Advanced Image Sharpening for internet display

[MartinBabies]

Advanced Image Sharpening
For internet display
By MartinBabies


When scaling down a photo for internet usage your photo might appear unsharp. This is because people tend to scale down way to quickly, apply some Unsharp Mask and then they're done. This is not good at all. The trick is to scale down a little, sharpen, scale down, sharpen and so on.
Some people think that the best way to sharpen images is to apply the Unsharp Mask filter. It will in this tutorial show how that in fact sucks. There is a much better way of sharpening your photos. The key is a filter called High Pass.

For this tutorial you might need image noise reduction software, like NeatImage. A guide to NeatImage can be found here: http://www.gfxvoid.com/forums/showthread.php?t=10889
Please not that if you're photo isn't grainy at all or if you have no people in it, maybe the noise reduction could be skipped. I recommend it for portraits though.

I will show you the whole process. I will be working with an original file of 2311x3471 px. This is the photo I'll be using. The model is David, I hope he won't mind.. :P




If you have shot with a higher ISO value, then you might need to remove some noise before you start.

Cleaning up

1) Open up neat image and your picture
2) Reduce some noice but try not to overdo it as that would mess up your end result quite badly.
3) Save as a new file (default is filename_filtered.jpg).

4) Open up Photoshop with your original photo.
5) Paste the filtered version over the original. Add a layer mask to this layer.
6) Lower the opacity a bit. We don't really want the filtered look. We just want to get rid of some of the noise.
7) Now pick a big soft brush and start masking away parts from the filtered layer. The parts you should concentrate on are mainly fabrics as the noise only will do good there. Do not remove much from the background or from skin.

Here's a close up on the skin before and after the quick retouch:

Before/after


Looking better... Now let's get on with the real deal.


Sharpening

1) Merge all layers.
2) Duplicate your layer and go Filter > Other > High Pass. Use 0,5 px radius and hit OK.
3) Change the layer's blending mode to Overlay.
4) Open up Brightness & Contrast (NOT as an adjustment layer) and pull the contrast up to +50.
5) Merge the layers.



Scaling

1) Go to Image > Image size. Make sure Constrain Proportions is checked.
2) Round off the vertical size to 3000 px.

3) Now repeat the sharpening process, but with 0,3 px radius.
4) Scale down 500 px so that your picture is 1664x2500 px.
5) Repeat sharpening.


Cleaning up again

You will probably notice that the more you sharpen your image the more noise you get. Well, it's time for another clean up with NeatImage.

1) Save as a new file.
2) Open the new file in NeatImage and repeat the NeatImage step. You might have to change your settings a little as the noise and size are different now.
3) Save as a new filtered file. Paste it over your Photoshop file and start masking away parts, playing with opacity etc.

Scaling and finish

1) Go to Image > Image size and scale down 500 px again.
2) Repeat the sharpening process, but with 0,2 px radius.
3) Go to Image > Image size and scale down 500 px again.
4) Repeat the sharpening process, but with 0,2 px radius.



5) From now on we begin scaling down with only 200 px instead of 500 px, so do that. Also repeat the sharpening process between each time you scale down.

Finally I stop at 800 px height by applying one last High Pass filter.
My final image looks like this:



Looks pretty good! It actually looks like I used a much better and sharper lens when shooting this. But in reality it was the crappy Canon 18-55 kit lens.
Now try comparing this method with simply scaling down only once and applying unsharp mask. You won't get as much detail at all.

That's it. Hope you liked it (and learned something)!

[Papa]

The tut looks awesome Martin thanks a lot.

I'll try it out next time i have photos and I'll post my results.

[Daemon]

Great your the best martin thx for the tut.

[robgasm]

This is how Ive been sharpening for about 4months, but with two levels rather than.. well, more. I might try it in more detail now, good tutorial for beginners to get to grips with too

[Pleymo]

sweet tutorial mate :')
I thought it was only your camera and skill which made your photos that wonderfull, but it's the tricky sharpening which finishes the photo.

good job

[MartinBabies]

Thanks. Yes, even not a professional camera and lens will look very sharp if you don't scale down your photo the right way. The trick is to get all these tiny details out to make it look real sharp!

[Sanji]

that photo of me is exceptionally dreadful. i look like a goat or something.

[MartinBabies]

Yes you do. Nice avatar btw ho!

[Pleymo]

Oh Martin thanks for this guide :') I tried it on one of my photos while I'm rowing.
I guess it's still way to big to post here(1600x1200, wallpapersize) but I like the result much more then the 'Image Size > Unsharp Mask'-way ... Thanks a lot :') I love it.

[XaiXo]

Awesome. I'll be using this. Thanks Martin.