pixel RIGHT. Then your 3rd overlay 1 pixel DOWN and finally the 4th overlay 1 pixel UP.
Step IV: Merge'em all
Starting from the top. merge (Ctrl-E) your duplicates down to the original overlay. Personally I like to keep my layers to a minimum.
Step V: Adjust value and color
Reduce your opacity to below 50%. You will have to play with this effect in relation to your texture to see how strong you want it. A strong effect can be beneficial for normal-mapped textures as the inverted overlay flattens the values.
Continue to desarate the image (Ctrl-U) according to your desired effect. No change for the image is pure grey, or leave some color to have some balancing desatuation effect (cool results usually).
- You may need to lighten or darken (Ctrl-L) to reduce global value change. In this example the change is actually minimal.
In the GIF you can see 3 versions of an area from the original image at 800%:
- Unsharpen mask 25 x4 (100)
- Pixel Boogie effect + unsharpen mask 100
While this may seem subtle at this level, you can see the full-effect on the image in the screen below.
- Save it to the end. If you are using several textures together in your image, don't apply it to every and each one of them seperately. Finish your texture to a certain combined extent and then apply it over everything.
- I used unsharpen value of 100 purely for demonstrational purposes. Do not try this at home!
- Try duplicating your boogie'd layer when you're done (like double-combined overlays). This can yield some poppy color results. Copy-merged (Ctrl-Shift-C) the result and add contrast to restore value data. Use Fade (Ctrl-Shift-F) on Luminosity mode to reclaim the pre-contrast colors.
Pixel Boogied and ready to go! don't tell your mother!
I explain how I did this ^^^ here.