Gradient banding

[chauncey]

How do I avoid the banding that occurs when using the gradient tool in PS CC?

[Manfred M]

Are you working in 8-bit mode? If so do your work in 16-bit.

[chauncey]

I thought of that but I always work in 16-bit.

[chauncey]

Screenshot...check the histogram...

[Rob Ekins]

Put your curves layer directly on top of your BG layer and see if that changes it.

[chauncey]

Had some time on my hands this morning...created a new image>10x255 inches filled with black>
duplicated image (CNTRLl J) filled with white>applied gradient mask...see notched histogram.
There is definite banding...I can only assume that there is 256 different bands.
Applying 50 pixel Gaussian blur/changing bit depth or color space... has no effect.
To add another monkey wrench...when I watch this video...https://www.youtube.com/watch?v=4yEumr1tg5s I see banding

[ST1]

I wonder if your issues is being caused by an issue with the graphics card or drivers.

[Round Tuit]

I'm on my laptop and I see the banding in the gradient on post #4 and an the youtube video. I'll have a look later on my main monitor to see if it makes a difference.

Andre

[DanK]

i get it also. I just tried with a white new document and black layer above it. Removing the duplicate of the base white layer had no effect. Checking dither seems to lessen it a bit. What is interesting is that if you use a curves adjustment above it to increase contrast, you can see the bands moving as you make the slope steeper. That implies that they are a fixed distance apart in terms of luminance.

I can't see any other relevant adjustments that might stop this from happening. Will be curious if anyone else does.

[Round Tuit]

I get the same result as Dan i.e. banding that move with an adjustment layer. I am using CS4 so it is not a new problem.

Andre

[xpatUSA]

For what it's worth, here's the banding in ImageJ:



The plot shows the levels for the little yellow line - it is not a histogram.

The plateaux vary in width from about 1 to 6px somewhat randomly and they are not evenly-distributed. And there are no plateaux at all in some places. I amigane that this is not what we would expect from a smooth gradient even if it were edited in 16-bit and saved as 8-bit.

Not being an Adobe user, I won't try to guess as to the cause.

[dragon76]

How do I avoid the banding that occurs when using the gradient tool in PS CC?

Hi William, Do you have the banding at 70% zoom? If you still do then try a few things like I did and hopefully you can get rid of it. Firstly, in the gradient tool window, make sure you increase "smoothness" level and check "Dither" option. If this does not fix the issue then you can focus on software side; ie upgrading your graphic cards driver or reduce your cache level setting in PS preferences. Sometimes, banding occur at the end of the workflow and all I do is add a bit of uniform noise to break it up and it should disappear. Hope this helps. Cheers Dean

[DanK]

Dean--where is the smoothness control? Here is the dialog I get, which has the dither option but no smoothness control:



Ted--what software did you use to generate the plot? You can see the same thing in the spikes in the histogram below, but the line graph is more informative.

Thanks

Dan

[dragon76]

Dean--where is the smoothness control? Here is the dialog I get, which has the dither option but no smoothness control:

Hi Dan




Dean

[DanK]

Dean,

Thanks. Are you using Elements? I don't see this in PS CC, although perhaps I am just missing where it is hidden.

Dan

[chauncey]

Okay...I think that I found the reason but, I don't know the why...it concerns the Cache Levels within
the Preferences>Performance section. Default is set to 2, I had been using 6 (don't remember why).

Anyway...when you choose anything twixt 2 and 8, you get banding. But, if you set it to 1 and repeat
the whole process...banding is major league reduced.

As a reminder, I opened an image>filled it with 05, 05, 05>duplicated with CTRL J>
filled with 250, 250, 250>applied gradient mask...very minimal banding with Cache Level set to 1.

Now, before you assume that I'm an effing genius...I found this...http://feedback.photoshop.com/photos...assive-banding

[DanK]

Thanks for tracking this down

[xpatUSA]

Ted--what software did you use to generate the plot? You can see the same thing in the spikes in the histogram below, but the line graph is more informative.

Hi Dan,

It's called "ImageJ":

https://en.wikipedia.org/wiki/ImageJ

If you google "ImageJ" including the quotes there are many download sites.

[DanK]

Thanks, Ted

[xpatUSA]

Thanks, Ted

Just found this which might be more user-friendly (but still ImageJ)

https://en.wikipedia.org/wiki/Fiji_%28software%29
.