Name of the image to be sampled. Source list table. Whether to get image positions directly or via RA/dec values. Name of the column of the source table which contains the X pixel coordinate. Name of the column of the source table which contains the Y pixel coordinate. Name of the column of the source table which contains RA in decimal degrees. Name of the column of the source table which contains dec in decimal degrees. Name of the column of the source table to which the image values should be written.