Patents by Inventor Vrishab Krishna

Vrishab Krishna 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: 10956735
    Abstract: A system for determining a refractive error from a red reflex image of the eyes of a subject by analyzing the red reflex image of the subject using deep learning and clustering algorithms is provided. The system (i) predicts a probability map for each of sixteen eye landmarks on a contour of an iris of the eye, (ii) determines a location of an eye landmark on the eye-region image, (iii) determines a circular mask of the iris, (iv) extracts an iris region image between the circular mask of the iris and the eye-region image, (v) generates a plurality of clusters by identifying a similarity between pixels of the iris region image, (vi) determines a crescent of the red reflex in the iris, (viii) predicts a pupil radius, (ix) determines a width of the crescent, and (x) determines a power in each eye by computing a width of an anti-crescent, eccentricity of an image capturing device, a working distance of the image capturing device.
    Type: Grant
    Filed: October 20, 2020
    Date of Patent: March 23, 2021
    Inventors: Vrishab Krishna, Viswesh Krishna
  • Patent number: 10617294
    Abstract: A system for determining a spherical power of the eyes of the subject based on the measured refractive error associated with the red reflex image is provided. The system (i) predicts a position of a plurality of facial landmarks on the facial image of the subject, (ii) extracts the eyes from the facial image based on the facial landmarks, (iii) determines a position of the eyelid, (iv) determines a red reflex in the iris of the eye, (v) locates the red reflex with a reddish hue and a crescent in the iris for measuring the refractive error, (vi) generates a mask of the crescent by thresholding the red reflex image, (vii) determines a width of anti-crescent in the red reflex image, and (viii) determines a spherical power using the width of the anti-crescent, eccentricity and working distance of the image capturing device and a diameter of the pupil.
    Type: Grant
    Filed: April 17, 2019
    Date of Patent: April 14, 2020
    Inventors: Viswesh Krishna, Vrishab Krishna
  • Patent number: 10580133
    Abstract: Techniques for estimating blepharoptosis from an image of a face are disclosed. The image is captured by a camera. Histogram of Oriented Gradients and Linear Classifiers are used to predict the location of the face and eyes. An Ensemble of Regression Trees is used to detect points on each eyelid and the canthi. The location of the iris is ascertained by thresholding HLS values of individual pixels and applying a sliding window algorithm. Using regression, the eyelid shape curve is approximated. The eyelid shape curve function is used to measure the MRD1 value and distance below the limbus after detecting the Purkinje image/corneal light reflex. Finally, the intensity of blepharoptosis is estimated by categorizing the measured MRD1 and distance-from-Limbus values.
    Type: Grant
    Filed: September 24, 2018
    Date of Patent: March 3, 2020
    Inventors: Viswesh Krishna, Vrishab Krishna
  • Publication number: 20190370959
    Abstract: Techniques for estimating blepharoptosis from an image of a face are disclosed. The image is captured by a camera. Histogram of Oriented Gradients and Linear Classifiers are used to predict the location of the face and eyes. An Ensemble of Regression Trees is used to detect points on each eyelid and the canthi. The location of the iris is ascertained by thresholding HLS values of individual pixels and applying a sliding window algorithm. Using regression, the eyelid shape curve is approximated. The eyelid shape curve function is used to measure the MRD1 value and distance below the limbus after detecting the Purkinje image/corneal light reflex. Finally, the intensity of blepharoptosis is estimated by categorizing the measured MRD1 and distance-from-Limbus values.
    Type: Application
    Filed: September 24, 2018
    Publication date: December 5, 2019
    Inventors: Viswesh Krishna, Vrishab Krishna