I have a black and white image of a person at a podium in a room. I want to extremely blur out the background. I selected the area that I want blurred and apply the filter about 30.
The problem is that the image has a sort of posterize effect to it where each grade of grey becomes a cleanly and smoothly defined section. I tried switching to 16bit mode, but it is still there to the same degree. I am also in grayscale, and I tried RGB and that also seemed to be the same. I cannot see a difference in any of the situations.
I also tried applying the filter in steps but that doesnt help either.
Learn how to optimize Photoshop for maximum speed, troubleshoot common issues, and keep your projects organized so that you can work faster than ever before!
Banding on smooth, subtle transitions is the bane of digital. You can find this happening in sky tone when using corner burndown or trying to help the values deepen as the sky approaches the zenith with the Gradient tool. Yes, you can apply some noise, but then you have just countered the blur!
I would love to see 16 bit output and printing capability. 65,000 steps instead of 256.
The eye is a damn good device for seeing differential values.
I have tried using all the blurring options available in CS, and it is still there. I have even tried combining them. Even adding noise and then blurring. This is the best option so far, by adding a small amount of blur, noise, then blur again. I can get a very blurry image, however, it gets muddy if the technique is used too much and really doesn’t solve banding.
And as said already, adding noise isn’t what I want, and removing grain and noise is important to me.
You can apply the filter in 16bit mode, but I do not know if the filter is really 16bit.
I guess it is a short coming of the current state of technology.
Yes, CS allows to use many new filters in 16bit not available before, but it just seems to still be 8bit results.
Maybe I need to test this out with an image from beginning to end in 16bit. I am sure that could cause problems, but I would think that a blurring effect wouldn’t matter.
It seems that applying noise and then blurring the image and then repeating works vry well because the blur is not an undo. So I am not really back to square one, just a muddy versuion of square one if repeated too much.
In the end this doesn’t solve the original problem of banding, weither or not in 8 or 16bit mode.
The answer is: If you can see it on the monitor, you will see it in the print. In fact, just because you don’t see it on the monitor does not mean you will not see it in the print.
(True if dithering is activated in advanced prefs, as per default).
I belive that Diffusion Dither (under Display & Cursors) is not set "on" as default. Should it and would it be better? I just recently did a reinstall so I know I did not change it.
In fact, one of the best advantages of 8bit>16bit>8bit is that the second conversion can add a bit of dithering, thus lowering the banding effect
Just going 8bit>16bit>8bit on a banded image will add little or no dithering. The dithering comes in when 16bit file values in the file would translate somewhere between 8bit levels, so the pixels dither to simulate the intermedate values. If you just go back and forth you basically get exactly what you started with.
Even if you do a tone change to a banded image while in 16bit, and come back to 8bit, the bands will be comprised of dithered pixels, but the well defined borders between the fields of tone will remain.
If the fine gradation is generated within 16bit, using even 12bits worth of gray levels, then dithering when going to 8bit should be complete.
I’ll be curious to see if Melameel’s Color prefs>advanced controls have dithering for conversions selected, and if not, how things come out when that option is selected…
Sorry about being away for so long, my internet has been down at home where I have been having this issue. (I mean that I home I do different type of work and I am not hinting that my work PS is acting diifferently.)
Anyway, The banding is still there even in teh 16bit gaussian blur. However, I will check tonight if the "Use Dither (8-bit/channel images" is checked or not. Here at work it is on which I woudl assume is on by default and therefore will be on at home. However I will confirm tonight.
This has helped me beat posterization on *some* files. You can run it more than once if a stronger effect is needed. If you have enough history states, you can step back through the stages of the action to dial in the look you want. As always, your mileage may vary.
Note to anyone who tries "Edgarian Blur": Please give it a rating using the Rate and Review section of the details page. The only rating so far is my own, which looks kind of bad because I’m the one who supplied the action. I reviewed it because it really isn’t my work, I just made it available. Dr. Edgar deserves the credit (or the criticism if you don’t care for the effect).