Lab Sharpening In Photoshop

Quicktime tutorial showing how to sharpen an image in Photoshop utilizing the Lab color space. This technique will minimize or eliminate color banding in the sharpened image. Time: 7:55 - This is a higher resolution version of the same video uploaded previously. Try viewing it full screen.

This tutorial is excerpted from my CD 'Sharpening Techniques in Photoshop', ©2006 C H Behrman Photography/ www.chbphoto.com

Category:

Howto & Style

Tags:

• instruction
• Photoshop
• sharpen
• tutorial
• video

[omega6667]

I was wondering; if you change color mode from rgb to lab, and then back again, will there be any changes in the colors? It wont be much of course, I mean that a color could be rgb 116,213,212 first and it would change to 117,213,212 or whatever...

[chbphoto]

from what I understand, with the newer versions of PS, you can safely change back and forth between RGB & Lab without degradation. Going to cmyk is a different story.

[leszken]

Thats TRUE, but... you don't need to sharpen all channels in any color mode (RGB, CMYK, LAB)

PS Using LAB we can clean color noise easy without contrast loss :-)

Just blur A abd B channels

[omega6667]

especially much damage to the blue channel, I noticed. Sometimes as much as 4 numbers of difference!

[omega6667]

Btw, when doing this on a 24 bit picture, and changing it to 16 bits/channel before changing color modes, and then changing back afterwards, the difference is a lot less; but still it is a bit destructive, especially when doing this multiple times, I guess. I've tested it on CS, have to do it at home on CS3, to see if that works better...

[omega6667]

I've just tested it by flipping back & forth between Lab and rgb once with a copy of the background. Then changed the top layer mode from 'normal' to difference. I then flattened the (almost completely dark) image and used levels on it, and unfortunately yes.... there is a difference :(