Releasing some RAM, when the work is done

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Releasing some RAM, when the work is done

I have noticed this quite some versions ago, but it didn't bother me on my ageing Win7 PC with 16 GB of RAM. (Plus two on the GPU, that some LightZone processes seem to use slightly.)

On my more modest new laptop (i3, 8 GB RAM, no decent GPU), the intelligent Win10 started to produce suggestions like "You might be short on resources, perhaps you should shut down lightzone.exe."

It looks - both on Windows and Ubuntu VM - that LightZone uses all the allowed RAM (50%) and even some more, when doing things, which is OK, but after the work is done and the program is idle in browser mode, displaying five thumbnails, it jealously keeps all the memory reserved for itself.

Other similar editors seem to be able to free the memory, when they don't need it anymore. I don't dare to make an issue on GitHub, since I'm illiterate in this and many other ways, I just wonder, whether this would be possible to make.

With best whishes,


I agree

The only way my RAM seems to released is that I have to exit the program and start it again.  My confusion in your post does leave me with a question.  Which OS are you running Ubuntu VM on and why?  You mention that you are using Win7 and Win10.



I tend to have

VirtualBox installed on all my Windows computers. And VMs with different OSs, some of them I actually need occasionally (like XP with MS Office, to check my LibreOffice documents that need to display correctly in Word), some out of curiosity or nostalgia (very old programs that don't behave well on Win7 or newer). Here and there I have to instal trial versions of different programs to help "friends and family" solving their problems.

I have tried different Linux distributions, currently using the nice and simple Ubuntu Studio. On a VM with 8 GB of dedicated RAM, darktable is, for instance, quite useful, and I'm actually using it for editing some of my photos. I find it a very capable program, probably the most complete open source editor of this kind. I'm also playing with Linux versions of LightZone, RawTherapee, Gimp, digiKam etc.

Here and there I make my PC dual-boot, usually until I run into (mostly Windows-related) problems.

Have a nice day!


Mart: Linux Darktable

Linux Darktable has a big/active user community as well, if you want to try.  As for trying so many different platforms I'm getting to burn out for my taste.  I keep a dual boot Ubuntu 16.01/Win7 PC and a Win10 HP mini as my primary devices.  Of course I also have access to tablets, smartphones, netbooks, etc. but I digress.



You can adjust



You can try to adjust "Memory limit"  down in settings menu (edit/settings). LZ. reserves half of your computers ram for itself. So if your camera is not having to many pixels (higher resolution uses a lot more memory) it might work. Try first with 1 GB less and see what happens.


On the other hand 8G ram is as of today not much. You might consider to buy some new stics, or if there is empty slots a couple more. New computers will normally could take at least 16GB. Its cheap and it will make the machine MUCH smoother in speed and performance.

If you run multiple operating systems in a VM, then you need as mutch ram as possible. Otherwise you will suffer severe performance impacts and stability issues.

Have a nice day

This works nicely on Ubuntu now,

I have built LightZone, master branch from April, on Ubuntu Studio 17.04, on my now dual-boot laptop. Idling after the work is done, LightZone releases about 70% of memory, it has been using.

Building was smooth, I only had to add lcms2 and liblcms2-dev to the mix. Great work, Masahiro!

Builds and works fine

also on my PC, from, from 20. July, with some new commits, on Ubuntu Studio 17.04.