Our SIGGRAPH '96 Electronic Theatre Video


Overview

Our video was accepted in the SIGGRAPH '96 Electronic Theatre. The title for our video is The OPTICAL Project at UC Berkeley: Computer Aided Cornea Modeling and Visualization.

The Video (big)

(1996 Siggraph Electronic Theatre OPTICAL Visualization big video)
28Mb 320x240 10fps (22KHz Audio)

The Video (small)

(1996 Siggraph Electronic Theatre OPTICAL Visualization small video)
5.7Mb 160x120 5fps (11KHz Audio)

The Storyboard

(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 00 called Title) (Title Screen)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 01 called Neha) At the University of California at Berkeley, the OPTICAL project is a multidisciplinary effort in the Computer Science Division and School of Optometry.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 02 called Acronym) "OPTICAL" is an acronym for "OPtics and Topography Involving the Cornea And Lens". This project is concerned with the computer-aided measurement, modeling, reconstruction, and visualization of the shape of the human cornea, called corneal topography.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 03 called NehasEye) The cornea is the transparent tissue covering the front of the eye.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 04 called LabeledCornea) It performs 3/4 of the refraction, or bending, of light in the eye, and focuses light towards the lens and the retina. Thus, subtle variations in the shape of the cornea can significantly diminish visual performance.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 05 called ContactLenses) Eye care practitioners need to know the shape of a patient's cornea to fit contact lenses,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 06 called Surgery) to plan and evaluate the results of surgeries that improve vision by altering the shape of the cornea,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 07 called Keratoconus) and to diagnose keratoconus, an eye condition where the cornea has an irregular shape with a local protrusion, or "cone", which has dramatic effects on vision.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 08 called ThreeReasons) (Summarized reasons why eye clinicians need to know the shape of patients' corneas)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 09 called BrianWheeledUp) Recently, instruments to measure corneal topography have become commercially available. These devices, called videokeratographs,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 10 called Measurement) typically shine rings of light onto the cornea and then capture the reflection pattern with a built-in video camera.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 11 called Videokeratograph) Instead of allowing the videokeratograph to process the pattern,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 12 called VKCloseUp) we at the OPTICAL project extract the data and
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 13 called MeasReconModelVis) construct a mathematical spline surface representation from these reflection patterns,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 14 called Reconstruction) as is described in our SIGGRAPH '96 paper. In addition to developing this novel modeling algorithm, we are exploring new scientific visualization techniques to display the resulting information in an intuitive and accurate manner. This video compares our new visualization methods with an existing technique. Using our modeling and visualization software, we will first show real keratoconic data and then a simulated keratoconic model.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 15 called Visualization) The most popular display of corneal topography is called the "corneal map". This is similar to a topographic map where equal values of some parameter are displayed in the same color.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 16 called AxialPower) The usual parameter that is displayed is called axial power. However, as we will show, this can produce misleading results.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 17 called GaussianPower) We are proposing a pair of alternative parameters that overcome this problem: Gaussian power, which is related to the geometric mean of the minimum and maximum curvatures at each data point,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 18 called Cylinder) and cylinder, related to the difference between the maximum and minimum curvatures at each data point.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 19 called ModellingWireframe) We compute the values of these parameters using our reconstructed spline surface model.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 20 called BrianWheeledUp) Let's look at the corneal data from the patient we saw being measured earlier.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 21 called BBAllNothing) His cornea has a cone in the lower right (our left).
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 22 called BBAllAxialPowerOnly) The top two corneal maps show axial power,
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 23 called BBAllAxialGaussLabel) and the bottom maps show Gaussian power.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 24 called BBAllRegularBoxed) The left pair shows regular fixation where the patient is looking directly into the videokeratograph.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 25 called BBAllConicBoxed) In the right pair, the patient has shifted his gaze up toward his left so that the cone aligns with the center of the videokeratograph; we call this conic alignment.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 26 called BBAllAxialArrows) As we compare the two representations, we note an important difference: For different gaze directions, the shape and values of the cone region as depicted in the axial power maps differ
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 27 called BBAllAxial5778Circled) (for example, the values at the cone center are 57 and 78 Diopters)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 28 called BBAllWithAllCircled) but remain invariant with our Gaussian power map. In other words, by simply changing the direction of the patient's gaze, axial power yields two conflicting descriptions of the cone whereas our proposed visualization does not have this problem.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 29 called ModelWithoutConus) Now let's look at a simulated cornea. These four windows all display the same keratoconic model. The upper left animation indicates how we scale and move the cone around, while the other images show corneal maps displaying different parameters. Axial power is shown in the upper right, Gaussian power in the lower left, and cylinder in the lower right.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 30 called ModelConus15Deg) The model of our simulated cone is rotationally symmetric, and maintains a constant shape when moving across and around the cornea.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 31 called ModelConus0Deg) Our two new visualizations faithfully represent the symmetry and shape invariance.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 32 called ModelConusNeg20Deg) However, axial power fails on both accounts, erroneously showing the cone region as significantly changing shape as it moves around and across the cornea, which is what we saw earlier.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 33 called MeasReconModelVis) This video has shown how the OPTICAL project is developing new computer aided cornea modeling and visualization techniques to enable eye care clinicians to help people overcome some of their difficult vision problems.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 34 called Credits0) Roll credits.
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 35 called Credits1)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 36 called Credits2)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 37 called Credits3)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 38 called Credits4)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 39 called Credits5)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 40 called Credits6)
(1996 Siggraph Electronic Theatre OPTICAL Visualization Scene 41 called Credits7) An inside joke. We found it funny.


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