SuperResolution
I thought I'd start a new topic to specifically discuss the SuperResolution feature that can be unlocked for $395 on all of Testo's current lineup of cameras.
First, the methodology is described in this nine-page technical writeup:
For those who are more visual, the same content is also available in this five-minute video:
By unlocking this feature, the camera takes five images in rapid succession when hand-held. By using the slight movement of the imager, the spaces in between the detector sites are filled in. Additional image processing helps improve overall sharpness from the offset images.
I can confirm that it really does improve resolution by about 50%, beyond the resolution of the detector when taking a single image in standard mode. I could probably make a stab at evaluating the system MTF because the Testo software can export the image array data to a CSV file, but that's for another time.
One thing I have noticed is the inherent vertical line artifacts (seem to be common in thermal imagers) are a little stronger in the SuperResolution mode - this may be due to its sharpening algorithm after merging the images.
Non Uniformity of Thermal Imagers
Here is a standard image taken of a neutral target, unfocused, to show uniformity of the detector:
Can someone explain the strong vertical lines in this image? They represent a variation of about +/- 0.075 C.
Here's a plot of the average values of all the columns in the above temperature array
The general trend across the image likely has to do with the lens and from a changing incident angle upon the detector.
Can someone explain these spikes that appear as vertical lines? They are in the same place all the time, I see them in the live view as well.
David Elfstrom, P.Eng, CEM, LEED® AP Toronto, Ontario elfstromengineering.com LinkedIn: linkedin.com/in/elfstrom