Scaling UI - bugs with image reproduction

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Scaling UI - bugs with image reproduction

Hey folks. Got a nice pair of 27-inch 4K's LG monitors and they look and work great. Mac OS did not have any issues with it, with the exception being that the image files and the image/video editing softwares scales the images in an incorrect way when using the UI scale options that are in between the first (looks like 1920x1080) and last (looks like 3840x2160) options. When using the 1920x1080-look-alike, its works fine, and using native 3840x2160 too. Any in-between option gives this problem.

Luckily the main software I am using (SideFX Houdini) ignores the UI scaling from the OS and have its own scaling properties, so the render frame buffer works fine, but I have to scale the UI and get huge icons (because using 3840 natively is weird) in any other software, like Photoshop, Nuke and Blender. Even the native Mac OS Preview scales stuff incorrectly. I'm attaching a screenshot that represents what I see when I open in Preview a 1920px wide image in a 3840px wide monitor. It should occupy half the width of the monitor, and you can see it's clearly more here

This is not a new problem as you can see here, though this guy didn't go too far debugging the problem https://www.youtube.com/watch?v=Y-c8UbtHrJY

As I tested, MS Windows works with only scaling the UI elements, so it works the way Mac OS does, but without this weird bug.

P.S.: When I did the screenshot, just noticed the screenshot resolution is 6016x3384 (doubled the scale option I use, which is the "looks like 3008x1692"), so we have some weird stuff going on indeed.

P.S.2: Divided 6016 over the 3840 monitor res, got 1.56. Multiplied the image zoom in Photoshop by 1.56 (156%) and it can look "correct" this way. In Preview, the image looks like its natively in 200% zoom over this wrong image scaling. Other softwares does not have this number input for precise zooming, neither Preview.

P.S.3: Also found out that the scaling is proportionally scaling the images from 200% to 100% altogether with the UI, and obviously it should not. A Full HD image should look like half the screen in a 4k monitor, or even if doubled to ease who is viewing, the in-between options should not resize.

Posted on Jun 11, 2021 3:41 PM

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Answer 1

Jun 11, 2021 4:17 PM in response to Vinicius Paciello

And sorry for editing this so much but I am quite intrigued by it and so I thought: Instead of doubling the 3008 or 2560 or whatever resolution and scaling it to the monitor (which can lead to a huge performance loss), why dont you guys at Apple just scale the UI proportionally? Isn't that way cleaner and much more resource-friendly?

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Answer 2

Jul 2, 2021 12:11 PM in response to Vinicius Paciello

FINAL:

Now I am using the 2560px look-alike. Which means MacOS is creating a 5k resolution and scaling it to the monitor. I was quite upset with it but found out it is actually pretty good for using different scaling monitors at the same time, because the whole MacOS is "retina" and what resizes is the emulated screen to the monitor and not the UI - its a quite pleasant experience. The problem is with images. You see, as I open a 1080p image, it should be half width and half height of the screen, but as the screen is a 5k-emulated screen, it will look smaller. So what I have to do in photoshop for example is to zoom precisely to match the monitor pixel count. Using the "looks like 2560" option, it is 133%. If you are using "looks like 2880" it is 156%. Worked great for me, while Apple doesn't fix this issue and scale images outside the scaling method, it is a workaround.

Problem is I can't open images in preview and precisely zoom them. Its 100 or 200%. Also, frame buffers (for 3D renderings) does not have precise zooming.

Apple should fix this in Preview making it not scale accordingly to the emulated-screen resize but to the pixel count of the monitor, and adding an option for developers do to so when displaying images.

Thank you!

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