Pravin U Rao

US Patent:

8089534, Jan 3, 2012

Filed:

Nov 4, 2008

Appl. No.:

12/264588

Inventors:

Pravin Rao - San Jose CA, US
Shane Hu - Fremont CA, US

Assignee:

Aptina Imaging Corporation - Grand Cayman

International Classification:

H04N 5/217

US Classification:

348241

Abstract:

Methods and systems for determining shading correction coefficients of an imaging device. An inversion surface is determined based on an image captured by the imaging device. The inversion surface is approximated using the captured image and eigenvectors associated with singular values of the inversion surface, to form multiple reconstruction weights. A polynomial fit is applied to: i) the multiple reconstruction weights to determine a first set of polynomial coefficients and ii) the eigenvectors to determine a second set of polynomial coefficients. The first and second sets of polynomial coefficients are used to form the shading correction coefficients.

US Patent:

20090076754, Mar 19, 2009

Filed:

Sep 17, 2007

Appl. No.:

11/898889

Inventors:

Dmitry Bakin - San Jose CA, US
Pravin Rao - San Jose CA, US

International Classification:

G06F 19/00

US Classification:

702 81

Abstract:

Methods, systems and apparatuses for modeling high resolution images which significantly shortens computation time and reduces image artifacts, as compared to known methods. Embodiments implement a look-up table, to compute once and store the point spread functions for various points of an image. During modeling of the optical system, previously stored point spread functions may be used to determine the point spread function for a specified point using a weighted interpolation of the point spread functions that have been stored for nearby points.

US Patent:

20130175429, Jul 11, 2013

Filed:

Jan 5, 2012

Appl. No.:

13/344111

Inventors:

Pravin Rao - San Jose CA, US
Ilia Ovsiannikov - Studio City CA, US

International Classification:

H01L 27/146

US Classification:

2502081

Abstract:

An image sensor that includes a pixel array including pixels that sample a plurality of modulation signals having different phases from the reflected light and that output pixel output signals corresponding to the plurality of modulation signals, the output pixel output signals being used to generate first images, an integral time adjusting unit that detects a change in an integral time applied to generate the first images such that the integral time adjusting unit compares intensities of the first images to a reference intensity and determines an adjusted integral time when the change in the integral time is detected, and when the change in the integral time is detected, the pixel array generates second images that are subsequent to the first images by applying the adjusted integral time determined by the integral time adjusting unit based on the first images.