I have myself a large raster (ecw) that comprises of 3 bands. I'm trying to find the most convenient way of clipping away unwanted black areas around the actual imagery itself. See the raster in question below.
The problem is that surrounding black cells are not classified as nodata, but have differing values such as 0/0/0, 1/0/1, 2/0/1...Thus it takes take time and effort to choose all of them in e.g. raster calculator. Also these values might exist in the area of interest.
For example, if I would set value 1/0/1 to be transparent in layer properties --> transparency dialog, I get the result shown below.
Does anyone have any tips about how to proceed with this? Am I forced to manually create a masking polygon?