Why are my images grey?
Raw 6X images off the 6X Thermal will appear solid grey when viewed on most basic image viewers (ex. Windows Photo Viewer).
Below is an example of a raw 6X image as appears when opened with Windows Default Photo Viewer.
Looking closely, you can make out some slightly
darker spots in the image.
Why Grey? The color scale on a basic photo viewer is set to the range of all possible temperatures that the 6X thermal sensor can record; Black being the coldest and white being the hottest. Relative to the range of possible temperatures, the range of temperatures recorded in a typical 6X image is relatively small. This relatively small range is somewhere in-between the coldest (black) and hotest (white) extremes, causing the image to appear as a nearly constant grey.
How to get rid of the grey?
Most advanced imagery software will automatically adjust the displayed color range to match the range of temperatures recorded in an image. As a result, raw images viewed using most GIS tools will highlight the temperature differences you'd expect to see in a thermal image.
The image shown below is the same "grey" image seen above, but as it appears in Irfanview. QGIS and other GIS tools will similarly convey the temperature differences in raw imagery.
.Tif files from the 6X thermal are recorded in Kelvin*100. As a result, images must be converted to be viewed in celsius.
The conversion to celsius is:
This conversion can be performed with Pix4D, Metashape or any other GIS tool.