I am looking at classifying an image to identify crop types.
I am interested in masking out all other landcover classes except crop class in the band stack false colour composite image e.g. buildings, roads, water, cloud,... in QGIS.
How would I go about this?
(a) classify the image, convert classes from raster to vector and clip the raster image to the vegetation vector polygon
(b) mask out the pixels using band math where by the pixel values for the unwanted classes are equaled to 0
I think both of these should theoretically work (apart from risk of pixel misclassification in approach (a) and an issue whereby the layer stack cannot be chosen as a source file in approach (b).