Method of digitally processing a plurality of pixels and temperature measurement apparatus

Patent metadata

Field	Value
Publication number	US-2022405949-A1
Application number	US-202217837448-A
Country	US
Kind code	A1
Filing date	Jun 10, 2022
Priority date	Jun 22, 2021
Publication date	Dec 22, 2022
Grant date	—

Abstract

A method of digitally processing a plurality of pixels of an image captured using an array of sensing pixels of an optical sensor device. The method comprises identifying a measurement pixel of the plurality of pixels corresponding to a measurement point on a target to be measured. The method then comprises identifying a number of pixels of the plurality of pixels neighbouring the measurement pixel, the number of pixels having a number of intensity values, respectively. A curve is then fitted to the number of pixels and the number of respective intensity values. An estimated intensity value is then determined from the curve in respect of the measurement pixel, thereby simulating a predetermined field of view in respect of the measurement pixel narrower than an actual field of view of the measurement pixel.

First claim

1 . A method of digitally estimating an intensity value associated with an electrical signal generated by a pixel of an array of sensing pixels of an optical sensor device, the method comprising:
identifying a measurement pixel of the plurality of pixels corresponding to a measurement point on a target to be measured; identifying a number of pixels of the plurality of pixels neighbouring the measurement pixel, the number of pixels having a number of intensity values, respectively; fitting a curve to the number of pixels and the number of respective intensity values; and determining an estimated intensity value from the curve in respect of the measurement pixel, thereby simulating a predetermined field of view in respect of the measurement pixel narrower than an actual field of view of the measurement pixel.

2 . The method according to claim 1 , wherein the curve is fitted with respect to distances of the number of pixels from the measurement pixel.

3 . The method according to claim 2 , wherein the distances of the number of pixels from the measurement pixel comprises a first distance and a second distance, the first distance comprising an intra-pixel distance and the second distance comprises an inter-cluster distance, the intra-pixel distance being different from the inter-cluster distance.

4 . The method according to claim 1 , wherein the number of pixels is located within a row of the array of pixels comprising the measurement pixel.

5 . The method according to claim 4 , further comprising:
identifying another number of pixels of the plurality of pixels neighbouring the measurement pixel, the another number of pixels having another number of intensity values, respectively; fitting another curve to the another number of pixels using the another number of respective intensity values; and determining another estimated intensity value from the another curve in respect of the measurement pixel.

6 . The method according to claim 5 , wherein the another number of pixels is located in a column of the array of pixels comprising the measurement pixel or a diagonal line in the array of pixels comprising the measurement pixel.

7 . The method according to claim 5 , further comprising:
using the fitted intensity value and the another fitted intensity value to determine a further estimated intensity value in respect of the measurement pixel.

8 . The method according to claim 1 , further comprising:
fitting the curve using a polynomial best fit algorithm or a bilinear interpolation algorithm.

9 . The method according to claim 1 , wherein identifying the measurement pixel further comprises:
searching the array of pixels in groups of a predetermined size in order to identify a block comprising a pixel having a highest intensity.

10 . The method according to claim 9 , wherein the groups of pixels of the predetermined size constitute a tessellation of a predetermined shape.

11 . The method according to claim 9 , wherein the groups of pixels constitute windows of pixels.

12 . The method according to claim 1 , further comprising:
identifying the measurement pixel by estimating an intensity value for a number of groups of pixels of the array of pixels, thereby yielding a plurality of estimated intensity values.

13 . The method according to claim 12 , further comprising:
selecting a highest value amongst the plurality of estimated intensity values as the measurement pixel.

14 . The method according to claim 1 , the method further comprising:
performing an alignment operation with respect to the target to be measured in order to identify the measurement pixel of the plurality of pixels corresponding to the measurement point on the target to be measured.

15 . A temperature measurement apparatus comprising:
a plurality of sensor pixels configured to capture a thermal image; a data point selector configured to identify a measurement pixel of the plurality of pixels corresponding to a measurement point on a target to be measured, the data point selector also being configured to identify a number of pixels of the plurality of pixels neighbouring the measurement pixel, the number of pixels having a number of intensity values, respectively; a curve fitting engine configured to fit a curve to the number of pixels and the number of respective intensity values; and a curve reader configured to determine an estimated intensity value from the curve in respect of the measurement pixel, thereby simulating a predetermined field of view in respect of the measurement pixel narrower than an actual field of view of the measurement pixel.

Assignees

• Melexis Technologies Nv

Inventors

• Reusen Wouter
• Buydens Luc
• Hill Adrian

Classifications

• H04N25/61

  the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" · CPC title

• G01J5/0025 Primary

  Living bodies (ear thermometers G01J5/0011; detecting, measuring or recording for diagnostic purposes A61B5/00) · CPC title

• G06T2207/10048

  Infrared image · CPC title

• G06T7/344 Primary

  involving models · CPC title

• A61B5/015

  By temperature mapping of body part · CPC title