In ImageViz, a volume data can be considered either as a 3D image or as a stack of 2D images. Most of ImageViz processing engine working on volumes can consider the input data in both ways thanks to the OIV.ImageViz.Engines.SoImageVizEngine.ComputeModes field.

The Image Manipulation category contains engines for applying operations specific to image stacks, such as extracting a 2D image from an image stack.