Prototype measurement setup to assess near-eye display imaging quality: an update
Near-eye displays–displays positioned in close proximity to the observer’s eye–are a technology continuing to gain significance in industrial and defense applications, e.g. for augmented reality and digital night vision. Fraunhofer IOSB has recently developed a specialized measurement setup for assessing the display capabilities of such devices as part of the optoelectronic imaging chain, with the primary focus on the Modulation Transfer Function (MTF). The setup consists of an imaging system with a high-resolution CMOS camera and a motorized positioning system. It is intended to run different measurement procedures semi-automatically, performing the desired measurements at specified points on the display. This paper presents the extended work on near-eye display imaging quality assessment following the initial publication. Using a commercial virtual reality headset as a sample display, we further refined the previously described MTF measurement procedures, with one method being based on bar pattern images and another method using a slanted edge image. Refinements include improvements to the processing of the camera images as well as to the method of extracting contrast measurements. Furthermore, we implemented an additional, line-image-based method for determining the device’s MTF. The impact of the refinements is examined and the results of the different methods are discussed with the goal to find the most suitable measurement procedures for our setup and to highlight the individual merits of different measurement methods.