Apparatus and methods for adjusting zoom of a PTZ camera

Patent metadata

Field	Value
Publication number	US-12593129-B2
Application number	US-202418807411-A
Country	US
Kind code	B2
Filing date	Aug 16, 2024
Priority date	Aug 18, 2023
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

A control apparatus for determining an amount of zoom to be applied in an image frame is provided and incudes identifying an imaging target in an image being captured by an image capture device, determining, based on a current imaging condition, an amount of zoom applied by the image capture device ensuring the imaging target is substantially centered in an image frame, modifying the determined zoom amount in response to a determination that that the determined zoom amount would cause the image capture device to exceed a directional movement limit, providing a control command to the image capture device that controls the image capture device to obtain an image of the imaging target using one of the determined amount of zoom or the modified zoom amount, and controlling the image capture device to capture an image of the imaging target at the zoom level included in the control command.

First claim

We claim:

1 . A method comprising:
identifying an imaging target in an image being captured by an image capture device; determining, based on a current imaging condition, an amount of zoom needed to be applied by the image capture device such that the imaging target is substantially centered in an image frame; modifying the determined zoom amount in response to a determination that that the determined zoom amount would cause the image capture device to exceed a directional movement limit; generating a control command to the image capture device that controls the image capture device to obtain an image of the imaging target using one of the determined amount of zoom or the modified zoom amount; determining if the generated control command would cause the image capture device to reach one of the maximum direction movement limit or the minimum direction movement limit in order to the determined amount of zoom to capture the imaging target; generating an updated zoom amount in response to the determination regarding the generated control command, wherein the updated zoom amount is lower than the determined zoom amount ensuring the imaging target is within the image frame to be captured; controlling the image capture device to capture an image of the imaging target at the zoom level included in the control command.

2 . The method according to claim 1 , wherein the activity of controlling the image capture device includes controlling the image capture device to perform one or both of a pan and tilt movement prior to controlling the zoom of the image capture device to be at the provided zoom level.

3 . The method according to claim 1 , wherein activity of determining includes
determining an amount of zoom based on a current position of the image capturing device and its location relative to a directional movement limit.

4 . The method according to claim 1 , wherein providing the control command includes
controlling the image capture device based on the modified zoom amount to move and approach the directional movement limit while maintaining the imaging target in the image frame to be captured.

5 . The method according to claim 1 , wherein the activity of determining the amount of zoom includes
obtaining, for the image capture device, at least one maximum directional movement limit and at least one minimum directional movement limit associated with at least one type of direction movement obtaining a current position of the image capturing device; obtain target position for the image capture device to capture the image of the imaging target; generate the control command that causes the image capture device to move in the at least one type of direction such that the target position is substantially in a center of an image frame to be captured using a first zoom amount; update the first zoom amount to a second different zoom amount in response to determining that the control command would cause the image capture device to exceed one of the minimum directional movement limit or the maximum directional movement limit, wherein the second different zoom amount is used in the activity of modifying the determined zoom amount.

6 . The method according to claim 1 , wherein the activity of determining the amount of zoom includes
using a location of the imaging target to compute an initial movement command needed to control the image capture device to move so that the image target is in the imaging frame; comparing one or more directional movement values in the initial movement command with one or more directional movement limits of the image capturing device; and generate a zoom amount based on a difference between requested zoom amount and the initial movement command, wherein the generated zoom amount is less than the requested zoom amount when the initial movement command would cause the image capture device to exceed a directional movement limit.

7 . The method according to claim 1 , wherein determining the zoom amount includes
using an identified imaging target location to calculate the zoom amount based on the imaging target being at substantially a center position of an image frame.

8 . The method according to claim 1 , further comprising:
selecting a region in the currently captured image as the imaging target for which the zoom amount is to be determined by using an input device to select the imaging target within an image currently being captured by the image capture device and displayed on a display device.

9 . The method according to claim 1 , further comprising:
determining, from within the image being captured, that a predetermined gesture is performed by a user; selecting, as the imaging target, a region of the captured image where the predetermined gesture is performed, wherein the imaging target corresponds to substantially a center point of a body part that performed the predetermined gesture; and generating a bounding box around the perimeter of the body part as the imaging target.

10 . The method according to claim 1 , further comprising
determining the zoom amount based on a difference between at least one set of parallel borders of the selected region and dividing the difference by a target width of the image frame that is currently being captured.

11 . The method according to claim 10 , further comprising
applying a boarder factor to the determined difference to expand the selected region a predetermined amount beyond the selected region.

12 . The method according to claim 1 , wherein the activity of determining the amount of zoom includes
determining a dimension of the identified imaging target; generating, using the determined dimension and a scaling factor, a region having a first size; comparing the first size of the region with a minimum region size and maximum region size; and selecting, as target region size, one of the first size, minimum region size or maximum based on the comparison, wherein
the first size is selected when the first size is between the minimum and maximum region size;
the minimum size is selected when the first size is less than the minimum region size; or
the maximum size is selected when the first size is greater than the maximum region size.

13 . The method according to claim 1 , wherein the activity of determining the amount of zoom includes
using a dimension of the identified imaging target to generate a region size by performing a non-linear scaling operation on the identified imaging target based on a proximity of the imaging target relative to an image capture device capturing the imaging target, wherein the non-linear scaling operation includes dividing a constant scaling factor by an exponential factor applied to the dimension.

14 . An apparatus that is configured to communicate with an image capture device comprising:
at least one memory storing instructions; and at least one processor that, upon execution of the stored instructions, is configured to execute the following operations: identifying an imaging target in an image being captured by an image capture device; determining, based on a current imaging condition, an amount of zoom needed to be applied by the image capture device such that the imaging target is substantially centered in an image frame; modifying the determined zoom amount in response to a determination that that the determined zoom amount would cause the image capture device to exceed a directional movement limit; and generating a control command to the image capture device that controls the image capture device to obtain an image of the imaging target using one of the determined amount of z

Assignees

• Canon Usa Inc

Inventors

• Huang Hung Khei
• Suzuki Stephanie Ann

Classifications

• H04N23/695

  Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects · CPC title

• H04N23/61 Primary

  based on recognised objects · CPC title

• H04N23/611

  where the recognised objects include parts of the human body · CPC title

• H04N23/62

  Control of parameters via user interfaces · CPC title

• H04N23/69 Primary

  Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming · CPC title