Feature Request: Lock capture region to predefined aspect ratios

[GioSale]

It would be useful to have an option to lock the capture region to well-defined aspect ratios (e.g. 16:9, 4:3, 1:1, etc.).
This would allow more precise captures without needing external tools.

Currently, I have to open the captured image in an external editing software to manually adjust it to the desired proportions.
Add an aspect ratio lock feature to the region selection tool, allowing users to quickly switch between common standards (16:9, 4:3, 1:1, etc.) or define a custom ratio.
There are already two related discussions from January 2023 and February 2024, but no follow-up or implementation has been made so far.

[mmahmoudian]

We don't have pre-set for the aspect ratios, but you kinda already can do that. You can trigger a screenshot with the aspect ratio you want through CLI, and then resize the area while holding Ctrl to preserve aspect ratio.

flameshot gui --region <WxH+X+Y>

Additional tip: Holding Shift would mirror the resize

[andrewanswer]

Hi,

holding CTRL does not lock aspect ratio. I tried it accurately on my Ubuntu 24.04 LTS, Flameshot 14.0.0

For example, select 600x200 area and extend it using CTRL to 900x300. You can't do it! The ratio slowly degrade to 1:1 during resize.

[ElTh0r0]

Thanks for reporting! There is already an open issue #3436 and a PR was work in progress but not finalized yet (#3439).

[mmahmoudian]

Thankfully @ElTh0r0 fixed this in #4651 by a logical shift of the aspect ratio calculation to a better location that is not prune to eventual drift of the aspect ratio.