Lower Resolution when Rasterize a Layer.

[Halex]

Hello guys

There is a problem in layer resolution when I rasterize an image in different angles and different positions. Take a look:

[thomaso]

The reduced quality appears to be caused by your various actions without having "Force Pixel Alignment" activated. This option avoids decimal pixel positions (e.g. in the Transform window) and reduces antialiasing applied to individual pixels. With every rasterization process after a position or size change, these pixels are then 'burned'.

https://affinity.help/photo2/English.lproj/pages/DesignAids/pixelAlign.html

In your video you seem to have the Toolbar currently deactivated. If it gets displayed you can access the "Force Pixel Alignment" with one click. It appears to be not available as menu command.

[SrPx]

But... why the need of rasterizing so often? Usually it its better to keep working without doing it even once (Affinity treats things like Photoshop's Smart Objects, but it lets you work with a bit more flexibility than PS), specially if you are going to do many layer transforms, rotates, etc. I would rasterize if I am only going to solely paint with a brush for the rest of the project... and even so... I might not have a need to rasterize. Indeed, I mostly rasterize as a fast way to flatten  a complex group of layers...if anything.

The video has quite some compression (the menu options can't almost be read), so, it is difficult to see if there's clearly less resolution or not... but one old problem (I would recommend you to work with the latest 2.4 of all Affinity apps, indeed... they are very solid now, and much better, in my opinion, than 1.x) is that the internal engine does a lot of "viewing" optimization, to allow you to work fast. For a painter, this is not always an advantage, so, if you want to really be sure about if resolution is lost, or if some blur is happening, but all happening "virtually" (not in  the real pixels that get saved to disk), to check that I would do an export to a TIFF, PSD or PNG, with resampling on and with a good method: Lanczos 3 separable or non separable. One is a bit too sharp, and the other method is a bit too soft... so, depends on your type of project (I tend to prefer the soft, and then do my own sharpening externally), to chose one or another.  Then look at the exported files in an external viewer like Irfanview or XnView (both have free versions), as those don't have a view optimization engine...  but disabling (at least in Irfanview) "resampling" in zooming and fit (top menu, under View/Display Options) as that can be doing a similar thing, maybe not convenient if you want to see the pure pixels.

For line work, line art, though, like that shown in the video, I would recommend you to a) work in vectors (Affinity Designer), which eliminates this issue or, b) if like me you prefer Photo for drawing and painting, then for line art like this you might want to work at very high resolution (much higher than in the video), and then reduce the size only when needing a final export. This would let you work without any worries about blur or detail lost. Provided you make all transforms and everything while at high resolution, the reduction being only the previous step to export the final thing. And even so, I'd keep my rule (had it with Photoshop, also) of doing the fewer operations possible that would degrade  the image quality. Llike multiple scaling, etc, specially AFTER rasterizing.

Indeed, the multiple, constant scaling, rotation and etc in Affinity can be lossless in a way , due to how Affinity treats it as a smart object, but... I might be wrong.. the moment you rasterize, you are doing it the "photoshop way" (when it is not a smart object). Then it stops being a lossless procedure. And just like with any "lossy" operation, you are degrading the image quality each time. So, do not constantly hit the rasterize button (in my opinion). Keep it for only a really needed operation (which is in rare occasions).  

And I might be wrong, but what Tomasso is saying sounds very accurate to me. Having forced pixel align on also allowed me to see better "the pixel". When you then move layers, the movement is slightly different, but perfectly fine for this use case, IMO.

If I am totally wrong, anyone, please do jump in...

 

[Halex]

23 hours ago, thomaso said:

The reduced quality appears to be caused by your various actions without having "Force Pixel Alignment" activated. This option avoids decimal pixel positions (e.g. in the Transform window) and reduces antialiasing applied to individual pixels. With every rasterization process after a position or size change, these pixels are then 'burned'.

https://affinity.help/photo2/English.lproj/pages/DesignAids/pixelAlign.html

In your video you seem to have the Toolbar currently deactivated. If it gets displayed you can access the "Force Pixel Alignment" with one click. It appears to be not available as menu command.

Thanks, but it doesn't work here. I recorded another video showing the same problem, please, look if I did something wrong in the settings.

[thomaso]

1 hour ago, Halex said:

it doesn't work here. I recorded another video showing the same problem, please, look if I did something wrong in the settings.

If you move an object from a decimal position by whole pixels    then these decimals are maintained when moving.

To avoid decimal pixel positions:

1. Open the Transform panel to have an eye on decimal pixels. (make sure 'decimals' are activated in the app Preferences > User Interface)
2. Set Pixels as ruler unit.
3. Deactivate the option "Move By Whole Pixels". (but keep Force Pixel Alignment activated)

[Halex]

23 hours ago, thomaso said:

If you move an object from a decimal position by whole pixels    then these decimals are maintained when moving.

To avoid decimal pixel positions:

1. Open the Transform panel to have an eye on decimal pixels. (make sure 'decimals' are activated in the app Preferences > User Interface)
2. Set Pixels as ruler unit.
3. Deactivate the option "Move By Whole Pixels". (but keep Force Pixel Alignment activated)

 

Thanks Thomaso, it works when I try just to move the layer, but still has some problems when I change the angle. I think it is not possible to keep the image perfectly rotating it, but I just want to check it with you. Please, look if my "User Interface" prefences is correct to use the tool you suggested me:

[R C-R]

1 hour ago, Halex said:

Please, look if my "User Interface" prefences is correct to use the tool you suggested me:

If you mean about 'activating' decimals, I think what @thomaso meant was to set Decimal Places for Unit Types for Pixels values to more than 1 decimal place, like to at least 3 or higher.

[Halex]

9 hours ago, R C-R said:

If you mean about 'activating' decimals, I think what @thomaso meant was to set Decimal Places for Unit Types for Pixels values to more than 1 decimal place, like to at least 3 or higher.

Wow, thank you very much! I changed the decimal to 3, deactivated the "Move by Whole Pixel" and it works perfectly now. You are amazing, guys! 
Thanks Thomaso and RC-R. I wish much success for you.