WO2018209650A1 - Automatic exposure method and device for camera - Google Patents

Abstract

An automatic exposure method for a camera (400), comprising: detecting the brightness of current ambient light (S110); querying exposure parameters corresponding to the brightness of the current ambient light in an exposure list (S120), the exposure parameters comprising a relative aperture value that is in a predetermined relationship with the aperture number of the camera (400); and adjusting an exposure element in the camera (400) according to the exposure parameters (S130). Also provided are an automatic exposure device for a camera and the camera (400) which has the automatic exposure device.

Description

Automatic exposure method and device for camera

Copyright statement

The disclosure of this patent document contains material that is subject to copyright protection. This copyright is the property of the copyright holder. The copyright owner has no objection to the reproduction of the patent document or patent disclosure contained in the official records and files of the Patent and Trademark Office.

Technical field

The invention belongs to the field of camera imaging, and in particular relates to an automatic exposure method and apparatus used in a device having an imaging function such as a camera.

Background technique

With the rapid development of imaging technology, cameras are increasingly used in medical imaging, astronomical observation, drone shooting, and daily life. Due to the different distances of the objects, or the different brightness of the surrounding environment, it is often necessary to adjust the camera to suit different shooting needs by switching the lens of the camera or changing the focal length of the zoom lens.

The parameters within the camera that control the brightness of the image include aperture size, exposure time, and sensitivity. When switching the lens of the camera or changing the focal length of the zoom lens, it is equivalent to suddenly changing the aperture size in the parameter. If the other two parameters cannot be adjusted, it will cause problems such as sudden brightness changes or oscillations.

The existing solution is mainly to install a plurality of exposure meters of different aperture levels in the camera, and select corresponding exposure meters for exposure control according to different aperture number ranges. This requires multiple built-in exposure meters, which consumes resources, and when there is no corresponding exposure meter in a certain aperture range, it is easy to cause the aperture control to be abnormal, resulting in abnormal brightness of the screen.

Summary of the invention

An aspect of the present invention provides an automatic exposure method for a camera, comprising: detecting a brightness of a current ambient light; and querying, in an exposure table, an exposure parameter corresponding to a brightness of the current ambient light, the exposure parameter including a relative aperture a value, the relative aperture value being a function of the number of apertures; adjusting an exposure element of the camera in accordance with the exposure parameter.

Another aspect of the present invention provides an automatic exposure apparatus for a camera, comprising: a storage unit for storing an exposure meter, the exposure meter recording an exposure parameter corresponding to brightness of different ambient light, the exposure parameter Include a relative aperture value, the relative aperture value is a function of the number of apertures; a brightness detection unit for detecting the brightness of the current ambient light; and a control unit for querying the brightness of the current ambient light in the exposure table The exposure parameters are adjusted and the exposure elements of the camera are adjusted to meet the exposure parameters.

Another aspect of the present invention provides a camera including an automatic exposure apparatus, wherein the automatic exposure apparatus includes: a storage unit for storing an exposure meter, the exposure table recording exposure parameters corresponding to brightness of different ambient light The exposure parameter includes a relative aperture value, the relative aperture value is a function of an aperture value, a brightness detection unit for detecting brightness of the current ambient light, and a control unit for querying the current in the exposure table The brightness of the ambient light corresponds to the exposure parameter and adjusts the exposure element of the camera to meet the exposure parameter.

Other aspects of the present invention can also include a non-transitory computer readable medium including program instructions for: establishing an exposure meter that records exposure parameters corresponding to brightness of different ambient light, The exposure parameter includes a relative aperture value, the relative aperture value is a function of the number of apertures; detecting the brightness of the current ambient light; and querying an exposure parameter corresponding to the brightness of the current ambient light in the exposure table, and adjusting an exposure component of the camera To meet the exposure parameters.

The method, device and computer readable medium of the present invention can be changed in the actual range of the aperture, but the relative range is not changed, the purpose of normal use without modifying the exposure meter can be achieved, and when the relative range of the aperture changes, You can also quickly create new exposure meters for quick control exposure.

DRAWINGS

For a more complete understanding of the present invention and its advantages, reference will now be made to the following description

FIG. 1 schematically shows a flow chart of an automatic exposure method for a camera according to an embodiment of the present invention.

FIG. 2 schematically illustrates a flow chart of a method for automatic exposure of a camera in accordance with another embodiment of the present invention.

FIG. 3 schematically shows a block diagram of an automatic exposure apparatus for a camera according to an embodiment of the present invention.

FIG. 4 schematically shows a block diagram of a camera in accordance with an embodiment of the present invention.

detailed description

Other aspects, advantages, and salient features of the present invention will become apparent to those skilled in the <

In the present invention, the terms "include" and "including" and their derivatives are intended to be inclusive and not limiting; the term "or" is inclusive, meaning and/or.

In the present specification, the following various embodiments for describing the principles of the present invention are merely illustrative and should not be construed as limiting the scope of the invention. The following description of the invention is intended to be understood as The description below includes numerous specific details to assist the understanding, but these details should be considered as merely exemplary. Accordingly, it will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. Further, the same reference numerals are used throughout the drawings for the same or similar functions and operations.

For the method and apparatus for automatic exposure of a camera, the present invention mainly considers a scene in which, when switching the lens of the camera or changing the focal length of the zoom lens and changing the range of the aperture number, how to implement exposure control using a smaller number of exposure meters And how to avoid the problem that the aperture control is not normal due to the absence of a corresponding exposure table in a certain aperture number range.

In the following, when the embodiment of the present invention is specifically described, although the camera is taken as an example for illustration, the method and apparatus of the present invention are not limited to use in a camera, and any device using the optical imaging function can reasonably utilize the present invention. For example, a camera, a video camera, and the like.

An embodiment of the present invention provides an automatic exposure method for a camera, including: detecting a brightness of a current ambient light; and querying, in an exposure table, an exposure parameter corresponding to a brightness of the current ambient light, the exposure parameter including a relative aperture a value, the relative aperture value being a function of the number of apertures; adjusting an exposure element of the camera in accordance with the exposure parameter.

Wherein, it is preferable that the second derivative of the function is less than 0, whereby when the number of apertures increases, the relative aperture value increases, so that the relative aperture value can perform a nonlinear mapping on the aperture number and the lens The actual optical performance is linearly matched.

More preferably, the relative aperture value is linear with the logarithm of the number of apertures.

The "camera" mentioned in the present invention may be any camera having an optical imaging function, such as a film camera, a digital camera or the like. The "camera" of the present invention can also be used in combination with a variety of devices, such as a mobile phone having a camera function, a drone having a photographing function, and the like.

The present invention will be further described in detail below with reference to the specific embodiments of the invention,

FIG. 1 schematically shows a flow chart of an automatic exposure method for a camera according to an embodiment of the present invention.

As shown in FIG. 1, the method includes operations S110-S130.

In operation S110, the brightness of the current ambient light is detected. According to an embodiment of the invention, detecting the brightness of the current ambient light may be detected using a sensor, such as a light sensor, a fiber optic sensor, or the like. The sensor may be located inside the camera, or in the lens of the camera, or external to the camera, etc., and the present invention does not limit the position of the sensor.

The brightness of the ambient light in the embodiment of the present invention may be a preset brightness level, for example, from 1 to 10, indicating that the brightness of the ambient light is getting brighter, and then determining the level to which the brightness of the detected ambient light belongs, such as the current The brightness of ambient light belongs to level 3. It should be understood by those skilled in the art that the brightness of the ambient light in the present invention is not limited to the preset level described above, and may be a linear correspondence or the like.

In operation S120, an exposure parameter corresponding to the brightness of the current ambient light is queried in the exposure table. Wherein, the exposure table records exposure parameters corresponding to the brightness of different ambient light, the exposure parameter includes a relative aperture value, and the relative aperture value is a function of the number of apertures. Preferably, the second derivative of the function is less than zero. One embodiment is a linear relationship between the relative aperture value and the logarithm of the aperture number, but the present invention is not limited thereto, and any function capable of easing the linear variation of the aperture number is applicable to the present invention. For example, the present invention can also be The relative aperture value is a linear relationship between the opening and the square of the aperture number.

The aperture is a device that controls the amount of light that passes through the lens into the photosensitive surface of the body, usually in the lens. The aperture number is used to indicate the amount of light passing through the lens. It is usually expressed by the F value. When the aperture is expressed as the number of apertures, for example, F1, F1.4, F2, F2.8, F4, F5.6, F8, F11, F16, F22 , F32, F44, F64, the smaller the aperture number, the more the amount of light entering the same unit time, and the amount of light entering the previous gear is twice that of the next gear. For example, if the number of apertures is adjusted from F8 to F5.6, It means that the number of apertures is increased by one step, and the amount of light is doubled. The range of apertures is related to the lens of the camera, indicating the range of apertures that can be adjusted by the lens. The range of apertures of different lenses is different. For example, the aperture range of lens A is F2.8~F16, and the aperture range of lens B is F4 ~ F32 and so on.

According to an embodiment of the invention, the relative aperture value is linear with the base 2 logarithm of the aperture number. E.g:

Wherein, LI represents the relative aperture value, Fnum represents the aperture number, Fmax represents the aperture of the maximum aperture of the lens, and LDR represents the number of copies of the first aperture of the camera lens.

For example, if the aperture of a lens ranges from F2.8 to F16 and divides it into 256×5 copies, the LDR can be divided into 256 copies of the first aperture. It should be understood by those skilled in the art that the LDR only represents the number of copies in which the first aperture of the aperture number range is equally divided. The embodiment of the present invention is not limited to the value of the LDR. For example, the LDR may also take 128, indicating that the first aperture number is equally divided. It is 128 copies.

According to an embodiment of the invention, the exposure table includes exposure parameters including aperture parameters, exposure time, and sensitivity. Under different ambient light levels, different combinations of parameters are used to meet the appropriate picture brightness. Among them, the aperture parameter is expressed as a relative aperture value.

By replacing the number of apertures with a relative aperture value in the exposure meter, the number of exposure meters can be reduced. For example, with lens A, lens A has a range of apertures from F2.8 to F16 (including 6 callable files: F2.8, F4, F5.6, F8, F11, and F16), and the exposure time is 8s to 1/ 8000s, sensitivity range is 12800 ~ 100. Table 1 schematically shows the exposure table corresponding to the lens A. As shown in Table 1, the brightness from 1 to 10 indicates that the ambient light is getting brighter and brighter, and the corresponding exposure parameters at different light levels.

Table 1

Ambient lightness	1	2	3	4	5	6	7	8	9	10
Aperture number	2.8	2.8	4.0	4.0	5.6	5.6	8.0	8.0	11	16
Relative aperture value	1	1	257	257	513	513	769	769	1025	1281
Exposure time (s)	8	1/15	1/15	1/15	1/15	1/500	1/500	1/8000	1/8000	1/8000
Sensitivity	12800	12800	12800	100	100	100	100	100	100	100

For example, there is lens B, the aperture number of lens B is F4 ~ F22 (including 6 callable files: F4, F5.6, F8, F11, F16 and F22), the exposure time is 8s ~ 1 / 8000s, sensitivity The range is 12800-100. Table 2 schematically shows the exposure table corresponding to the lens B. As shown in Table 2, the brightness from 1 to 10 indicates that the ambient light is getting brighter and brighter, and the corresponding exposure parameters at different light levels.

Table 2

Ambient light	1	2	3	4	5	6	7	8	9	10
Aperture number	4.0	4.0	5.6	5.6	8.0	8.0	11.0	11.0	16	twenty two
Relative aperture value	1	1	257	257	513	513	769	769	1025	1281
Exposure time (s)	8	1/15	1/15	1/15	1/15	1/500	1/500	1/8000	1/8000	1/8000
Sensitivity	12800	12800	12800	100	100	100	100	100	100	100

As shown in Table 1 and Table 2, the range of apertures of lens A and lens B are different, but the range of relative aperture values is the same. If the aperture number is used as the exposure parameter to establish the exposure meter, two corresponding exposure meters are needed, but if relative The aperture value is used as an exposure parameter to create an exposure meter that can be satisfied using only one exposure meter. For example, if the exposure meter shown in Table 3 includes the relative aperture value, exposure time, and sensitivity, the exposure meter can be used for the lens with the number of apertures in the range of 6 recallable positions, for example, the aperture number ranges from F1 to F5. .6 lens, lens with aperture range F1.4 to F8, lens with aperture range F2 to F11, lens with aperture range F2.8 to F16, lens with aperture range F4 to F22, aperture Lenses with a range of F5.6 to F32, lenses with a range of apertures from F8 to F44, and lenses with a range of apertures from F11 to F64.

In the embodiment of the present invention, by using the relative aperture value instead of the aperture number as the exposure parameter, the number of exposure tables can be reduced, and the storage space can be saved.

table 3

Ambient lightness	1	2	3	4	5	6	7	8	9	10
Relative aperture value	1	1	257	257	513	513	769	769	1025	1281
Exposure time (s)	8	1/15	1/15	1/15	1/15	1/500	1/500	1/8000	1/8000	1/8000
Sensitivity	12800	12800	12800	100	100	100	100	100	100	100

It should be understood by those skilled in the art that the exposure table of the present invention is not limited to the form of the table in the above examples, and may be a linear comparison table or the like which can be used to indicate different exposure parameter selections under different ambient light brightness.

It should be understood by those skilled in the art that the aperture number range of the present invention is not limited to the six callable range of the above examples, and may include more or less callable range, such as F1.0 to F22 (including 10). Callable files: F1, F1.4, F2, F2.8, F4, F5.6, F8, F11, F16 and F22) or F4~F11 (including 4 callable files: F4, F5.6, F8 and F11) and the like, depending on the lens, the aperture number ranges are different, and embodiments of the present invention can establish different exposure tables according to different callable range.

It should be understood by those skilled in the art that the variation of the aperture number of the present invention is not limited to only one shift position at a time in the above example, and may also be changed by two or three or more, for example, the aperture number ranges from F1.0. In ~F22, only five gear positions F1.0, F2.0, F4.0, F8.0, and F22 are used.

It should be understood by those skilled in the art that the exposure meter of the present invention may not include the aperture number in the above example, and includes only the relative aperture value, the exposure time, and the sensitivity. The relative aperture value, exposure time, and sensitivity in the exposure meter are not limited to the above. Numerical values, the above examples are only for help understanding.

In operation S130, an exposure element of the camera is adjusted according to the exposure parameter. According to the present invention, as described above, the exposure parameter includes a relative aperture value, whereby adjusting the exposure element of the camera according to the exposure parameter comprises: converting the relative aperture value into an aperture number, and according to the The number of apertures adjusts the exposure elements of the camera.

For example, the current lens is lens A, and the aperture number of lens A is F2.8 to F16 (including 6 callable files: F2.8, F4, F5.6, F8, F11, and F16), and the exposure time is 8s~ For 1/8000s, the sensitivity range is 12800~100, and the exposure meter shown in Table 1 above can be used. When it is detected that the brightness of the current ambient light is level 3, the corresponding exposure parameters queried in Table 1 are the relative aperture value 257, the exposure time 1/15 s, and the sensitivity 12800, and the aperture of the camera can be controlled according to the exposure parameter. Adjust the aperture to the relative aperture value of 257 (aperture adjustment to F4.0), control the camera's shutter exposure time to 1/15s, and control the camera's sensitivity to 12800, thus achieving automatic exposure of the camera.

According to an embodiment of the present invention, by establishing an exposure table using relative aperture values as exposure parameters, the number of exposure tables can be reduced, and memory space can be reduced.

FIG. 2 schematically illustrates a flow chart of a method for updating an exposure meter for a camera in accordance with another embodiment of the present invention.

As shown in FIG. 2, the method includes operations S210-S240.

At operation S210, lens information is acquired. The acquiring lens information includes information such as a lens focal length and a lens aperture range. Acquiring the lens information may trigger the acquisition according to a specific condition, for example, acquiring the current lens information when the lens is changed or the lens focal length is adjusted.

In operation S220, it is judged whether or not the aperture number range has changed, and if a change occurs, operation S230 is performed, otherwise, the operation ends. According to the embodiment of the present invention, if the range of the aperture number changes, it is determined whether the adjustment exposure table needs to be updated to adapt to the new lens information. If the aperture number range does not change, the current exposure meter can be used to satisfy the exposure of the camera. control. For example, the range of the number of apertures may be changed from F2 to F16 to F2 to F22, or the range of apertures may be changed from F2 to F16 to F4 to F22.

In operation S230, it is determined whether the range of the relative aperture value of the lens of the camera has changed, and if a change occurs, operation S240 is performed, otherwise, the process ends. According to the embodiment of the present invention, if the range of the relative aperture value changes, the exposure table needs to be updated. If the range of the relative aperture value does not change, the control of the camera exposure can be satisfied by using the current exposure meter. For example, the range of apertures varies from F2.8 to F16 (including 6 callable files, relative aperture range from 1 to 1281) to F4.0 to F22 (including 6 callable files, relative aperture range For the range of 1 to 1281), although the range of the aperture number has changed, but the range of the relative aperture value has not changed, the current exposure meter can be used to control the exposure of the camera. For example, the range of apertures is changed from F2.8-F16 (including 6 callable files, relative aperture range is 1~1281) to F2~F22 (including 8 callable files, relative aperture range is 1~1793) ), the aperture number range has changed, and the relative aperture value range has also changed. You need to use the new exposure meter for exposure control.

The exposure table is updated in operation S240. According to the embodiment of the present invention, when the relative aperture value range changes, it indicates that the callable file has changed, so the brightness can be selected by a new adjustment under the brightness of different ambient light, and the exposure table needs to be updated. For example, if the exposure table corresponding to the range of relative aperture values of the six callable files is shown in Table 3, when the range of relative aperture values changes to be larger or smaller, the exposure table needs to be updated to accommodate different numbers of callables. The choice of file.

For example, replace lens A (the number of apertures is F2.8 to F16, the exposure time is 8s to 1/8000s, and the sensitivity range is 12800 to 100) to lens C (the number of apertures is F2.8 to F11, exposure time). For 8s to 1/8000s, the sensitivity range is 12800 to 100), the relative aperture value in the exposure parameter of lens C can be selected in 5 steps, for example, the exposure meter shown in Table 4.

Table 4

Ambient lightness	1	2	3	4	5	6	7	8	9	10
Relative aperture value	1	1	257	257	513	513	513	769	769	1025
Exposure time (s)	8	1/15	1/15	1/15	1/15	1/500	1/500	1/500	1/8000	1/8000
Sensitivity	12800	12800	12800	400	400	400	100	100	100	100

According to the embodiment of the present invention, the lens having the same relative aperture value range can use the same exposure meter, for example, the relative aperture value ranges from 1 to 1025, and the exposure can be used for the lens including the five callable range in the aperture number range. table. The exposure meter of the lens having different relative aperture value ranges should be relatively changed. For example, the relative aperture value shown in Table 3 ranges from 1 to 1281, and the exposure table with the relative aperture value range of 1 to 1025 as shown in Table 4 is different. .

It should be understood by those skilled in the art that the present invention is not limited to the specific numerical values exemplified above, and any combination of exposure parameters meeting the exposure criteria can be established in the exposure table. When the relative aperture value range is large, the number of apertures that can be called is correspondingly larger, and the adjustment of the aperture can be correspondingly increased in the exposure table. When the relative aperture value range is small, the number of apertures that can be called is relatively small, and the exposure time and the sensitivity adjustment can be correspondingly increased in the exposure table. The present invention is not limited to a specific combination of parameters of exposure parameters, and any combination of exposure parameters that can satisfy ambient light brightness can be established in the exposure table.

In the embodiment of the present invention, an exposure meter that establishes a plurality of different relative aperture value ranges may be selected. When the lens of the camera is switched or the focal length of the zoom lens is changed, the exposure table that is called may be selected by determining a range of relative aperture values. Alternatively, when switching the lens of the camera or changing the focal length of the zoom lens, the current exposure table is refreshed according to the preset rule according to the detected current lens information.

In the solution of the embodiment of the present invention, the exposure table is established by using the relative aperture value instead of the aperture number, and the same exposure table can be used for various lenses having the same aperture value range, thereby reducing the number of exposure tables in the camera and alleviating the memory pressure. When the relative aperture value range changes, the exposure table can be refreshed according to the preset rule corresponding to the relative aperture value range, so that a new exposure meter can be quickly established to adapt to the current lens. When the range of the relative aperture value changes, it is also possible to directly call the corresponding exposure meter for exposure control in the exposure table in which a plurality of different relative aperture values are established, so that the purpose of quickly controlling the exposure can be achieved.

FIG. 3 schematically shows a block diagram of an automatic exposure apparatus for a camera according to an embodiment of the present invention.

As shown in FIG. 3, the automatic exposure device includes a storage unit 310, a brightness detecting unit 320, a control unit 330, a lens detecting unit 340, and an exposure table generating unit 350. The automatic exposure apparatus can perform the method described above with reference to FIGS. 1 to 2 to achieve automatic exposure of the camera.

Specifically, the storage unit 310 is configured to store an exposure table, the exposure table records exposure parameters corresponding to brightness of different ambient lights, the exposure parameters include relative aperture values, and the relative aperture value is a function of the number of apertures, and The second derivative of this function is less than zero. According to an embodiment of the present invention, the storage unit 310 may perform, for example, the operation S110 described above with reference to FIG.

The brightness detecting unit 320 is configured to detect the brightness of the current environment. According to an embodiment of the present invention, the brightness detecting unit 320 may perform, for example, the operation S120 described above with reference to FIG. Preferably, the brightness detecting unit 320 employs a CMOS sensor. In a specific embodiment, a CMOS sensor of a camera can be used as a brightness detecting unit to simplify the device structure and reduce weight and cost.

The control unit 330 is configured to query, in the exposure table, an exposure parameter corresponding to the brightness of the current ambient light, and adjust an exposure element of the camera to satisfy the exposure parameter. According to an embodiment of the present invention, the control unit 330 may perform, for example, the operation S130 described above with reference to FIG.

Specifically, after the control unit 330 converts the relative aperture value into the aperture number, the exposure element of the camera is adjusted according to the aperture number.

The lens detecting unit 340 is configured to detect whether a range of the relative aperture value of the lens of the camera changes. According to an embodiment of the present invention, the lens detecting unit 340 can perform, for example, the operation described above with reference to FIG. 2 S210 to S230.

The exposure table generating unit 350 is configured to recalculate the relative aperture value in the exposure table when the range of the relative aperture value changes. According to an embodiment of the present invention, the exposure table generating unit 350 may perform, for example, the operation S240 described above with reference to FIG.

It can be understood that the storage unit 310, the brightness detecting unit 320, the control unit 330, the lens detecting unit 340, and the exposure table generating unit 350 can be implemented in one module, or any one of the modules can be split into multiple modules. . Alternatively, at least some of the functionality of one or more of the modules may be combined with at least some of the functionality of the other modules and implemented in one module. According to an embodiment of the present invention, at least one of the storage unit 310, the brightness detecting unit 320, the control unit 330, the lens detecting unit 340, and the exposure table generating unit 350 may be at least partially implemented as a hardware circuit, such as a field programmable gate array. (FPGA), Programmable Logic Array (PLA), System on Chip, System on Substrate, System on Package, Application Specific Integrated Circuit (ASIC), or any other reasonable way to integrate or package the circuit, etc. The firmware is implemented or implemented in a suitable combination of three implementations of software, hardware, and firmware. Alternatively, at least one of the storage unit 310, the brightness detecting unit 320, the control unit 330, the lens detecting unit 340, and the exposure table generating unit 350 may be at least partially implemented as a computer program module, which may be executed when the program is run by the computer The function of the corresponding module.

FIG. 4 schematically shows a block diagram of a camera 400 in accordance with an embodiment of the present invention.

As shown in FIG. 4, the camera 400 includes the automatic exposure apparatus described above with reference to FIG. According to an embodiment of the present invention, the camera 400 can automatically control exposure under different ambient light brightness using an automatic exposure device. The camera generally includes a body and a lens, and the body and lens may be integral or detachable. The automatic exposure device is usually located in the body, but may also be partially located in the lens, and the present invention does not limit the position of the automatic exposure device. The camera further includes that the exposure element can be located in the body or in the lens. The exposure element includes at least one of a shutter, an aperture, and an ISO adjuster.

In summary, the present invention uses the relative aperture value instead of the aperture number as an exposure parameter to establish an exposure table, and the same exposure table can be used for various lenses having the same range of aperture values, thereby reducing the number of exposure tables in the camera and alleviating memory pressure. When the relative aperture value range changes, the exposure table can be refreshed according to the preset rule corresponding to the relative aperture value range, so that a new exposure meter can be quickly established to adapt to the current lens. When the range of the relative aperture value changes, it is also possible to directly call the corresponding exposure meter for exposure control in the exposure table in which a plurality of different relative aperture values are established, so that the purpose of quickly controlling the exposure can be achieved.

The above method and module according to various embodiments of the present invention may be implemented by executing a computer-containing software by a computing-capable electronic device. The system can include storage devices to implement the various storages described above. The computing capable electronic device can include a general purpose processor, a digital signal processor, a dedicated processor, a reconfigurable processor, etc., but is not limited thereto. Executing such instructions causes the electronic device to be configured to perform the operations described above in accordance with the present invention. The above methods and/or modules may be implemented in one electronic device or in different electronic devices.

Embodiments of the invention use software, which may be stored in the form of volatile memory or non-volatile storage (such as a storage device such as a ROM), whether erasable or rewritable, or stored as The form of the memory (eg, RAM, memory chip, device, or integrated circuit) is either stored on an optically readable medium or a magnetically readable medium (eg, CD, DVD, magnetic or tape, etc.). It should be appreciated that the storage device and the storage medium are embodiments of a machine-readable storage device adapted to store one or more programs, the program or programs comprising instructions that, when executed, implement the present invention An embodiment. Moreover, these programs can be routed via any medium, such as a communication signal carried via a wired connection or a wireless connection, and various embodiments suitably include such programs.

Although the present invention has been shown and described with respect to the specific exemplary embodiments of the present invention, those skilled in the art Various changes in form and detail are made to the invention. Therefore, the scope of the invention should not be construed as being limited by the appended claims.

Claims (21)

1. An automatic exposure method for a camera, comprising:

   Detecting the brightness of the current ambient light;

   Querying, in the exposure table, an exposure parameter corresponding to the brightness of the current ambient light, the exposure parameter includes a relative aperture value, and the relative aperture value is in a predetermined relationship with the aperture number of the camera;

   The exposure elements in the camera are adjusted according to the exposure parameters.
2. The automatic exposure method for a camera according to claim 1, wherein the adjusting the exposure elements in the camera according to the exposure parameter comprises:

   Converting the relative aperture value into a number of apertures;

   The exposure elements in the camera are adjusted according to the number of apertures.
3. The automatic exposure method for a camera according to claim 1, wherein said predetermined relationship is a linear relationship between said relative aperture value and a logarithm of the number of apertures.
4. The automatic exposure method for a camera according to claim 3, wherein said relative aperture value is linear with a base 2 logarithm of the number of apertures.
5. The automatic exposure method for a camera according to claim 4, wherein said relative aperture value is expressed by the following formula:

   

   Wherein, LI represents a relative aperture value, Fnum represents the aperture number of the lens in the camera, Fmax represents the aperture number of the maximum aperture of the lens in the camera, and LDR indicates that the range of the first aperture of the lens of the camera is equal. The number of copies.
6. The automatic exposure method for a camera according to claim 1, further comprising: detecting whether a range of said relative aperture value of said lens of said camera changes if said range of relative aperture values exceeds The exposure table is updated by describing the range of relative aperture values in the exposure meter.
7. An automatic exposure device for a camera, comprising:

   a storage unit, configured to store an exposure table, wherein the exposure table records exposure parameters corresponding to brightness of different ambient light, the exposure parameter includes a relative aperture value, and the relative aperture value is a function of the number of apertures;

   a brightness detecting unit, configured to detect brightness of current ambient light;

   And a control unit, configured to query an exposure parameter corresponding to the brightness of the current ambient light in the exposure table, and adjust an exposure component of the camera to satisfy the exposure parameter.
8. The automatic exposure apparatus for a camera according to claim 7, wherein the brightness detecting unit is a CMOS sensor.
9. The automatic exposure apparatus for a camera according to claim 7, wherein the control unit is further configured to adjust the exposure component of the camera according to the number of apertures after converting the relative aperture value into a number of apertures .
10. The automatic exposure apparatus for a camera according to claim 7, wherein said relative aperture value is linear with a logarithm of the number of apertures.
11. The automatic exposure apparatus for a camera according to claim 10, wherein said relative aperture value is linear with a base 2 logarithm of the number of apertures.
12. An automatic exposure apparatus for a camera according to claim 11, wherein said relative aperture value is expressed by the following formula:

    

    Wherein, LI represents a relative aperture value, Fnum represents the aperture number of the lens in the camera, Fmax represents the aperture number of the maximum aperture of the lens in the camera, and LDR indicates that the range of the first aperture of the lens of the camera is equal. The number of copies.
13. The automatic exposure apparatus for a camera according to claim 7, wherein the camera further comprises:

    a lens detecting unit configured to detect whether a range of the relative aperture value of the lens of the camera changes

    The exposure table generating unit is configured to update the exposure table when the range of the relative aperture value exceeds a range of the relative aperture value in the exposure table.
14. A camera includes a body, a lens mounted to the body, and an automatic exposure device mounted to the body or the lens, the exposure device comprising:

    a storage unit, configured to store an exposure table, wherein the exposure table records exposure parameters corresponding to brightness of different ambient light, the exposure parameter includes a relative aperture value, and the relative aperture value is a function of the number of apertures;

    a brightness detecting unit, configured to detect brightness of current ambient light;

    And a control unit, configured to query an exposure parameter corresponding to the brightness of the current ambient light in the exposure table, and adjust an exposure component of the camera to satisfy the exposure parameter.
15. The camera of claim 14 wherein said brightness detecting unit is a CMOS sensor.
16. The camera of claim 14 wherein said exposure element comprises at least one of a shutter, an aperture, and an ISO adjuster.
17. The camera according to claim 14, wherein the control unit is further configured to adjust the exposure element of the camera according to the number of apertures after converting the relative aperture value into a number of apertures.
18. The camera of claim 14 wherein said relative aperture value is linear with a logarithm of the number of apertures.
19. The camera of claim 18 wherein said relative aperture value is linear with a base 2 logarithm of the number of apertures.
20. The camera of claim 19 wherein said relative aperture value is represented by the following formula:

    

    Wherein, LI represents a relative aperture value, Fnum represents the aperture number of the lens in the camera, Fmax represents the aperture number of the maximum aperture of the lens in the camera, and LDR indicates that the range of the first aperture of the lens of the camera is equal. The number of copies.
21. The camera of claim 14 further comprising:

    a lens detecting unit configured to detect whether a range of the relative aperture value of the lens of the camera changes

    The exposure table generating unit is configured to update the exposure table when the range of the relative aperture value exceeds a range of the relative aperture value in the exposure table.

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