Selective Sharpening

[wulf]

In discussions about my one gold ring shot, I was asked to explain the selective sharpening technique I used. I had another photo that I wanted to publish so I made sure I saved all the intermediate stages that got me from this:



to this:



First, I cropped the picture down to a square format to make the bird larger in the frame. I also applied some colour and contrast enhancements.

Next, I applied an Unsharp Mask on a duplicate layer. The settings I used (in The Gimp) were radius 9.6, amount 0.79 and threshold 3 but that needs to be judged by eye depending on the picture. I went over the top and then toned the result down by reducing the opacity of the layer to 40% (again the amount will vary depending on the image and your personal taste).

However, that was still too sharp overall. Everything in the picture has been sharpened and the foreground is too dominant. The next step was a black (fully transparent) layer mask. I then used a white brush to paint back in the areas I wanted sharpened (and also a touch of grey for areas I wanted a bit sharper but not so much). The mask was also blurred to avoid any strong edges between sharpened and unaffected areas and I made a preview of what this looks like over a white background.

It isn't one of my best photographs and other pictures, like this self portrait show a better end result, but hopefully the stages (available as a set on Flickr) will give you an idea of where some of your pictures might benefit from a similar approach.

Wulf

[xxpinballxx]

Wulf, this is a great way to do it. I basically do the same thing but didnt think about using the the grey to get a partial sharpening effect. Thanks for posting this....

[windrider86]

Thanks Wulf for that, very helpful!
Perhaps you wouldnt mind explaining something for regarding layers. As you well know i"m still figuring this all out and would like to a portion of a picture vs simply ereasing the part ont he top image that wouldnt want to show? I hoep that makes sense

[wulf]

Originally Posted by windrider86

Thanks Wulf for that, very helpful!
Perhaps you wouldnt mind explaining something for regarding layers. As you well know i"m still figuring this all out and would like to a portion of a picture vs simply ereasing the part ont he top image that wouldnt want to show? I hoep that makes sense

Do you mean this kind of thing, where I use shades of grey as well as just black and white on the mask:



Wulf

[windrider86]

Well hadnt thought of that, so that raises yet another question.lol
I'm sure I'm doing ti worng but in order for me to paint anything in black and white on alayer mask I have found I have to use the selective tool forst and then i can go ahead and paint to add or remove what ever i wanted to show in the layer beneath. But, Lets say I created a blur on the duplacte layer but wanted the sharper image below to show thru, How would painting the image in black (to show the image beneath) compare to just erasing the part of the image on the top layer?

[wulf]

A layer is more flexible - you can erase a couple of things by painting them black and then go and bring the first one back by painting it white (or experimenting with a shade of grey). If you erased directly on the top layer you would need to undo both steps and then erase the second one again to get the same result.

Does that make sense?

What editing software are you using by the way? I'm using The Gimp; the steps might be a little different on other software although I suspect the concept holds.

Wulf

[windrider86]

I think it makes sense. I'm gonna try it again but are you saying that if you are working on a layer and you want something to show up fromt he bottom layer that you need to paint the top layer object black and then go down and paint the original white?
I'm using paint shop pro 12

[ELAY]

Wulf, have you tried the smart sharpening redux plug-in (script-fu) for Gimp?

It may be kind of cheating, but it is a very helpful (and easy) way to get excellent selective sharpening results.

It works by creating a sharpened duplicate of your photo, and then creates a layer mask using edge detection and other fancy things to determine what will be masked. If you want to reveal or hide more sharpened areas, you can just paint on the mask that the plug-in generates. The masked second layer is then blended onto your original using the value mode, and is set default at 80% -- but obviously you can play with that.

Here's the layer setup when you run the plug-in:



Here's what the mask looks like for your photo (white indicates areas where sharpening will be visible on the resulting photo; black where it will be masked):



And here's what the photo looks like, using the default settings:



PS -- I use Gimp, but there are obviously smart sharpening routines available for PS too.

PPS -- Here, for the technically-minded, is a tutorial going through the steps for a smart sharpening.

EL

[wulf]

I haven't used the plug-in but I have sometimes used a similar technique, with edge detection used to create a mask. That could be combined with the ideas above to use sharpening only in selected areas and concentrating on edges rather than whole blocks (with the picture above, avoiding the edge of the old chimney pot feeder being sharper than the bird, which is intended as the main target).

Thanks for the link.

Wulf

[ELAY]

Originally Posted by wulf

That could be combined with the ideas above to use sharpening only in selected areas and concentrating on edges rather than whole blocks (with the picture above, avoiding the edge of the old chimney pot feeder being sharper than the bird, which is intended as the main target).

Thanks for the link.

Wulf

That's what I was thinking. Here's a link to the download for the plug-in