# US 10,769,810 B2 · Apparatus, systems and methods for shadow assisted object recognition and tracking

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- Number: US 10,769,810 B2
- Document ID: US10769810B2
- Status: Granted
- Kind: B2
- Application number: 16/577,000
- Filed: 2019-09-20
- Published: 2020-01-09
- Granted: 2020-09-08
- Earliest claimed: 2016-06-14
- Assignees: Disney Enterprises, Inc.
- Applicants: Disney Enterprises, Inc.
- Inventors: Yuecheng Zhang; Ilke Akin
- Web page: https://patentgrep.com/patent/US10769810B2

## CPC

- G06T 7/73: using feature-based methods
- G06T 7/90: Determination of colour characteristics
- G06V 20/42: {of sport video content}
- G06T 2207/30196: Human being; Person
- G06T 2207/30221: Sports video; Sports image
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING

## Abstract

Described herein are apparatus, systems and methods for shadow assisted object recognition and tracking. The methods performed by the apparatus and system include identifying a blob within a video image, the video image having at least one object and at least one shadow of the at least one object, the at least one shadow of the at least one object cast by at least one light source. Identifying the blob includes identifying an object projection corresponding to the at least one object and a shadow projection corresponding to the at least one shadow. A location of an object portion of the at least one object is determined based on the shadow projection.

## Claims

### Claim 1

A method, comprising:
receiving a video image that includes:
an object that is elevated with respect to ground level in the video image,
a first shadow of the object and a second shadow of the object; and
determining three-dimensional positional information corresponding to a location of the object based on a detected position of the object in the video image and an intersection point of i) a first direction line corresponding to the first shadow and ii) a second direction line corresponding to the second shadow.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
determining a location of a light source that casts the first shadow of the object, wherein the location of the light source is further used to determine the three-dimensional positional information.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first direction line is a line between the first shadow and a light source that casts the first shadow.

### Claim 4 (depends on 1)

The method of claim 1, wherein the video image is from a single frame of captured video.

### Claim 5 (depends on 1)

The method of claim 1, wherein the video image comprises a plurality of frames of captured video and the three-dimensional positional information is determined for each of the plurality of frames, wherein the three-dimensional positional information changes between a first one of the plurality of frames and a last one of the plurality of frames.

### Claim 6

A device, comprising:
a memory having a program stored thereon; and
a processor coupled to the memory, wherein the processor executes the program to cause the processor to perform operations comprising:
receiving a video image that includes:
an object that is elevated with respect to ground level in the video image,
a first shadow of the object, and
a second shadow of the object; and
determining three-dimensional positional information corresponding to a location of the object based on a detected position of the object in the video image and an intersection point of i) a first direction line corresponding to the first shadow and ii) a second direction line corresponding to the second shadow.

### Claim 7 (depends on 6)

The device of claim 6, wherein the operations further comprise:
determining a location of a light source that casts the first shadow of the object, wherein the location of the light source is further used to determine the three-dimensional positional information.

### Claim 8 (depends on 6)

The device of claim 6, wherein the first direction line is a line between the first shadow and a light source that casts the first shadow.

### Claim 9 (depends on 6)

The device of claim 6, wherein the video image is from one of a single frame of captured video or a plurality of frames of captured video and the three-dimensional positional information is determined for each of the plurality of frames, wherein the three-dimensional positional information changes between a first one of the plurality of frames and a last one of the plurality of frames.

### Claim 10

A non-transitory computer readable storage medium comprising a plurality of instructions, that when executed by a processor cause the processor to perform operations comprising:
receiving a video image that includes:
an object that is elevated with respect to ground level in the video image,
a first shadow of the object, and
a second shadow of the object; and
determining three-dimensional positional information corresponding to a location of the object based on a detected position of the object in the video image and an intersection point of i) a first direction line corresponding to the first shadow and ii) a second direction line corresponding to the second shadow.

### Claim 11 (depends on 10)

The non-transitory computer readable storage medium of claim 10, wherein the operations further comprise:
determining a location of a light source that casts the first shadow of the object, wherein the location of the light source is further used to determine the three-dimensional positional information.

### Claim 12 (depends on 10)

The non-transitory computer readable storage medium of claim 10, wherein the first direction line is a line between the first shadow and a light source that casts the first shadow.

### Claim 13 (depends on 10)

The non-transitory computer readable storage medium of claim 10, wherein the video image is from a single frame of captured video.

### Claim 14 (depends on 10)

The non-transitory computer readable storage medium of claim 10, wherein the video image comprises a plurality of frames of captured video and the three-dimensional positional information is determined for each of the plurality of frames, wherein the three-dimensional positional information changes between a first one of the plurality of frames and a last one of the plurality of frames.