Does FLIR One actually create 320x240 thermal images? - Page 1
Forum section: electronics / testgear

author: Ben321
author_rank: Frequent Contributor
timestamp: July 16, 2015, 07:54:28 am
content: The new FLIR One creates an MSX blended image from a 640x480 visual camera and a 160x120 (supposedly) far-infrared imager. However I have just finished writing a major component for software that will be writing, and this component's sole purpose is to extract the raw 2-byte-per-pixel thermal image from the radiometric FLIR image files. Well when I ran this software component that I created on a known FLIR One JPEG image, I got something quite unexpected. I got a 320x240 raw radiometric image. Is it possible that the new FLIR One is actually BETTER than advertised? Given that FLIR is a well respected thermal IR company I would hardly expect that they would follow such bad practice as upscaling (even if it is only a 2x upscaling) the raw data in the device itself, and then saving that as the raw data (with no possibility to recover the truly original raw thermal data) in the output file. Can somebody let me know what's going on here? What are the actual pixel dimensions of the upgraded Lepton chip used in the upgraded FLIR One? Has anybody been brave enough to (and had enough time to) break open their FLIR One and put the far-IR imager chip under a microscope, and actually count the number of pixels wide that it is to make sure it is actually 160 pixels wide?Here's the JPEG image file I tested it on.http://cdn.slashgear.com/wp-content/uploads/2015/06/flir_20150630T131523.jpgHere's the original webpage where that image is embedded.http://www.slashgear.com/flir-one-thermal-camera-for-android-hands-on-30391243/

author: bookaboo
author_rank: Frequent Contributor
timestamp: July 16, 2015, 08:44:16 am
content: No, the Flir One initially used the Lepton 80x60 and the new version uses the Lepton 160x120. Flir are probably doing some clever image processing to make the image look like it's higher resolution.

author: tomas123
author_rank: Frequent Contributor
timestamp: July 16, 2015, 09:18:23 am
content: 2x upscale for embedded RAW imagesQuote from: tomas123 on July 05, 2015, 11:30:29 am

author: Ben321
author_rank: Frequent Contributor
timestamp: July 16, 2015, 09:52:31 am
content: Quote from: tomas123 on July 16, 2015, 09:18:23 amWell that is HORRIBLE engineering practice. I am shocked and appalled that such a well respected company like FLIR would do such a STUPID thing. Raw is supposed to be truly raw, so that when you are looking at the value of a given pixel you know that is the value that it is SUPPOSED TO BE, and not a value that some interpolation algorithm GUESSED. What kind of interpolation was done with the FLIR One? Is it linear? How is it calculated? Does it just take every even numbered pixel (0, 2, 4, 6, 8, etc) and average them together to generated the odd numbered pixels (1, 3, 5, 7, etc)? If so, I could just discard all the odd numbered pixels (both vertically and horizontally), and only keep the even numbered pixels. If the interpolation though does alter the original pixels that were detected by the sensor, then the situation is much worse, because then it would be irreversible.

author: tomas123
author_rank: Frequent Contributor
timestamp: July 16, 2015, 11:16:40 am
content: Quote from: Ben321 on July 16, 2015, 09:52:31 amno, I am glad that Flir the sensor readings corrected (e.g. Non Uniformity Correction)

author: Fraser
author_rank: Super Contributor
timestamp: July 16, 2015, 12:24:55 pm
content: @Ben321,The New LEPTON is 160 x 120 pixels as I have already advised. I went to some lengths with FLIR to establish this.Whilst I understand your disappointment that FLIR upscale the resolution to 320 x 240 and present that as RAW data, please consider the intended market of this device. It is one step above being a consumer toy.For more professional Radiometric Thermography FLIR would expect you to buy one of their better cameras.The new ONE is definitely an entry level budget device built to meet a certain market and it would not be in FLIRs interests to make it a serious competitor to their more expensive Radiometric cameras. Sadly that is just marketing for you.It sounds like you have a demanding application for your thermal camera. The Ex series may be a better fit, or if better optics are needed, go for the Exx series. Both series can be upgraded to 320 x 240 pixels fully Radiometric.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: July 16, 2015, 12:51:07 pm
content: Regarding counting the physical pixels on a microbolometer...... Sadly this is not possible without de-capping the capsule and so destroying the imaging core. Microbolometer cores have a thermally transparent but visible light opaque window as their cap. In HQ cores this is a Germanium window. I suspect the LEPTON uses silicon as this is used for the lens.I have a thermal imaging microscope lens so can see through a microbolomter window, but that cannot see the pixels at 12um, and there would be little contrast present anyway.Aurora

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 17, 2015, 02:35:22 am
content: Aurora, you have a lot of interesting gear sitting around. If that includes a CO2 laser that has a gated output you could create all the contrast you want fairly easily.

author: Fraser
author_rank: Super Contributor
timestamp: July 17, 2015, 04:09:55 am
content: @catalinawow,Thanks for the suggestionSadly Lasers are not one of my interests, so I do not own any.For my wildlife work in the thermal domain I rely upon good quality thermal cameras and narrow FOV lenses.Aurora

author: Ben321
author_rank: Frequent Contributor
timestamp: July 17, 2015, 04:29:35 am
content: Quote from: Aurora on July 16, 2015, 12:24:55 pmIf it's not intended to be much above a "toy", then why even make the pretense that it has unaltered radiometric data in it, when it really is upscaled? Why not just save a JPEG of whatever is on screen, and throw out the radiometric data altogether, if it's just a "toy"?Are you aware of what type of 2x upscaling algorithm is used? Is it simple bilinear interpolation, where each interpolated pixel is calculated as the average of surrounding pixels? For example, if the pixels are:A B CD E FG H IA = originalC = originalG = originalI = originalB = (A+C)/2H = (G+I)/2D = (A+G)/2F = (C+I)/2E = (A+C+G+I)/4Is this how the interpolation is done? If so, to reverse this, I would just skip every other pixel both vertically and horizontally, and I would have all of the original pixels, and none of the interpolated pixels. Is this the case? Or does their 2x interpolation algorithm alter the original pixel values as well, such that the true original pixel values cannot be retrieved?

author: Fraser
author_rank: Super Contributor
timestamp: July 17, 2015, 05:02:24 am
content: @Ben321,You would need to ask FLIR what upscaling method they have employed. They will not divulge details of their image processing algorithms but this upscaling is likely less sensitive information.I would suggest phrasing your questions very simply and directly as I had trouble getting a straight answer from FLIR on the true physical resolution of the microbolometer until I made it very clear I wanted the exact X by Y pixel count. FLIR have a dedicated FLIR ONE customer support team and I do not think they are very used to in-depth technical questions on the unit.With regard to your "toy" comments. I stated that the FLIR ONE is one stepabovea "toy". IMHO this is an accurate description of the device when compared to FLIR's more capable cameras. FLIR are providing an SDK to developers to enable use of the ONE in varied scenarios with a wide range of applications to suit. It would appear that FLIR do not consider individual non upscaled pixels to be essential to such development.Please also be aware that the LEPTON core uses a temperature compensated, rather than temperature stabilized, microbolometer. Sensors are used to measure ambient and internal temperature and a compensation table used to offset the output data. The camera is likely to provide accurate temperature readings at 30C (internal temperature) and will likely be less accurate as its temperature moves further away from 30C. The compensation table is generic and not unique to each camera. The Ex series is also temperature compensated rather than temperature stabilized. This reduced cost and current consumption of the core.Aurora

author: encryptededdy
author_rank: Frequent Contributor
timestamp: July 17, 2015, 06:36:14 am
content: Quote from: Ben321 on July 17, 2015, 04:29:35 amWhat do you plan to use the FLIR One for?I think you need to understand that there is some very heavy image processing going on in the FLIR One, and I bet if you were to look at the raw data from the microbolometer (especially since this is using a very small 12um pixel size) it would be near-unusable (see what happened on the Seek when the raw data was read), therefore I think interpolation should be the least of your worries in terms of acquiring a "raw" image.If you wish to read accurate temperature data, I think you'll be better off just averaging together 4 or 9 pixels - this will decrease inaccuracies due to noise and also "overcome" any issue you may have with the 2x interpolation.As for the interpolation method, I doubt it's bilinear or anything simple like that. It's probably a integral part of FLIR's image processing pipeline (and isn't something that's just tacked on after the image is processed). There would be no point in FLIR just doing a bilinear upscale on the sensor when literally any software reading the image can upscale it to any resolution it needs.

author: tomas123
author_rank: Frequent Contributor
timestamp: July 17, 2015, 08:45:00 am
content: Quote from: Ben321 on July 17, 2015, 04:29:35 amThe interpolation algorithm is more complex.See my experiments from last year with a heating wire.Flir One G1 with Sensor 80x60 upscaled to RAW 160x120watch for the nice FlirOne artefacts (from sharping)Quote from: tomas123 on November 16, 2014, 05:15:09 pm

author: Ben321
author_rank: Frequent Contributor
timestamp: July 17, 2015, 09:27:05 pm
content: So then the interpolation is irreversible?Is there any way to configure the Flir One app to NOT interpolate the output, or is this interpolation done in-hardware, by a microcontroller in the Flir One unit itself? With the SDK there are a number of 3rd party apps that have been created. Do any of these 3rd party apps allow the disabling of the interpolation, or does the SDK have some "black box" proprietary components (which you DON'T get to see the source code for), which do (among other things) interpolation of the pixels, without any way of disabling this interpolation operation?