How to remove gradient banding?

[abdul10000]

How do you remove gradient banding that you get when you use the gradient tool create a narrow range gradient? The attached example was made in 16bit and saved as jpeg 8bit. Both dither in photoshop cs6 color settings and in the gradient tool options were enabled.

I tired searching for this but could not find anything specific on the site. There is one person that created an action for this that I tired and it didn't work.

http://nomorebanding.com/

[Doug Nelson]

Re: How to remove gradient banding?

Try adding noise first or save as GIF instead of JPG.

The bands you're seeing are the discrete jumps from 1 gray tone to the next. 8bit file formats can only display 256 gray tones, regardless of how many you started with, and that includes the entire range up to pure white. You're effectively zooming in on those 256 to only show a few, so of course you're going to see the transitions. Adding noise will break up the transitions, and the GIF format will remove JPG compression and add some randomness. PNG might work even better, but you'll probably need noise for that.

[abdul10000]

Re: How to remove gradient banding?

Thanks for thew fast reply.

I dont think this has anything to do with the save option because the banding is showing inside photoshop in 16bit before saving.

I tired adding noise and that didn't remove the banding just changed its shape a little. Do you have any specific tool/settings you suggest trying?

[Doug Nelson]

Re: How to remove gradient banding?

It could be a screen limitation, since screens are essentially 8bit devices. I recreated your scenario and used the info panel and even though I saw banding the info panel showed smooth transitions (when viewed in 16bit mode).

Attached find the exact same 16bit image, saved as 24bit PNG. The second has .2% monochromatic noise added.

[Repairman]

Re: How to remove gradient banding?

If you could show the actual gradation you are having problems with it would help to find a solution. This is such an everyday problem that apart from the first and second steps that Doug mentions i.e. working 16 bit and adding noise there maybe further tricks to disguise the problem. FWIW, very often the banding isn't quite as bad on output to print when the screen dot effectively adds further noise.

[klev]

Re: How to remove gradient banding?

It could be a screen limitation, since screens are essentially 8bit devices.

Screens or printers are ultimately used to display these things, so they should be prepared in a way that they look fine in 8 bit mode. My guess would be either too big of steps or rounding errors. To test whether it's predominantly a screen problem (which happens with bad profiles), you just need 256 steps, assuming this only considers values of the form r=g=b. I can tell you that on most displays you won't see a difference until 4 or 5 from 0. It might go a little lower if your room is completely blackened and the display is of high quality. Otherwise even if the display resolves that, minor reflections simply wash it out.

[Greg Curran]

Re: How to remove gradient banding?

new layer, fill with 50% grey, blend mode to softlight, add noise. Then you can have a bit more control over the amount. Always non destructive retouching.

[John Wheeler]

Re: How to remove gradient banding?

Hi Abdul

As already mentioned, if you are displaying on an 8 bit display or convert to 8 bit mode you will see the banding. The eye is really good at picking up subtle luminosity changes that have sharp edges.

One approach I did not see mentioned is using the filter under brushes called spatter. Set the smoothness to "1" and the radius to the ~dimension of the band which I set to max since you bands were about 30 pixels in size.

I created the same gradient in 16 bit and added the spatter filter shown on the right below. Did a pretty good job.

Hope that helps

[marcchristopher]

Re: How to remove gradient banding?

One approach I did not see mentioned is using the filter under brushes called spatter. Set the smoothness to "1" and the radius to the ~dimension of the band which I set to max since you bands were about 30 pixels in size.

Neat trick! I have always used the common procedure of adding monochromatic noise to counter banding, but the spatter filter seems to deliver a slightly cleaner and more subtle result.

Thanks for posting.

[John Wheeler]

Re: How to remove gradient banding?

Neat trick! I have always used the common procedure of adding monochromatic noise to counter banding, but the spatter filter seems to deliver a slightly cleaner and more subtle result.

Thanks for posting.

You're welcome marcchristopher. Just another tool in the toolbox as both can have their application in reducing banding noise.

[KAKA_KHAN_2007]

Re: How to remove gradient banding?

Thanks for great tip and technique. Results is much better than using adding noise technique.