US 11,812,167 B2
Determining pixel intensity values in imaging
Mathivanan Damodaran, 'S-Hertogenbosch (NL); Rieko Verhagen, Vught (NL); Yannyk Parulian Julian Bourquin, Eindhoven (NL); and Jonathan Alambra Palero, Waalre (NL)
Assigned to KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
Appl. No. 17/798,585
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
PCT Filed Feb. 3, 2021, PCT No. PCT/EP2021/052460
§ 371(c)(1), (2) Date Aug. 10, 2022,
PCT Pub. No. WO2021/165035, PCT Pub. Date Aug. 26, 2021.
Claims priority of application No. 20158431 (EP), filed on Feb. 20, 2020.
Prior Publication US 2023/0089886 A1, Mar. 23, 2023
Int. Cl. H04N 25/47 (2023.01); H04N 23/745 (2023.01); H04N 25/48 (2023.01)
CPC H04N 25/47 (2023.01) [H04N 23/745 (2023.01); H04N 25/48 (2023.01)] 19 Claims
OG exemplary drawing
 
1. A computer-implemented method comprising:
accessing data from a sequence of images, obtained by an imaging device, of a subject illuminated with ambient lighting and illumination having a sinusoidal intensity modulation in time, wherein the imaging device is configured to operate in rolling shutter mode to obtain, within each image of the sequence of images, a first spatial portion of the image at a different time to a different, second spatial portion of the image, wherein a relationship between a frequency of the sinusoidal intensity modulation and a frame rate of the imaging device is such that a different spatial intensity modulation pattern is apparent in consecutive images of the sequence of images, and
determining, based on a set of measure pixel intensity values in each image of the sequence of images, a set of revised pixel intensity values for generating a revised image of the subject by computing, for each pixel of the set of revised pixel intensity values, a specified combination of the pixel's measured pixel intensity values from each image of the sequence of images that generates the set of revised pixel intensity values that correspond to a reduced level of ambient lighting and a reduced modulation depth of the spatial intensity modulation pattern being apparent in the revised image compared with a level of ambient lighting and a modulation depth of the spatial intensity modulation pattern apparent in at least one image of the sequence of images, wherein the specified combination is based on the image device operating in the rolling shutter mode and the sinusoidal intensity modulation of the illumination resulting, due to a convolution property of harmonic temporal modulation, in each of the pixel's measured pixel intensity values from each image of the sequence of images exhibiting a sinusoidal intensity variation across the sequence of images.