Spatial Transfiguration: Anamorphic Mixed-Reality in the Virtual Reality Panorama

Spatial illusion and immersion was achieved in Renaissance painting through the manipulation of linear perspective’s pictorial conventions and painterly technique. The perceptual success of a painted trompe l’œil, its ability to fool the observer into believing they were viewing a real three-dimensional scene, was constrained by the limited immersive capacity of the two-dimensional painted canvas. During the baroque period however, artists began to experiment with the amalgamation of the ‘real’ space occupied by the observer together with the pictorial space enveloped by the painting’s picture plane: real and pictorial space combined into one pictorial composition resulting in a hybridised ‘mixed-reality’. Today, the way architects, and designers generally, use the QuickTime Virtual Reality panorama to represent spaces of increasing visual density have much to learn from the way in which Renaissance and baroque artists manipulated the three-dimensional characteristics of the picture plane in order to offer more convincing spatial illusions. This paper outlines the conceptual development of the QuickTime VR panorama by Ken Turkowski and the Apple Advanced Technology Group during the late 1980s. Further, it charts the technical methods of the Virtual Reality panorama’s creation in order to reflect upon the VR panorama’s geometric construction and range and effectiveness of spatial illusion. Finally, through a brief analysis of Hans Holbein’s Ambassadors [1533] and Andrea Pozzo’s nave painting in Sant ‘Ignazio [1691-94] this paper proposes an alternative conceptual model for the pictorial construction of the VR panorama that is innovatively based upon an anamorphic ‘mixed-reality’

Laryngoscopic Image Stitching for View Enhancement and Documentation - First Experiences

One known problem within laryngoscopy is the spatially limited view onto the hypopharynx and the larynx through the endoscope. To examine the complete larynx and hypopharynx, the laryngoscope can be rotated about its main axis, and hence the physician obtains a complete view. If such examinations are captured using endoscopic video, the examination can be reviewed in detail at a later time. Nevertheless, in order to document the examination with a single representative image, a panorama image can be computed for archiving and enhanced documentation. Twenty patients with various clinical findings were examined with a 70 rigid laryngoscope, and the video sequences were digitally stored. The image sequence for each patient was then post-processed using an image stitching tool based on SIFT features, the RANSAC approach and blending. As a result, endoscopic panorama images of the larynx and pharynx were obtained for each video sequence. The proposed approach of image stitching for laryngoscopic video sequences offers a new tool for enhanced visual examination and documentation of morphologic characteristics of the larynx and the hypopharynx

Dual-fisheye lens stitching for 360-degree imaging

Dual-fisheye lens cameras have been increasingly used for 360-degree immersive imaging. However, the limited overlapping field of views and misalignment between the two lenses give rise to visible discontinuities in the stitching boundaries. This paper introduces a novel method for dual-fisheye camera stitching that adaptively minimizes the discontinuities in the overlapping regions to generate full spherical 360-degree images. Results show that this approach can produce good quality stitched images for Samsung Gear 360 -- a dual-fisheye camera, even with hard-to-stitch objects in the stitching borders.Comment: ICASSP 17 preprint, Proc. of the 42nd IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), New Orleans, USA, March 201

An optimized algorithm of image stitching in the case of a multi-modal probe for monitoring the evolution of scars

International audienceWe propose a new system that makes possible to monitor the evolution of scars after the excision of a tumorous dermatosis. The hardware part of this system is composed of a new optical innovative probe with which two types of images can be acquired simultaneously: an anatomic image acquired under a white light and a functional one based on autofluorescence from the protoporphyrin within the cancer cells. For technical reasons related to the maximum size of the area covered by the probe, acquired images are too small to cover the whole scar. That is why a sequence of overlapping images is taken in order to cover the required area. The main goal of this paper is to describe the creation of two panoramic images (anatomic and functional). Fluorescence images do not have enough salient information for matching the images; stitching algorithms are applied over each couple of successive white light images to produce an anatomic panorama of the entire scar. The same transformations obtained from this step are used to register and stitch the functional images. Several experiments have been implemented using different stitching algorithms (SIFT, ASIFT and SURF), with various transformation parameters (angles of rotation, projection, scaling, etc...) and different types of skin images. We present the results of these experiments that propose the best solution. Thus, clinician has two panoramic images superimposed and usable for diagnostic support. A collaborative layer is added to the system to allow sharing panoramas among several practitioners over different places

Beyond Gr\"obner Bases: Basis Selection for Minimal Solvers

Many computer vision applications require robust estimation of the underlying geometry, in terms of camera motion and 3D structure of the scene. These robust methods often rely on running minimal solvers in a RANSAC framework. In this paper we show how we can make polynomial solvers based on the action matrix method faster, by careful selection of the monomial bases. These monomial bases have traditionally been based on a Gr\"obner basis for the polynomial ideal. Here we describe how we can enumerate all such bases in an efficient way. We also show that going beyond Gr\"obner bases leads to more efficient solvers in many cases. We present a novel basis sampling scheme that we evaluate on a number of problems