112/03/2004 Vision-Realistic Rendering: Simulation of the Scanned Foveal Image from Wavefront Data of Human Subjects, Brian A. Barsky, 2004 Gazihan Alankus

212/03/2004 Introduction ● A new concept: vision-realistic rendering – Rendering scenes as someone really sees them – Simulating the optical properties of the eye to get the retinal image ● Applications – Creating more realistic renderings – Educating eye doctors and patients

312/03/2004 Ideal Way ● Trace rays from every photoreceptor in retina – Not feasible with current technology ● Approximation using wavefront aberromery – A technology used for laser surgeries such as LASIK – Measures only one point in retina with a laser beam

412/03/2004 Wavefront Aberrometry ● 1mm laser beam is sent to the fovea using the half-silvered mirror ● Fovea acts as a point light source and sends light out of the eye ● The light is focused on the sensor using a lenslet array

512/03/2004 Wavefront Aberrometry Actual Image

612/03/2004 Algorithm

712/03/2004 Object Space Point Spread Function ● The vectors computed using the displacements of spots are converted to a surface using Zernkie polynomials ● A continuous blurring function in object space is necessary – A discrete approximated version is used for a number of depth levels (Depth point spread functions) – Each surface normal is traced and counters in grids of given depth levels are incremented, and normalized at the end

812/03/2004 Rendering ● In order to see the whole image, people scan the image by moving their eyes ● All the image is rendered using the simulation for the fovea – Looks realistic since people will move their eyes to see the whole image

912/03/2004 Rendering ● For each chosen depth, an image is rendered ● Each depth image is convolved with its corresponding grid (DPSF) ● A composite image is created using alpha blending from far to near

1012/03/2004 Results

1112/03/2004 Results Patient with keratoconus

1212/03/2004 Results

1312/03/2004 Results

1412/03/2004 Results

1512/03/2004 Conclusion ● The image on the fovea is simulated to have a much better perceptually realistic image ● How patients with certain eye conditions see is made available for education and better treatment ● Whole image is rendered using the same distortion – If we have the technology to get information about more than one spot on retina, eye tracking can be used to show different renderings at different eye directions