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Products => Thermal Imaging => Topic started by: eg14 on October 30, 2017, 09:06:44 pm

Title: Enhancing FLIR image quality
Post by: eg14 on October 30, 2017, 09:06:44 pm
I'm still working on my scripts, but here's a rundown of the process.

What you need:

The steps:
Code: [Select]
exiftool -b -RawThermalImage inputFile | convert - -auto-level outputFile.tif

In the gradient layer, open my FLIR gradient pack and choose one of the options.
Adjust the black and white levels in the level adjustment layer to suit your needs.

Noise reduction for FLIR images is best accomplished by using Photoshop's surface blur. Set the pixel radius to 2-10 and adjust the threshold as desired. Make sure you have the background layer selected in photoshop (not one of the adjustment layers)

More to come
Title: Re: Enhancing FLIR image quality
Post by: Chanc3 on October 30, 2017, 09:09:58 pm
Do you have any examples?


Sent from my iPad using Tapatalk
Title: Re: Enhancing FLIR image quality
Post by: eg14 on October 30, 2017, 09:24:13 pm
Here's some
Title: Re: Enhancing FLIR image quality
Post by: LesioQ on October 31, 2017, 07:31:04 am
Gained CGI-look  :-\ Overdone ?
Title: Re: Enhancing FLIR image quality
Post by: Ultrapurple on October 31, 2017, 08:33:52 am
I see what you mean about a 'CGI' look to the images but, assuming one is looking at it from a purely aesthetic rather than measurement viewpoint, I think it's a matter of taste. I think the car wheel looks excellent - but my interest in thermal imaging is mostly from the 'pretty pictures' end of things (even though I do have a technical background).

I know at least one thermography forum where anyone who dared suggest improving subjective image quality would be beaten to a pulp, ripped to shreds and then have their entrails cremated in a flamewar. Other places - like this - are  lot more tolerant and encouraging of experiments!

Please, eg14, keep up the good work. We need people who are prepared to investigate limits and push the boundaries: that's the way the state of the art moves forward.
Title: Re: Enhancing FLIR image quality
Post by: LesioQ on October 31, 2017, 01:09:33 pm
Perhaps I was not clear enough. I think there is a thermal information loss, perhaps due to overprocessing.
This is similar to Penthouse posters  - the image is smoother, but fine shades and details are lost  ???
In astropohotography - to reach finer details - several frames are combined.
Title: Re: Enhancing FLIR image quality
Post by: Vipitis on October 31, 2017, 01:26:21 pm
Stacking will reduce noise. But you can't really add up exposure time to make small details visible.
Title: Re: Enhancing FLIR image quality
Post by: eg14 on November 01, 2017, 01:00:19 am
Yes, details will be lost, for sure. But I'm in it for the art. I'm not an engineer or building inspector.
Title: Re: Enhancing FLIR image quality
Post by: Vipitis on November 01, 2017, 10:40:58 am
You can setup .batch files that run all the scrips on an image. But there is quite the manual work included.
Title: Re: Enhancing FLIR image quality
Post by: Ultrapurple on January 31, 2020, 10:29:09 pm
After some digging, I found a magic incantation that will do a very basic conversion of ALL the FLIR JPGs in a directory and produce TIFFs (16-bit, no adjustment so they will appear terribly low contrast - all the info is there, you just need to use an image editor to make it display properly)

Code: [Select]
exiftool -rawthermalimage -b -w tif -ext jpg

Usage: in a command window, set the current directory to the location of your files, eg

Code: [Select]
CD "D:\thermal\may\my image files"

(note: the double quotes mean you can include spaces in the Change Directory instruction)
(note II: depending on your file browser, you may be able to copy this location string from an address bar; paste it into the command box by clicking on the top left corner to open the menu, then select Edit ... Paste. There is no keystroke shortcut that I'm aware of)

Code: [Select]
C:\usefulstuff\exiftool -rawthermalimage -b -w tif -ext jpg

(I assume here that your exiftool program is located in C:\usefulstuff - if it's somewhere included in the PATH then you can omit C:\usefulstuff\ )


I don't claim any originality: I found the answer here (https://exiftool.org/forum/index.php?topic=9060.msg46737#msg46737). The Exiftool forum Newbies section (https://exiftool.org/forum/index.php?board=12.0) is very useful, particularly if you use the keyword search :)