I am looking for quick ways to mask images. I have tried a couple of ways so far but while they work, they always seem to be a bit more cumbersome than seems necessary. What I really want to do is find a quick, readily repeatable way using minimal SQL. My masking endeavours are largely aimed at single channel DEM images, though it would be great to have something that would also work for multiple channels.
Most usually, my scenario would be to create a vector feature or features and to use this as a clipper or mask modifying the image to only show pixels that are inside the vector features. My plan for this attempt was to create a vector feature, then join this into a single channel image as a new channel (Channel 1) with a value of one where the vector feature is present and zero where it is absent. So far so good (see attached test data and image).
I then wanted to simply multiply Channel 0 by Channel 1 and put the result back into Channel 0 before dropping Channel 1 but I can’t see how to do this in my attempts thus far. I typically get an ‘invalid key value’ error or some such.
Could anyone in the know let me know if this method would work and if so how to approach the last bit. If it does, I think that it will be simple enough that I can remember how to do it which I cannot with the other methods I have tried.
Thanks in advance
Sample data: High veg classified LiDAR points interpolated with a 5m search radius. I want to remove the 5m interpolation ‘skirt’ by preparing an inner buffer [CROP] which I have already used to add a second channel to the vegetation grid [PGF HI VEGETATION IDW], which has a value of 1 for pixels inside the buffer polygons and a value of zero outside.
M9 MASK SAMPLE.mxb
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