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US 9,866,763 B2Granted
Auto-iris control method
AssigneeHuawei Technologies Co., Ltd.
InventorsTao Huang, Jianzhang Li
Life of this patent
Estimating the term…
Abstract
An auto-iris control method, including setting a target luminance value of an auto iris; collecting an image at a current moment and calculating a luminance value of the image collected at the current moment; comparing the target luminance value with the luminance value of the image collected at the current moment; comparing an absolute value of the luminance difference at the current moment with a preset luminance difference threshold, determining a status of the auto iris at the current moment, and using a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment; and adjusting an action of the auto iris according to the calculated direct current control voltage.
Claims10
An auto-iris control method, comprising:
- setting a target luminance value of an auto iris;
- collecting an image at a current moment;
- calculating a luminance value of the image collected at the current moment, wherein calculating the luminance value of the image collected at the current moment comprises:
- sampling a luminance value of each pixel in the image collected at the current moment;
- and
- using the following formula to calculate an average value of luminance values of all pixels in the image to obtain the luminance value of the image collected at the current moment:
- Y
- t
- =
- ∑
- i
- =
- 1
- n
-
- ∑
- j
- =
- 1
- m
-
- Y
- ij
- n
- ×
- m
- ,
- wherein Yt is the luminance value of the image collected at the current moment, Yij is the luminance value of each pixel in the image collected at the current moment, m is a number of pixels horizontally comprised in the image, n is a number of pixels vertically comprised in the image, and n and m are both natural numbers;
- comparing the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- comparing an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determining a status of the auto iris at the current moment;
- using a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment;
- and
- adjusting an action of the auto iris according to the calculated direct current control voltage.
31 more elements
An auto-iris control method, comprising:
- setting a target luminance value of an auto iris;
- collecting an image at a current moment;
- calculating a luminance value of the image collected at the current moment, wherein calculating the luminance value of the image collected at the current moment comprises:
- sampling a luminance value of each pixel in the image collected at the current moment;
- selecting a central region of the image;
- and
- using the following formula to calculate an average value of luminance values of pixels comprised in the central region of the image to obtain the luminance value of the image collected at the current moment:
- Y
- t
- =
- ∑
- i
- =
- a
- b
-
- ∑
- j
- =
- c
- d
-
- Y
- ij
- (
- b
- -
- a
- +
- 1
- )
-
- (
- d
- -
- c
- +
- 1
- )
- ,
- wherein Yt is the luminance value of the image collected at the current moment, Yij is the luminance value of each pixel in the image collected at the current moment, a is a value of a start horizontal coordinate of the central region, b is a value of an end horizontal coordinate of the central region, c is a value of a start vertical coordinate of the central region, d is a value of an end vertical coordinate of the central region, and a, b, c, and d are all natural numbers;
- comparing the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- comparing an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determining a status of the auto iris at the current moment;
- using a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment;
- and
- adjusting an action of the auto iris according to the calculated direct current control voltage.
44 more elements
An auto-iris control method, comprising:
- setting a target luminance value of an auto iris;
- collecting an image at a current moment;
- calculating a luminance value of the image collected at the current moment;
- comparing the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- comparing an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determining a status of the auto iris at the current moment;
- using a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment, wherein comparing the absolute value of the luminance difference at the current moment with the preset luminance difference threshold, determining the status of the auto iris at the current moment, and using the corresponding PID algorithm to calculate the direct current control voltage at the current moment comprises:
- using a positional PID algorithm to calculate the direct current control voltage at the current moment when the absolute value of the luminance difference at the current moment is greater than the preset luminance difference threshold;
- and
- using an incremental PID algorithm to calculate the direct current control voltage at the current moment when the absolute value of the luminance difference at the current moment is less than or equal to the preset luminance difference threshold;
- and
- adjusting an action of the auto iris according to the calculated direct current control voltage.
9 more elements
An auto-iris control system, comprising:
- an auto iris;
- a processor coupled to the auto iris and configured to set a target luminance value of an auto iris;
- and
- an image sensor coupled to the processor and configured to collect an image at a current moment,
- wherein the processor is further configured to:
- calculate a luminance value of the image collected at the current moment by:
- sampling a luminance value of each pixel in the image collected at the current moment;
- and
- using the following formula to calculate an average value of luminance values of all pixels in the image to obtain the luminance value of the image collected at the current moment:
- Y
- t
- =
- ∑
- i
- =
- 1
- n
-
- ∑
- j
- =
- 1
- m
-
- Y
- ij
- n
- ×
- m
- ,
- and wherein Yt is the luminance value of the image collected at the current moment, Yij is the luminance value of each pixel in the image collected at the current moment, m is a number of pixels horizontally comprised in the image, n is a number of pixels vertically comprised in the image, and n and m are both natural numbers;
- compare the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- compare an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determine a status of the auto iris at the current moment;
- use a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment;
- and
- adjust an action of the auto iris according to the calculated direct current control voltage.
34 more elements
An auto-iris control system, comprising:
- an auto iris;
- a processor coupled to the auto iris and configured to set a target luminance value of an auto iris;
- and
- an image sensor coupled to the processor and configured to collect an image at a current moment,
- wherein the processor is further configured to:
- calculate a luminance value of the image collected at the current moment by:
- sampling a luminance value of each pixel in the image collected at the current moment;
- selecting a central region of the image;
- and
- using the following formula to calculate an average value of luminance values of pixels comprised in the central region of the image to obtain the luminance value of the image collected at the current moment:
- Y
- t
- =
- ∑
- i
- =
- a
- b
-
- ∑
- j
- =
- c
- d
-
- Y
- ij
- (
- b
- -
- a
- +
- 1
- )
-
- (
- d
- -
- c
- +
- 1
- )
- ,
- and wherein Yt is the luminance value of the image collected at the current moment, Yij is the luminance value of each pixel in the image collected at the current moment, a is a value of a start horizontal coordinate of the central region, b is a value of an end horizontal coordinate of the central region, c is a value of a start vertical coordinate of the central region, d is a value of an end vertical coordinate of the central region, and a, b, c, and d are all natural numbers;
- compare the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- compare an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determine a status of the auto iris at the current moment;
- use a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment;
- and
- adjust an action of the auto iris according to the calculated direct current control voltage.
47 more elements
An auto-iris control system, comprising:
- an auto iris;
- a processor coupled to the auto iris and configured to set a target luminance value of an auto iris;
- and
- an image sensor coupled to the processor and configured to collect an image at a current moment,
- wherein the processor is further configured to:
- calculate a luminance value of the image collected at the current moment;
- compare the target luminance value with the luminance value of the image collected at the current moment to obtain a difference between the target luminance value and the luminance value of the image collected at the current moment and use the difference as a luminance difference at the current moment;
- compare an absolute value of the luminance difference at the current moment with a preset luminance difference threshold;
- determine a status of the auto iris at the current moment;
- use a positional proportional-integral-derivative (PID) algorithm to calculate the direct current control voltage at the current moment when the absolute value of the luminance difference at the current moment is greater than the preset luminance difference threshold;
- use an incremental PID algorithm to calculate the direct current control voltage at the current moment when the absolute value of the luminance difference at the current moment is less than or equal to the preset luminance difference threshold;
- use a corresponding PID algorithm to calculate a direct current control voltage at the current moment;
- and
- adjust an action of the auto iris according to the calculated direct current control voltage.
11 more elements
Dependencies are inferred from the claim text.