Move RGB/RGBA checks to base class (#4171)
Move RGB/RGBA checks to base class (#4171)

Signed-off-by: Behrooz <fa30078e2c18f830d36abc3155a658058044d11c@users.noreply.github.com>

Co-authored-by: Nic Ma <b0dc69321d91891b55520ef34f868910ffd06e02@nvidia.com>
Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI