Temporal presentation protocols in stereoscopic displays: Flicker visibility, perceived motion, and perceived depth

Abstract

Most stereoscopic displays rely on field-sequential presentation to present different images to the left and right eyes. With sequential presentation, images are delivered to each eye in alternation with dark intervals, and each eye receives its images in counter phase with the other eye. This type of presentation can exacerbate image artifacts including flicker, and the appearance of unsmooth motion. To address the flicker problem, some methods repeat images multiple times before updating to new ones. This greatly reduces flicker visibility, but makes motion appear less smooth. This paper describes an investigation of how different presentation methods affect the visibility of flicker, motion artifacts, and distortions in perceived depth. It begins with an examination of these methods in the spatio-temporal frequency domain. From this examination, it describes a series of predictions for how presentation rate, object speed, simultaneity of image delivery to the two eyes, and other properties ought to affect flicker, motion artifacts, and depth distortions, and reports a series of experiments that tested these predictions. The results confirmed essentially all of the predictions. The paper concludes with a summary and series of recommendations for the best approach to minimize these undesirable effects.

Stereoscopic 3D display technique using spatiotemporal interlacing has improved spatial and temporal properties

“…Temporal interlacing is prone to temporal artifacts such as flicker, unsmooth motion appearance, and distortions of perceived depth [1]. Spatial interlacing results in lower spatial resolution at typical viewing distances [2] and can also cause distortions of perceived depth [3].…”

Stereoscopic 3D display with color interlacing improves perceived depth

“…The viewer wears passive glasses that contain filters with opposite polarization states such that one eye sees the images presented on odd pixel rows while the other eye sees the images presented on even rows [1,2]. By sending information simultaneously to the two eyes, spatial interlacing is not as prone to temporal artifacts as other techniques [3]. But spatial interlacing reduces the number of pixels delivered to each eye by half and therefore reduces the effective resolution of the display when the viewer is at the recommended viewing distance (for example, three times picture height for high-definition television).…”

“…Yet another instantiation uses active glasses that alternate between transmitting and blocking the images delivered to an eye [1,5]. These temporalinterlacing techniques present all pixels to each eye thereby maximizing effective resolution, but they are prone to temporal artifacts such as flicker and distortions of perceived depth [3]. It also restricts the frame rate of each view to half of the display's native frame rate.…”

“…For example, Fig. 2 shows data from Hoffman et al [3] in which a particular temporal-interlacing protocol was used to present a stimulus with a spatial disparity of zero that was moving at different speeds. There is close agreement between the predicted and observed depth distortions.…”

“…There is close agreement between the predicted and observed depth distortions. [3] presented stimuli using a temporal-interlacing protocol with Δt = 1/75sec (frame rate of 75Hz) and Δi = 1/150sec. They added spatial disparity in order to eliminate the distortion in perceived depth.…”