Reading an RGB image from purethermal 2 using opencv?

1

Hello
I am not sure if this the right to forum to ask this question, however I am unable to post this question, on the FLIR developers forum, so I will ask here.

I am planning to use the purethermal 2 with a lepton 2.5, to detect people.
The purethermal 2 seems to work just fine with the FLIR application on windows, and also with window’s Camera.
However when I switch to python and opencv and try to do:
cap = cv2.VideoCapture(0)
_, img = cap.read()

the program gets stuck, and the white LED, on the camera flashes rapidly (I believe that it mean that it does capture video), and in the end I am unable to read the image.

After some searching around, I found I should to use:
cap = cv2.VideoCapture(0, cv2.CAP_DSHOW)

While I can get an image using this declaration, I get a mostly grey image which seems broken, and not an RGB image.

How should I use the purethermal 2 and opencv?

many thanks!

2

Hi,
thermal image are grey image not rgb. Pixel unit is kelvin

3

Not clear how you coded it, are you calling both above VideoCapture() and read() methods inline ? It would be expected to have the first one ( device select ) instantiated just once, whereas the last one ( capture the frame from video stream ) inside a loop.

4

Yes, I Do read the frame in a loop, what I wrote was just an example, In my real code I mean to write in a loop.
However it does matter if I do it inline or, in a loop, the result is cannot read the frame.