Square pixel color distortion

[markhartphotography]

I really have no good way to describe the issue that I am having other than uploading an image of the issue itself.  Basically, I am editing this photo and I keep finding random square pixels that become solid colors after I apply certain edits to the photo.  I started noticing the issue after applying some adjustments masks.  The issue became worse after I exported the image as a .jpg

Thank you for any help with this issue.

[walt.farrell]

21 minutes ago, markhartphotography said:

I started noticing the issue after applying some adjustments masks.

Which adjustments?

Can you provide the the .afphoto file (preferrably saved with the History), so we can see it for ourselves?

[markhartphotography]

The adjustments are basic exposure/HSL/Shaddows/highlights.  The afphoto file is about a gig due to the layers.  I do not think I have the history saved on the file.  Do you think this has anything to do with it being in 32 bit mode?

 

 

[markhartphotography]

I uploaded my afphoto file to a google drive.  Let me know if there are any issues downloading.  

https://drive.google.com/file/d/1piumHO-7wHWd2QysYnd0P1191iTyCghR/view?usp=sharing

Thank you,

Cody

 

[markhartphotography]

4 hours ago, walt.farrell said:

Which adjustments?

Can you provide the the .afphoto file (preferrably saved with the History), so we can see it for ourselves?

https://drive.google.com/file/d/1piumHO-7wHWd2QysYnd0P1191iTyCghR/view?usp=sharing

[firstdefence]

If you try to use the inpainting tool or the patch tool it will not patch over them, some of the squares also scale up and down as you zoom in and out. If you change the top layer to Hue you get to see a lot more.

Without the masks and adjustment layers it's hard to say why or what caused this, I think the only thing you can do is re process the original image and take notes as you apply each edit.

[markhartphotography]

18 minutes ago, firstdefence said:

If you try to use the inpainting tool or the patch tool it will not patch over them, some of the squares also scale up and down as you zoom in and out. If you change the top layer to Hue you get to see a lot more.

Without the masks and adjustment layers it's hard to say why or what caused this, I think the only thing you can do is re process the original image and take notes as you apply each edit.

That is a massive bummer. This looks like a big software issue to me. 
 

[markhartphotography]

I would be really interested in hearing other opinions on what happened here. This took a lot of work and I would hate to have to re process this photo because of these square issues. 
thanks. 

[Greyfox]

@firstdefence

@markhartphotography

I too downloaded the file and have opened it multiple times in Affinity Photo.

Strangely the squares have not appeared here at all.

Out of interest, I saved it (saved as) to a new .afphoto file. The two files are not the same size. The original as downloaded is 1,067,703,979 bytes, the resaved file  1,060,711,600 bytes. I know "save as" will often reduce the size of the project file that has had repeated "saves", so the size difference probably doesn't mean much. More importantly, the squares don't show when the new file is opened either.

I using Windows 10 Pro  (1903, build 18362.476), Intel i7 processor, 16GB RAM, GTX 1050ti 4GB graphics card.

Affinity Photo 1.7.3.481.  Renderer set to Nvidia GeForce GTX 1050ti, Retina Rendering set to Automatic (Best)

 

 

[markhartphotography]

@Greyfox

Thank you so much for your help.  I also resaved the file, however Im still seeing the same distorted squares as the original afphoto file (see image attached).  The issue becomes worse when I save the image to a .jpg, as seen on the window in the post above.  

@Greyfox in the file that you saved do you see the issue on the front/grill as shown here?

The .afphoto has the issue on the front/grill of the car, when I export it to .jpg the issue is worse.  

 

 

[walt.farrell]

I don't think you've said what OS you're using, @markhartphotography, and (if Mac) what kind of computer and what performance options you've chosen in the Affinity Photo Preferences. That could be relevant information.

[markhartphotography]

16 minutes ago, walt.farrell said:

I don't think you've said what OS you're using, @markhartphotography, and (if Mac) what kind of computer and what performance options you've chosen in the Affinity Photo Preferences. That could be relevant information.

Thank you for your help @walt.farrell I am using a MacBook Pro. See attached stats.  I have not changed any performance preferences in Affinity photo.  I just downloaded it and started using it.  Also see attached performance settings from Affinity Photo. 

 

[h_d]

I am definitely seeing the square glitches reported by @markhartphotography They are less prominent in the original .afphoto file, but in an exported .jpg they're glaringly obvious. This is a grab from my . jpg export:

 

I'm on a 2018 MacBook Pro, 32GB RAM, MacOS 10.15 Catalina, with an AMD Radeon Pro Vega integrated GPU (though I don't believe Affinity Photo is actually using the card - that's another issue...)

All very odd - the green glitch on the wing mirror in the export is red when I view all layers of the .afphoto file; some of the glitches in the .afphoto file appear and disappear depending on which layers are made visible. Converting to CMYK produces even more horrible results - dark blue squares all over the image. I've also tried merging all the layers down to one and exporting, but the problem persists.

I fear though that because of the way the original has been edited, there's little or no chance of working out when, why or how these glitches were introduced. There's no history, and all the edits on the individual layers have been made destructively (or flattened). There are basically five different images in one .afphoto document, and no way of telling which derived from which, or what edits were done on which. 

Hopefully someone from Serif will have an idea...

 

 

 

 

 

[markhartphotography]

Thank you for taking a look @h_d

 Hope someone can figure something out. At least if I have to reprocess the photo I want to know what to try differently to avoid this issue. 

[h_d]

9 minutes ago, markhartphotography said:

I want to know what to try differently to avoid this issue

It's worth taking some time to learn how to use adjustment layers. Apply these to the base image, using masks on specific areas if need be, rather than creating different versions of the same image in different layers. The official Affinity tutorial videos are excellent on this.

It might also be worth posting the original image out of the camera for others to take a look at...

[Greyfox]

2 hours ago, markhartphotography said:

@Greyfox in the file that you saved do you see the issue on the front/grill as shown here?

If I zoom the image to around 430% then I can see the one below the grill, but nowhere near as pronounced as in your screen shot. It becomes pronounced if I untick the top Mural/Background layer.

However if I convert the format to either RGB/16 or RGB/8 then the issue becomes really obvious. Lots of colored squares (Red, Green, Blue, as well as what I could call a light magenta) all over the car and quite visible at 100% zoom.

 

 

[carl123]

There are numerous "invisible" NaN pixels in your APhoto file that correspond to the artifacts that appear in an exported JPG file and also relate to the respective RGB colour channel.

 

[Medical Officer Bones]

*EDIT* Ah, of course. NaN pixels. I forgot about those. Thanks FirstDefence and Carl123.

Since the original image is unaffected, to me it seems Affinity added these when the original layer was copied and edited, or during another layer action. It seems to affect the darkest values, which leads me to think Affinity buggered up the conversion somehow. It is the first time I see these caused by a regular image editor.

 

[firstdefence]

There are multiple apps that attempt to fix these NaN (Not a Number) pixels, generally they will fix single Nan's by using pixels around them, one such app is Blackmagicdesigns Fusion studio app, it has a node based method for processing images and video and in this post: https://forum.blackmagicdesign.com/viewtopic.php?f=22&t=35915 they talk about detecting Nan pixels with a tool called Detect gremlins the code for that is below.
 

{
   Tools = ordered() {
      INPUT = BrightnessContrast {
         NameSet = true,
         ViewInfo = OperatorInfo { Pos = { 176.206, 274.766, }, },
      },
      Detect_Gremlins = Custom {
         NameSet = true,
         Inputs = {
            LUTIn1 = Input {
               SourceOp = "Detect_GremlinsLUTIn1",
               Source = "Value",
            },
            LUTIn2 = Input {
               SourceOp = "Detect_GremlinsLUTIn2",
               Source = "Value",
            },
            LUTIn3 = Input {
               SourceOp = "Detect_GremlinsLUTIn3",
               Source = "Value",
            },
            LUTIn4 = Input {
               SourceOp = "Detect_GremlinsLUTIn4",
               Source = "Value",
            },
            Intermediate1 = Input { Value = "min(min(min(r1/r1, g1/g1), b1/b1), a1/a1)", },
            RedExpression = Input { Value = "i1", },
            GreenExpression = Input { Value = "i1", },
            BlueExpression = Input { Value = "i1", },
            AlphaExpression = Input { Value = "i1", },
            ShowNumber1 = Input { Value = 0, },
            ShowNumber2 = Input { Value = 0, },
            ShowNumber3 = Input { Value = 0, },
            ShowNumber4 = Input { Value = 0, },
            ShowNumber5 = Input { Value = 0, },
            ShowNumber6 = Input { Value = 0, },
            ShowNumber7 = Input { Value = 0, },
            ShowNumber8 = Input { Value = 0, },
            ShowPoint1 = Input { Value = 0, },
            ShowPoint2 = Input { Value = 0, },
            ShowPoint3 = Input { Value = 0, },
            ShowPoint4 = Input { Value = 0, },
            Image1 = Input {
               SourceOp = "INPUT",
               Source = "Output",
            },
            Comments = Input { Value = "Detects render errors (pixels with \"infinite\" float values). They are tinted red for debugging and the alpha channel is an error mask.", },
         },
         ViewInfo = OperatorInfo { Pos = { 301.735, 273, }, },
      },
      Detect_GremlinsLUTIn1 = LUTBezier {
         KeyColorSplines = {
            [0] = {
               [0] = { 0, RH = { 0.333333333333333, 0.333333333333333, }, Flags = { Linear = true, }, },
               [1] = { 1, LH = { 0.666666666666667, 0.666666666666667, }, Flags = { Linear = true, }, },
            },
         },
         SplineColor = { Red = 204, Green = 0, Blue = 0, },
         NameSet = true,
      },
      Detect_GremlinsLUTIn2 = LUTBezier {
         KeyColorSplines = {
            [0] = {
               [0] = { 0, RH = { 0.333333333333333, 0.333333333333333, }, Flags = { Linear = true, }, },
               [1] = { 1, LH = { 0.666666666666667, 0.666666666666667, }, Flags = { Linear = true, }, },
            },
         },
         SplineColor = { Red = 0, Green = 204, Blue = 0, },
         NameSet = true,
      },
      Detect_GremlinsLUTIn3 = LUTBezier {
         KeyColorSplines = {
            [0] = {
               [0] = { 0, RH = { 0.333333333333333, 0.333333333333333, }, Flags = { Linear = true, }, },
               [1] = { 1, LH = { 0.666666666666667, 0.666666666666667, }, Flags = { Linear = true, }, },
            },
         },
         SplineColor = { Red = 0, Green = 0, Blue = 204, },
         NameSet = true,
      },
      Detect_GremlinsLUTIn4 = LUTBezier {
         KeyColorSplines = {
            [0] = {
               [0] = { 0, RH = { 0.333333333333333, 0.333333333333333, }, Flags = { Linear = true, }, },
               [1] = { 1, LH = { 0.666666666666667, 0.666666666666667, }, Flags = { Linear = true, }, },
            },
         },
         SplineColor = { Red = 204, Green = 204, Blue = 204, },
         NameSet = true,
      },
      BrightnessContrast1 = BrightnessContrast {
         Inputs = {
            Alpha = Input { Value = 1, },
            ClipBlack = Input { Value = 1, },
            ClipWhite = Input { Value = 1, },
            Input = Input {
               SourceOp = "Detect_Gremlins",
               Source = "Output",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 411.735, 271, }, },
      },
      OUTPUT = BrightnessContrast {
         CtrlWZoom = false,
         NameSet = true,
         Inputs = {
            Alpha = Input { Value = 1, },
            ClipBlack = Input { Value = 1, },
            ClipWhite = Input { Value = 1, },
            Input = Input {
               SourceOp = "INPUT",
               Source = "Output",
            },
            EffectMask = Input {
               SourceOp = "Bitmap1",
               Source = "Mask",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 415.353, 350.34, }, },
      },
      Bitmap1 = BitmapMask {
         Inputs = {
            Invert = Input { Value = 1, },
            MaskWidth = Input { Value = 2048, },
            MaskHeight = Input { Value = 1556, },
            PixelAspect = Input { Value = { 1, 1, }, },
            ClippingMode = Input { Value = FuID { "None", }, },
            Image = Input {
               SourceOp = "BrightnessContrast1",
               Source = "Output",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 415.353, 317.34, }, },
      },
   },
}

The app accepts PSD files.