CN114598807A - Camera, automatic exposure method thereof and computer readable storage medium - Google Patents

Camera, automatic exposure method thereof and computer readable storage medium Download PDF

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Publication number
CN114598807A
CN114598807A CN202011439483.7A CN202011439483A CN114598807A CN 114598807 A CN114598807 A CN 114598807A CN 202011439483 A CN202011439483 A CN 202011439483A CN 114598807 A CN114598807 A CN 114598807A
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exposure time
confidence value
value
duty cycle
target
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CN114598807B (en
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魏守德
陈韦志
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Lite On Technology Corp
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Lite On Technology Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/70—Circuitry for compensating brightness variation in the scene
    • H04N23/73—Circuitry for compensating brightness variation in the scene by influencing the exposure time
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/667—Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/70—Circuitry for compensating brightness variation in the scene
    • H04N23/75—Circuitry for compensating brightness variation in the scene by influencing optical camera components
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/40—Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
    • H04N25/42—Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode

Abstract

An automatic exposure method for a camera. The camera has a plurality of operating modes. These operation modes correspond to different combinations of duty cycles and exposure times. The automatic exposure method comprises the following steps: one of these operating modes is selected. And sending a modulation signal to the object to be measured according to the work period of the selected operation mode. To receive the modulated signal reflected from the object to be measured during the exposure time of the selected mode of operation. A plurality of images of the object to be measured in different phases are obtained during the exposure time. A confidence value is calculated according to the images. And determining to adjust the exposure time and/or the working period according to the confidence value, the target confidence value and the selected operation mode, and adjusting the working period and the exposure time to ensure that the shooting effect of the camera is better. Moreover, by selecting various modes, energy consumption can be saved, and time and fast response can be realized.

Description

Camera, automatic exposure method thereof and computer readable storage medium
Technical Field
The present invention relates to a camera, an automatic exposure method thereof and a computer readable storage medium, and more particularly, to a camera with adjustable exposure time and/or duty cycle, an automatic exposure method thereof and a computer readable storage medium.
Background
The traditional camera is used for shooting a two-dimensional image, and the automatic exposure method calculates the automatic exposure time according to the brightness information of the image.
A Time of Flight (TOF) camera is used to capture a three-dimensional image, and obtains a three-dimensional image by calculating a Time difference between a transmission signal and a reflection signal to obtain depth information of an object to be measured. The surface reflectivity of the object to be measured and the distance from the flight-time distance measuring camera all affect the intensity of the reflected signal received by the flight-time distance measuring camera, so that the acquired depth information is inaccurate.
However, the conventional automatic exposure method does not work for the time of automatic exposure calculated by the brightness information of the image, and thus cannot solve the problem of exposure when the flight time ranging camera acquires a three-dimensional image.
Therefore, how to improve the above disadvantages has become an objective of the industrial research.
Disclosure of Invention
The invention relates to a camera, an automatic exposure method thereof and a computer readable storage medium, which can make the shooting effect of the camera better by adjusting the working period and the exposure time.
According to an embodiment of the present invention, an auto exposure method for a camera is provided. The camera has a plurality of operating modes. The operation modes respectively correspond to different combinations of a duty cycle and an exposure time. The automatic exposure method includes the following steps. One of the operating modes is selected. And sending a modulation signal to an object to be detected in the working period of the selected operation mode. To receive the modulated signal reflected from the object to be measured during the exposure time of the selected mode of operation. And acquiring a plurality of images of the object to be measured in different phases within the exposure time. A confidence value is calculated from the image. The exposure time and/or duty cycle is adjusted based on the confidence value, a target confidence value, and the selected operating mode.
According to another embodiment of the present invention, a camera is provided. The camera has a plurality of operating modes. The operation modes respectively correspond to different combinations of a working period and an exposure time. The camera comprises a transmitting unit, a receiving unit, a signal acquisition unit and a control unit. The transmitting unit is used for transmitting a modulation signal to an object to be detected in the working period of the selected operation mode. The receiving unit is used for receiving the modulation signal reflected from the object to be measured in the exposure time of the selected operation mode. The signal acquisition unit is used for acquiring a plurality of images of different phases of the object to be measured in the exposure time. The control unit is coupled to the transmitting unit, the receiving unit and the signal acquiring unit, and is used for selecting one of the operation modes, calculating a confidence value according to the images, and determining and adjusting the exposure time and/or the working period according to the confidence value, a target confidence value and the selected operation mode.
According to another embodiment of the present invention, a computer-readable storage medium is provided. The computer readable storage medium stores a computer program. The computer program is executed by a processing unit to implement the steps of the automatic exposure method of the camera.
Based on the above, in the camera, the automatic exposure method thereof and the computer readable storage medium of the present disclosure, the intensity of the received reflection signal can be improved by adjusting the exposure time and the duty cycle. Therefore, the shooting effect can be better for the object to be measured with long distance or low surface reflectivity. In addition, the invention has a plurality of operation modes, each mode has a combination of different initial exposure time and initial work period, and each mode has different ways of adjusting the exposure time and the work period, and different operation modes can be selected according to different conditions of the object to be measured so as to deal with various conditions. Moreover, by selecting various modes, energy consumption can be saved, and time and fast response can be realized.
The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.
Drawings
Fig. 1 is a schematic view of a camera according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating an auto-exposure method according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of a duty cycle according to an embodiment of the present invention.
Fig. 4 is a flowchart of the substeps of step S160 when the selected operation mode is the power saving mode.
Fig. 5 is a flowchart of the substeps of step S160 when the selected operation mode is the operation mode.
Fig. 6 is a flowchart of the substeps of step S160 when the selected operation mode is the normal mode.
Fig. 7 is a flowchart of the substeps of step S160 when the selected operation mode is the hybrid mode.
Detailed Description
The present invention is not intended to show all possible embodiments and other embodiments not specifically set forth herein may be utilized. Moreover, the dimensional ratios on the drawings are not shown to scale according to actual products. Accordingly, the description and drawings are only for the purpose of illustrating embodiments and are not to be construed as limiting the scope of the invention. Moreover, the descriptions of embodiments, such as specific structures, process steps, and material applications, are provided for illustrative purposes only and are not intended to limit the scope of the present disclosure. Various details of the steps and structures of the embodiments may be changed and modified as required by the actual manufacturing process without departing from the spirit and scope of the invention. The following description will refer to the same/like elements with the same/like reference numerals.
The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:
fig. 1 is a schematic diagram of a camera 100 according to an embodiment of the invention. The camera 100 is, for example, a time-of-flight range camera, but the embodiment of the invention is not limited thereto.
The camera 100 includes a control unit 110, a transmitting unit 120, a receiving unit 130, and a signal acquiring unit 140. The control unit 110 and the signal acquisition unit 140 are, for example, a chip, a circuit board or a circuit. The transmitting unit 120 is, for example, a light emitter. The receiving unit 130 is, for example, a photo sensor. The control unit 110 is coupled to the transmitting unit 120, the receiving unit 130 and the signal acquiring unit 140. The transmitter unit 120 may emit a modulation signal S to an object OB to be measured with a duty cycle. The receiving unit 130 may receive the modulation signal RS reflected from the object OB to be measured during an exposure time. The signal acquisition unit 140 may obtain a plurality of images of the object OB to be measured in different phases during the exposure time. The control unit 110 can adjust the duty cycle and the exposure time. The camera 100 has a plurality of operation modes, which are a power saving mode, an operation mode, a normal mode and a hybrid mode. Each operation mode corresponds to different combinations of the initial duty cycle and the initial exposure time.
Please refer to fig. 1, fig. 2 and fig. 3. FIG. 2 is a flowchart illustrating an auto-exposure method according to an embodiment of the present invention. The auto exposure method of fig. 2 is applicable to the camera 100 of fig. 1. FIG. 3 is a schematic diagram of a duty cycle according to an embodiment of the present invention. In fig. 3, the duty cycles are shown for example at 50%, 25% and 75%. For convenience of illustration, the duty cycle minimum Ds (25%), the intermediate value Dm (50%), the maximum value Dx (75%), and the exposure time minimum Ts (50 microseconds), the intermediate value Tm (525 microseconds), and the maximum value Tx (1000 microseconds) are taken as examples in the following, however, the present invention is not limited thereto. The exposure time may have different minimum Ts, intermediate Tm, and maximum Tx values depending on the hardware design of the camera 100. The working period can be set by itself. It should be noted that different duty cycles correspond to different calibration data, and the control unit 110 needs to calibrate the reflected modulation signal according to the calibration data corresponding to the duty cycles. The calibration data may be obtained in advance and stored in a memory (not shown) of the camera 100. For example, if the camera 100 is set to be operable in three duty cycles of 25%, 50%, and 75%, the calibration data for 25% duty cycle, 50% duty cycle, and 75% duty cycle can be acquired in advance. The correction method may be performed by other similar hardware, firmware, or software.
In step S110, the control unit 110 selects one of a plurality of operation modes. The control unit 110 selects one of the power saving mode, the operation mode, the normal mode and the hybrid mode according to a selection command. The selection command may be transmitted to the control unit 110 by an input unit (not shown). The input unit is, for example, a touch screen or a physical key, but is not limited thereto, and may also include other input devices with non-physical structures. The initial duty cycle of the power saving mode is preset to a minimum value (first minimum value) Ds and the initial exposure time is preset to a minimum value (second minimum value) Ts. The initial duty cycle of the operation mode is preset to a maximum value (first maximum value) Dx and the initial exposure time is preset to a minimum value (second minimum value) Ts, for example. The initial duty cycle of the normal mode is preset to an intermediate value (first intermediate value) Dm and the initial exposure time is preset to an intermediate value (second intermediate value) Tm, for example. The initial duty cycle of the hybrid mode is preset to a minimum value (first minimum value) Ds and the initial exposure time is preset to a minimum value (second minimum value) Ts. In another embodiment, the initial duty cycle of the hybrid mode can also be preset to be the middle value Dm, and the initial exposure time can also be set to be the middle value (second middle value) Tm or the maximum value (second maximum value) Tx, but not limited thereto, and the hybrid mode can be applied to allow the user to select the adjustment of the camera more flexibly.
In step S120, the transmitting unit 120 sends a modulation signal S to an object OB to be measured in a duty cycle of the selected operation mode. For example, if the selected operation mode is the power saving mode, the transmitting unit 120 sends the modulation signal S to the object OB to be tested at the minimum value Ds (e.g., 25%) of the preset duty cycle.
In step S130, the receiving unit 130 is configured to receive the modulation signal RS reflected from the object OB to be measured within an exposure time of the selected operation mode. For example, if the selected operation mode is the power saving mode, the receiving unit 130 receives the modulation signal RS reflected from the object OB within a minimum value Ts (e.g., 50 μ sec) of the preset exposure time. And the control unit 110 corrects the reflected modulation signal RS according to the correction data corresponding to the initial duty cycle (e.g., 25%).
In step S140, the signal acquisition unit 140 obtains a plurality of images of the object OB to be measured in different phases within the exposure time. For example, if the selected operation mode is the power saving mode, the signal acquisition unit 140 obtains a plurality of images (e.g. 0 degree, 90 degree, 270 degree, 360 degree images) of the object OB to be tested with different phases within the initial exposure time (e.g. 50 μ sec).
In step S150, the control unit 110 calculates a confidence value CV according to a plurality of images (e.g. 0 degree, 90 degree, 270 degree, 360 degree images) of different phases of the object OB to be measured0(confidence value). Confidence value CV0The formula for calculating (a) is as follows,
Figure BDA0002821818840000051
wherein I is the difference between the 90 degree and 270 degree phase images, and Q is the difference between the 0 degree and 180 degree phase images. For example, if the selected operation mode is the power saving mode, the control unit 110 can calculate the confidence value CV according to the plurality of images of different phases of the object OB to be measured when the initial duty cycle is the minimum value Ds and the initial exposure time is the minimum value Ts0As a basis for adjusting the exposure time and/or duty cycle.
In step S160, the control unit 110 determines the confidence value CV0A preset target confidence value CVtAnd the selected operation mode, determining the adjusted exposure time and/or duty cycle. In this step, the control unit 110 bases on the confidence value CV0Whether it is greater or less than the target confidence value CVtAnd the selected mode of operation, to adjust the exposure time and/or duty cycle. If the confidence value CV0Less than target confidence value CVtIndicating that the exposure time and/or duty cycle needs to be increased. If the confidence value CV0Greater than target confidence value CVtIndicating that the exposure time and/or duty cycle needs to be reduced. Different modes of operation have different ways of adjusting the exposure time and/or duty cycle. The manner in which the exposure time and/or duty cycle is adjusted for each mode of operation is further described below.
Fig. 4 is a flowchart of the substeps of step S160 when the selected operation mode is the "power saving mode". Fig. 5 is a flowchart of the substeps of step S160 when the selected operation mode is the "motion mode". Fig. 6 is a flowchart of the substeps of step S160 when the selected operation mode is the "normal mode". Fig. 7 is a flowchart of the sub-steps of step S160 when the selected operation mode is "hybrid mode".
Referring to fig. 4, when the selected operation mode is the "power saving mode", step S160 includes steps S1600 to S1605. Since the initial duty cycle of the power saving mode is the minimum value Ds and the initial exposure time is the minimum value Ts, power consumption of the camera 100 can be reduced.
In step S1600, the control unit 110 determines the confidence value CV0Whether or not it is equal to the target confidence value CVt. If yes, ending the process, and showing that the current exposure time and the working period meet the requirements; if not, the process proceeds to step S1601.
In step S1601, the control unit 110 determines the confidence value CV0Greater or less than the target confidence value CVt. If the confidence value CV0Less than target confidence value CVtThen, go to step S1602; if the confidence value CV0Greater than target confidence value CVtThen, the process proceeds to step S1605.
In step S1602, the control unit 110 determines whether the exposure time reaches the maximum value Tx. If not, the process proceeds to step S1603; if yes, the flow proceeds to step 1604.
Step S1603, when the exposure time does not reach the maximum value Tx and the confidence value CV0Less than target confidence value CVtThe control unit 110 increases the exposure time. For example, the control unit 110 adjusts the exposure time from the minimum value Ts (e.g., 50 microseconds) to the intermediate value Tm (e.g., 525 microseconds). In one embodiment, the control unit 110 may also increase the exposure time by a fixed value, such as 100 μ s; that is, the control unit 110 increases the exposure time from the minimum value Ts (e.g., 50 microseconds) to 150 microseconds, but the present invention is not limited thereto. Then, the process returns to step S120, and steps S120 to S160 are performed again with the adjusted exposure time (the middle value Tm (e.g., 525 μ S)). That is, steps S120 to S160 are repeated until the confidence value is reachedCV0Equal to the target confidence value CVtUntil now.
Step S1604, when the exposure time reaches the maximum value Tx and the confidence value CV0Less than target confidence value CVtThe control unit 110 adjusts the increased duty cycle instead. In this step, since the exposure time has reached the maximum value Tx, but the confidence value CV0Is still less than the target confidence value CVtTherefore, the control unit 110 increases the duty cycle to make the confidence value CV0And (4) increasing. For example, the control unit 110 increases the duty cycle from the minimum value Ds (e.g., 25%) to the intermediate value Dm (e.g., 50%), but the invention is not limited thereto. Then, the process returns to step S120, and steps S120 to S160 are executed again with the adjusted duty cycle (the middle value Dm (e.g., 50%)). That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
Step S1605, when the confidence value CV0Greater than target confidence value CVtThe control unit 110 decreases the exposure time. For example, the control unit 110 reduces the exposure time from the maximum value Tx to the intermediate value Tm, or from the intermediate value Tm to the minimum value Ts, but the invention is not limited thereto. The control unit 110 may also reduce the exposure time by a fixed value. Then, the process returns to step S120, and steps S120 to S160 are performed again with the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In the power-saving mode, when the confidence value CV0Not equal to the target confidence value CVtThe control unit 110 preferentially adjusts the exposure time until the exposure time reaches the maximum value Tx and the confidence value CV0Is still less than the target confidence value CVtThe control unit 110 increases the duty cycle.
Referring to fig. 5, when the selected operation mode is the "operation mode", step S160 includes steps S1610 to S1615. Since the initial duty cycle of the operation mode is preset to the maximum value Dx and the initial exposure time is preset to the minimum value Ts, the method is applicable to the object OB to be measured which moves fast.
Step S1610, controlThe system unit 110 determines the confidence value CV0Whether or not it is equal to the target confidence value CVt. If yes, ending the process, and indicating that the current exposure time and the work period reach the requirements; if not, the process proceeds to step S1611.
In step S1611, the control unit 110 determines the confidence value CV0Greater or less than the target confidence value CVt. If the confidence value CV0Less than target confidence value CVtThen the flow advances to step S1612; if the confidence value CV0Greater than target confidence value CVtThen, the process proceeds to step S1613.
Step S1612, when the confidence value CV0Less than target confidence value CVtThe control unit 110 increases the exposure time. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In step S1613, the control unit 110 determines whether the exposure time reaches the minimum value Ts. If not, go to step S1614; if yes, the process proceeds to step S1615.
Step S1614, when the exposure time does not reach the minimum value Ts and the confidence value CV0Greater than target confidence value CVtThe control unit 110 decreases the exposure time. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
Step S1615, when the exposure time reaches the minimum value Ts and the confidence value CV0Greater than target confidence value CVtThe control unit 110 instead reduces the duty cycle. In this step, the exposure time has reached the minimum value Ts, but the confidence value CV0Is still greater than the target confidence value CVtTherefore, the control unit 110 decreases the duty cycle to make the confidence value CV0And (4) reducing. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted duty cycle. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now。
In the action mode, when the confidence value CV0Not equal to the target confidence value CVtThe control unit 110 preferably adjusts the exposure time until the exposure time reaches the minimum value Ts and the confidence value CV0Is still greater than the target confidence value CVtThe control unit 110 then decreases the duty cycle.
Referring to fig. 6, when the selected operation mode is the "normal mode", step S160 includes steps S1620 to S1627. The initial duty cycle of the normal mode is preset to an intermediate value Dm, for example, and the initial exposure time is preset to an intermediate value Tm, for example, which is suitable for general applications of the camera 100.
In step S1620, the control unit 110 determines the confidence value CV0Whether or not it is equal to the target confidence value CVt. If yes, ending the process, and indicating that the current exposure time and the work period reach the requirements; if not, the process proceeds to step S1621.
In step S1621, the control unit 110 determines the confidence value CV0Greater or less than the target confidence value CVt. If the confidence value CV0Less than target confidence value CVtThen go to step S1622; if the confidence value CV0Greater than target confidence value CVtThen, the process proceeds to step S1625.
In step S1622, the control unit 110 determines whether the exposure time reaches the maximum value Tx. If not, go to step S1623; if yes, the process proceeds to step S1624.
Step S1623, when the exposure time does not reach the maximum value Tx, and the confidence value CV0Less than target confidence value CVtThe control unit 110 increases the exposure time. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
Step S1624, when the exposure time reaches the maximum value Tx and the confidence value CV0Less than target confidence value CVtThe control unit 110 increases the duty cycle. In this step, since the exposure time has reached the maximum value Tx, but the confidence value CV0Is still less than the target confidence value CVtTherefore, the control unit 110 increases the duty cycle to make the confidence value CV0And (4) increasing. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted duty cycle. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In step S1625, the control unit 110 determines whether the exposure time reaches the minimum value Ts. If not, go to step S1626; if yes, the process proceeds to step S1627.
Step S1626, when the exposure time does not reach the minimum value Ts and the confidence value CV0Greater than target confidence value CVtThe control unit 110 decreases the exposure time. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
Step S1627, when the exposure time reaches the minimum value Ts and the confidence value CV0Greater than target confidence value CVtThe control unit 110 decreases the duty cycle. In this step, the exposure time has reached the minimum value Ts, but the confidence value CV0Is still greater than the target confidence value CVtTherefore, the control unit 110 decreases the duty cycle to make the confidence value CV0Is reduced to approach the target confidence value CVt. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted duty cycle. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In the general mode, when the confidence value CV0Not equal to the target confidence value CVtThe control unit 110 preferably adjusts the exposure time until the exposure time reaches the minimum value Ts and the confidence value CV0Is still greater than the target confidence value CVtThen, the control unit 110 decreases the duty cycle; or until the exposure time reaches the maximum value Tx and the confidence value CV0Is still less than the target confidence value CVtThe control unit 110 increases the duty cycle.
Referring to fig. 7, when the selected operation mode is "hybrid mode", step S160 includes steps S1630 to S1637. The initial duty cycle of the hybrid mode is preset to a minimum value Ds and the initial exposure time is preset to a minimum value Ts, for example, which allows the user to more flexibly select and adjust the camera 100 for optimal accuracy and photographing response.
In step S1630, the control unit 110 determines the confidence value CV0Whether or not it is equal to the target confidence value CVt. If yes, ending the process, and indicating that the current exposure time and the work period reach the requirements; if not, the process proceeds to step S1631.
In step S1631, the control unit 110 determines the confidence value CV0Greater or less than the target confidence value CVt. If the confidence value CV0Less than target confidence value CVtThen, go to step S1632; if the confidence value CV0Greater than target confidence value CVtThen, the process proceeds to step S1635.
In step S1632, the control unit 110 determines whether one of the duty cycle or the exposure time reaches a maximum value. If not, go to step S1633; if yes, the process proceeds to step S1634.
Step S1633, when neither the duty cycle nor the exposure time reaches the maximum value, and the confidence value CV is obtained0Less than target confidence value CVtThe control unit 110 increases one of the duty cycle and/or the exposure time.
Step S1634, when one of the duty cycle and the exposure time reaches the maximum value, and the confidence value CV0Less than target confidence value CVtThe control unit 110 increases one of the exposure time or the duty cycle. That is, in this step, if the exposure time has reached the maximum value Tx, but the confidence value CV is reached0Is still less than the target confidence value CVtThe control unit 110 increases the duty cycle to make the confidence value CV0Increases to approach the target confidence value CVt. Conversely, if the duty cycle has reached the maximum value Ds, but the confidence value CV is0Is still less than the target confidence value CVtThe control unit 110 increases the exposure time to make the confidence value CV0Increases to approach the target confidence value CVt. Then, go back to step S120 to adjust the duty cycle or adjust the duty cycleThe exposure time of (2) is again performed to steps S120 to S160. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In step S1635, the control unit 110 determines whether one of the duty cycle or the exposure time reaches a minimum value. If not, go to step S1636; if yes, the process proceeds to step S1637.
Step S1636, when neither the duty cycle nor the exposure time reaches the minimum value, and the confidence value CV is obtained0Greater than target confidence value CVtThe control unit 110 decreases one of the duty cycle and/or the exposure time.
Step S1637, when one of the duty cycle and the exposure time reaches the minimum value, and the confidence value CV0Greater than target confidence value CVtThe control unit 110 decreases one of the exposure time or the duty cycle. In this step, if the exposure time has reached the minimum value Ts, but the confidence value CV0Is still greater than the target confidence value CVtThe control unit 110 decreases the duty cycle to make the confidence value CV0And (4) reducing. If the duty cycle has reached the minimum value Ds, but the confidence value CV0Is still greater than the target confidence value CVtThe control unit 110 decreases the exposure time to make the confidence value CV0And (4) reducing. Then, the process returns to step S120 to perform steps S120 to S160 again with the adjusted duty cycle or the adjusted exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to the target confidence value CVtUntil now.
In the mixed mode, when the confidence value CV0Is not equal to the target confidence value CVtThe control unit 110 can adjust one of the exposure time or the duty cycle until the one of the exposure time or the duty cycle reaches the minimum value and the confidence value CV0Is still greater than the target confidence value CVtThe control unit 110 decrements the other. Or when the confidence value CV0Not equal to the target confidence value CVtThe control unit 110 can adjust one of the exposure time or the duty cycle until the one of the exposure time or the duty cycle reaches the maximum value and the confidence value CV0Is still less than the target confidence value CVtThe control unit 110 adds another. Or when the confidence value CV0Is not equal to the target confidence value CVtThe control unit 110 may adjust the exposure time and the duty cycle at the same time.
In the steps shown in fig. 4 to 7, once the exposure time or the duty cycle is adjusted, the process returns to step S120 of fig. 2, and the steps S120 to S160 are executed with the adjusted duty cycle and/or exposure time. That is, steps S120 to S160 are repeated until the confidence value CV is reached0Equal to or close to the target confidence value CVtUntil now. In another embodiment, the control unit 110 may set a threshold value, and stop adjusting the exposure time and/or the duty cycle when the number of times of adjusting the exposure time and/or the duty cycle exceeds the threshold value. In fig. 4 to 7, the confidence value CV is shown0Whether it is greater or less than the target confidence value CVtTo adjust the exposure time and/or duty cycle, in another embodiment, the control unit 110 can adjust the exposure time and/or duty cycle according to the confidence value CV0Setting a target confidence range (interval) and according to the confidence value CV0And determining whether the exposure time and/or the working period is larger or smaller than the target confidence range. If the confidence value CV0Within the target confidence range, the current exposure time and working period are satisfied.
The camera and the automatic exposure method can improve the intensity of the received reflection signal by adjusting the exposure time. Preferably, the camera and the automatic exposure method provided by the invention can improve the intensity of the received reflected signal by adjusting not only the exposure time but also the duty cycle. Therefore, the shooting effect can be better for the object to be measured with long distance or low surface reflectivity. The invention has a plurality of operation modes, each mode has different initial exposure time and initial work period, and each mode has different ways of adjusting the exposure time and the work period, and different operation modes can be selected according to different conditions of the object to be measured so as to deal with various conditions.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (23)

1. An automatic exposure method for a camera, the camera having a plurality of operation modes, the operation modes respectively corresponding to different combinations of a duty cycle and an exposure time, the method comprising:
selecting one of the plurality of operating modes;
sending a modulation signal to an object to be detected according to the selected work period of the operation mode;
to receive the modulation signal reflected from the object to be measured during the selected exposure time of the operation mode;
obtaining a plurality of images of different phases of the object to be measured within the exposure time;
calculating a confidence value according to the plurality of images;
and determining to adjust the exposure time and/or the working period according to the confidence value, a target confidence value and the selected operation mode.
2. The automatic exposure method of claim 1, wherein the plurality of operation modes include a power saving mode, an active mode, a normal mode and a mixed mode, the power saving mode corresponds to a first duty cycle and a first exposure time, the active mode corresponds to a second duty cycle and a second exposure time, the normal mode corresponds to a third duty cycle and a third exposure time, and the mixed mode corresponds to a fourth duty cycle and a fourth exposure time.
3. The automatic exposure method according to claim 2, wherein the preset value of the second duty cycle is greater than the preset value of the third duty cycle, and the preset value of the third duty cycle is greater than the preset values of the first duty cycle and the fourth duty cycle; and the preset value of the third exposure time is greater than the preset values of the first exposure time, the second exposure time and the fourth exposure time.
4. The automatic exposure method of claim 3, wherein the preset values of the first duty cycle and the fourth duty cycle are a first minimum value, the preset value of the second duty cycle is a first maximum value, and the preset value of the third duty cycle is a first intermediate value; the preset values of the first exposure time, the second exposure time and the fourth exposure time are a second minimum value, and the preset value of the third exposure time is a second intermediate value.
5. The automatic exposure method according to claim 4, wherein the step of determining to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence value and the selected operation mode comprises:
in the power-saving mode,
when the confidence value is smaller than the target confidence value, increasing the first exposure time;
when the confidence value is larger than the target confidence value, reducing the first exposure time; and
when the first exposure time reaches a second maximum value and the confidence value is smaller than the target confidence value, the first working period is increased.
6. The automatic exposure method according to claim 4, wherein the step of determining to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence value and the selected operation mode comprises:
in the mode of operation of the device, the user can select the operation mode,
when the confidence value is smaller than the target confidence value, increasing the second exposure time;
when the confidence value is larger than the target confidence value, reducing the second exposure time; and
and when the second exposure time reaches the second minimum value and the confidence value is larger than the target confidence value, reducing the second working period.
7. The automatic exposure method according to claim 4, wherein the step of determining to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence value and the selected operation mode comprises:
in the normal mode, the first mode is,
when the confidence value is less than the target confidence value, increasing the third exposure time;
when the confidence value is larger than the target confidence value, reducing the third exposure time;
when the third exposure time reaches a second maximum value and the confidence value is smaller than the target confidence value, increasing the third working period; and
and when the third exposure time reaches the second minimum value and the confidence value is greater than the target confidence value, reducing the third working period.
8. The automatic exposure method according to claim 4, wherein the step of determining to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence value and the selected operation mode comprises:
in the hybrid mode, in which the first and second modes are combined,
increasing one of the fourth duty cycle and/or the fourth exposure time when the confidence value is less than the target confidence value;
decreasing one of the fourth duty cycle and/or the fourth exposure time when the confidence value is greater than the target confidence value;
increasing one of the fourth exposure time or the fourth duty cycle when one of the fourth duty cycle or the fourth exposure time reaches the first or a second maximum value and the confidence value is less than the target confidence value; and
when one of the fourth duty cycle or the fourth exposure time reaches the first or the second minimum value and the confidence value is greater than the target confidence value, one of the fourth exposure time or the fourth duty cycle is decreased.
9. The automatic exposure method of claim 1, wherein different duty cycles correspond to different calibration data, the automatic exposure method further comprising:
the reflected modulated signal is corrected according to the correction data.
10. The automatic exposure method according to claim 1, wherein the step of determining to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence value and the selected operation mode comprises:
setting a threshold value;
and stopping adjusting the exposure time and/or the working period when the number of times of adjusting the exposure time and/or the working period exceeds the threshold value.
11. The automatic exposure method according to claim 1, comprising:
setting a target confidence range according to the confidence value; and
and determining to adjust the exposure time and/or the working period according to the confidence value, the target confidence range and the selected operation mode.
12. A computer-readable storage medium, in which a computer program is stored, which, when being executed by a processing unit, carries out the steps of the method for automatic exposure of a camera according to any one of claims 1 to 11.
13. A camera having a plurality of operation modes corresponding to different combinations of a duty cycle and an exposure time, the camera comprising:
the transmitting unit is used for transmitting a modulation signal to an object to be detected in a working period;
the receiving unit is used for receiving the modulation signal reflected from the object to be measured in an exposure time;
the signal acquisition unit is used for acquiring a plurality of images of different phases of the object to be detected in the exposure time; and
the control unit is coupled with the transmitting unit, the receiving unit and the signal acquisition unit and used for selecting one of the plurality of operation modes, calculating a confidence value according to the plurality of images and determining and adjusting the exposure time and/or the working period according to the confidence value, a target confidence value and the selected operation mode.
14. The camera as in claim 13, wherein the plurality of operation modes include a power saving mode, an active mode, a normal mode and a hybrid mode, the power saving mode corresponds to a first duty cycle and a first exposure time, the active mode corresponds to a second duty cycle and a second exposure time, the normal mode corresponds to a third duty cycle and a third exposure time, and the hybrid mode corresponds to a fourth duty cycle and a fourth exposure time.
15. The camera of claim 14, wherein the predetermined value for the second duty cycle is greater than the predetermined value for the third duty cycle, the predetermined value for the third duty cycle being greater than the predetermined values for the first duty cycle and the fourth duty cycle; and the preset value of the third exposure time is greater than the preset values of the first exposure time, the second exposure time and the fourth exposure time.
16. The camera of claim 15, wherein the preset values for the first duty cycle and the fourth duty cycle are a first minimum value, the preset value for the second duty cycle is a first maximum value, and the preset value for the third duty cycle is a first intermediate value; the preset values of the first exposure time, the second exposure time and the fourth exposure time are a second minimum value, and the preset value of the third exposure time is a second intermediate value.
17. The camera as claimed in claim 16, wherein in the power saving mode, when the confidence value is less than the target confidence value, the control unit increases the first exposure time;
when the confidence value is larger than the target confidence value, the control unit reduces the first exposure time; and
when the first exposure time reaches a second maximum value and the confidence value is smaller than the target confidence value, the control unit increases the first working period.
18. The camera as in claim 16, wherein in the active mode, when the confidence value is less than the target confidence value, the control unit increases the second exposure time;
when the confidence value is larger than the target confidence value, the control unit reduces the second exposure time; and
when the second exposure time reaches the second minimum value and the confidence value is larger than the target confidence value, the control unit reduces the second working period.
19. The camera as in claim 16, wherein in the normal mode, when the confidence value is less than the target confidence value, the control unit increases the third exposure time;
when the confidence value is larger than the target confidence value, the control unit reduces the third exposure time;
when the third exposure time reaches a second maximum value and the confidence value is smaller than the target confidence value, the control unit increases the third working period; and
when the third exposure time reaches the second minimum value and the confidence value is greater than the target confidence value, the control unit decreases the third duty cycle.
20. The camera as in claim 16, wherein in the hybrid mode, when the confidence value is less than the target confidence value, the control unit increases one of the fourth duty cycle and/or the fourth exposure time;
when the confidence value is larger than the target confidence value, the control unit reduces one of the fourth working period and/or the fourth exposure time;
when one of the fourth working period or the fourth exposure time reaches the first maximum value or a second maximum value and the confidence value is smaller than the target confidence value, the control unit increases one of the fourth exposure time or the fourth working period; and
when one of the fourth working period or the fourth exposure time reaches the first minimum value or the second minimum value and the confidence value is larger than the target confidence value, the control unit reduces one of the fourth exposure time or the fourth working period.
21. The camera as in claim 13, wherein different duty cycles correspond to different calibration data, the control unit calibrating the reflected modulated signal based on the calibration data.
22. The camera of claim 13, wherein the control unit sets a threshold value;
when the number of times of adjusting the exposure time and/or the working period exceeds the threshold value, the control unit stops adjusting the exposure time and/or the working period.
23. The camera as in claim 13, wherein the control unit sets a target confidence range according to the confidence value and determines to adjust the exposure time and/or the duty cycle according to the confidence value, the target confidence range, and the selected operation mode.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120098964A1 (en) * 2010-10-22 2012-04-26 Mesa Imaging Ag System and Method for Multi TOF Camera Operation Using Phase Hopping
US20170061601A1 (en) * 2015-08-31 2017-03-02 Mitutoyo Corporation Multi-level image focus using a tunable lens in a machine vision inspection system
CN109819174A (en) * 2017-11-22 2019-05-28 浙江舜宇智能光学技术有限公司 Automatic explosion method and automatic exposure time calculation method and TOF camera based on TOF imaging system
CN110392204A (en) * 2018-04-19 2019-10-29 英飞凌科技股份有限公司 Imaging system and the method executed by imaging system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120098964A1 (en) * 2010-10-22 2012-04-26 Mesa Imaging Ag System and Method for Multi TOF Camera Operation Using Phase Hopping
US20170061601A1 (en) * 2015-08-31 2017-03-02 Mitutoyo Corporation Multi-level image focus using a tunable lens in a machine vision inspection system
CN109819174A (en) * 2017-11-22 2019-05-28 浙江舜宇智能光学技术有限公司 Automatic explosion method and automatic exposure time calculation method and TOF camera based on TOF imaging system
CN110392204A (en) * 2018-04-19 2019-10-29 英飞凌科技股份有限公司 Imaging system and the method executed by imaging system

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