IP Library › Granted Patent US 12688561

Granted Patent B2

US 12688561 · App. 18/138,975 · Granted Jul 21, 2026

Image processing method for removal of glare spots and system for the same

Inventors: Weiquan Cong (Singapore, SG); Keng Loong Lim (Singapore, SG); Yau Wai Lucas Hui (Singapore, SG); Guoji Wang (Singapore, SG); Heng Guo (Singapore, SG)

Assignee: CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH

G06T5/77 G06T7/0002 G06T7/70 G06T2207/10016 G06T2207/30168

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Quick Facts

Patent No.: US 12688561
App. No.: 18/138,975
Granted: Jul 21, 2026
Kind: B2

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Abstract

An image processing method for removal of glare spots appearing on images captured is disclosed. The method comprises transmitting, by way of a first illumination source, a first light ray towards a first gaze and by way of a second illumination source, a second light ray towards a second gaze. An image sensor captures a first gaze image comprising an image of the first gaze and captures a second gaze image comprising an image of the second gaze. A saturation spot removal algorithm selects a primary gaze image between the first gaze image captured and the second gaze image captured, in which the primary gaze image selected is suitable for removing a glare spot to yield a resultant gaze image for ascertaining a gaze direction, for eye tracking functions. A system, a computer program product, and a computer-readable medium of the same is also disclosed.

Claims (49)

1 . An image processing method for removal of glare spots appearing on images captured, the method comprising:

transmitting, by way of a first illumination source, a first light ray towards a first gaze, and by way of a second illumination source, a second light ray towards a second gaze;

capturing, by way of an image sensor, a first gaze image comprising an image of the first gaze, and a second gaze image comprising an image of the second gaze; and

selecting, by way of a saturation spot removal algorithm, a primary gaze image between the first gaze image captured and the second gaze image captured by comparing the first gaze image captured and the second gaze image captured and identifying a gaze image with no glare spot overlapping a glint spot or a gaze image with at least an overlapping area of glare spot covering the glint spot;

wherein the saturation spot removal algorithm identifies at least one saturation spot resembling a glare spot based upon the saturation spot appearing in only one of the first and the second gaze images, and wherein a size of the glare spot is larger than a saturation spot resembling the glint spot; and

wherein the primary gaze image is selected for a saturation spot removal process, to yield a resultant gaze image for ascertaining a gaze direction, for eye tracking applications.

2 . The method of claim 1 , further comprising:

removing, by way of the saturation spot removal algorithm, the at least one saturation spot resembling the glare spot from the primary gaze image selected.

3 . The method of claim 1 , further comprising:

capturing, by way of the image sensor, the first gaze image and the second gaze image in a continuously alternating sequence.

4 . The method of claim 3 , wherein the continuously alternating sequence comprises:

capturing in an initial sequence the first gaze image in response to the first light rays being transmitted toward the first gaze; and

capturing in a subsequent sequence, the second gaze image in response to the second light rays being transmitted toward the second gaze.

5 . The method of claim 3 , wherein the continuously alternating sequence further comprises:

continuously executing, by way of the saturation spot removal algorithm, one initial sequence for capturing the first gaze image, followed by one subsequent sequence for capturing the second gaze image.

6 . The method of claim 3 , wherein the alternating sequence further comprises:

continuously executing, by way of the saturation spot removal algorithm, at least two sequences of the initial sequence for capturing the first gaze image, followed by at least two sequences of the subsequent sequence for capturing the second gaze image.

7 . The method of claim 1 , wherein identifying the at least one saturation spot resembling the glare spot based upon the saturation spot appearing in only one of the first and the second gaze images, and wherein the size of the glare spot size is larger than the saturation spot resembling the glint spot, further comprises:

identifying, by way of the saturation spot removal algorithm, at least one saturated pixel area, by comparing the first gaze image captured against the second gaze image captured.

8 . The method of claim 7 , further comprising:

classifying, by way of the saturation spot removal algorithm, the saturated pixel area as the at least one saturation spot resembling the glare spot.

9 . The method of claim 7 , further comprising:

removing, by way of the saturation spot removal algorithm, the saturated pixel area resembling a glare spot from the primary gaze image; and

replacing, by way of the saturation spot removal algorithm, the saturated pixel area resembling a glare spot with a corresponding area obtained from one of the first gaze image or the second gaze image captured.

10 . The method of claim 1 , further comprising:

determining, by way of the saturation spot removal algorithm, a glint spot present in the resultant gaze image.

11 . A system for processing of images for eye tracking applications, the system comprising:

a first illuminating source operable to transmit a first light ray towards a first gaze; and

a second illumination source operable to transmit a second light ray towards a second gaze;

an image sensor operable to capture a first gaze image comprising an image of the first gaze and a second gaze image comprising an image of the second gaze; and

a processing unit operable to process images captured by the image sensor,

wherein the system further comprises a saturation spot removal algorithm operable to select a primary gaze image between the first gaze image captured and the second gaze image captured by comparing the first gaze image captured and the second gaze image captured and identifying a gaze image with no glare spot overlapping a glint spot or a gaze image with at least an overlapping area of glare spot covering the glint spot;

wherein the primary gaze image is selected for a saturation spot removal process, to yield a resultant gaze image for ascertaining a gaze direction, the resultant gaze image for eye tracking applications.

12 . The system of claim 11 , wherein the image sensor, the first illumination source and the second illumination source are integrated as a single module.

13 . The system of claim 11 , wherein each of the first illumination source and the second illumination source is operable to switch on and off in an alternating mode, such that when the first illumination source is switched on, the second illumination source is switched off, and when the first illumination source is switched off, the second illumination source is switched on.

14 . A system comprising:

a processing unit comprising a computer program product with instructions for:

transmitting, by way of a first illumination source, a first light ray towards a first gaze, and by way of a second illumination source, a second light ray towards a second gaze;

capturing, by way of an image sensor, a first gaze image comprising an image of the first gaze, and a second gaze image comprising an image of the second gaze; and

selecting, by way of a saturation spot removal algorithm, a primary gaze image between the first gaze image captured and the second gaze image captured by comparing the first gaze image and the second gaze image and identifying a gaze image with no glare spot overlapping a glint spot or a gaze image with at least an overlapping area of glare spot covering the glint spot;

15 . A non-transitory computer-readable medium with instructions for:

transmitting, by way of a first illumination source, a first light ray towards a first gaze, and by way of a second illumination source, a second light ray towards a second gaze;

capturing, by way of an image sensor, a first gaze image comprising an image of the first gaze, and a second gaze image comprising an image of the second gaze;