"Merging Down" Pixel Layers leads to undesired Anti-Aliasing for Illustration work

[josbin]

This is basically a repost to carry it over to the Affinity V2 Forum Section:

As discussed in several Post is the "Merging Down" function causing Anti-Aliasing in many cases. For Illustration this is an undesirable result, as it blurs your edges. Especially in Brush and Line Work this is making the "Merge Down" (and "Merge Selected") function virtually unsuable. 

I am not sure of all the things that cause layers to merge blurred but it is anyways too big a risk for an intuitive illstration workflow to use the "merge down" function with a hotkey (which is a often used and important function). For now the work around is:

1. Select the layer below the layer you want to merge down.

2. "Rasterise & Trim" it.

3. Select the layer you want to merge down and select "merge down" function.

 

As I understand this is not a bug but a intended behaviour. For Photo Editing this is understandable. But Illustartion work suffers, because we need this pixel precision to keep the sharp look of the image. Especially on lower resolution images.

Here are the mentioned Threads:

Shout out to @NotMyFault He illustrates the problem quite extensively and easy to understand!

 

 

Some Screenshots to show the problem:

[josbin]

Suggested Fix would be the same as @NotMyFault suggested in this Post:

 

[loukash]

46 minutes ago, josbin said:

I am not sure of all the things that cause layers to merge blurred

Essentially, most of the time it's just one thing:
The layers are not aligned to the absolute pixel grid.

• In some instances it's a "user error" based on the flexibilty that a user can but doesn't have to align objects to the pixel grid. 
  E.g. "Force pixel alignment" being off, pixel or image layers being scaled so that they don't match the document dpi, etc.
   
• In other instances it's a programming flaw / serious bug because the user has no or not much control or even visual reference about where the actual X,Y=0 origin of the absolute pixel grid is, see e.g. this thread, among many others.

[josbin]

6 minutes ago, loukash said:

Essentially, most of the time it's just one thing:
The layers are not aligned to the absolute pixel grid.

• In some instances it's a "user error" based on the flexibilty that a user can but doesn't have to align objects to the pixel grid. 
  E.g. "Force pixel alignment" being off, pixel or image layers being scaled so that they don't match the document dpi, etc.
   
• In other instances it's a programming flaw / serious bug because the user has no or not much control or even visual reference about where the actual X,Y=0 origin of the absolute pixel grid is, see e.g. this thread, among many others.

Cool, thanks for the calrification!

[loukash]

To clarify a bit more:  
Since this appears to be mostly about merging layers in Photo, the "absolute pixel grid" bug is less likely to be an issue because afphoto documents usually don't have bleed or multiple pages, unlike Publisher or Designer. 

So often the issue is with objects being placed at fractional pixel values. To avoid blurring, all values should be integer pixels.
And here come the next conceptual flaw in Affinity, and that is Preferences > User Interface > Decimal Places. This setting only affects the display of values in the Transform panel etc., not the actual values. So even when you see an integer pixel value of e.g. 267 px, the actual value could be 267.0494, and that will already introduce some antialiasing and thus blur.
I keep all my Decimal Places display preferences at 6. Not "1" which is the default setting for pixels.

[josbin]

Thanks for the information! 

One more question: So if I have the "Force Pixel Alignment" and the "Move by whole Pixel" on all the time, the problem of blurry merges should never happen?

I wonder where those errors (probably user errors as I hear from your first comment) normally occur. From a UX perspective this sucks a lot, cause I would like "hard enforce" that everything is aligned to the pixel grid which is what those buttons do I would assume. Where do they fail to enforce it? While using the move tool or creating a vector shape and then rasterising? Moving between apps? Kinda hard to understand and not intuitive at all.

I think a closer look how PS does it would help, as I have used PS for 10 years and not once did I have this problem...

[NotMyFault]

Besides fractional positions of layers who are probably the majority of cases, the 2nd issue are resized layers which is less obvious to detect and more complex to correct.

I still recommend „rasterize and trim“ as best option to avoid unwanted blurriness in the specific case before a merge down step. Often it does not make sense to pixel-align or „reset to original size“ the lower layer: this could wreck havoc to the overall structure or misplace edits done while the layer dpi or position was not aligned.

[josbin]

Agreed!

Macro Shortcuts would also be a really nice workaround as you pointed out in one of the posts.

[loukash]

1 hour ago, josbin said:

if I have the "Force Pixel Alignment" and the "Move by whole Pixel" on all the time, the problem of blurry merges should never happen?

Um… it's complicated.
It may appear counterintuitive, but "Move by whole pixels" should be off unless you have a specific case where an object must be off the grid by a defined amount, e.g. 0.5 px, and you don't want it to snap back to integer pixels. Thats because "Move by whole pixels" overrides "Force pixel alignment".

In general:

• "Force Pixel Alignment" on
• "Move By Whole Pixels" off
• Decimal Places: 6 (especially pixels)
• Transform panel: keep an eye on it all the time

[josbin]

haha been doing it wrong the whole time 😅 thanks for clearing that up for me!

[NotMyFault]

2 hours ago, josbin said:

One more question: So if I have the "Force Pixel Alignment" and the "Move by whole Pixel" on all the time, the problem of blurry merges should never happen?

This does not protect against resizing, which causes far more blurriness 

[Red Sands]

It shouldn’t blur images - period. 

[walt.farrell]

27 minutes ago, Red Sands said:

It shouldn’t blur images - period. 

When you're merging layers of different DPIs that are not aligned to the same pixel grid I'm not sure there's a choice.

[Red Sands]

I have not seen this behaviour in Photoshop. I expect what I see on the screen.

[josbin]

10 minutes ago, walt.farrell said:

When you're merging layers of different DPIs that are not aligned to the same pixel grid I'm not sure there's a choice.

Different DPI for sure makes it so that there is no choice. But resizing is normally not a problem as people are less suprised to have blurry quality when reszing images and merging down, as it seems more intuitive that there will be blurring.

But on a different but somehow related note : In my creative process I sometimes have to move around images to try different design ideas/patterns/etc.. In PS you could convert those images to a "smart object". This would to a certain degree prevent many resolution Loss and Blurring problems, when performing many transforms in a row. I am not aware of quick way to do that in Affinity Photo. The only way is to safe it out as a file and then place it in the document as an embedded layer or linked file. Or is there a more convenient way to have embedded layer or linked files?

 

[NotMyFault]

In Affinity, every layer is more like a smart object. As long as you not rasterize them, either directly or by merge down, all details are preserved and can be utilized by resetting size to original. 
 

Image layers behave different (wrt to rasterizing/merge down) only in special cases, like resize document with resample: Pixel layers get resample, image layers not. 

[josbin]

5 minutes ago, NotMyFault said:

In Affinity, every layer is more like a smart object. As long as you not rasterize them, either directly or by merge down, all details are preserved and can be utilized by resetting size to original. 
 

Image layers behave different (wrt to rasterizing/merge down) only in special cases, like resize document with resample: Pixel layers get resample, image layers not. 

One more time I am getting schooled  Thanks for pointing that out. Actually thats a great beaviour. 👍

[walt.farrell]

19 minutes ago, Red Sands said:

I have not seen this behaviour in Photoshop. I expect what I see on the screen.

Perhaps Photoshop does not let you have layers whose DPI is different from the document DPI, as Affinity allows?

[NotMyFault]

24 minutes ago, walt.farrell said:

Perhaps Photoshop does not let you have layers whose DPI is different from the document DPI, as Affinity allows?

I don’t use PS, but it seems to always enforce pixel alignment, and automatically rasterize bottom layer before merge down. This eliminates 2 most frequent causes for unintended blurriness

[Red Sands]

35 minutes ago, NotMyFault said:

I don’t use PS, but it seems to always enforce pixel alignment, and automatically rasterize bottom layer before merge down. This eliminates 2 most frequent causes for unintended blurriness

Photoshop does all the work, yes, never had to consider all of the workarounds mentioned. It is madness to expect customers to learn and understand all this and perform it manually.

[NotMyFault]

Affinity is not Photoshop and no clone. They must be an independent product, with intentional differences. 

[josbin]

@Red Sands Hey man I get your frustration, and for me as an illustrator (mainly) it is also frustrating. But stick wth PS if you cant handle it...  
I think your statement that it's "madness" has some truth to it. I wouldnt express it this way but I agree, that probably a lot of new users will be put off by this behavior of affinity. And I would strongly suggest the dev team to take the suggestions made by @NotMyFault into account. I get that the "illustration" user base probably is quite small but none the less affinity photo is marketed as an illustration app... So hopefully they will implement it sonner than later

[Red Sands]

55 minutes ago, NotMyFault said:

Affinity is not Photoshop and no clone. They must be an independent product, with intentional differences. 

It certainly is not. But very much inspired by, eh? Not exactly original. But not learning about usability and great workflows and how to shield users from Linux like workflows is not a clever move.

If this is an intentional difference, then this product is for masochists.

[Red Sands]

25 minutes ago, josbin said:

@Red Sands Hey man I get your frustration, and for me as an illustrator (mainly) it is also frustrating. But stick wth PS if you cant handle it...  

Never intended to replace Photoshop with any other program - nothing delivers the same high quality output and algorithms are exceptional.

I’d like to see Serif focus on key workflows and the involved algorithms soon. Many, many issues could be fixed with a bit of focus and allocated time.

But again I don’t see traces of exactly where Serif is heading with their programs or any real company focus. 

[Dan C]

Hi all,

Apologies for the delayed response here - I just want to provide a little extra information and context, as I have previously covered this in the following thread -

On 1/26/2023 at 8:46 PM, Red Sands said:

If this is an intentional difference

I've also covered this in my reply further down the above linked thread - 

On 7/13/2022 at 11:18 AM, Dan C said:

other image editors will force all layers to be the same DPI as the document, however Affinity allows users control over each layer, independent of the document DPI

I hope this clears things up