Hi,
I want to make a small side-project and am considering IR:Infrared (thermal imaging) Cameras. Being a newbie to openCV and never having done image processing with IR images, I would like to know -
Thanks a lot !
All of the basics work. Blurring, morphology, template matching.
About half of the more advanced stuff does too. But particularly in the feature detection and optical flow some don't. Sometimes it's a pretty easy fix, but calcPyrLK is not very easy.
If you want to visualize the image, you can simple use
normalize(image16, image8, 0, 255, NORM_MINMAX, CV_8U)
or, for a better quality, use the CLAHE algorithm
I don't recommend using CLAHE or minmax normalization for thermal imaging - except if you want to do purely image processing operations. It will make you lose the temperature data.
I converted the thermal image to 8 bit image using a fixed ratio. For example if your temperature range is between 0-60°C, you can use normalize(image16, image8, 0.25, 0, NORM_L2, CV_8U); (or image16.convertTo(image8,CV_8U,0.25,0);`). Like this, each number will correspond to 1/4°C (the pixel value for 20°C will be 80).
That's true. I suppose you do have to be aware of what the numbers actually mean. Sometimes they're meaningful, sometimes (all the IR cameras I use) they aren't.
I'm not sure what camera you're using, but with the Kinect v1.x, the infrared image is greyscale and has a pixel type of unsigned short int (e.g. a 16-bit integer). This type of image is supported by OpenCV (e.g. CV_16UC1), but it might not be supported by certain functions. One function that comes to mind is applyColorMap. It requires that the input image is of type CV_8UC1 or CV_8UC3, and it will give you an assertion failure if you try to pass in an input image of type CV_16UC1.
Why don't you experiment with OpenCV and the CV_16UC1 format before you invest in a camera?
Asked: 2018-01-09 15:48:36 -0600
Seen: 18,974 times
Last updated: Jan 09 '18
I don't know which camera you use but imho biggest problem with thermal images is energy calibration.Type IR images are 16 bits or float (and only one channel).