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Image banding in Affinity Photo


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I'm outputting separate layers from Cinema 4D to composite within Affinity Photo. The images are RGB/16 and look perfectly fine when opened in Apple Preview. However when I open them in Affinity Photo I get very bad banding, especially if I then use the brush tool. Is there something I can do to stop this happening. I've attached an example file here. Affinity Banding Test_specular.tif

The screenshots show what I'm seeing with Apple Preview, and Affinity Photo. On Affinity it's most noticeable at the edges. If you use a white brush with the flow / hardness / opacity settings turned down you can see the banding in real time, as if it's an 8 bit image or something. I think the image is 16 bit as it show that in the Info Panel (Studio).

Have I got something set incorrectly ? What would I need to do to stop the image banding like this.

Many Thanks
Gary

 

Screenshot_from_Apple_Preview.thumb.png.43b19ca96d14502b58e55dc0642d1586.pngScreenshot_from_Affinity_Photo.thumb.png.25e97124f5ffeb5e2d5c3167e50ec575.png

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Affinity currently has only 8 bits per channel display of 16 bits per channel images.

Apple's Preview has 10 bits per channel display of these images, which gives a 4 times finer gradation in each channel when you have a 10 bits per channel display as many Apple devices have.

Although factually correct, I should have realised that it's not the explanation in this case since the screenshots are only 8 bits per channel. See my later posts.

Edited by anon2
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Thanks Anon2,

It seems to look ok in Photoshop CS6 and even in Pixelmator, surely this can't be as good as it gets in Affinity Photo ? It makes editing greyscale images very hit and miss.
I even tried it in Microsoft Paint on a PC and it worked a lot better, even on a really cheap monitor.

Is there a way to improve things or am I stuck with it if I use Affinity Photo ?

 

Screenshot From Microsoft Paint.png

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Thanks for checking that Lagarto,

I respect Anon2's answer, he's probably right about the 10 bit stuff, but something else doesn't seem right to me.

Affinity is supposed to be a pro photo editing product, I think it must be a bug or something. I can imagine Photoshop possibly doing a better job at showing gradients, but not Microsoft Paint Pot, on a very cheap PC, using a very poor 8 year old monitor.

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OK, I discovered something. If I select Document > Convert Format / ICC Profile

And switch RGB/16 to RGB/32 Everything smoothes out.

If I then switch back to RGB/16 everything remains smooth, although there is still a bit of banding when I use a brush, but not as bad.
Perhaps it's better to work in RGB/32 and possibly switch it back to RGB/16 when finished editing.

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22 hours ago, Gaz said:

OK, I discovered something. If I select Document > Convert Format / ICC Profile

And switch RGB/16 to RGB/32 Everything smoothes out.

If I then switch back to RGB/16 everything remains smooth, although there is still a bit of banding when I use a brush, but not as bad.
Perhaps it's better to work in RGB/32 and possibly switch it back to RGB/16 when finished editing.

 

Now I am at my Mac and have downloaded the TIFF file, I think I can explain what is happening. First, the 10 bpc display of Preview versus the 8 bpc display of Affinity does not explain the horrific banding in Affinity, and I should have realised that earlier because the screenshots are only 8 bpc and any 10 bpc advantage is lost in a 8 bpc screenshot.

The 16 bpc TIFF has a linear colour profile and Affinity is doing a poor job of converting the linear 16 bpc image to the gamma encoded display profile with the result being the extreme banding. Preview, Photoshop and other apps are managing that display conversion properly.

When the document is converted to 32 bpc by Affinity, Affinity correctly manages that conversion of a linear 16 bpc image to linear 32 bpc image, and Affinity correctly manages the conversion of the linear 32 bpc image to the gamma encoded display profile.

When the document is then converted back to 16 bpc by Affinity, Affinity correctly manages the conversion of a linear 32 bpc image to a gamma encoded 16 bpc image, and Affinity correctly manages the conversion of the gamma encoded 16 bpc image to the gamma encoded display profile.

In short, Affinity does not correctly handle 16 or 8 bpc images which have a linear colour profile.

 

Edited by anon2
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4 hours ago, Lagarto said:

I have no idea what my Windows laptop display has bits per channel but definitely nothing fancy. But I get this when placed side by side with PS:

banding_problem.jpg.20386d69a9d87c67f110c7f7111b2331.jpg

I tried if it is better in latest Photo beta but it looks just the same there.

 

 

My 10 bits versus 8 bits per channel display explanation was a mistake. See my more recent explanation after inspecting the TIFF in various apps.

There is something else for you to be concerned about. I see (and can measure) in your screenshot that Affinity is displaying the neutral image with a slight reddish cast while everything else (including the Photoshop document view) that should be neutral is neutral. Affinity on my Mac produces a neutral display of the neutral TIFF.

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6 minutes ago, Lagarto said:

Thanks for the explanation. I have a poor understanding of 16- and 32-bpc images so I really do understand what happens here but I noticed that simply reassigning to e.g. ProPhoto RGB removes banding. On the other hand, it causes a kind of moire... Could it be that the assigned wsRGB profile works somehow incorrectly in Affinity apps (as it does not behave similarly in other apps when viewing this image)?

 

2 minutes ago, Lagarto said:

The color cast is also removed when changing that wsRGB profile.

 

Where are you using wsRGB?

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24 minutes ago, Lagarto said:

Sorry, I seem to be confusing things (here shows that I have not much clue on linear color modes), probably because Affinity shows this screen when I choose "Document > Assign ICC Profile":

image.png.46ca515d541993ff208347305f153b60.png

...implying as if wsRGB were the current color profile. In Photoshop, this is shown, instead, as follows:

image.png.9f0022250a0cf8f1022747ff02be92ff.png

But when I assign another profile and then assign wcsRGB (instead of wsRGB that was highlighted), I seem to get exactly the same banding and color cast that was initially shown when I open this TIFF file in Affinity Photo (Windows version). So could it be that the cause of the problem is that Affinity Photo actually assigns wcsRGB color profile on an image using linear color space? (I am not sure if my question even makes any sense...)

 

The banding problem is occurring in Affinity on Windows and in Affinity on macOS which does not have the Windows virtual device profiles wsRGB and wscRGB. The banding happens in Affinity on my Mac when the TIFF file's linear profile named Linear Color Space (it's from Cinema4D) is the profile of the integer 16 bpc document. Affinity currently does not correctly manage an integer image with a linear profile instead of gamma encoded profile.

The Affinity Assign ICC Profile dialog is not informing you that the current profile is wsRGB when it highlights wsRGB in its list; it is simply highlighting the first entry in the list because the current profile (Linear Color Space) is not in the list, and that's not in the list because Affinity never allows the assigning of a linear profile to an integer image.

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I have an idea about where Affinity is going wrong when producing an 8 bpc display of a 16 bpc document.

I think the document composite's 16-bit values are being truncated to 8-bit before the colour transform to the display colour space

Affinity should be doing the transform before the truncation.

Affinity correctly does the transform before truncation when the document is 32 bpc.

 

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Here I have open the file submitted, I open used Affinity Photo ver 1.8.5.703 & Affinity Photo Beta Version 1.9.0.834 and Lightroom for the comparation, here the sample:

As per result the Affinity Photo Beta version 1.9.0.834 more bending then Affinity Photo version 1.8.5.703.

Probably the codec to read a TIFF?

*Affinity Photo Version 1.8.5.703Banding in Affinity Photo 1.8.5.703.jpg

 

*Affinity Photo Beta Version 1.9.0.834Banding in Affinity Photo 1.9.0.834.jpg

 

*LightroomBanding Lightroom.jpg

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@HANDJOJO to me, these images all look the same. For a valid comparison, you need to capture and display all three images at 100%. This will probably mean cropping the display images to around 800px.

John

Windows 11, Affinity Photo 2.4.2 Designer 2.4.2 and Publisher 2.4.2 (mainly Photo).

CPU: Intel Core i5 8500 @ 3.00GHz. RAM: 32.0GB  DDR4 @ 1063MHz, Graphics: 2047MB NVIDIA GeForce GTX 1050

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37 minutes ago, John Rostron said:

@HANDJOJO to me, these images all look the same. For a valid comparison, you need to capture and display all three images at 100%. This will probably mean cropping the display images to around 800px.

John

They look far from the same. You've said images look the same in numerous threads when comparisons with blatant differences are shown

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2 minutes ago, anon2 said:

They look far from the same. You've said that in numerous threads when comparisons with blatant differences are shown

Note that I said:  "to me, these images all look the same".  I had my eyes tested on Monday. You must have exceptional perspicacity.

John

Windows 11, Affinity Photo 2.4.2 Designer 2.4.2 and Publisher 2.4.2 (mainly Photo).

CPU: Intel Core i5 8500 @ 3.00GHz. RAM: 32.0GB  DDR4 @ 1063MHz, Graphics: 2047MB NVIDIA GeForce GTX 1050

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21 minutes ago, John Rostron said:

Note that I said:  "to me, these images all look the same".  I had my eyes tested on Monday. You must have exceptional perspicacity.

John

No, I don't have exceptional perspicacity (did you really mean to use that word since it has nothing to do with eyesight?). My eyesight is nothing special either.

I'm only saying there are numerous occasions when you've posted that things look the same to you when other people and myself have been able to see distinct differences. Maybe try recalibrating and profiling your display or try another display.

 

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I was making my judgement based on what  could see in the forum display. I have looked there again and and I still could not see any differences. I downloaded the three images and loaded them into an aligned stack  (ungrouped) so that I could flick from one image to another at near 100% zoom. Under these circumstances, I could readily see that there was more banding on the AP1.8 image compared with the others. Which reinforces my point that the OP should have posted images captured at 100%. This applies here and perhaps to other threads where I have made a similar comment about not being able to discern differences.

I will concede that perspicacity (a clarity of vision or intellect ) was not quite the right word. Although it can mean clarity of vision, it is mainly used in the metaphorical sense of clarity of intellect. 

Pax!

John

Windows 11, Affinity Photo 2.4.2 Designer 2.4.2 and Publisher 2.4.2 (mainly Photo).

CPU: Intel Core i5 8500 @ 3.00GHz. RAM: 32.0GB  DDR4 @ 1063MHz, Graphics: 2047MB NVIDIA GeForce GTX 1050

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1 hour ago, John Rostron said:

I was making my judgement based on what  could see in the forum display. I have looked there again and and I still could not see any differences. I downloaded the three images and loaded them into an aligned stack  (ungrouped) so that I could flick from one image to another at near 100% zoom. Under these circumstances, I could readily see that there was more banding on the AP1.8 image compared with the others. Which reinforces my point that the OP should have posted images captured at 100%. This applies here and perhaps to other threads where I have made a similar comment about not being able to discern differences.

I'm posting this message not to be provoking a fight, but to provide information.

Maybe your browser is faulty. The differences between HANDJOJO's screenshots are equally apparent in the forum page in my browser (Safari) as in my image editing apps.

It's not just the distinctness of banding that differs, the tonal profile differs significantly and the 1.9.0.834 screenshot has an obvious magenta cast in the darker tones of the document view but is correctly neutral in the similar tones of the surrounding Affinity UI.

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13 hours ago, John Rostron said:

@HANDJOJO to me, these images all look the same. For a valid comparison, you need to capture and display all three images at 100%. This will probably mean cropping the display images to around 800px.

John

Dear John,

Yes I enlarge for all with the same magnification around 100% (in Affinity Photo and Lightroom, not the screen shot I made it), and my monitor has calibrated with the Spyder Pro 4, as per screenshot the file open by Photo version 1.9.0.834 the picture more bending then two others, and there are the gradation in the colour tonal as look like separate colours.

We hope the solution for this case.

Regards,

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8 minutes ago, HANDJOJO said:

Dear John,

Yes I enlarge for all with the same magnification around 200% and my monitor has calibrated with the Spyder Pro 4, as per screenshot the file open by Photo version 1.9.0.834 the picture more bending then two others, and there are gradation in the tone colour as look separate colours.

We hope the solution for this case.

Regards,

For the additional information I only crop the area not crop by enlarge the screenshot, so it's mean nothing deviation of the picture between the screen shot of three apps and the screen shot I attached here. Three screen shots I have attached were actually what I got it by three applications.

Regards,

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