In Press
Peli E, Jung J-H. Multiplexing prisms for field expansion. Optometry and Vision Science . In Press.
Peli E, Jung J-H.; Submitted. Active confocal imaging systems and methods for visual prostheses. United States of America patent Provisional Patent Application 2014.
Peli E, Bowers A, Keeney K, Jung J-H. High Power Prismatic Devices for Oblique Peripheral Prisms. Optometry and Vision Science. 2016;93 (5).
Jung J-H, Pu T, Peli E. Comparing object recognition from binary and bipolar edge images for visual prostheses. Journal of Electronic Imaging [Internet]. 2016;25 (6) :061619 . Publisher's VersionAbstract

Visual prostheses require an effective representation method due to the limited display condition which has only 2 or 3 levels of grayscale in low resolution. Edges derived from abrupt luminance changes in images carry essential information for object recognition. Typical binary (black and white) edge images have been used to represent features to convey essential information. However, in scenes with a complex cluttered background, the recognition rate of the binary edge images by human observers is limited and additional information is required. The polarity of edges and cusps (black or white features on a gray background) carries important additional information; the polarity may provide shape from shading information missing in the binary edge image. This depth information may be restored by using bipolar edges. We compared object recognition rates from 16 binary edge images and bipolar edge images by 26 subjects to determine the possible impact of bipolar filtering in visual prostheses with 3 or more levels of grayscale. Recognition rates were higher with bipolar edge images and the improvement was significant in scenes with complex backgrounds. The results also suggest that erroneous shape from shading interpretation of bipolar edges resulting from pigment rather than boundaries of shape may confound the recognition.

Qiu C, Spano L, Tuccar M, Goldstein R, Jung J-H, Peli E. Judging pedestrian collisions in open-space walking simulations, in American Academy of Optometry 2016. ; 2016.
Jung J-H, Pu T, Peli E. Comparing object recognition from binary and bipolar edge features. IS&T Human Vision and Electronic Imaging XXI. 2016.
Jung J-H, Peli E. Multiplexing prism prescription glasses for field expansion of monocular vision. American Academy of Optometry 2015. 2015.
Jung J-H, Aloni D, Yitzhaky Y, Peli E. Active Confocal Imaging for Visual Prostheses. Vision Research [Internet]. 2015;111 (June) :182-196. Publisher's VersionAbstract

There are encouraging advances in prosthetic vision for the blind, including retinal and cortical implants, and other “sensory substitution devices” that use tactile or electrical stimulation. However, they all have low resolution, limited visual field, and can display only few gray levels (limited dynamic range), severely restricting their utility. To overcome these limitations, image processing or the imaging system could emphasize objects of interest and suppress the background clutter. We propose an active confocal imaging system based on light-field technology that will enable a blind user of any visual prosthesis to efficiently scan, focus on, and “see” only an object of interest while suppressing interference from background clutter. The system captures three-dimensional scene information using a light-field sensor and displays only an in-focused plane with objects in it. After capturing a confocal image, a de-cluttering process removes the clutter based on blur difference. In preliminary experiments we verified the positive impact of confocal-based background clutter removal on recognition of objects in low resolution and limited dynamic range simulated phosphene images. Using a custom-made multiple-camera system, we confirmed that the concept of a confocal de-cluttered image can be realized effectively using light field imaging.

Kim J, Jung J-H, Jeong Y, Hong K, Lee B. Real-time integral imaging system for light field microscopy. Opt. Express [Internet]. 2014;22 :10210–10220. Publisher's VersionAbstract
We propose a real-time integral imaging system for light field microscopy systems. To implement a 3D live in-vivo experimental environment for multiple experimentalists, we generate elemental images for an integral imaging system from the captured light field with a light field microscope in real-time. We apply the f-number matching method to generate an elemental image to reconstruct an undistorted 3D image. Our implemented system produces real and orthoscopic 3D images of micro objects in 16 frames per second. We verify the proposed system via experiments using Caenorhabditis elegans.
Jung J-H, Peli E. Confocal Imaging for Visual Prostheses, in US Army Medical Research and Materiel Command/“Art of the Possible” in Vision Restoration Workshop. Vol [Invited Talk]. Frederick, MD ; 2014.
Jung J-H, Peli E. Multiplexing prism glasses for field expansion in bitemporal hemianopia, in ARVO 2014. Orlando, FL ; 2014.
Jung J-H, Peli E. Configuring multiplexing prism for field expansion of acquired monocular vision and normally sighted, in Vision 2014 (11th International Conference on Low Vision). Melbourne, Australia ; 2014. [PDF]
Jung J-H, Peli E. Impact of high power and high incidence angles on peripheral prisms for homonymous hemianopia, in Vision 2014 (11th International Conference on Low Vision). Melbourne, Australia ; 2014. [PDF]
Jung J-H. Distortions to visual field expansion with high-power Fresnel prisms. SPIE Newsroom [Internet]. 2014 :DOI: 10.1117/2.1201402.005350. Publisher's Version [PDF]
Jung J-H, Peli E. Impact of high power and angle of incidence on prism corrections for visual field loss. Optical Engineering [Internet]. 2014;53 (6) :061707. Publisher's VersionAbstract
Abstract.  Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high-power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.
Jung J-H, Kim J, Lee B. Solution of pseudoscopic problem in integral imaging for real-time processing. Opt. Lett. [Internet]. 2013;38 :76–78. Publisher's VersionAbstract
Proposed is a very effective conversion method from pseudoscopic (PS) to orthoscopic elemental image with adjustable depth position of a reconstructed three-dimensional (3D) object for integral imaging (InIm) in real-time. The proposed method is based on the interweaving process in multi-view display (MVD) with consideration of the difference between the ray sampling method of MVD and InIm. The simple transformation matrix formalism enables the real-time conversion from pickup image to display image based on InIm without a PS problem.
Kim J, Jung J-H, Lee B. Real-time pickup and display integral imaging system without pseudoscopic problem, in Proc. SPIE. 8643, Advances in Display Technologies III. ; 2013 :864303-864303-7. Publisher's Version
Park S-gi, Jung J-H, Jeong Y, Lee B. Depth-fused display with improved viewing characteristics. Opt. Express [Internet]. 2013;21 (23) :28758–28770. Publisher's VersionAbstract
We propose a depth-fused display (DFD) with enhanced viewing characteristics by hybridizing the depth-fusing technology with another three-dimensional display method such as multi-view or integral imaging method. With hybridization, the viewing angle and expressible depth range can be extended without changing the size of the volume of the system compared to the conventional DFD method. The proposed method is demonstrated with experimental system.
Kim J, Jung J-H, Jang C, Lee B. Real-time capturing and 3D visualization method based on integral imaging. Opt. Express [Internet]. 2013;21 :18742–18753. Publisher's VersionAbstract
We propose a real-time capturing and 3D visualization method based on integral imaging. We applied real-time conversion algorithm to conventional integral imaging pickup system. Gap control method with depth plane adjustment is also applied to improve image quality. Implemented system provides real-time 3D images with ultra high definition resolution in 20 frames per second, and the observer can change depth planes freely. Simulations and experimental results show the validity of proposed system.
Dupuis M, Jung J-H, Peli E. Calculating Field Expansion and Apical Scotoma Size in Optical Correction for Homonymous Hemianopia, in BMES 2013 Annual meeting. ; 2013 :P-Sat-B-24.