Fedzilla_Bob
man with cat
A Method for non destructive sharpening
I learned this technique in a Canon Digital forum . It allows you to sharpen an image without blowing away the original data from a scan. The technique was originally developed to sharpen images taken with earlier digital cameras shooting .jpg format. I found that it worked brilliantly for images that were soft due to scanning or even due to my eye. Photoshop ver. 7 is the tool used. I have tweaked the original info a bit.
Take your original image (pic 1) duplicate that layer, de-saturate it using Hue/Saturation (pic 2) then open “Filters>Other>High Pass.”
In the High Pass dialog, set the pixel radius to 1.0 (pic 3)
On this same new layer open curves (ctrl M) and adjust as shown in pic 4.
Change this layer’s blending mode to “Hard Light,” you should see the sharpening effect now. It most likely will appear harsh. You can adjust the sharpening effect by decreasing the opacity amount to your taste. I find that setting the opacity for the effect layer between 30 and 60% gives desirable results (pic5).
The definition of the effect also seems to be affected by adjusting the amount of High Pass or Curves for the effect layer. I urge you to experiment.
I learned this technique in a Canon Digital forum . It allows you to sharpen an image without blowing away the original data from a scan. The technique was originally developed to sharpen images taken with earlier digital cameras shooting .jpg format. I found that it worked brilliantly for images that were soft due to scanning or even due to my eye. Photoshop ver. 7 is the tool used. I have tweaked the original info a bit.
Take your original image (pic 1) duplicate that layer, de-saturate it using Hue/Saturation (pic 2) then open “Filters>Other>High Pass.”
In the High Pass dialog, set the pixel radius to 1.0 (pic 3)
On this same new layer open curves (ctrl M) and adjust as shown in pic 4.
Change this layer’s blending mode to “Hard Light,” you should see the sharpening effect now. It most likely will appear harsh. You can adjust the sharpening effect by decreasing the opacity amount to your taste. I find that setting the opacity for the effect layer between 30 and 60% gives desirable results (pic5).
The definition of the effect also seems to be affected by adjusting the amount of High Pass or Curves for the effect layer. I urge you to experiment.
DougK
This space left blank
Thanks, I've been looking for a way to do this since I usually shoot JPEG. I'm betting it'll work pretty well with my scans too.
Fedzilla_Bob
man with cat
I use it with scans mostly. 
lubitel
Well-known
I was kind of suspicious of your method, but it does seem to work. Although it did add some noise in my case.
Here is an example from a cheap scanner.
Here is an example from a cheap scanner.
K
Kin Lau
Guest
Sharpening b&w is always a bit of a problem since you're also sharpening the grain. I played with this, and found playing with the "Pixel radius" will change the amount of "sharpening", but using "Soft Light" with 1 pix radius seems to work quite well for b&w.
Unfortunately, lubitel's shot is very grainy to begin with, so the only way to help that, is to use selective sharpening.
Unfortunately, lubitel's shot is very grainy to begin with, so the only way to help that, is to use selective sharpening.
RayPA
Ignore It (It'll go away)
Well done, Bob! Thanks for the tip!
Gabriel M.A.
My Red Dot Glows For You
You could also bookmark the Luminous-Landscape tutorial describing the method:
http://www.luminous-landscape.com/tutorials/high-pass-sharpening.shtml
Sometimes I use it; also remember that the Radius and the Opacity percentage should depend on the size of your image.
http://www.luminous-landscape.com/tutorials/high-pass-sharpening.shtml
Sometimes I use it; also remember that the Radius and the Opacity percentage should depend on the size of your image.
kmack
do your job, then let go
For those of us too cheap for Photoshop this technique will also work in The GIMP.
You can simulate the high pass filter in GIMP using the following method:
1. Duplicate the image
2. Using the duplicate open the layers dialog and select "Duplicate Layer"
3. Gaussian blur the top layer, you can experiment to find good values, try 6x6 pixels and go from there.
4. Invert the top layer Layer-->Colors-->Invert
5. Blend using the layer dialog to 50%
6. Flatten the image.
The dupe will now be your high pass filter image.
You can simulate the high pass filter in GIMP using the following method:
1. Duplicate the image
2. Using the duplicate open the layers dialog and select "Duplicate Layer"
3. Gaussian blur the top layer, you can experiment to find good values, try 6x6 pixels and go from there.
4. Invert the top layer Layer-->Colors-->Invert
5. Blend using the layer dialog to 50%
6. Flatten the image.
The dupe will now be your high pass filter image.
jano
Evil Bokeh
This method seems to be a variation on USM. When learning about sharpening earlier this year, I came across a site which broke down USM, and they used the high-pass filter with a bit of guassian blur. Neat