An imaging system employing a volume holographic optical element (vHOE) has a unique feature by which the image of an object placed in front of a transparent screen can be captured. The system obtains an image of the light diffracted by the vHOE; however, unwanted background components, including direct reflection or transmitted components, are present in the captured image. In this study, we propose a method to eliminate such background components from the captured images via multispectral image processing. The image components obtained from the diffraction by vHOE can be successfully extracted utilizing the facts that it diffracts light with a narrow spectral range and the reflection spectrum of a natural object is mostly smooth in the wavelength axis. Computer simulations and experiments confirm the effectiveness of the proposed method, along with video applications that demonstrate its real-time capability.