Projection control method and apparatus, electronic device, and computer readable storage medium

Abstract

Disclosed in embodiments of the present application are a projection control method and apparatus, an electronic device, and a computer readable storage medium. The method comprises: in response to a picture projection instruction for at least one projection device, controlling projection devices to respectively project corresponding target sub-pictures; if a projection overlapping area is identified to be present between the projection devices on the basis of the target sub-pictures, determining a first projection device and a second projection device from among the projection devices having the projection overlapping area; acquiring a captured picture corresponding to the target sub-picture projected by the first projection device, the captured picture containing a partial picture of the target sub-picture of the second projection device; and on the basis of the captured picture, determining a proportion of a projection area, within the partial picture, overlapping the target sub-picture of the first projection device, and adjusting projection areas of the first projection device and the second projection device on the basis of the projection area proportion. In this way, the accuracy and efficiency of projection area adjustment during projection of multiple projection devices are improved.

Description

Projection control method and device, electronic equipment and computer readable storage medium

[0001] The present application claims priority to the Chinese patent application No. 202410866450.2, filed on June 28, 2024, entitled "Projection control method and device, electronic equipment and computer readable storage medium", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of projectors, in particular to a projection control method and device, electronic equipment and computer readable storage medium. BACKGROUND

[0003] A projector is a device that projects images or videos onto a screen or wall, commonly used in home entertainment, meetings, teaching and other demonstration occasions. It projects images by shining a light source (such as LED, laser or fluorescent lamp) onto a small curtain or transparent projection surface, and then projecting the image through an optical system to form a larger visual display.

[0004] However, with the development of projectors and the increasing demand for projection, a single projection device cannot meet the user's projection needs. For example, the projection screen of a single projection device is usually small, while for meeting, movie, presentation and other scenarios, a larger screen is needed to convey information. Therefore, the use of multiple projection devices to project a larger screen has become the current development trend. TECHNICAL PROBLEM

[0005] The projection scene of multiple devices requires coordination of the projection areas of each projection device to avoid overlapping. Currently, it still mainly relies on the human eye and manual adjustment, resulting in the need to improve the adjustment efficiency and accuracy. TECHNICAL SOLUTION

[0006] Embodiments of the present application provide a projection control method, device, electronic equipment and computer readable storage medium, which can improve the accuracy and efficiency of adjusting the projection area when multiple projection devices coordinate projection.

[0007] In a first aspect, the embodiments of the present application provide a projection control method, which comprises:

[0008] In response to a picture projection instruction for at least one projection device, controlling each of the projection devices to project a corresponding target sub-picture respectively;

[0009] If it is identified according to the target sub-picture that there is a projection overlapping area between the projection devices, determining a first projection device and a second projection device from the projection devices with the projection overlapping area;

[0010] obtain a captured picture of the target sub-picture projected by the first projection device, the captured picture containing a partial picture in the target sub-picture of the second projection device;

[0011] determine, according to the captured picture, a projection area ratio of the partial picture overlapping the target sub-picture of the first projection device, and adjust projection areas of the first projection device and the second projection device according to the projection area ratio. In a second aspect, the embodiments of the present application further provide a projection control device, which comprises:

[0012] a response module, configured to control each of the projection devices to project a corresponding target sub-picture in response to a picture projection instruction for at least one of the projection devices;

[0013] a determination module, configured to determine a first projection device and a second projection device from the projection devices having a projection overlapping area if it is identified according to the target sub-pictures that there is a projection overlapping area between the projection devices;

[0014] an obtaining module, configured to obtain a captured picture of the target sub-picture projected by the first projection device, the captured picture containing a partial picture in the target sub-picture of the second projection device;

[0015] an adjusting module, configured to determine, according to the captured picture, a projection area ratio of the partial picture overlapping the target sub-picture of the first projection device, and adjust projection areas of the first projection device and the second projection device according to the projection area ratio.

[0016] Optionally, in some embodiments of the present application, the adjusting module comprises:

[0017] a first determination unit, configured to determine a coordinate conversion coefficient according to the target sub-picture in a light machine coordinate system of the projection device and the target sub-picture in a picture coordinate system of the captured picture;

[0018] a conversion unit, configured to perform coordinate conversion on the captured picture according to the coordinate conversion coefficient to obtain a target captured picture corresponding to the target sub-picture of the first projection device, wherein the target captured picture contains a first picture corresponding to the target sub-picture projected by the first projection device, and contains a second picture in the partial picture overlapping the first picture;

[0019] a calculation unit, configured to calculate a picture ratio of the second picture in the target captured picture with respect to the first picture, and take the picture ratio as a projection area ratio.

[0020] Optionally, in some embodiments of the present application, the determination unit comprises:

[0021] The first determining sub-unit is configured to determine at least one reference point from the target sub-picture;

[0022] The second determining sub-unit is configured to determine the optical-mechanical point coordinates of the at least one reference point from the target sub-picture in the optical-mechanical coordinate system of the projection device;

[0023] The third determining sub-unit is configured to determine the picture point coordinates of the at least one reference point from the target sub-picture in the picture coordinate system of the photographed picture;

[0024] The calculating sub-unit is configured to calculate the coordinate conversion coefficient according to the optical-mechanical point coordinates and the picture point coordinates.

[0025] In some embodiments of the present application, the adjusting module comprises:

[0026] The first adjusting unit is configured to adjust the projection area of the first projection device according to the projection area ratio, and keep the projection area of the second projection device unchanged, or

[0027] The second adjusting unit is configured to adjust the projection area of the second projection device according to the projection area ratio, and keep the projection area of the first projection device unchanged.

[0028] In some embodiments of the present application, there are three projection devices that have projection overlapping areas, and the determining module comprises a second determining unit configured to, if it is identified according to the target sub-picture that there are projection overlapping areas among the projection devices, determine the first projection device according to the number of overlapping areas, and take the projection devices other than the first projection device among the projection devices that have projection overlapping areas as the second projection device.

[0029] The adjusting module comprises:

[0030] The third determining unit is configured to determine the projection area ratio corresponding to the partial picture of each second projection device according to the photographed picture respectively;

[0031] The third adjusting unit is configured to, for each second projection device, adjust the projection area of the second projection device according to the projection area ratio corresponding to the second projection device respectively, and keep the projection area of the first projection device.

[0032] In some embodiments of the present application, the device further comprises a correction module, and the correction module comprises:

[0033] The acquisition unit is configured to determine the heading angle, the pitch angle and the roll angle of each projection device;

[0034] The correction unit is configured to perform trapezoidal correction processing on the target sub-picture projected by the projection device according to the heading angle, the pitch angle and the roll angle, to obtain a corrected target sub-picture.

[0035] In some embodiments of the present application, the device further comprises a projection module, which comprises:

[0036] The projection unit is configured to project a corresponding target sub-picture by the first projection device and the second projection device respectively after adjusting the projection area.

[0037] Each target sub-picture is combined to obtain a target complete picture according to the position information of each projection device.

[0038] In a third aspect, the embodiments of the present application further provide a projection control system, which comprises:

[0039] The central control console is configured to control each projection device to project a corresponding target sub-picture in response to a picture projection instruction for at least one projection device, and if it is identified that there is a projection overlapping area between the projection devices according to the target sub-pictures, determine a first projection device and a second projection device from the projection devices having the projection overlapping area, acquire a photographed picture of the target sub-picture projected by the first projection device, the photographed picture containing part of the target sub-picture of the second projection device, determine a projection area proportion corresponding to the part of the picture according to the photographed picture, and adjust the projection area of the first projection device and the second projection device according to the projection area proportion.

[0040] The projection device is configured to be controlled by the central control console, project a corresponding target sub-picture under the control of the central control console, and adjust the projection area based on the projection area proportion.

[0041] In a fourth aspect, the embodiments of the present application further provide an electronic device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the computer program is executed by the processor to implement the steps in the projection control method described above.

[0042] In a fifth aspect, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program, and the computer program is executed by the processor to implement the steps in the projection control method described above.

[0043] In a sixth aspect, the embodiments of the present application further provide a computer program product or computer program, which comprises computer instructions stored in a computer readable storage medium. A processor of a computer device reads the computer instructions from the computer readable storage medium, and the processor executes the computer instructions to enable the computer device to perform the method provided in any of the various optional implementation manners described in the embodiments of the present application. Advantages

[0044] To sum up, in response to a picture projection instruction for at least one projection device, the embodiments of the present application control each projection device to project a corresponding target sub-picture, and if it is identified according to the target sub-picture that there is a projection overlapping area between the projection devices, a first projection device and a second projection device are determined from the projection devices with the projection overlapping area, a captured picture of the target sub-picture projected by the first projection device is obtained, the captured picture contains part of the target sub-picture of the second projection device, a projection area proportion corresponding to the part of the picture is determined according to the captured picture, and the projection area of the first projection device and the second projection device is adjusted according to the projection area proportion.

[0045] In this way, by capturing the captured picture containing the projected target sub-picture and the overlapping part of the picture when there is the projection overlapping area, the projection area proportion corresponding to the part of the picture can be calculated by using the captured picture, and then the projection area of the projection device is adjusted based on the projection area proportion, so that the picture overlapping problem when the projection device projects can be overcome. By capturing the image and calculating the projection area proportion, and adjusting the projection area of the projection device based on the projection area proportion, compared with the manual adjustment scheme by using the human eye, the accuracy and efficiency of the projection area adjustment can be improved by the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0047] FIG. 1 is a schematic diagram of a scene of a projection control method provided by the embodiments of the present application;

[0048] FIG. 2 is a schematic flow diagram of a projection control method provided by the embodiments of the present application;

[0049] FIG. 3 is a schematic diagram of a target sub-picture projected by a first projection device provided by the embodiments of the present application;

[0050] FIG. 4 is a schematic diagram of a captured picture provided by the embodiments of the present application;

[0051] FIG. 5 is a schematic diagram of a target shooting picture according to an embodiment of the present application;

[0052] FIG. 6 is a schematic diagram of projection area adjustment of a second projection device according to an embodiment of the present application;

[0053] FIG. 7 is a schematic diagram of perspective transformation according to an embodiment of the present application;

[0054] FIG. 8 is an architecture diagram of a projection control system according to an embodiment of the present application;

[0055] FIG. 9 is a structural schematic diagram of a projection control apparatus according to an embodiment of the present application;

[0056] FIG. 10 is a structural schematic diagram of an electronic device according to an embodiment of the present application. Embodiments of the present application

[0057] The technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0058] The embodiments of the present application provide a projection control method, apparatus, electronic device and computer readable storage medium. Specifically, the embodiments of the present application provide a projection control apparatus suitable for an electronic device, which includes a terminal device or a server. The terminal device includes, but is not limited to, a projection device such as a projector, a center console or a projection remote controller, and the like, which has data processing and sending control instructions. The server can be a stand-alone physical server, a server cluster or a distributed system composed of multiple physical servers, a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content distribution networks (CDN, Content Delivery Network), and basic cloud computing services such as big data and artificial intelligence platforms, etc. The server can be directly or indirectly connected through wired or wireless communication.

[0059] Specifically, please refer to FIG. 1, which is a schematic diagram of a scene where a terminal device (e.g., a center console) executes the projection control method according to an embodiment of the present application. The case where a server executes the projection control method can be understood by reference, and similarly, the case where a projection device (e.g., a projector) executes the control method can be understood as integrating the center console into the projection device. The specific execution process of the terminal device (e.g., the center console) executing the projection control method is as follows:

[0060] The terminal device 10 controls each projection device 11 to respectively project a corresponding target sub-picture in response to a picture projection instruction for at least one projection device 11, and if it is identified according to the target sub-picture that there is a projection overlap region between the projection devices 11, determines a first projection device 12 and a second projection device 13 from the projection devices 11 in which the projection overlap region exists, acquires a captured picture of the target sub-picture projected by the first projection device 12, wherein the captured picture contains part of the target sub-picture of the second projection device 13, determines a projection area ratio corresponding to the part of the picture according to the captured picture, and adjusts the projection area of the first projection device 12 and the second projection device 13 according to the projection area ratio.

[0061] In summary, the embodiment of the present application can obtain a captured picture containing a projected target sub-picture and an overlapped part of the picture when there is a projection overlap region, can calculate a projection area ratio corresponding to the part of the picture by using the captured picture, and further adjust the projection area of the projection device based on the projection area ratio, thereby overcoming the picture overlap problem when the projection device projects. Compared with the manual adjustment scheme by the human eye, the embodiment of the present application can improve the accuracy and efficiency of the projection area adjustment by capturing the image and calculating the projection area ratio, and adjusting the projection area of the projection device based on the projection area ratio.

[0062] The following will be described in detail. It should be noted that the order of the following embodiments is not limited as the priority order of the embodiments.

[0063] Please refer to FIG. 2, which is a flowchart of a projection control method provided by the embodiment of the present application. Although the logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in an order different from that shown in the figure. Specifically, the specific process of the projection control method is as follows:

[0064] 101、responding to a picture projection instruction for at least one projection device, controlling each projection device to respectively project a corresponding target sub-picture.

[0065] The picture projection instruction can be obtained by a remote controller or automatically generated after a set time is reached, or automatically triggered to be generated after a target scene is sensed, for example, if a target user is detected, the picture projection instruction is generated, or a specific gesture, a specific behavior action or a wake-up word of the user is sensed to automatically trigger the generation of the picture projection instruction.

[0066] The target sub-picture corresponding to each projection device is a picture projected by each projection device, and the target sub-pictures can be independent of each other or be associated with each other. For example, the target sub-pictures projected by the projection devices can be the same or different, and the target sub-pictures can be associated with each other. For example, the target sub-pictures are combined to form a complete large picture, such as four target sub-pictures arranged in a square or in a line to form a large projection picture.

[0067] 102. If it is identified according to the target sub-pictures that there is a projection overlap area between the projection devices, a first projection device and a second projection device are determined from the projection devices with the projection overlap area.

[0068] It can be understood that when the target sub-pictures projected by the projection devices overlap, it is considered that there is a projection overlap area, and the projection overlap area not only wastes projection resources, but also easily causes picture overlap, affects picture presentation, and reduces picture browsing experience.

[0069] In the embodiments of the present application, whether there is a projection overlap area between the projection devices can be determined based on a region range of the target sub-pictures projected by the projection devices on a projection object (such as a wall or a curtain cloth). For example, whether the projection overlap phenomenon occurs is determined according to whether the coordinates of the region ranges projected by the projection devices overlap.

[0070] Optionally, in the embodiments of the present application, the region range projected by the projection device can be determined by image recognition or by sensing the distance between the projection device and the projection object and combining the projection angle (such as the heading angle, the pitch angle, and the roll angle) of the projection device to calculate the region range.

[0071] When there is a projection overlap area, the projection device with the projection overlap area can be determined, and the projection area of the projection device is adjusted to eliminate the projection overlap phenomenon.

[0072] It can be understood that by determining the first projection device and the second projection device, the selection of the reference device for eliminating the projection overlap phenomenon is realized. For example, the first projection device is taken as the reference device to eliminate the projection overlap phenomenon with the second projection device.

[0073] Optionally, the first projection device and the second projection device can be determined according to the device position. For example, the projection device located on the left side or at the front is taken as the first projection device. The selection of the device on the left side or at the front conforms to the reading or browsing habit from left to right or from top to bottom. Correspondingly, after the first projection device is determined, the remaining projection devices with the projection overlap area are taken as the second projection device.

[0074] 103. acquire a shooting picture of the target sub-picture projected by the first projection device, the shooting picture containing part of the target sub-picture of the second projection device.

[0075] The shooting picture contains the target sub-picture projected by the first projection device and part of the target sub-picture projected by the second projection device.

[0076] For example, refer to FIG. 3 and FIG. 4, FIG. 3 is a schematic diagram of a target sub-picture projected by a first projection device according to an embodiment of the present application, and FIG. 4 is a schematic diagram of a shooting picture according to an embodiment of the present application. It is assumed that the resolution of the projection device is 1080p. The shooting picture contains the target sub-picture in FIG. 3 (for example, the inner rectangular region in FIG. 4) and part of the target sub-picture of the second projection device (for example, the dark image on the right in FIG. 4).

[0077] The shooting device of the shooting picture can be a camera installed on the projection device.

[0078] 104. determine the projection area ratio corresponding to the part of the picture according to the shooting picture, and adjust the projection area of the first projection device and the second projection device according to the projection area ratio.

[0079] The shooting picture contains the target sub-picture projected by the first projection device and part of the target sub-picture projected by the second projection device, so that the target sub-picture and the part of the picture are presented on one image. Then, the projection area ratio can be obtained according to the picture ratio of the part of the picture, and the projection area of the first projection device and the projection area of the second projection device can be controlled.

[0080] The projection area ratio refers to the ratio information of the picture area projected by the projection device. The ratio contains the ratio of the target picture area of the projection device to the current picture area.

[0081] In summary, in the presence of a projection overlap area, the embodiment of the present application obtains a captured image containing the projected target sub-image and the overlapping partial image. The projection area ratio corresponding to the partial image can be calculated using the captured image, and the projection area of the projection device is adjusted based on the projection area ratio, thereby overcoming the problem of image overlap when the projection device projects. By capturing an image and calculating the projection area ratio, and adjusting the projection area of the projection device based on the projection area ratio, compared with the manual adjustment scheme through the human eye, the embodiment of the present application can improve the accuracy and efficiency of the projection area adjustment.

[0082] Optionally, in the embodiment of the present application, the projection area ratio can be calculated by directly framing the area of the target sub-image projected by the first projection device in the captured image, and then directly using the image ratio as the projection area ratio. For example, referring to FIG. 4, the inner rectangular area is directly framed, and the image ratio is calculated based on the overlapping area in the inner rectangular area and the entire target sub-image, and then the image ratio is used as the projection area ratio.

[0083] In the embodiment of the present application, the method of framing the inner rectangular area can be implemented by an image recognition model. For example, after the captured image is obtained, the captured image is input into the image recognition model, and the image recognition model is used to frame the area corresponding to the target sub-image projected by the first projection device from the captured image to obtain the inner rectangular frame as shown in FIG. 4.

[0084] Optionally, in the embodiment of the present application, after the captured image is obtained, the sub-image (e.g., the target captured image in the embodiment of the present application) corresponding to the target sub-image projected by the first projection device in the captured image can be obtained by coordinate conversion. That is, in some embodiments of the present application, the step of “determining the projection area ratio of the partial image overlapping with the target sub-image of the first projection device according to the captured image” includes:

[0085] determining a coordinate conversion coefficient according to the target sub-image in the optical-mechanical coordinate system of the projection device and the target sub-image in the picture coordinate system of the captured image;

[0086] performing coordinate conversion on the captured image according to the coordinate conversion coefficient to obtain a target captured image corresponding to the target sub-image of the first projection device, wherein the target captured image contains a first image corresponding to the target sub-image projected by the first projection device, and contains a second image in the partial image overlapping on the first image;

[0087] Calculate a picture proportion of the second picture in the target shooting picture relative to the first picture, and take the picture proportion as the projection area proportion.

[0088] In the embodiment, the target sub-picture of the first projection device and the partial picture of the second projection device are contained in the shooting picture, and the adjustment of the projection area of the projection device is made for the projection device. Therefore, the shooting picture needs to be converted from the picture coordinate system to the optical-mechanical coordinate system for the projection device, and then the projection area proportion of the projection area for the projection device is calculated. For example, referring to FIG. 3 and FIG. 4, FIG. 3 is a target sub-picture in the optical-mechanical coordinate system, and FIG. 4 is a shooting picture in the picture coordinate system. The conversion coefficient of the coordinates can be calculated according to the target sub-picture of the first projection device contained in the target sub-picture, and then the shooting picture is converted to obtain a target shooting picture. Subsequently, the projection area proportion can be obtained by the proportion of the overlapping picture (i.e., the second picture) in the target shooting picture.

[0089] For example, referring to FIG. 5, FIG. 5 is a schematic diagram of a target shooting picture provided by the embodiment of the present application. The projection area proportion is obtained by calculating the percentage of the overlapping area relative to the target sub-picture of the first projection device. For example, the projection area proportion is 10%, and the projection area of the first projection device or the second projection device is adjusted according to the 10%.

[0090] The adjustment of the projection area can be realized by adjusting the projection area of the first projection device or by adjusting the projection area of the second projection device. That is, in some embodiments of the present application, the step of "adjusting the projection area of the first projection device and the second projection device according to the projection area proportion" includes:

[0091] adjusting the projection area of the first projection device according to the projection area proportion, and keeping the projection area of the second projection device unchanged, or

[0092] adjusting the projection area of the second projection device according to the projection area proportion, and keeping the projection area of the first projection device unchanged.

[0093] For example, taking the adjustment of the projection area of the second projection device as an example, referring to FIG. 6, FIG. 6 is a schematic diagram of the adjustment of the projection area of the second projection device provided by the embodiment of the present application. Based on the projection area proportion of 10%, the projection area of the second projection device is scaled by 10% or the overlapping 10% is divided off, to obtain the projection area of 100% of the first projection device and the projection area of 90% of the second projection device.

[0094] Optionally, in the embodiments of the present application, the reference points can be selected from the target sub-picture, and the coordinate conversion coefficients are calculated according to the coordinate information of the reference points. That is, in some embodiments of the present application, the step of "determining coordinate conversion coefficients according to the target sub-picture in the optical-mechanical coordinate system of the projection device and the target sub-picture in the picture coordinate system of the captured picture" comprises:

[0095] determining at least one reference point from the target sub-picture;

[0096] determining optical-mechanical point coordinates of the at least one reference point from the target sub-picture in the optical-mechanical coordinate system of the projection device;

[0097] determining picture point coordinates of the at least one reference point from the target sub-picture in the picture coordinate system of the captured picture;

[0098] calculating coordinate conversion coefficients according to the optical-mechanical point coordinates and the picture point coordinates.

[0099] For example, in the embodiments of the present application, the coordinates of the multiple reference points of the target sub-picture in the picture coordinate system and the coordinates of the multiple reference points of the target sub-picture in the optical-mechanical coordinate system are calculated respectively by using the processing function (findChessboardCorners) of the computer vision image processing library (Opencv), and then the coordinate conversion coefficients (i.e., the coordinate conversion matrix) from the picture coordinate system to the optical-mechanical coordinate system are obtained by using perspective transformation.

[0100] For example, as shown in FIG. 7, FIG. 7 is a schematic diagram of perspective transformation provided by the embodiments of the present application. The essence of perspective transformation is that a plane (a coordinate system, such as the original video plane coordinate system) is projected to another plane (another coordinate system, such as the new bottom plane coordinate system) by a transformation matrix. The specific principle is as follows:

[0101] In the above formula, u and v represent the original image coordinates, and x and y represent the picture coordinates after perspective transformation. The transformation matrix is in the form of 3*3, and the following can be obtained: x=a 11 u+a 12 v+a 13 y=a 21 u+a 22 v+a 23 z=a 31 u+a 32 v+a 33

[0102] Wherein, four reference points are taken in the original image and the perspective transformation image, and substituted into the above equation group to solve the coordinate transformation matrix. For example, in the embodiment of the present application, the target sub-picture of the first projection device takes the chessboard picture as an example. Four corner point coordinates are calculated from the chessboard in the picture coordinate system by using the processing function (findChessboardCorners), and the corresponding four corner point coordinates are calculated from the optical-mechanical coordinate system. Wherein, every 4 grids in the chessboard form a 2*2 square, and the center point of the square is the corner point.

[0103] Correspondingly, after the coordinate transformation matrix is calculated, the coordinate conversion of the shooting picture can be performed to obtain the target shooting picture. For example, for each original image coordinate in the shooting picture, the new image coordinate is obtained by substituting the coordinate transformation matrix, and the target shooting picture is obtained by combining each new image coordinate, as follows:

[0104] Wherein, in the above formula, x and y are each original image coordinate in the shooting picture, and x' and y' are new image coordinates, wherein, a 11 , a 12 , a 21 , a 22 , a 31 , a 32 is the rotation amount, and a 13 , a 23 , a 33 is the translation amount. It can be understood that the above is an example of the overlapping of two projection devices, and for three or four or even more overlapping cases, it can be understood with reference, for example, for the projection overlapping of three projection devices, the first projection device can be selected according to whether the number of overlapping regions is the most, and the remaining other two projection devices are taken as the second projection device, and the projection area ratio of the first projection device and each second projection device is calculated respectively, and the projection area of the first projection device or the projection area of each second projection device is adjusted. For example, when there are three projection devices that project overlapping regions, taking the adjustment of each second projection device as an example, the step "if it is identified according to the target sub-picture that there is a projection overlapping region between the projection devices, a first projection device and a second projection device are determined from the projection devices that have projection overlapping regions" includes: if it is identified according to the target sub-picture that there is a projection overlapping region between the projection devices, the first projection device is determined according to the number of overlapping regions, and the projection devices that have projection overlapping regions except the first projection device are taken as the second projection device.

[0105] The projection area ratio corresponding to the part of the picture is determined according to the shooting picture, including:

[0106] According to the photographed picture, the proportion of the projection area corresponding to the part picture of each second projection device is determined respectively;

[0107] According to the projection area proportion, the projection area of the first projection device and the second projection device is adjusted, including: for each second projection device, the projection area of the second projection device is adjusted according to the projection area proportion corresponding to the second projection device respectively, and the projection area of the first projection device is kept.

[0108] By calculating the projection area proportion of the first projection device respectively and adjusting the projection area of each second projection device respectively, the design of taking the first projection device as the main device and adjusting the projection area of other secondary devices is realized, which helps to improve the accuracy of projection area adjustment.

[0109] It can be understood that, since it is the projection scene of the projection device, there will inevitably be non-orthogonal projection when installing the projection, or even if the projection device is installed and the picture is projected according to the standard of orthogonal projection, it is still difficult to avoid the case of lateral projection. Therefore, the trapezoidal correction method can be used to adjust the trapezoidal picture to a rectangular picture to improve the picture browsing experience, that is, in some embodiments of the present application, before the step "if it is determined that there is a projection overlapping area between the projection devices according to the target sub-picture, determining the first projection device and the second projection device from the projection devices with the projection overlapping area", the method further comprises:

[0110] Determine the heading angle, the pitch angle and the roll angle of each projection device;

[0111] According to the heading angle, the pitch angle and the roll angle, the target sub-picture projected by the projection device is processed by trapezoidal correction to obtain the corrected target sub-picture.

[0112] Among them, the heading angle can be calculated by TOF according to the projection distance and FOV, and the pitch angle and the roll angle can be calculated by 6-axis Gsensor to obtain 3-axis acceleration and 3-axis angular velocity data.

[0113] Among them, the trapezoidal correction at least includes optical trapezoidal correction and digital trapezoidal correction, by calling the corresponding interface, the picture is corrected to keep the straight line in the image, such as correcting the trapezoidal picture to a rectangular picture.

[0114] Among them, in the embodiments of the present application, the projection area proportion is calculated based on the corrected target sub-picture.

[0115] Wherein, in the embodiments of the present application, after adjusting the projection area of each projection device, a larger complete picture can be projected by the position combination of each projection device, that is, in some embodiments of the present application, after the step of "determining the projection area ratio of the partial picture corresponding to the partial picture according to the captured picture, and adjusting the projection area of the first projection device and the second projection device according to the projection area ratio", the method further comprises:

[0116] The first projection device and the second projection device respectively project the target sub-pictures corresponding thereto after the projection area adjustment;

[0117] Wherein, each target sub-picture is combined to obtain a target complete picture according to the position information of each projection device.

[0118] For example, a projection picture is respectively assigned to a corresponding sub-picture according to the position and the adjusted projection area of each projection device, each projection device respectively projects the corresponding sub-picture, and then each sub-picture is combined to obtain a complete projection picture based on the position of each projection device, so as to realize the combination projection of a larger picture by multiple projection devices. Wherein, the larger picture can be understood as a larger screen or a larger presentation area.

[0119] In summary, in the embodiments of the present application, when there is a projection overlap area, a captured picture containing the projected target sub-picture and the overlapped partial picture is captured, the projection area ratio of the partial picture can be calculated by using the captured picture, and then the projection area of the projection device is adjusted based on the projection area ratio, so as to overcome the picture overlap problem when the projection device projects. Compared with the manual adjustment scheme by the human eye, the embodiments of the present application can improve the accuracy and efficiency of the projection area adjustment by capturing the image and calculating the projection area ratio, and adjusting the projection area of the projection device based on the projection area ratio.

[0120] Wherein, the target captured picture in the optical-mechanical coordinate system is obtained by coordinate conversion, the picture ratio of the overlapped picture to the complete target sub-picture can be calculated based on the target captured picture, that is, the projection area ratio is obtained, and then the projection area of the projection device can be directly adjusted by using the projection area ratio.

[0121] Correspondingly, the embodiments of the present application also provide a projection control system for the projection control method, for example, please refer to FIG. 8, the projection control system comprises:

[0122] The center console 201 is configured to control each of the projection devices 202 to project a corresponding target sub-picture in response to a picture projection instruction for at least one of the projection devices 202, and if it is identified according to the target sub-pictures that there is a projection overlapping area between the projection devices 202, determine a first projection device 203 and a second projection device 204 from the projection devices 202 that have the projection overlapping area, acquire a captured picture of the target sub-picture projected by the first projection device 203, the captured picture containing part of the target sub-picture of the second projection device 204, determine a projection area proportion corresponding to the part of the picture according to the captured picture, and adjust the projection areas of the first projection device 203 and the second projection device 204 according to the projection area proportion.

[0123] The projection device 202 is configured to be controlled by the center console 201 to project a corresponding target sub-picture and adjust a projection area based on a projection area proportion under the control of the center console 201.

[0124] The projection control system formed by the center console and the projection devices is configured to control the projection devices to project pictures by the center console.

[0125] To better implement the projection control method, the application further provides a projection control device based on the projection control method. The meanings of the terms are the same as those in the projection control method, and the specific implementation details can be referred to the description in the method embodiment.

[0126] Referring to FIG. 9, FIG. 9 is a structural schematic diagram of a projection control device according to an embodiment of the application. The projection control device can be specifically as follows:

[0127] The response module 301 is configured to control each of the projection devices to project a corresponding target sub-picture in response to a picture projection instruction for at least one of the projection devices.

[0128] The determination module 302 is configured to determine a first projection device and a second projection device from the projection devices that have a projection overlapping area if it is identified according to the target sub-pictures that there is a projection overlapping area between the projection devices.

[0129] The acquisition module 303 is configured to acquire a captured picture of the target sub-picture projected by the first projection device, the captured picture containing part of the target sub-picture of the second projection device.

[0130] The adjustment module 304 is configured to determine a projection area proportion of the part of the picture that overlaps with the target sub-picture of the first projection device according to the captured picture, and adjust the projection areas of the first projection device and the second projection device according to the projection area proportion.

[0131] Optionally, in some embodiments of the present application, the adjusting module 304 comprises:

[0132] a first determining unit, configured to determine a coordinate conversion coefficient according to the target sub-picture in the optical-mechanical coordinate system of the projection device and the target sub-picture in the picture coordinate system of the captured picture;

[0133] a conversion unit, configured to perform coordinate conversion on the captured picture according to the coordinate conversion coefficient to obtain a target captured picture corresponding to the target sub-picture of the first projection device, wherein the target captured picture comprises a first picture corresponding to the target sub-picture projected by the first projection device and a second picture in the partial picture overlapping on the first picture;

[0134] a calculation unit, configured to calculate a picture proportion of the second picture with respect to the first picture in the target captured picture, and take the picture proportion as a projection area proportion.

[0135] In some embodiments of the present application, the determining unit comprises:

[0136] a first determining sub-unit, configured to determine at least one reference point from the target sub-picture;

[0137] a second determining sub-unit, configured to determine optical-mechanical point coordinates of the at least one reference point from the target sub-picture in the optical-mechanical coordinate system of the projection device;

[0138] a third determining sub-unit, configured to determine picture point coordinates of the at least one reference point from the target sub-picture in the picture coordinate system of the captured picture;

[0139] a calculation sub-unit, configured to calculate a coordinate conversion coefficient according to the optical-mechanical point coordinates and the picture point coordinates.

[0140] In some embodiments of the present application, the adjusting module 304 comprises:

[0141] a first adjusting unit, configured to adjust a projection area of the first projection device according to the projection area proportion, and keep a projection area of the second projection device unchanged, or

[0142] a second adjusting unit, configured to adjust a projection area of the second projection device according to the projection area proportion, and keep a projection area of the first projection device unchanged.

[0143] In some embodiments of the present application, there are three projection devices projecting overlapping areas, and the determining module 302 comprises:

[0144] The second determining unit is configured to, if it is identified according to the target sub-picture that there is a projection overlapping area between the projection devices, determine a first projection device according to the number of overlapping areas, and determine a second projection device as a projection device other than the first projection device in the projection devices in which there is a projection overlapping area.

[0145] The adjusting module 304 comprises:

[0146] The third determining unit is configured to determine, according to the photographed picture, a projection area proportion corresponding to a partial picture of each second projection device.

[0147] The third adjusting unit is configured to, for each second projection device, respectively adjust a projection area of the second projection device according to the projection area proportion corresponding to the second projection device, and keep the projection area of the first projection device.

[0148] In some embodiments of the present application, the device further comprises a correction module, and the correction module comprises:

[0149] The acquisition unit is configured to determine a heading angle, a pitch angle and a roll angle of each projection device.

[0150] The correction unit is configured to perform trapezoidal correction processing on the target sub-picture projected by the projection device according to the heading angle, the pitch angle and the roll angle, to obtain a corrected target sub-picture.

[0151] In some embodiments of the present application, the device further comprises a projection module, and the projection module comprises:

[0152] The projection unit is configured to project a corresponding target sub-picture through the first projection device and the second projection device respectively after the projection area is adjusted.

[0153] Each target sub-picture is combined to obtain a target complete picture according to the position information of each projection device.

[0154] The embodiment of the present application first controls each of the projection devices to respectively project a corresponding target sub-picture in response to a picture projection instruction for at least one projection device by the response module 301, then determines a first projection device and a second projection device from the projection devices with a projection overlapping area if the projection overlapping area between the projection devices is identified according to the target sub-pictures by the determination module 302, subsequently acquires a captured picture of the target sub-picture projected by the first projection device, the captured picture containing a partial picture in the target sub-picture of the second projection device by the acquisition module 303, and then determines a projection area ratio of the partial picture overlapping the target sub-picture of the first projection device according to the captured picture and adjusts the projection area of the first projection device and the second projection device according to the projection area ratio by the adjustment module 304.

[0155] In the embodiment of the present application, when there is a projection overlapping area, a captured picture containing a projected target sub-picture and an overlapping partial picture is obtained, the projection area ratio of the partial picture can be calculated by using the captured picture, and then the projection area of the projection device is adjusted based on the projection area ratio, so that the picture overlapping problem during projection of the projection device is overcome. By capturing an image and calculating the projection area ratio, and adjusting the projection area of the projection device based on the projection area ratio, compared with the manual adjustment scheme by the human eye, the accuracy and efficiency of the projection area adjustment can be improved in the embodiment of the present application.

[0156] In addition, the present application also provides an electronic device, as shown in FIG. 10, which shows a structural schematic diagram of the electronic device related to the present application, in particular:

[0157] The electronic device can include a processor 401 with one or more processing cores, a memory 402 with one or more computer readable storage media, a power supply 403, and an input unit 404, and the like. Those skilled in the art can understand that the electronic device structure shown in FIG. 10 does not constitute a limitation on the electronic device, and can include more or fewer components than the illustration, or combine certain components, or different component arrangements. Among them:

[0158] The processor 401 is the control center of the electronic device, connects each part of the entire electronic device by various interfaces and lines, executes various functions of the electronic device and processes data by running or executing software programs and / or modules stored in the memory 402 and calling data stored in the memory 402, thereby overall monitoring the electronic device. Optionally, the processor 401 can include one or more processing cores; preferably, the processor 401 can integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface and application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 401.

[0159] The memory 402 can be used to store software programs and modules, and the processor 401 executes various functions and data processing by running the software programs and modules stored in the memory 402. The memory 402 can mainly include a storage program area and a storage data area, wherein the storage program area can store an operating system, at least one application program required by a function (such as a sound playing function, an image playing function, etc.), etc.; and the storage data area can store data created according to the use of the electronic device, etc. In addition, the memory 402 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. Accordingly, the memory 402 can also include a memory controller to provide the processor 401 with access to the memory 402.

[0160] The electronic device further includes a power supply 403 for supplying power to each component, and preferably, the power supply 403 can be logically connected to the processor 401 through a power management system, so as to realize functions such as management of charging, discharging and power consumption management through the power management system. The power supply 403 can also include one or more than one direct current or alternating current power supply, a recharging system, a power supply device debugging circuit, a power supply converter or inverter, a power supply state indicator and any other components.

[0161] The electronic device can also include an input unit 404, which can be used to receive input digital or character information, and generate keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control. Although not shown, the electronic device can also include a display unit, etc., which will not be described here. Specifically in this embodiment, the processor 401 in the electronic device will load the executable file corresponding to the process of one or more than one application program into the memory 402 according to the following instructions, and run the application program stored in the memory 402 by the processor 401, thereby realizing the steps in any of the projection control methods provided in the embodiments of the present application.

[0162] In response to a picture projection instruction for at least one projection device, the embodiment of the application controls each projection device to project a corresponding target sub-picture, and if it is identified according to the target sub-picture that there is a projection overlapping area between the projection devices, a first projection device and a second projection device are determined from the projection devices with the projection overlapping area, a shooting picture of the target sub-picture projected by the first projection device is acquired, the shooting picture contains part of the target sub-picture of the second projection device, the projection area proportion corresponding to the part of the picture is determined according to the shooting picture, and the projection area of the first projection device and the second projection device is adjusted according to the projection area proportion.

[0163] In the above, by shooting the shooting picture containing the projected target sub-picture and the overlapping part of the picture when there is a projection overlapping area, the projection area proportion corresponding to the part of the picture can be calculated by using the shooting picture, and then the projection area of the projection device is adjusted based on the projection area proportion, so that the picture overlapping problem when the projection device projects can be overcome. By shooting the image and calculating the projection area proportion, and adjusting the projection area of the projection device based on the projection area proportion, compared with the manual adjustment scheme by the human eye, the accuracy and efficiency of the projection area adjustment can be improved by the embodiment of the application.

[0164] The specific implementation of the above operations can be referred to the foregoing embodiments, which will not be described here.

[0165] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructions, or by instructions controlling related hardware, the instructions can be stored in a computer readable storage medium and loaded and executed by a processor.

[0166] Therefore, the application provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program can be loaded by a processor to execute the steps in any projection control method provided by the application. The specific implementation of the above operations can be referred to the foregoing embodiments, which will not be described here.

[0167] The computer readable storage medium can include a read only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0168] Since the instructions stored in the computer readable storage medium can execute the steps in any projection control method provided by the application, the beneficial effects of any projection control method provided by the application can be achieved, which will be described in detail in the foregoing embodiments, and will not be described here.

[0169] The projection control method and device, the electronic device, and the computer readable storage medium provided in the present application are described in detail above, the principles and implementation manners of the present application are described in the present article by applying specific examples, and the above example description is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed, and on the basis of the above, the content of the specification should not be understood as a limitation on the present application.

[0170] It should be noted that in the specific embodiments of the present application, data related to the projection picture of the projection device, the coordinate information of the reference point in the picture, the heading angle, the pitch angle and the roll angle of the projection device, etc. are involved. When the above embodiments of the present application are applied to specific products or technologies, the user's permission or consent needs to be obtained, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards of relevant countries and regions.

Claims

A projection control method, wherein, The method includes: In response to a screen projection command for at least one projection device, each of the projection devices is controlled to project its corresponding target sub-screen; If a projection overlap area is identified between the projection devices based on the target sub-screen, then the first projection device and the second projection device are determined from the projection devices with the projection overlap area. Acquire a captured image of the target sub-image projected by the first projection device, wherein the captured image includes a portion of the target sub-image from the second projection device; The proportion of the projection area that overlaps with the target sub-image of the first projection device in the captured image is determined, and the projection areas of the first projection device and the second projection device are adjusted according to the proportion of the projection area. According to the projection control method of claim 1, wherein, Determining the proportion of the projection area overlapping with the target sub-image of the first projection device in the partial image based on the captured image includes: Based on the target sub-image in the optical-mechanical coordinate system of the projection device and the target sub-image in the image coordinate system of the captured image, determine the coordinate transformation coefficients; The captured image is transformed according to the coordinate transformation coefficient to obtain a target captured image corresponding to the target sub-image of the first projection device. The target captured image includes a first image corresponding to the target sub-image projected by the first projection device, and a second image including the portion of the image superimposed on the first image. Calculate the percentage of the second frame relative to the first frame in the target captured image, and use the percentage of the second frame as the percentage of the projection area. According to claim 2, the projection control method, wherein, The step of determining the coordinate transformation coefficients based on the target sub-image in the optical-mechanical coordinate system of the projection device and the target sub-image in the image coordinate system of the captured image includes: Determine at least one reference point from the target sub-screen; Determine the optical-mechanical coordinates of the at least one reference point from the target sub-image in the optical-mechanical coordinate system of the projection device; Determine the image point coordinates of the at least one reference point from the target sub-image in the image coordinate system of the captured image; The coordinate transformation coefficient is calculated based on the coordinates of the optical engine point and the coordinates of the image point. According to the projection control method of claim 1, wherein, The step of adjusting the projection areas of the first projection device and the second projection device according to the projection area ratio includes: Adjust the projection area of ​​the first projection device according to the projection area ratio, while keeping the projection area of ​​the second projection device unchanged, or... Adjust the projection area of ​​the second projection device according to the projection area ratio, while keeping the projection area of ​​the first projection device unchanged. According to the projection control method of claim 1, wherein, The projection devices with overlapping projection areas include three; If a projection overlap area is identified between the projection devices based on the target sub-image, then determining the first projection device and the second projection device from the projection devices with the projection overlap area includes: If a projection overlap area is identified between the projection devices based on the target sub-screen, then the first projection device is determined based on the number of overlapping areas, and the projection devices other than the first projection device among the projection devices with projection overlap areas are designated as the second projection devices. Determining the proportion of the projected area corresponding to the captured image based on the captured image includes: Based on the captured images, determine the projection area percentage corresponding to a portion of the image from each second projection device. According to the projection control method of claim 5, wherein, The step of adjusting the projection areas of the first projection device and the second projection device according to the projection area ratio includes: For each second projection device, the projection area of ​​the second projection device is adjusted according to the proportion of the projection area corresponding to the second projection device, while the projection area of ​​the first projection device is maintained. According to the projection control method of claim 1, wherein, Before determining the first and second projection devices from the projection devices with overlapping projection areas based on the target sub-image, the method further includes: Determine the heading angle, pitch angle, and roll angle for each projection device; The target sub-image projected by the projection device is subjected to trapezoidal correction based on the heading angle, pitch angle and roll angle to obtain the corrected target sub-image. According to the projection control method of claim 1, wherein, After determining the projection area ratio corresponding to the captured image based on the captured image, and adjusting the projection areas of the first projection device and the second projection device according to the projection area ratio, the method further includes: After the projection area is adjusted, the first projection device and the second projection device respectively project their respective target sub-images; In this process, each target sub-image is combined based on the position information of each projection device to form the complete target image. According to the projection control method of claim 1, wherein, The projection overlap area is determined based on the range of the target sub-image projected by each projection device within the area of ​​the projected object. The range of the area is obtained through image recognition or calculated based on the distance between the projection device and the projected object and the projection angle of the projection device. According to the projection control method of claim 1, wherein, The method further includes: using an image recognition model to select the target sub-image from the captured image to obtain the inner rectangular region of the selected image; Calculate the screen ratio of the overlapping image in the inner rectangular region to the target sub-image, wherein the overlapping image corresponds to the overlapping area in the inner rectangular region; Set the screen ratio to the projection area ratio. According to the projection control method of claim 4, wherein, The step of adjusting the projection area of ​​the first projection device according to the projection area ratio includes: The projection area of ​​the first projection device is scaled or divided according to the stated projection area ratio. A projection control device, wherein, The device includes: A response module is used to respond to a screen projection command for at least one projection device and control each of the projection devices to project its corresponding target sub-screen. The determining module is used to determine a first projection device and a second projection device from the projection devices that have a projection overlap area if the target sub-screen is identified as having a projection overlap area. The acquisition module is used to acquire a captured image of the target sub-image projected by the first projection device, wherein the captured image includes a portion of the target sub-image of the second projection device; An adjustment module is used to determine the proportion of the projection area that overlaps with the target sub-image of the first projection device in the captured image, and to adjust the projection areas of the first projection device and the second projection device according to the proportion of the projection area. According to the projection control device of claim 12, wherein, The adjustment module includes: Based on the target sub-image in the optical-mechanical coordinate system of the projection device and the target sub-image in the image coordinate system of the captured image, determine the coordinate transformation coefficients; The captured image is transformed according to the coordinate transformation coefficient to obtain a target captured image corresponding to the target sub-image of the first projection device. The target captured image includes a first image corresponding to the target sub-image projected by the first projection device, and a second image including the portion of the image superimposed on the first image. Calculate the percentage of the second frame relative to the first frame in the target captured image, and use the percentage of the second frame as the percentage of the projection area. According to the projection control device of claim 13, wherein, The step of determining the coordinate transformation coefficients based on the target sub-image in the optical-mechanical coordinate system of the projection device and the target sub-image in the image coordinate system of the captured image includes: Determine at least one reference point from the target sub-screen; Determine the optical-mechanical coordinates of the at least one reference point from the target sub-image in the optical-mechanical coordinate system of the projection device; Determine the image point coordinates of the at least one reference point from the target sub-image in the image coordinate system of the captured image; The coordinate transformation coefficient is calculated based on the coordinates of the optical engine point and the coordinates of the image point. According to the projection control device of claim 12, wherein, The step of adjusting the projection areas of the first projection device and the second projection device according to the projection area ratio includes: Adjust the projection area of ​​the first projection device according to the projection area ratio, while keeping the projection area of ​​the second projection device unchanged, or... Adjust the projection area of ​​the second projection device according to the projection area ratio, while keeping the projection area of ​​the first projection device unchanged. According to the projection control device of claim 12, wherein, The projection devices with overlapping projection areas include three; If a projection overlap area is identified between the projection devices based on the target sub-image, then determining the first projection device and the second projection device from the projection devices with the projection overlap area includes: If a projection overlap area is identified between the projection devices based on the target sub-screen, then the first projection device is determined based on the number of overlapping areas, and the projection devices other than the first projection device among the projection devices with projection overlap areas are designated as the second projection devices. Determining the proportion of the projected area corresponding to the captured image based on the captured image includes: Based on the captured images, determine the projection area percentage corresponding to a portion of the image from each second projection device. According to the projection control device of claim 16, wherein, The step of adjusting the projection areas of the first projection device and the second projection device according to the projection area ratio includes: For each second projection device, the projection area of ​​the second projection device is adjusted according to the proportion of the projection area corresponding to the second projection device, while the projection area of ​​the first projection device is maintained. According to the projection control device of claim 12, wherein, Before determining the first and second projection devices from the projection devices with overlapping projection areas based on the target sub-image, the device further includes: Determine the heading angle, pitch angle, and roll angle for each projection device; The target sub-image projected by the projection device is subjected to trapezoidal correction based on the heading angle, pitch angle and roll angle to obtain the corrected target sub-image. An electronic device, wherein, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the projection control method as described in any one of claims 1-11. A computer-readable storage medium, wherein, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the projection control method as described in any one of claims 1-11.

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