A method and apparatus for establishing nondestructive inspection (106) porosity standards. In one illustrative embodiment, a plurality of samples (112) is formed using a different technique for each sample in the plurality of samples (112) such that each sample in the plurality of samples (112) has a different porosity from other samples in the plurality of samples (112). Each sample in the plurality of samples has a same set of selected properties as a selected part type (104). A porosity level is identified for each sample using volumetric data (148) extracted from a three-dimensional image (136) for each sample generated using a computed tomography system (132). A group of standards (102) is established for a group of selected porosity levels (156) from the plurality of samples (112) based on the porosity level identified for each sample in the plurality of samples (112). The group of standards (102) is configured for use in performing nondestructive inspection (106) of a part (108) of the selected part t
