I have a 3-band RGB DEM raster. However, the pixel values are not very useful for any actual depth computations. How can I extract the depth values from the DEM?
I understand that it is not easy to decode the encoded colour map but I was still wondering if there was a workaround for it. I would ideally have to convert the 3-band DEM to grayscale using QGIS but the labels were broken. If it helps I know the range of possible depths (ie. minimum and maximum) in meters but I was unable to get QGIS to label it accordingly.
Edit - Some screenshots
I am not sure what all of the terminology means but I know that the 3 bands are not very useful to get the actual depth information needed, or at least I don't know how. I am working with python and I intend to convert the DEM to a numpy array and then work on it how I would work with any other image in python.