Resolution Difference between jpg image and thermal data (FLIR) - Page 1
Forum section: electronics / general

author: anushkasw
author_rank: Newbie
timestamp: January 08, 2019, 09:15:24 pm
content: Hello,I am working on a project which requires me to analyse temperature variations between a set of thermal images. I am new to thermal imaging so I am having some issues with the difference in the size of the data.I am using a FLIR Duo thermal camera for image acquisition. I am trying to get the temperature value for every pixel of the IR images that I captured. I am able to extract a csv file with the temperature values using the FLIR Research IR software. I was hoping to assign it to the pixels of the jpeg image but I found that the temperature data has the size of 120X160 whereas my jpg image is of size 480X640.Is there anyway through which I can compensate for this size variation and register the temperature data to the jpg image? It would be great if anybody could help me out or point me in the right direction.Thanks!

author: Bud
author_rank: Super Contributor
timestamp: January 09, 2019, 04:22:03 am
content: Did you try changing image format on the camera to TIFF ? The user manual for Duo saysQuote

author: Bud
author_rank: Super Contributor
timestamp: January 09, 2019, 06:02:14 am
content: BTW why don't you just analyze the extracted 160x120 images? Your 480x640 jpg image is just an upscaled version of that data with extra pixels interpolated, not measured.

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 09, 2019, 06:40:10 am
content: Quote from: anushkasw on January 08, 2019, 09:15:24 pmyes there is... 1x1 pixel temperature = 4x4 pixels jpg. if you wan to get fancy you can do nearest neighboorhood, bilinear or bicubic interpolation (upscaling/resize)

author: anushkasw
author_rank: Newbie
timestamp: January 09, 2019, 06:58:20 pm
content: Yes I have tried using tiff images. I am able to get the 120X160 temperature data from those images as well.But I am unable to visualize this data. I mean I want to know exactly what part of the image has a certain temperature. That is why I was hoping to extract a 120X160 image file with intensity values along with the temperature data. I don't think that is possible though.Any suggestions?

author: anushkasw
author_rank: Newbie
timestamp: January 09, 2019, 06:58:57 pm
content: Yes, that can be done. I'll try.Thanks!

author: railrun
author_rank: Regular Contributor
timestamp: January 09, 2019, 07:24:47 pm
content: Can you upload a file?

author: Bud
author_rank: Super Contributor
timestamp: January 09, 2019, 10:50:51 pm
content: Quote from: anushkasw on January 09, 2019, 06:58:20 pmOpen the TIFF in Photoshop and adjust contrast and brightness to your liking, try that.

author: eKretz
author_rank: Frequent Contributor
timestamp: January 10, 2019, 09:31:08 am
content: If you are using a FLIR this is very easy. The images are radiometric - that means the temp at every pixel is stored in the image. Open your image in FLIR Tools or whatever program you're using and add a "Spot" tool to get spot temperature. You can then drag it wherever you want with the mouse and get a temp reading. You could also do min/max or any of the other measurements. I think this is what you're asking for anyway.

author: Bud
author_rank: Super Contributor
timestamp: January 10, 2019, 04:28:15 pm
content: That would be an obvious way to do it but it can't be automated. I assumed OP was looking at an automated solution for processing a mumber of photos.

author: eKretz
author_rank: Frequent Contributor
timestamp: January 10, 2019, 04:31:39 pm
content: Not sure how that could be automated. How would that even be done? Write the temperature text over the image at every pixel? That's basically what the palette is for. I don't think there's any way to analyze the images but one by one without a specialized program that would probably need to be created.

author: Bud
author_rank: Super Contributor
timestamp: January 10, 2019, 05:26:31 pm
content: Raw thermal images can be processes just like normal images. In terms of code it depends on what you want. There is OpenCV library with which you can write custom code and do wonderful things, but also can use a scripting language (Python or something) bundled with off the shelf image processing software such as ImageMagic. There is extensive information here in Thermal Imaging board on using ImageMagic and ExifTool to manipulate Flir thermal images, like extracting/embedding raw data from/to jpg, sizing, creating panoramic images out of a series of, etc. Automation possibilities are endless, i do not see any problems with tooling but you need to learn how to use it.

author: railrun
author_rank: Regular Contributor
timestamp: January 10, 2019, 05:29:11 pm
content: Exaclty. But without any further information and sample pictures it is also hard to help.

author: eKretz
author_rank: Frequent Contributor
timestamp: January 10, 2019, 06:01:44 pm
content: Yes, I understand automating workflow. It doesn't seem to me that is what the OP is trying to do. It sounds like he wants to do image analysis but just doesn't understand how his software works. Automating analysis is not an easy task.

author: Chanc3
author_rank: Frequent Contributor
timestamp: January 12, 2019, 10:57:39 am
content: FLIR released a free SDK that supports most newer (and some older) radiometric image formats. Perhaps this could be used?

author: anushkasw
author_rank: Newbie
timestamp: January 14, 2019, 09:43:30 pm
content: Yes, I am trying to develop an automated system which can analyse a batch of images.I can use FLIR tools or their Research IR software but that would be manual work

author: anushkasw
author_rank: Newbie
timestamp: January 14, 2019, 09:44:46 pm
content: Quote from: Mechatrommer on January 09, 2019, 06:40:10 amSo yea I tried interpolating the temperature data to the IR image size. It seems to be working. Though I need to check how accurate the output is.

author: anushkasw
author_rank: Newbie
timestamp: January 14, 2019, 09:46:00 pm
content: Quote from: Bud on January 10, 2019, 05:26:31 pmI will try exploring all these options. Thanks for the suggestion!

author: anushkasw
author_rank: Newbie
timestamp: January 14, 2019, 09:50:48 pm
content: Quote from: railrun on January 10, 2019, 05:29:11 pmSo I have some images of leaves of plants and I want to distinguish between wet and dry leaves. I am using thermal images so as to detect the temperature variation between wet and dry leaves. I want to develop an automated program in matlab or opencv for that.

author: railrun
author_rank: Regular Contributor
timestamp: January 14, 2019, 10:43:40 pm
content: Can you upload two files (wet&dry)?

author: Vipitis
author_rank: Frequent Contributor
timestamp: January 15, 2019, 12:11:26 am
content: I believe your task can be handled by a automation/industrial observation installation. Flir has their own line of cameras for it with the entry product of the A8X.https://www.flir.com/products/ax8-automation/Now I am not sure if you can just rig up your duo and run it through their alert software. It theory it should work but it reality it probably won't.If your application isn't stationary and you want to check like a lot of leaves at once, ResearchIR should allow you to do so. It lets you load in multiple images over time and graph a single pixel over time for example if you want to measure that.