Does gimp have optical filter imitations?

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Does gimp have optical filter imitations? - godek - 12-11-2017

I saw this in this book called mastering filters for photography. I am guessing it is from photoshop. Here is the image below.
I am curious if gimp has anything like this or ufraw does maybe? I tried looking for it but wasn't able to find it as why I am asking here in this forum.
[Image: 24grc4w.jpg]

RE: Does gimp have optical filter imitations? - Espermaschine - 12-11-2017

G'MIC has a Colour Temperature filter.

RE: Does gimp have optical filter imitations? - Ofnuts - 12-11-2017

This can be done with pre-sets for the Curves tool. However... in 8-bt processing such filters can introduce banding, so if you can apply them on a "raw" file from the camera using a demosaicing app that works in 16-bit or better you'll likely get better results.

RE: Does gimp have optical filter imitations? - rich2005 - 12-11-2017

I had to look up those PS filters

Warming Filter (85), (81), and (LBA). These adjust the white balance in an image to make the colors warmer, or more yellow. Filter (81) is like (85) and (LBA), but it’s best used for minor adjustments.

Cooling Filter (80), (82), and (LBB). These also adjust the white balance that’s shown, but instead of making the colors warmer, they make the colors cooler, or bluer. Filter (82) is like (80) and (LBB), but it’s designed for slight adjustments.

Using UfRAW or in this case the updated nufraw, it is going to be very hands-on for white balence although there is an option to save any curves created.

screenshot: https://i.imgur.com/uNdA82k.jpg

Or some after opening presets You can try the gimp-gmic plugin, http://www.gmic.eu One plugin with hundreds of filters, including a section of photographic presets. Looks like this screenshot https://i.imgur.com/w9yx8am.jpg

Red, Orange, Yellow, and so on. The various color filters adjust the hue, or color, of a photo. Choose a color filter to try to eliminate a colorcast or to apply a special effect.

Standard Gimp:
A plain colour overlay is in Colors -> Colorify there is an option to set your own
One that is often overlooked Colors -> Filter Pack see: https://docs.gimp.org/en/plug-in-filter-pack.html

edit: Just out of interest, which version of linux are you using?

RE: Does gimp have optical filter imitations? - godek - 12-11-2017

I noticed that gmic has plugins for krita too. I know you can edit 16bit in that program but can it be a raw file also? Maybe krita is the better options guys?? I prefer to use gimp afterwards though.

I am using manjaro lxde linux fully rolling release distribution of linux.

What is banding?

edit: What else can cause banding with editing images in the gimp?

RE: Does gimp have optical filter imitations? - Ofnuts - 12-12-2017

Banding is color bands appearing in an area with a soft color change:, such a pale blue sky. Applying color filters leads to a reduction (sometimes rather dramatic) of the number of colors,so you get the same effect as Color>Posterize in random places.

RE: Does gimp have optical filter imitations? - rich2005 - 12-12-2017

(12-11-2017, 11:40 PM)godek Wrote: I noticed that gmic has plugins for krita too. I know you can edit 16bit in that program but can it be a raw file also? Maybe krita is the better options guys?? I prefer to use gimp afterwards though.

I am using manjaro lxde linux fully rolling release distribution of linux.

Messing around with some options

Although I mainly use Kubuntu 16.04 at the moment, my desktop computer has PClinuxOS KDE installed. That is also a rolling distro and (loosely) based on Mandriva, maybe just a little closer to Arch/Manjaro than 'buntu. Might be snags with lxde DE.

Some options for 16 bit.

1. Krita
This did open a panasonic filename.rw2 file but I had to rename it to filename.raw
There is the option to make some adjustments but the interface is 'nasty' Screenshot: https://i.imgur.com/TCgPCaP.jpg
It did open as 16 bit. Depending on version of krita you might get an old gmic (1.7-ish) or this Krita 3.2.2 and gmic 2.1 Screenshot: https://i.imgur.com/lylYr90.jpg
There is a 3.2.2 appimage download from the Krita site that might be worth a try.

2. Gimp
You could try the development version Gimp 2.9.7 as a portable linux 'appimage'
This one might (stress might) work
https://github.com/aferrero2707/gimp-appimage/releases/download/continuous/gimp-2.9.7-20170907.glibc2.14-x86_64.AppImage (big download 180 MB -ish)
Make it executable, run it from your home partition.
If it does work, it already has the nufraw plugin installed which will open as 16 bit when enabled. https://i.imgur.com/xvXB720.jpg
What it does not support is gimp_gmic but after a bit of tweaking there is always the option to export as a 16 bit tiff. https://i.imgur.com/UKzEEyR.jpg

3. RawTherapee
The more obvious solution, Open your raw files, do as much colour correction as required, then save as a 16 bit tiff.
Krita will open that, regular Gimp 2.8 will open as an 8 bit.

RE: Does gimp have optical filter imitations? - godek - 12-12-2017

Thanks for all the information guys! I highly recommend you check out manjaro it is pretty sweet distro of linux. I may have questions later so please don't close this post. I will be back maybe after work?? Smile

RE: Does gimp have optical filter imitations? - godek - 12-14-2017

(12-12-2017, 09:46 AM)Ofnuts Wrote: Banding is color bands appearing in an area with a soft color change:, such a pale blue sky. Applying color filters leads to a reduction (sometimes rather dramatic) of the number of colors,so you get the same effect as Color>Posterize in random places.

Seems like the best option is to do the optical filters instead of the digital ones? What if you are doing it in 16bit same deal? Does photoshop have this problem?

(12-12-2017, 12:36 PM)rich2005 Wrote:
(12-11-2017, 11:40 PM)godek Wrote: I noticed that gmic has plugins for krita too. I know you can edit 16bit in that program but can it be a raw file also? Maybe krita is the better options guys?? I prefer to use gimp afterwards though.

I am using manjaro lxde linux fully rolling release distribution of linux.

2. Gimp
You could try the development version Gimp 2.9.7 as a portable linux 'appimage'
This one might (stress might) work
https://github.com/aferrero2707/gimp-appimage/releases/download/continuous/gimp-2.9.7-20170907.glibc2.14-x86_64.AppImage (big download 180 MB -ish)
Make it executable, run it from your home partition.
If it does work, it already has the nufraw plugin installed which will open as 16 bit when enabled. https://i.imgur.com/xvXB720.jpg
What it does not support is gimp_gmic but after a bit of tweaking there is always the option to export as a 16 bit tiff. https://i.imgur.com/UKzEEyR.jpg

My distribution of linux(manjaro) has an option to install unstable packages they are usually in the AUR repo. I was able to find gimp 2.99 and I installed it but I have to open it via terminal since other wise it will open gimp 2.8 which I also have installed.

RE: Does gimp have optical filter imitations? - Ofnuts - 12-14-2017

(12-14-2017, 12:31 AM)godek Wrote:
(12-12-2017, 09:46 AM)Ofnuts Wrote: Banding is color bands appearing in an area with a soft color change:, such a pale blue sky. Applying color filters leads to a reduction (sometimes rather dramatic) of the number of colors,so you get the same effect as Color>Posterize in random places.

Seems like the best option is to do the optical filters instead of the digital ones? What if you are doing it in 16bit same deal? Does photoshop have this problem?

Optical filters really just patch up things and are really accurate only for a given pair of {actual light temperature, film assumed color temperature}. Keeping all the data and doing post-processing is best.

Color loss is due to the nature of digital processing, but the fewer bits of data you have, the more acute it is. And Gimp 2.8 works on 8 bits/channel while Photoshop (and the next version of Gimp, and many other apps) can work on 16 bit or more, where this is much less visible.

Also, if you are dealing with these kind of issues, you should be "shooting raw" because the JPEG from your camera is 8bit/channel when the "raw" file from the camera sensor is 12 to 14bits/channel (even if in practice high-ISO noise reduces this somewhat). And if you shoot raw, you need a raw processing app to convert your sensor data, and all these apps have powerful color processing.