CN117097872A - Automatic trapezoid correction system and method for projection equipment - Google Patents
Automatic trapezoid correction system and method for projection equipment Download PDFInfo
- Publication number
- CN117097872A CN117097872A CN202311113689.4A CN202311113689A CN117097872A CN 117097872 A CN117097872 A CN 117097872A CN 202311113689 A CN202311113689 A CN 202311113689A CN 117097872 A CN117097872 A CN 117097872A
- Authority
- CN
- China
- Prior art keywords
- projection
- image
- module
- projection plane
- focusing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 34
- 230000008569 process Effects 0.000 claims abstract description 7
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 238000003384 imaging method Methods 0.000 claims 2
- 230000003287 optical effect Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3179—Video signal processing therefor
- H04N9/3185—Geometric adjustment, e.g. keystone or convergence
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/317—Convergence or focusing systems
Abstract
The invention relates to the field of projection display equipment, discloses an automatic trapezoid correction system and an automatic trapezoid correction method for projection equipment, and solves the problems that in the prior art, when an image is corrected through projection, the accuracy is insufficient, data are required to be acquired through a sensor, and the cost is high. The correction method in the invention can be summarized as follows: the method comprises the steps of projecting an image simultaneously containing focusing and trapezoid correction characteristic points on a projection plane, capturing the image through a camera, adjusting a motor through judging the definition of the projection image to enable the projection device to achieve an optimal focusing state, calculating the distance between the projection device and the projection plane through the state of the motor in the optimal focusing state and the inverse process of a ranging focusing method, taking the distance as a depth reference value of trapezoid correction, and completing trapezoid correction of a picture, so that the accuracy of trapezoid correction is improved. The invention is suitable for automatic trapezoid correction of projection display equipment.
Description
Technical Field
The invention relates to the field of projection display equipment, in particular to an automatic trapezoid correction system and method for projection equipment.
Background
A projection apparatus is an optical instrument apparatus that projects an image or video onto a screen by enlarging the outline of a workpiece with an optical element, projecting laser light of a specific color into a projection area by the refraction action of an optical lens assembly, and forming a specific image. The portable projection device has the advantages of small size, light weight and strong mobility, is a substitute for a traditional slide projector and a large and medium projector, and can be moved by a user in the projection process based on the portability of the projection device so as to project images or videos in different directions.
In general, in the use of a projection device, due to the application scene requirement, when the position of the projection device needs to be moved, that is, the position of the projection device changes, there is unfocused, or when a non-rectangular state of a picture appears, the focusing and trapezoidal correction of the device need to be readjusted; if a manual adjustment method is adopted, the operation is complicated, the adjustment ratio is manually determined, and the aspect ratio of the image quality may be changed, so that the image quality is deformed, and the like, so that automatic trapezoid correction is particularly important in projection display.
However, the accuracy of the automatic trapezoidal correction is not high when the image is corrected by projection, and many sensors are required to acquire related data, such as depth information of a projection plane by a TOF ranging sensor, so that the data can be acquired conveniently and the accuracy can be improved by the sensors, but the cost is increased.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: the automatic trapezoid correction system and method for the projection equipment solve the problems that in the prior art, accuracy is insufficient when an image is corrected through projection in automatic trapezoid correction, data are required to be acquired through a sensor, and cost is high.
The technical scheme adopted for solving the technical problems is as follows:
in one aspect, the present invention provides an automatic trapezoid correction system for a projection apparatus, comprising: the device comprises a projection module, a camera module, a processing module and an adjusting module; the projection module and the camera module are fixed in the projection equipment, and the positions of the projection module and the camera module are relatively fixed;
the projection module is used for projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane;
the camera module is used for capturing images on the projection plane;
the processing module is used for processing and analyzing the images captured by the camera shooting module, and determining the distance between the projection equipment and the projection plane by analyzing and comparing the definition of the images and determining the position of the motor according to the clearest state of the photo; and calculating coordinates of the projection plane and determining an optimal projection plane by calculating depth information between each feature point in the image and the projection plane;
the adjusting module is used for continuously adjusting the definition of the projected image through the motor, focusing the picture and adjusting the output of the projection equipment according to the determined optimal projection plane to complete automatic trapezoidal correction.
Based on the system, the invention also provides an automatic trapezoid correction method for the projection equipment, which comprises the following steps:
s1, calibrating a camera module in a system;
s2, projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane through projection;
s3, capturing an image on a projection plane through a camera module;
s4, repeatedly adjusting the motor, and comparing the definition of the image captured by the camera module to obtain the motor state in the optimal focusing state corresponding to the clearest image;
s5, calculating the distance between the projection equipment and the projection plane according to the motor state in the optimal focusing state;
s6, taking the distance between the projection equipment and the projection plane calculated in the step S5 as a reference distance value for trapezoidal correction;
s7, correcting the depth distance which is fitted through image calculation during trapezoidal correction according to the trapezoidal correction reference distance value obtained in the step S6, and obtaining an optimal projection plane;
s8, adjusting the output of the projection equipment according to the determined optimal projection plane, and completing automatic trapezoid correction.
Further, in step S1, the required parameters of the camera module, including internal parameters, external parameters and distortion parameters of the camera, are obtained by manufacturing a calibration board to calibrate the camera module in the system.
Further, in step S2, in the image including both the focusing and the trapezoidal correction feature points, the middle part is a black-and-white checkerboard for trapezoidal correction, and the periphery is a cluster pattern for focusing.
Further, in step S4, the definition of the image captured by the comparison camera module is the definition of the cluster pattern used for focusing on the comparison image before and after the motor adjustment.
Further, in step S5, according to the motor state in the optimal focusing state, the distance between the projection device and the projection plane is calculated by solving the inverse phase process of the ranging focusing method.
Further, in step S7, the correction of the depth distance fitted by the image calculation during the trapezoidal correction according to the reference distance value specifically includes:
firstly, eliminating the depth value of which the difference value between the calculated depth value of the trapezoid correction characteristic point on the image and the focus reference distance value is larger than a set threshold value; then fitting a plane information by the reserved depth values of the feature points and the X coordinates and Y coordinates of the corresponding feature points, calculating a yaw angle and a pitch angle to obtain four vertex information of the projected plane, and finally selecting a maximum rectangle meeting the length-height ratio in the projection plane as an optimal projection plane.
The beneficial effects of the invention are as follows:
the invention adjusts the motor by judging the definition of the projection image, so that the projection equipment reaches the optimal focusing state, then calculates the distance between the projection equipment and the projection plane by the state of the motor in the optimal focusing state and by the inverse process of the ranging focusing method, and takes the distance as the depth reference value of the trapezoidal correction to finish the trapezoidal correction of the picture, thereby improving the accuracy of the trapezoidal correction.
Drawings
FIG. 1 is a block diagram of an automatic trapezoidal correction system for a projection device according to an embodiment of the present invention;
fig. 2 is a flowchart of an automatic trapezoid correction method for a projection apparatus according to an embodiment of the present invention.
Detailed Description
The invention aims to provide an automatic trapezoid correction system and an automatic trapezoid correction method for projection equipment, which solve the problems that in the prior art, the accuracy is insufficient when an image is corrected through projection, data is required to be acquired through a sensor, and the cost is high. The core idea is as follows: the method comprises the steps of projecting an image simultaneously containing focusing and trapezoid correction characteristic points on a projection plane, capturing the image through a camera, adjusting a motor through judging the definition of the projection image to enable the projection device to achieve an optimal focusing state, calculating the distance between the projection device and the projection plane through the state of the motor in the optimal focusing state and the inverse process of a ranging focusing method, taking the distance as a depth reference value of trapezoid correction, and completing trapezoid correction of a picture, so that the accuracy of trapezoid correction is improved.
Examples:
the structure of the automatic trapezoid correction system of the projection equipment provided by the embodiment is shown in fig. 1, and the automatic trapezoid correction system comprises a projection module, a camera module, a processing module and an adjusting module; the projection module and the camera module are fixed in the projection equipment, and the positions of the projection module and the camera module are relatively fixed;
the projection module is used for projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane;
the camera module is used for capturing images on the projection plane;
the processing module is used for processing and analyzing the images captured by the camera shooting module, and determining the distance between the projection equipment and the projection plane by analyzing and comparing the definition of the images and determining the position of the motor according to the clearest state of the photo; and calculating coordinates of the projection plane and determining an optimal projection plane by calculating depth information between each feature point in the image and the projection plane;
the adjusting module is used for continuously adjusting the definition of the projected image through the motor, focusing the picture and adjusting the output of the projection equipment according to the determined optimal projection plane to complete automatic trapezoidal correction.
Based on the above system, the flow of the automatic trapezoid correction method for the projection device provided in this embodiment is shown in fig. 2, and includes the following implementation steps:
s1, calibrating a camera module in a system;
in the step, the required camera parameters including internal parameters, external parameters and distortion parameters of the camera can be obtained by manufacturing a calibration plate for calibration. The specific calibration method is a prior art and will not be described in detail herein.
S2, projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane through projection;
in the step, the projected image is a pattern containing the required characteristic points of focusing and trapezoidal correction at the same time, so that the image captured by the camera can be directly used as the trapezoidal corrected image when the definition is highest after focusing is finished, thereby effectively reducing the time of focusing and trapezoidal correction and improving the correction efficiency.
An exemplary image includes an image with a black and white checkerboard in the middle for trapezoidal correction and a pie pattern for focusing around.
S3, capturing an image on a projection plane through a camera module;
in this step, an image on a projection plane is photographed in real time by an image pickup module (camera).
S4, repeatedly adjusting the motor, and comparing the definition of the image captured by the camera module to obtain the motor state in the optimal focusing state corresponding to the clearest image;
in the step, the motor is continuously regulated to change the position and the size of a projection picture of the projection equipment, the definition of the cluster pattern used for focusing on the image before and after the motor is regulated is compared until the most clear image is obtained, and the state of the motor at the moment is recorded.
S5, calculating the distance between the projection equipment and the projection plane according to the motor state in the optimal focusing state;
in this step, the distance between the projection device and the projection plane can be calculated according to the inverse process of the ranging focusing method in the prior art, which is not described here again.
S6, taking the distance between the projection equipment and the projection plane calculated in the step S5 as a reference distance value for trapezoidal correction;
in this step, the depth distance between the projection device and the projection plane calculated in the focusing state in the previous step is used as a reference value for trapezoidal correction, so that when trapezoidal correction is performed, the depth distance fitted according to the characteristic points of trapezoidal correction is corrected, so that the accuracy of the depth distance is improved.
S7, correcting the depth distance which is fitted through image calculation during trapezoidal correction according to the trapezoidal correction reference distance value obtained in the step S6, and obtaining an optimal projection plane;
in the step, the calculated depth information of the trapezoid correction feature points on the image and the obtained depth information of the points with larger reference distance are removed, so that error interference is reduced, the depth information of the feature points with the difference within a certain range is reserved, then the depth information and plane information are obtained through fitting, and finally the coordinates of a projection plane are calculated and the optimal plane of projection is selected. The calculation of the depth information of the trapezoid correction feature points belongs to the prior art, for example, the relation between the depth and the pixel coordinates is obtained through a triangle similarity relation, and then the depth information of each feature point projected can be solved.
During correction, fitting one plane information through the reserved depth values of the feature points and the X coordinates and Y coordinates of the corresponding feature points, calculating a yaw angle and a pitch angle to obtain four vertex information of a projected plane, and finally selecting a maximum rectangle meeting the length-height ratio in the projection plane as an optimal projection plane.
S8, adjusting the output of the projection equipment according to the determined optimal projection plane, and completing automatic trapezoid correction.
In this step, after the coordinate information of the optimal projection plane is obtained, the output of the projection device can be adjusted, so that the projected picture is projected according to the coordinate information of the optimal projection plane, thereby completing the automatic trapezoidal correction.
Finally, it should be noted that the above examples are only preferred embodiments and are not intended to limit the invention. It should be noted that modifications, equivalents, improvements and others may be made by those skilled in the art without departing from the spirit of the invention and the scope of the claims, and are intended to be included within the scope of the invention.
Claims (7)
1. An automatic trapezoid correction system for projection equipment is characterized in that,
comprising the following steps: the device comprises a projection module, a camera module, a processing module and an adjusting module; the projection module and the camera module are fixed in the projection equipment, and the positions of the projection module and the camera module are relatively fixed;
the projection module is used for projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane;
the camera module is used for capturing images on the projection plane;
the processing module is used for processing and analyzing the images captured by the camera shooting module, and determining the distance between the projection equipment and the projection plane by analyzing and comparing the definition of the images and determining the position of the motor according to the clearest state of the photo; and calculating coordinates of the projection plane and determining an optimal projection plane by calculating depth information between each feature point in the image and the projection plane;
the adjusting module is used for continuously adjusting the definition of the projected image through the motor, focusing the picture and adjusting the output of the projection equipment according to the determined optimal projection plane to complete automatic trapezoidal correction.
2. A projection device automatic trapezoid correction method applied to the projection device automatic trapezoid correction system according to claim 1, characterized in that the method comprises the steps of:
s1, calibrating a camera module in a system;
s2, projecting an image which simultaneously comprises focusing and trapezoid correction characteristic points onto a projection plane through projection;
s3, capturing an image on a projection plane through a camera module;
s4, repeatedly adjusting the motor, and comparing the definition of the image captured by the camera module to obtain the motor state in the optimal focusing state corresponding to the clearest image;
s5, calculating the distance between the projection equipment and the projection plane according to the motor state in the optimal focusing state;
s6, taking the distance between the projection equipment and the projection plane calculated in the step S5 as a reference distance value for trapezoidal correction;
s7, correcting the depth distance which is fitted through image calculation during trapezoidal correction according to the trapezoidal correction reference distance value obtained in the step S6, and obtaining an optimal projection plane;
s8, adjusting the output of the projection equipment according to the determined optimal projection plane, and completing automatic trapezoid correction.
3. An automatic trapezoid correcting method for a projection apparatus according to claim 2, wherein,
in step S1, the imaging module in the system is calibrated by manufacturing a calibration board, so as to obtain required parameters of the imaging module, including internal parameters, external parameters and distortion parameters of the camera.
4. An automatic trapezoid correcting method for a projection apparatus according to claim 2, wherein,
in step S2, in the image including both focusing and trapezoidal correction feature points, the middle part is a black-white checkerboard for trapezoidal correction, and the periphery is a cluster pattern for focusing.
5. The method for automatic trapezoid correction of a projection apparatus according to claim 4, wherein,
in step S4, the definition of the image captured by the comparison camera module is the definition of the cluster pattern used for focusing on the comparison image before and after the motor adjustment.
6. An automatic trapezoid correcting method for a projection apparatus according to claim 2, wherein,
in step S5, according to the motor state in the optimal focusing state, the distance between the projection device and the projection plane is calculated by the inverse phase process of the ranging focusing method.
7. An automatic trapezoid correcting method for a projection apparatus according to any of claims 2 to 6, wherein,
in step S7, correcting the depth distance fitted by image calculation during trapezoidal correction according to the reference distance value, specifically including:
firstly, eliminating the depth value of which the difference value between the calculated depth value of the trapezoid correction characteristic point on the image and the focus reference distance value is larger than a set threshold value; then fitting a plane information by the reserved depth values of the feature points and the X coordinates and Y coordinates of the corresponding feature points, calculating a yaw angle and a pitch angle to obtain four vertex information of the projected plane, and finally selecting a maximum rectangle meeting the length-height ratio in the projection plane as an optimal projection plane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311113689.4A CN117097872A (en) | 2023-08-31 | 2023-08-31 | Automatic trapezoid correction system and method for projection equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311113689.4A CN117097872A (en) | 2023-08-31 | 2023-08-31 | Automatic trapezoid correction system and method for projection equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117097872A true CN117097872A (en) | 2023-11-21 |
Family
ID=88771304
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311113689.4A Pending CN117097872A (en) | 2023-08-31 | 2023-08-31 | Automatic trapezoid correction system and method for projection equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117097872A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117440139A (en) * | 2023-12-19 | 2024-01-23 | 深圳新智联软件有限公司 | Automatic trapezoid correction method, device, equipment and medium for projection generation |
-
2023
- 2023-08-31 CN CN202311113689.4A patent/CN117097872A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117440139A (en) * | 2023-12-19 | 2024-01-23 | 深圳新智联软件有限公司 | Automatic trapezoid correction method, device, equipment and medium for projection generation |
| CN117440139B (en) * | 2023-12-19 | 2024-03-12 | 深圳新智联软件有限公司 | Automatic trapezoid correction method, device, equipment and medium for projection generation |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2021103347A1 (en) | Projector keystone correction method, apparatus, and system, and readable storage medium | |
| US7899270B2 (en) | Method and apparatus for providing panoramic view with geometric correction | |
| CN110493525B (en) | Zoom image determination method and device, storage medium and terminal | |
| US7868915B2 (en) | Photographing apparatus, method and computer program product | |
| US20090021600A1 (en) | Image pickup device and control method thereof | |
| JP6999802B2 (en) | Methods and equipment for double camera-based imaging | |
| WO2005002240A1 (en) | Method for calculating display characteristic correction data, program for calculating display characteristic correction data, and device for calculating display characteristic correction data | |
| JP3996617B2 (en) | Projector device with image distortion correction function | |
| JP2002202218A (en) | Lens evaluation method and device therefor | |
| TWI393981B (en) | Use the flash to assist in detecting focal lengths | |
| CN117097872A (en) | Automatic trapezoid correction system and method for projection equipment | |
| JP2000358157A (en) | Method and device for compensating optical attenuation of digital image | |
| CN111064939A (en) | Projection system and trapezoidal correction method | |
| US8872932B2 (en) | Apparatus and method for removing lens distortion and chromatic aberration | |
| US20130128002A1 (en) | Stereography device and stereography method | |
| CN114125411A (en) | Projection equipment correction method and device, storage medium and projection equipment | |
| JP6016622B2 (en) | Imaging apparatus, control method therefor, and program | |
| KR100835058B1 (en) | Image processing method for extending depth of field | |
| JP2001250114A (en) | Method and device for image processing and computer- readable recording medium | |
| CN114900675A (en) | Laser projection apparatus and projected image correction method | |
| CN111179180B (en) | Image correction method and device | |
| CN114339179A (en) | Projection correction method, projection correction device, storage medium and projection equipment | |
| RU2305320C2 (en) | Method for creating matrix image of an object | |
| WO2024080234A1 (en) | Projection device, correction device, projection system, correction method, and computer program | |
| CN115103169B (en) | Projection picture correction method, projection picture correction device, storage medium and projection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |