Patents by Inventor Shrinath Ramaswami

Shrinath Ramaswami has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10319113
    Abstract: A method for performing restoration for highlights and saturated regions in a digital image includes analyzing the pixels in the image and compensating an appropriate amount to identified highlights and saturated pixels. For a pixel with vertical color channels, the output for each channel is highly correlated, and each color channel can be recovered as a combination of the other channels. Each selected pixel in the highlights or saturated regions is identified as a restorable pixel only if at least two color channels of the pixel are not saturated. For each restorable pixel, a replacement pixel value is generated by using the equation derived from the color channels correlation. For pixels where more than one color channel is saturated, the similarity is calculated between these pixels and restored pixels. These pixels can be compensated using the combination of the similarity index and the pixel values of other color channels.
    Type: Grant
    Filed: June 21, 2017
    Date of Patent: June 11, 2019
    Assignee: Foveon, Inc.
    Inventors: Jiashu Zhang, Shrinath Ramaswami, Ion Uehara
  • Patent number: 10178328
    Abstract: A method for performing color density filtering of images captured in a digital camera having a mechanical shutter and an imaging array including a plurality of pixels each including different color sensors aligned with each other, including opening the mechanical shutter, resetting all of the color sensors in each pixel by asserting a row reset signal, separately asserting color-select signals for each color after the mechanical shutter is opened, independently starting exposure for each different color sensor at a color sensor exposure start time by de-asserting its color select signal, the exposure start time for each different color sensor being a function of a color density filter function, closing the mechanical shutter, and reading color exposure values from the color sensors by separately asserting color-select signals after the mechanical shutter has closed, the reading being unrelated to the start times for the color sensors.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: January 8, 2019
    Assignee: Foveon, Inc.
    Inventors: Shrinath Ramaswami, Glenn J. Keller
  • Publication number: 20180374240
    Abstract: A method for performing restoration for highlights and saturated regions in a digital image includes analyzing the pixels in the image and compensating an appropriate amount to identified highlights and saturated pixels. For a pixel with vertical color channels, the output for each channel is highly correlated, and each color channel can be recovered as a combination of the other channels. Each selected pixel in the highlights or saturated regions is identified as a restorable pixel only if at least two color channels of the pixel are not saturated. For each restorable pixel, a replacement pixel value is generated by using the equation derived from the color channels correlation. For pixels where more than one color channel is saturated, the similarity is calculated between these pixels and restored pixels. These pixels can be compensated using the combination of the similarity index and the pixel values of other color channels.
    Type: Application
    Filed: June 21, 2017
    Publication date: December 27, 2018
    Applicant: Foveon, Inc.
    Inventors: Jiashu Zhang, Shrinath Ramaswami, Ion Uehara
  • Publication number: 20180324372
    Abstract: A method for performing color density filtering of images captured in a digital camera having a mechanical shutter and an imaging array including a plurality of pixels each including different color sensors aligned with each other, including opening the mechanical shutter, resetting all of the color sensors in each pixel by asserting a row reset signal, separately asserting color-select signals for each color after the mechanical shutter is opened, independently starting exposure for each different color sensor at a color sensor exposure start time by de-asserting its color select signal, the exposure start time for each different color sensor being a function of a color density filter function, closing the mechanical shutter, and reading color exposure values from the color sensors by separately asserting color-select signals after the mechanical shutter has closed, the reading being unrelated to the start times for the color sensors.
    Type: Application
    Filed: June 29, 2018
    Publication date: November 8, 2018
    Applicant: Foveon, Inc.
    Inventors: Shrinath Ramaswami, Glenn J. Keller
  • Patent number: 10021320
    Abstract: In a digital camera having an imaging array including a plurality of pixels arranged in rows and columns, the digital camera having a mechanical shutter, a method for performing neutral density filtering of images captured by the imaging array, the method comprising opening the mechanical shutter, operating each row in the array by resetting all of the pixel sensors in the row, starting exposure for all of the pixel sensors in the row, closing the mechanical shutter, reading pixel values from the pixels in the array after the mechanical shutter has closed at a time unrelated to a time at which any pixel-select signal was de-asserted, and wherein the interval of time between starting exposure for all of the pixel sensors in the row and closing the mechanical shutter for each row a function of a neutral density filter function applied to an image to be captured.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: July 10, 2018
    Assignee: Foveon, Inc.
    Inventors: Shrinath Ramaswami, Glenn J. Keller
  • Publication number: 20170374302
    Abstract: In a digital camera having an imaging array including a plurality of pixels arranged in rows and columns, the digital camera having a mechanical shutter, a method for performing neutral density filtering of images captured by the imaging array, the method comprising opening the mechanical shutter, operating each row in the array by resetting all of the pixel sensors in the row, starting exposure for all of the pixel sensors in the row, closing the mechanical shutter, reading pixel values from the pixels in the array after the mechanical shutter has closed at a time unrelated to a time at which any pixel-select signal was de-asserted, and wherein the interval of time between starting exposure for all of the pixel sensors in the row and closing the mechanical shutter for each row a function of a neutral density filter function applied to an image to be captured.
    Type: Application
    Filed: June 28, 2016
    Publication date: December 28, 2017
    Applicant: Foveon, Inc.
    Inventors: Shrinath Ramaswami, Glenn J. Keller
  • Patent number: 6777662
    Abstract: An extended dynamic range pixel cell providing blooming protection is disclosed herein. By applying a timed varying signal to a shunt transistor in order to shunt excess charge generated by a photosensor in response to high intensity illumination, blooming protection can be provided. In particular configurations, blooming protection is provided not only during an integration period but also during a readout period when the pixel cell is generally most susceptible to blooming problems. The time varying voltage is also used to extend the dynamic range of the pixel cell thereby increasing the pixel cells usefulness in high contrast conditions, such as bright sunlight casting deep shadows, nighttime automotive applications, and the like.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: August 17, 2004
    Assignee: FreeScale Semiconductor, Inc.
    Inventors: Clifford I. Drowley, Shrinath Ramaswami
  • Publication number: 20040021058
    Abstract: An extended dynamic range pixel cell providing blooming protection is disclosed herein. By applying a timed varying signal to a shunt transistor in order to shunt excess charge generated by a photosensor in response to high intensity illumination, blooming protection can be provided. In particular configurations, blooming protection is provided not only during an integration period but also during a readout period when the pixel cell is generally most susceptible to blooming problems. The time varying voltage is also used to extend the dynamic range of the pixel cell thereby increasing the pixel cells usefulness in high contrast conditions, such as bright sunlight casting deep shadows, nighttime automotive applications, and the like.
    Type: Application
    Filed: July 30, 2002
    Publication date: February 5, 2004
    Inventors: Clifford I. Drowley, Shrinath Ramaswami
  • Patent number: 6541794
    Abstract: An imaging circuit (10) is formed on a semiconductor substrate (40) having first and second regions (41, 42) for capturing a light signal (LIGHT) to produce first and second charges, respectively. A conductive material (52, 53) is extended from the first region to the second region for controlling the first and second charges in response to a control signal (COL1, ROW1) to produce an output signal (VOUT) of the imaging circuit.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: April 1, 2003
    Assignee: Motorola, Inc.
    Inventors: Jennifer J. Patterson, Clifford I. Drowley, Shrinath Ramaswami
  • Patent number: 6221686
    Abstract: An image sensor (10) has an image sensing element that includes an N-type conducting region (26) and a P-type pinned layer (37). The two regions form two P-N junctions at different depths that increase the efficiency of charge carrier collection at different frequencies of light. The conducting region (26) is formed by an angle implant that ensures that a portion of the conducting region (26) can function as a source of a MOS transistor (32).
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: April 24, 2001
    Assignee: Motorola, Inc.
    Inventors: Clifford I. Drowley, Mark S. Swenson, Jennifer J. Patterson, Shrinath Ramaswami
  • Patent number: 6023081
    Abstract: An image sensor (10) has an image sensing element that includes an N-type conducting region (26) and a P-type pinned layer (37). The two regions form two P-N junctions at different depths that increase the efficiency of charge carrier collection at different frequencies of light. The conducting region (26) is formed by an angle implant that ensures that a portion of the conducting region (26) can function as a source of an MOS transistor (32).
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: February 8, 2000
    Assignee: Motorola, Inc.
    Inventors: Clifford I. Drowley, Mark S. Swenson, Jennifer J. Patterson, Shrinath Ramaswami
  • Patent number: 5783475
    Abstract: A method of forming a spacer (41) around a gate electrode (32) includes sequentially disposing a first layer (48), a second layer (36), and a third layer (37) of dielectric over a semiconductor substrate (31) and over the gate electrode (32) and, thereafter, sequentially etching the third (37), second (36), and first (48) layers. The third layer (37) is etched with a first etchant to define a width (51) for the spacer (41). The first etchant selectively etches the third layer (37) versus the second layer (36). Etching the third layer (37) does not expose the first layer (48) located beneath the second layer (36). A second etchant, which is different from the first etchant, is used to selectively etch the second layer (36) versus the first layer (48). Etching the second layer (36) does not expose the semiconductor substrate (31) located beneath the first layer (48).
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: July 21, 1998
    Assignee: Motorola, Inc.
    Inventor: Shrinath Ramaswami
  • Patent number: 5374568
    Abstract: A method for forming an improved base link for a bipolar transistor is provided. The wall where the base link (44) is formed is substantially vertical (32,34). An oxide mask (24) is use during etching of the polysilicon layer (18) that provides the wall, instead of a conventional photoresist mask. The preferred method is compatible with manufacturing BiCMOS devices.
    Type: Grant
    Filed: September 23, 1993
    Date of Patent: December 20, 1994
    Assignee: Motorola, Inc.
    Inventors: Wen-Ling M. Huang, Shrinath Ramaswami, Maureen F. Grimaldi