Jump to content
You must now use your email address to sign in [click for more info] ×

smooth anti-aliasing when rotating a graphic in Photo


Recommended Posts

Hi all,

 

(1st post)

 

I'm not sure how best to describe it, so it's not something I can easily search for - in case this has already been discussed.

 

Affinity Photo brand new user, testing as a possible alternative to Photoshop.

 

Situation: I display an A4 document's cover artwork as a PDF (resolution set to show full page). I take a screen grab of the displayed full page... so we're working a screen resolution here. I then have a smaller graphic, say 400px by 200px and wish to display a central part of that document cover within that smaller graphic.

 

I select-all from the screen grab and paste into the smaller graphic. I then have the ability to rotate that document cover, I'm after only a small angle, maybe only 25 degrees. Now, the actual design of that document cover has various horizontal blocks of colour, some green, some white and thus we end up with angled lines of where the two colours butt-up.

 

Now, in Photoshop when you're initially rotating, you get a very un-anti-aliased edge to these line, with very obvious jagged edge. But upon clicking the tick-box to approve the element change, the edges get smoothed out and it looks like the document in question, just rotated.

 

Doing exactly the same in Affinity Photo and I can easily rotate the element... but as far as I can see, the sharp / pixely / non-anti-aliased edges remain and to be blunt, the image looks pretty shit.

 

Do I assume there's some setting I've missed, to overcome this?

 

Thanks in advance,

Martin.

Link to comment
Share on other sites

  • Staff

Hi Martin,

Welcome to Affinity Forums :)

Without a screenshot of what you are seeing is difficult to guess what's going on so i may be off here. Go to Affinity Preferences, Performance section and check if you have the View Quality dropdown set to Bilinear (Best Quality) - note this only affects the rendering on screen not the exported image which should be better by default.

Link to comment
Share on other sites

Many thanks!

 

(1) I changed that preference and "boom" the low res pixel-i-ness of angled lines became well anti-aliased

(2) Even without that change, you're right that the actual output was fine and it was just on-screen rendering within the app itself.

 

m.

Link to comment
Share on other sites

  • 4 months later...

I'm seeing this as well.

The smooth one is from Krita (way to blurry to be useful, but it shows the difference) and the jagged one is from Affinity. 

How can I export it to png and get it to be nice?

 

Thanks, specs below.

 

macOS 10.12.5

Macbook pro 13" 2015 (intel GPU)

Affinity Photo 1.5.2

Screenshot 2017-08-17 21.46.25.png

Screenshot 2017-08-17 21.46.15.png

Link to comment
Share on other sites

Also here is a screenshot of a detail from 100% of the exported file. Still looks too jaggy to be used.

 

I forgot to say: New user, using Live Perspective to embed a screen into a laptop. Tried setting the Preferences as noted above, and I exported to JPG and PNG. both with bicubic, and bilinear and Lanczos.

 

Screenshot 2017-08-17 21.59.31.png

Link to comment
Share on other sites

And this is a piece from 100% of what I'm starting with.

 

The screen I'm pasting in is 2880*1800px and it's perepective skewed into a canvas with smaller dimensions, so there is enough pixeldata in the image to make a perfect render. 

I would fix this in 15 mins in PS, but I no longer pay for PS after Affinity Photo. :)

Screenshot 2017-08-17 22.26.05.png

Link to comment
Share on other sites

  • 3 months later...
  • Staff

Hi chrleon,

Welcome to Affinity Forums :)

Sometimes a thread or two goes under the radar and gets missed. Please accept our apologies for the delay.

Are you able to attach the .afphoto file so i can check what's going on please? You can delete all elements except the ones pertaining to the issue.

Thanks.

Link to comment
Share on other sites

  • Staff
32 minutes ago, chrleon said:

Still no reply on this from the people in support. Basically $49 out the window. Thanks.

 

With a simple example I can't reproduce the issue here. Without actual files it is very hard to offer advice.

 

Link to comment
Share on other sites

  • 2 years later...
6 minutes ago, MEB said:

Hi AdrianB,
Do you mind uploading the afphoto document shown in your screenshot above using this link so we can take a look please? Thank you.

I've done that now. Also included the PDF that I placed in Photo (probably not necessary, I assume Photo is embedding the file rather than linking it). 

Link to comment
Share on other sites

  • Staff

Hi Adrain,
There's a few circumstances here that exacerbates the problem a little - I'm not sure we can do better. Having a white rectangle behind the embedded document will make the white bleed a little through the edges due to the antialiasing (also exacerbated by the rotation) particularly when there is high contrast with the images in the PDF. This coupled with a dark shadow behind them makes the problem worst (increases contrast). One thing you can do is reduce the width/height of the white rectangle a little (1px) so it doesn't match exactly with the embedded document edges and recedes a little - reducing the white artefacts (visually is still imperceptible). The other which you are already doing (in a way) is super sampling the output (export the whole thing 4x or 8x bigger) and then resample down to the original document dimensions with an appropriate resample algorithm to smooth out the edges.

Link to comment
Share on other sites

27 minutes ago, MEB said:

Hi Adrain,
There's a few circumstances here that exacerbates the problem a little - I'm not sure we can do better. Having a white rectangle behind the embedded document will make the white bleed a little through the edges due to the antialiasing (also exacerbated by the rotation) particularly when there is high contrast with the images in the PDF. This coupled with a dark shadow behind them makes the problem worst (increases contrast). One thing you can do is reduce the width/height of the white rectangle a little (1px) so it doesn't match exactly with the embedded document edges and recedes a little - reducing the white artefacts (visually is still imperceptible). The other which you are already doing (in a way) is super sampling the output (export the whole thing 4x or 8x bigger) and then resample down to the original document dimensions which an appropriate resample algorithm to smooth out the edges.

Ah, yes, the white background, it makes sense that it was part of the problem, I actually forgot about it. 

Supersampling worked well for me this time and I'm happy with the end result of that.

(Now that I think about: would it make sense to add a supersampling function to bitmap export? Like a checkbox "Supersample eight times before export" or something like that.)

Anyway, thanks for the fast and detailed response!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Terms of Use | Privacy Policy | Guidelines | We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.