I have an issue to enable alpha channel in arcgis image service.
Image service published from a mosaic dataset in sde DB. The image files are geotiff images with 2 bands. First band supposed to be grey value and second - alpha channel. I use extract band function (with parameter "1 1 1 2") in function chain of image service and it returns 4 bands as i want. But the alpha band still not activated - returned image is just first three band raster with no alpha.
In client i tried to set raster format to "png32" but it not help.
As alternative I published Map Service of this mosaic dataset and manually activate alpha channel in symbology tab. But I want an image service with alpha channel not a map service.