1. An E-mode imaging apparatus comprising: a compressor adapted to apply a varying deformation to a material to be imaged; an image acquisition system collecting a series of images of the material to be imaged during different stages of deformation by the compressor; an electronic computer receiving the series of images to generate E-mode images with a quality value singly indicating a quality of E-mode data obtainable from a currently acquired subset of the series of images; and an output of the quality value in adjusting the varying deformation to improve the quality of E-mode data.