Flir E4 Thermal imaging camera teardown

[tomas123]

see my post above and try between colorspaces sRGB/RGB for better results

Imagemagick handles color translations to RGB/sRGB different
it's try and error (depend on version, plattform and color table)
I haven't found a perfect color space transformation for the embbed color table to jpg.

You can also download and try the flir palettes from my post
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg342072/#msg342072

here is my version (Windows 7 and ImageMagick 6.7.5-5 2012-02-11 Q16)
flir.php line 171

exec($exiftool.' '.$flirimg.' -b -Palette | '.$convert.' -size "'.$exif[0]['PaletteColors'].'X1" -depth 8 YCbCr:- -separate -swap 1,2 -set colorspace YCbCr -combine -colorspace RGB -auto-level '.$embpal);

and cmd line

Code: [Select]

>php flir.php --pip --msx -i FLIR0010.jpg -o rgb.jpg
I think my colors are better looking

[tomas123]

Is anyone interested in panorama images?

The panarama feature of Flir Tools is bad (several rows).
I have a php script to generate Flir radiometric jpg from 16 Bit grayscale high resolution panoramas, stitched from Flir radiometric images with free MS ICE (Microsoft Research Image Composite Editor) or Photoshop (Photomerge).
The generated jpg are compatible with Flir Tools etc.


As attachment two compressed megapixel jpg (without radiometric part of 2MB)
images without msx 

[Fraser]

There has been some discussion on the accuracy (or lack thereof) of the E4 at low temperatures.

I just found the pictures I took some time ago when we had a nippy spell here in the UK. The temperature on the evening when the pictures were taken was +2 Degrees Celsius. I measured the concrete slab and wall with a thermocouple and an IR thermometer. Both confirmed a true surface temperature of +2.5 Degrees Celsius on the wall and  and +2.0 Degrees Celsius on the slab.

As can be seen from the pictures, the E4 was somewhat confused in its measurement of the brick wall and concrete slab Temperatures. Both surfaces were dry and clean.

[eliocor]

Is anyone interested in panorama images?

Yes, I would be interested in (without using Flir Tools+)

[OrBy]

Is anyone interested in panorama images?

The panarama feature of Flir Tools is bad (several rows).
I have a php script to generate Flir radiometric jpg from 16 Bit grayscale high resolution panoramas, stitched from Flir radiometric images with free MS ICE (Microsoft Research Image Composite Editor) or Photoshop (Photomerge).
The generated jpg are compatible with Flir Tools etc.


As attachment two compressed megapixel jpg (without radiometric part of 2MB)
images without msx 

Dear god that's awesome looking!

Please post that up

[daves]

Is anyone interested in panorama images?

Sure. Would be great.

I am playing with flir.php, blur reduced to 0x1 seems better to me.
I plan to make batch process for more pictures. I would like also to add some automatic hot/cold spot. But I noticed gradient is not linear. I wanted pick up come RGB point from image and then locate same value on gradient to compute temperature. But not sure if this will work. I will give a try. I though to do some VB application for it, but since it would be limiting to windows user, I will stay with php and javascript.

[john19]

There has been some discussion on the accuracy (or lack thereof) of the E4 at low temperatures.

I just found the pictures I took some time ago when we had a nippy spell here in the UK. The temperature on the evening when the pictures were taken was +2 Degrees Celsius. I measured the concrete slab and wall with a thermocouple and an IR thermometer. Both confirmed a true surface temperature of +2.5 Degrees Celsius on the wall and  and +2.0 Degrees Celsius on the slab.

As can be seen from the pictures, the E4 was somewhat confused in its measurement of the brick wall and concrete slab Temperatures. Both surfaces were dry and clean.

Yes, I have exactly the same experience, and the magnitude of the error seems to be the same. I wasn't very happy when I discovered it. I made some water/ice-slush with my mixer, and my E4 claimed that it was -7 degrees C. Way out of spec. I hoped that maybe it was just a bad thermal connection between the temperature sensor and the metal chassis, but I opened it and applied some thermal paste, and it didn't help.

The error is smaller at room temperature, but increases rapidly at low temperatures. Compared with my IR termometer, which I now trust more, the E4 also shows too high temperature at higher temperatures.

I find it curious that many users seem to have the same problem. A consistent error should be possible to calibrate away (before delivery). I have a plot of the error compared to my IR termometer below. Temperature on the X axis and error on the Y axis

I then used excel to fiddle around with the planck calibration parameters in an highly unscientific way in an attempt to minimize the error. The result is in the second plot below. The point at 300 degrees is extrapolated, not measured. I just wanted to make sure that the graph didn't behave in any unexpected way in the extreme end when I changed the parameters.

After uploading these new parameters to calib.rsc my E4 seems to measure much better. Now my room temperature is a comfortable 21.5 degrees C, not 18 degrees, and my freezer is no longer colder than -40, but I'm still suspicious. This should not be needed. I also have a nagging suspicion that my E4 didn't have this error when it was new, but I can't prove it.

[nacke]

Cold temperature behaviour is surely somehow perverted. When you decrease emissivity setting in room temperature, surfaces look warmer to the camera as theory suggest. When I do the same outside (-10 C), the effect is opposite, what's going on in there?

Absolute error in those temperatures is around 9-12 celsius

I also left camera outside for an hour to cool thoroughly to see how it changes things, and tested again. Error got even larger, to 14-17 C.

[OrBy]

I plan to make batch process for more pictures. I would like also to add some automatic hot/cold spot. But I noticed gradient is not linear. I wanted pick up come RGB point from image and then locate same value on gradient to compute temperature.

I did a really quick/dirty cmd file that you can drop a flir image onto and it will spit out a completed file but for some reason it will only work when the file is in the same folder as the cmd/php.

_{"%~dp0php-5.4.22-nts-Win32-VC9-x86\php.exe" "%~dp0flir.php" --pal iron.png -i %1 -o done.jpg}

[Fraser]

In my experience it would appear that FLIR have provided somewhat optimistic accuracy specifications for the stated -20 to 250 Degrees Celsius measurement range. It would be interesting to hear whether an E8 is better behaved than its budget sibling. I am thinking that the E8 may have a more comprehensive calibration routine at the factory ?

DaveLJ.... anything to report on the performance of the E8 you have on loan for review please ?

I am going to get my Pace Heat Wave preheater from the lab and set up some positive temperature tests. The PACE preheater has a closed loop temperature controller but I will use an IR thermometer of known accuracy to check the thermal emission temperature of the hot plate. I may also use the PM695 for comparison tests as well. The preheater is supposed to produce plate temperatures of between 38 Degrees C and 371 Degrees C so plenty higher than the stated E4 top end measurement capability.

I may not get this done tonight though as other tasks are demanding my attention.

[tomas123]

I then used excel to fiddle around with the planck calibration parameters in an highly unscientific way in an attempt to minimize the error. The result is in the second plot below.
...
After uploading these new parameters to calib.rsc my E4 seems to measure much better.

great idea
Which values do you have changed in calib.rsc ?

Code: [Select]

.calib.extRBF.ds250C_we_apNOA_fiNOF_le.B double xxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.F double xxxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.J0 double xxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.J1 double xxxxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.R double xxxx

[john19]

I then used excel to fiddle around with the planck calibration parameters in an highly unscientific way in an attempt to minimize the error. The result is in the second plot below.
...
After uploading these new parameters to calib.rsc my E4 seems to measure much better.

great idea
Which values do you have changed in calib.rsc ?

Code: [Select]

.calib.extRBF.ds250C_we_apNOA_fiNOF_le.B double xxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.F double xxxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.J0 double xxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.J1 double xxxxx
.calib.extRBF.ds250C_we_apNOA_fiNOF_le.R double xxxx

R, called R1 in your post here: http://u88.n24.queensu.ca/exiftool/forum/index.php/topic,4898.msg23972.html#msg23972
B and J0 (also called O). I cant find R2 in calib.rsc, but it has the same effect as R1, so it would be pointless. F seems to be the same for all cameras, so I didn't want to touch it. I have no idea what J1 is.

By the way, the parameters exist in three different places in the calib.rsc file. I changed all of them just to be sure.

I find it really strange that the calibration is so far off. There is some information missing here. I mean, what's the point of being able to fine tune emissivity and ambient temperature if the camera is 10 degrees off at moderately low temperatures, and 10 degrees off the other way at higher temperatures anyway?

[tomas123]

it took me some sleepless nights to find the formula in flir exif header
http://u88.n24.queensu.ca/exiftool/forum/index.php/topic,4898.msg23972.html#msg23972

after then, I found the formula everywhere, like here on page 14
http://www.workswell.cz/manuals/flir/hardware/Ax5_models/ICD_GenICam_ICD_FLIR_Ax5_Camera_PC.pdf

[tomas123]

Is anyone interested in panorama images?

create a panorama image with exiftool, imagemagick, MS ICE  and php


preparation
(1) download free MS ICE from
http://research.microsoft.com/en-us/um/redmond/groups/ivm/ICE/
I use a virtual machine (vmware with windows guest)
(2) install php, see here https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg342072/#msg342072
(3) install imagemagick
(4) edit paths inside splitjpg.php

expand raw values from flir images

Variant A: radiometric jpg with embedded 16 Bit RAW (like Flir Exx)

Code: [Select]

> exiftool -b -RawThermalImage IR_*.jpg -w _%f.tif
    8 image files read
    8 output files created

Variant B.1: radiometric jpg with embedded 16 Bit PNG with reverse byte order (like Flir Ex)

Code: [Select]

// first extract all png
$ exiftool -b -RawThermalImage -if '$RawThermalImageType eq "PNG"' *.jpg -w %f.png
// now change byte order (Linux/Mac code)
$ for i in *.png ; do convert $i gray:- | convert -size 320x240 -depth 16 -endian msb gray:- _$i.tif ; done

Variant B.2: if you don't use pipes try Imagemagick mogrify (inside the same folder as convert)
a sample with reverse byte order (like Flir Ex)

Code: [Select]

$ exiftool -b -RawThermalImage FLIR*.jpg -w %f.png
$ mogrify -format tif -fx 'u/256+int(u*65536)%256)/256' *.png

Variant B.3: as Windows User use a *.cmd like this (untested)

Code: [Select]

@echo off
for /f "usebackq delims=" %%f in (`dir /a:-d /b /oN IR*.jpg`) do call :over %%f
goto :eof
:over
set a=%1
echo %a:~3,4%
exiftool -b -RawThermalImage %1 | convert - gray:- | convert -depth 16 -endian msb -size 320x240 gray:- RAW%a:~3,4%.tifAttention: all tiffs are black (check image with convert my_dark.tif -auto-level preview.jpg )
convert to larger size (and sharp it as you like)

Code: [Select]

> convert _*.tif -resize 480x -sharpen 0x1 _a%03d.png
now drop the 16 bit png to MS ICE
select "rotating motion"
crop the image
select export Format Tiff (16 Bit)
-> save as stitch.tiff

create a real thermal flir jpg,
importend: use an image from the same camera as template (same planck values)
template is here IR_0554.jpg - the first image of serie

Code: [Select]

> php splitjpg.php -i IR_0554.jpg -r stitch.tiff -o pano1

open the new build image pano1.jpg with flir tools and rebuild the preview jpg image

I can't post the recreated image pano1.jpg (>1MB blocked), but it looks like here after saving the preview image in Flir Tools



variant

MS ICE is great for stitching untouched raw radiometric 16bit images witch low in contrast
is you are not satisfied with the result of ICE, you can expand the brightness range and use another panorama software (every 16 Bit panorama tool that finds the control points)

real RAW values are in a narrow range
see here for a table with the relationship RAW and °C  https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg356616/#msg356616


first expand 16 Bit RAW values to _*.tif as described above

now use a sample image for analyze the temperature range (=raw values)

Code: [Select]

$ exiftool -rawval* IR_0548.jpg
Raw Value Median                : 14530
Raw Value Range                 : 1268 raw range is here 14530 +/- (1268/2)

alternativ analyze all tif images all at once (Linux syntax)

Code: [Select]

$ identify -verbose _*.tif | grep -n3 statist | grep -e 'min\|max' | sort -k3 -n | awk '{ if (NR ==1) print} END {print}'
137-      min: 13426 (0.204868)
138-      max: 15962 (0.243565)
we generous chose 13000 to 16000

change brightness with -level (minus)

Code: [Select]

$ convert _*.tif -resize 480x -sharpen 0x1 -level 13000,16000 _c%03d.png
now stitch the images with a 16 bit panorama software
I use here Photoshop with Photomerge (select Auto and correct lens..)

save the panorama as 16 Bit grayscale image with name pano-ps.png

after then limit the brightness to original brightness with  +level (plus)
use the same values from above

Code: [Select]

$ convert pano-ps.png +level 13000,16000 stitch-ps16.png

the last step:
create the real thermal flir jpg,
use a image from the same camera as template (same planck values !!)

Code: [Select]

$ php splitjpg.php -i IR_0556.jpg -r stitch-ps16.png -o pano1ps
open pano1ps.jpg with flir tools and rebuild the preview jpg image

compare the MS ICE panorama with a Flir Tools+ panorama
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg356910/#msg356910


generate zoom images from embedded RAW sensor values
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg359747/#msg359747

edit 15.01.2014 : handle spaces in filenames
splitjpg.php

Code: [Select]

exec($convert." \"$raw16img\" -depth 16 -endian lsb gray:$rawimage");
edit 22.01.2014
a 360 degree panorama from john19
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg370770/#msg370770

edit 03.03.2015
new MS ICE V 2.0 (Image Composite Editor)

see stitched sample here (with some nice windows scripts for E4/E40)
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg620145/#msg620145
discription of the panorama image workflow:
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg621514/#msg621514
for images with hot spots use a additional gamma correction for ICE 2.0
https://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg623573/#msg623573

[Fraser]

E4 thermal accuracy test for positive temperatures

I have just completed testing my E4 using the following equipment

Pace HS200 Heat Wave digitally temperature controlled pre-heater
RS 1315 Datalogging thermocouple thermometer (New). Specified accuracy = +-0.05% +0.5C
Exergen D seriesD-501 non contact IR thermometer. Specified accuracy = +-2%

Details of RS 1315 may be found here:

http://uk.rs-online.com/web/p/digital-thermometers/7126039/

Details of Exergen D series may be found here:

http://www.exergen.com/industrial/dseries/

The test comprised of placing the thermocouple and non contact thermometer such that they recorded an accurate temperature reading for a piece of black pvc insulation tape, and later, a black anodised heat-sink.

The following temperatures were chosen (all in Degrees Celsius):

40C, 60C, 80C, 100C, 120C, 140C, 160C, 180C, 200C, 220C, 230C, 236C,240C, 250C.

It was not always possible to obtain an exact plate temperature in line with the above so the reading on the thermocouple or IR thermometer should be used as the temperature used for each test. The E4 was set at its 0.3m alignment to achieve the best possible MSX image but it was still a compromise in some images. The PVC tape gave up the fight at almost 200C so I used a black anodised heat-sink as a decent radiator and measured its base temperature with the thermocouple and E4. The Exergen IR thermometer could not be used above 200C when the tape failed. It did not read accurately on the heat sink due to target shape.

I continued to increase temperature until the E4 alerted me that it was above range. I then increased temperature a little more to see what the E4 read above its maximum specification.

The results should be self explanatory. I will place numeric results here later.

Now for the pictures

First the set-up and then the E4 images.

UPDATE: Readings listed from test:

Thermocouple Reading   E4 Reading  (In Celsius)  Delta % (Rounded)

39.9                              39.5                              -1.0%
59.6                              60.9                              +2.1%
79.5                              82.2                              +3.4%
100.0                            102                               +2.0%
120.9                            125                               +3.4%
141.0                            146                               +3.5%
160.0                            169                               +5.6%
180.1                            192                               +6.6%
200.6                            217                               +8.2%
220.2                            226                               +2.6%
236.7                            251 Overtemp Warning   +6.0%
240.0                            254 Overtemp Warning   +5.8%
250.8                            264 Overtemp Warning   +5.3%

[mrflibble]

Those panorama's sure look neat. I notice you run it in a vm, which is sorta doable but wouldn't be my first choice. Have you tried it in wine yet? According to this here link it should be reasonably useable. With the added bonus that it mentions that compositing works automatically. Preferably I would just run it from a batch script (hence the wine question). Does MS ICE support batching or do you have to pointey clickey the relative positions of the various pictures before running the solver?

Is says export as jpg has issues but who the hell cares, since export as png does work...

[Fraser]

Last few pictures from E4 test

[mrflibble]

Interesting results there Aurora!  So to give a simplistic summary it looks like for low temperatures the E4 shows a lower temperature and for high temperatures the E4 shows a higher temperature. And by the looks of it a crossover at somewhere a little over 40 degrees C. I wonder what causes this? Are we not using it properly (wrong setting for emissivity or some such), or is this something systematic in the Ex range?

Or maybe this is a limitation of the calibration procedure for a budget model? As in ... yes the E4 would support better settings for the various parameters but this would mean a lengthy calibration procedure, which would be too expensive? 

[tomas123]

Does MS ICE support batching or do you have to pointey clickey the relative positions of the various pictures before running the solver?

not really
http://social.microsoft.com/Forums/en-US/806bf0c5-af8f-4526-9b90-6d28096441d2/faq-frequently-asked-questions-for-image-composite-editor?forum=ice

Code: [Select]


What are the command-line options for Image Composite Editor?
Currently the command line is interpreted quite simply:
If the command line contains a file with the ".spj" extension (an Image Composite Editor project), the specified project is opened.
...
Otherwise, the command line is interpreted as a list of source images which are immediately stitched.
I found, that ICE is the only tool that can stitch those images (low in contrast)


if you use the variant with stretching the level " -level min,max" than you can use every 16 Bit panorama tool like Hugin

but I have a bad experience with Hugin - it don't found good control points on small grayscale images (360x240 etc)
try Hugin (Linux/Mac/Win) for yourself and enjoy the scripting features of Hugin

Photoshop works great with 16 Bit Grayscale (level expanded)
http://sites.duke.edu/oit-mps/2010/11/16/stitching-a-panorama-in-photoshop-cs5/

[Taucher]

Interesting results there Aurora!  So to give a simplistic summary it looks like for low temperatures the E4 shows a lower temperature and for high temperatures the E4 shows a higher temperature. And by the looks of it a crossover at somewhere a little over 40 degrees C. I wonder what causes this? Are we not using it properly (wrong setting for emissivity or some such), or is this something systematic in the Ex range?

Or maybe this is a limitation of the calibration procedure for a budget model? As in ... yes the E4 would support better settings for the various parameters but this would mean a lengthy calibration procedure, which would be too expensive? 

Just a tought - does the offset error happen with unaltered, factory-like Flirs, too ... or was it somehow introduced by hacking around?

[Fraser]

@mrflibble,

I set the emissivity for the test to suit the target so that should be correct. I also used three IR thermometers to check the radiated heat and they all read accurately when aimed at the tape or heat-sink. The Exergen is a quality product designed for this type of testing and it apparently produces its own black body within its head cone to lessen errors. I used my cheap IR thermometer and then my very expensive Raytek Germanium optics IR thermometer with emissivity settings. It is definitely the E4 that is wonky 

The error is not massive, but it does seem to point to a poor calibration table. Maybe the E8 has a more comprehensive calibration stage and this is why it costs more ? It is a bit sad that a cheap $15 Actron IR thermometer is more accurate though 

FLIR publish a specification that includes accuracy of +-2% or +-2 Degrees. Mine would definitely fail a test against that specification.

I am still not worried though as the E4 is a visual thermometer to me and I can achieve more accuracy of readings using other units if desired. I need the relative temperature displays and the rough measurement.

I must say the MSX was very useful during the test. As you can see from the pictures, the visual camera was defocused a little (due to focal distance) but still captured the read-outs on the meters. Very useful 

[pomonabill221]

I am trying to use my camera in a program called Blue Iris (a serveilance with motion detection).  I handles IP cameras and USB cameras.

On my desktop machine, the flir shows up just fine when the camera is in UVC and MSD and UVC and RNDIS as a "Flir USB video".
When I switch it to UVC only, it is listed as "Flir Ex-series".
The video is the same in both modes, but I was wondering why the different "types" vs. modes?

Also, on my laptop (same software/mode), it appears to connect (when Blue Iris connects, the time increments in the camera's frame), but the screen is black... NO video.  Is this a codec that my laptop is missing?

Also, is there any way to make the framed window for min/max temp detection larger or full screen rather than just the center ~"half"?

Anybody come up with an LCD screen protector?  Thinking of the pieces of silicon rubber for smart phones or something similar.

[Taucher]

Also, on my laptop (same software/mode), it appears to connect (when Blue Iris connects, the time increments in the camera's frame), but the screen is black... NO video.  Is this a codec that my laptop is missing?

Also, is there any way to make the framed window for min/max temp detection larger or full screen rather than just the center ~"half"?

check if you're using video overlay and output is sent to a different display (not connected) or different card...
@detection window: you can check out the default parameter files in the menu hack - I've kept them sized down as increasing them will probably slow stuff down

[pomonabill221]

Also, on my laptop (same software/mode), it appears to connect (when Blue Iris connects, the time increments in the camera's frame), but the screen is black... NO video.  Is this a codec that my laptop is missing?

Also, is there any way to make the framed window for min/max temp detection larger or full screen rather than just the center ~"half"?

check if you're using video overlay and output is sent to a different display (not connected) or different card...
@detection window: you can check out the default parameter files in the menu hack - I've kept them sized down as increasing them will probably slow stuff down

That is very possible that video overlay is turned on... it is a laptop with dual display capability although when the internal webcam is selected in Blue Iris, the image (video) is fine... hhmmm.

I'll take a look at the menu hack as well for the large pip! 
Thanks!

[pomonabill221]

Got Blue Iris to work!  Thanks!  Didn't really find the setting that redirected the video to another display, but I went through the menus, and clicked ok, and it started working!
Thank You!

For the "cursor box", what file has the size for the large box?  All I found in toolbar-config_Z3.xml was the menu to select that mode, not the definition of the box's size. hhmmm...
Thank you again!