I have various scanned images in different file formats (jpg, tiff, png) and I need to georeference, clip by polygons and export those images.
As a result I need to have a 8 bit png file with transparacy (the clipped areas) on colormap index value 255. I can set the NoData value during the clipping process but as a result I have an image with only 254 colors and a transparancy in ArcGIS (through symbology) but outside of my GIS environment the clipped areas appear as black 'borders'. Could someone describe a workflow where I get png files with 8 bit color depth and transparancy outside of GIS, saved on the index 255?