CN108805108B - Method for recording handwriting of blackboard - Google Patents
Method for recording handwriting of blackboard Download PDFInfo
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- CN108805108B CN108805108B CN201810782439.2A CN201810782439A CN108805108B CN 108805108 B CN108805108 B CN 108805108B CN 201810782439 A CN201810782439 A CN 201810782439A CN 108805108 B CN108805108 B CN 108805108B
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- 230000003287 optical effect Effects 0.000 claims description 24
- 238000005070 sampling Methods 0.000 claims description 15
- 238000001914 filtration Methods 0.000 claims description 10
- 230000006698 induction Effects 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 230000001960 triggered effect Effects 0.000 claims description 5
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 230000008569 process Effects 0.000 description 6
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Classifications
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V30/00—Character recognition; Recognising digital ink; Document-oriented image-based pattern recognition
- G06V30/10—Character recognition
- G06V30/32—Digital ink
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/10—Image acquisition
- G06V10/12—Details of acquisition arrangements; Constructional details thereof
- G06V10/14—Optical characteristics of the device performing the acquisition or on the illumination arrangements
- G06V10/145—Illumination specially adapted for pattern recognition, e.g. using gratings
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/10—Image acquisition
- G06V10/12—Details of acquisition arrangements; Constructional details thereof
- G06V10/14—Optical characteristics of the device performing the acquisition or on the illumination arrangements
- G06V10/147—Details of sensors, e.g. sensor lenses
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- Engineering & Computer Science (AREA)
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- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
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Abstract
The technical scheme of the invention comprises a method for recording the handwriting of the board, which comprises the following steps: a handwriting signal is sent out along a writing track; acquiring a blackboard image; capturing and processing handwriting signals in real time to generate handwriting point image coordinates; converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard; and storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals, and generating a handwriting file. The beneficial effects of the invention are as follows: the writing track of the blackboard writing is obtained by capturing the handwriting signal sent out along with the writing focus, and the handwriting signal is sampled and stored to obtain the handwriting file.
Description
Technical Field
The invention relates to an on-board handwriting recording method, and belongs to the technical field of teaching.
Background
Currently, in the teaching activities of China schools, teachers commonly need to carry out blackboard-writing (blackboard-writing, whiteboard-writing, electronic blackboard-writing, etc.) of lecture contents, and students often need to record lecture contents in real time. Due to the influence of factors such as limited blackboard area, more blackboard writing content and the like, a teacher often can repeat the process of erasing and blackboard writing, and the students are required to listen and talk with several efforts and also to record the blackboard writing content quickly. Therefore, too high learning requirements are put forward for students, and learning effects are affected.
Some schools are built with recording classrooms, which can record the content of the whole class, but the construction cost of the recording classrooms is high, and each classroom of the schools is not suitable to be constructed as the recording classrooms; the recording and broadcasting process is also complicated, and a teacher is required to control and coordinate with the recording and broadcasting, so that the lecture thought and the lecture efficiency are affected; the recorded and played files also need to be clipped, which is tedious, time-consuming and takes a teacher too much effort; meanwhile, the most important point is that recorded and broadcast contents are stored in a video form, the video file capacity is large, the transmission and sharing are not facilitated, the quick retrieval of key learning contents is not facilitated, and the requirement on hardware conditions of a user is too high.
Under the background, there is an urgent need for an blackboard writing handwriting collection method which does not change the current teaching mode, does not need the intervention of a teacher, automatically forms a blackboard writing data file with small volume and has low cost.
Disclosure of Invention
In order to solve the problems, the invention aims to provide the writing trace recording method for the blackboard writing, which is capable of automatically forming the writing data file with small volume without the participation of a teacher, improves the efficiency, has simple process and low use requirement, and acquires the writing trace by capturing and collecting the optical signal sent by the following writing focus and sampling and storing the writing signal to obtain the writing file.
The invention solves the problems by adopting the following technical scheme:
a method for writing handwriting on a board comprises the following steps:
a handwriting signal is sent out along a writing track;
capturing and processing handwriting signals in real time to generate handwriting point image coordinates;
acquiring a blackboard image;
converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard;
and storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals, and generating a handwriting file.
Further, the writing signal is emitted from a pen tip of the writing instrument.
Further, the handwriting signal is triggered by pressure induction.
Further, the handwriting signal is an optical signal of a preset frequency band.
Further, the step of capturing and processing the handwriting signal in real time and generating handwriting point image coordinates includes:
filtering out optical signals except handwriting signals;
capturing the filtered handwriting signals in real time to obtain handwriting images;
and establishing a first coordinate system for the handwriting image to obtain the image coordinates of the handwriting point.
Further, before the step of converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard, the method further comprises the following steps:
detecting whether the blackboard image has distortion or not;
and if the blackboard image has distortion, correcting the image distortion of the blackboard image.
Further, the step of converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard comprises the following steps:
establishing a second coordinate system according to the blackboard position;
and carrying out coordinate conversion on the image coordinates of the handwriting points according to the coordinate relation of the image distortion correction to obtain the relative coordinates of the handwriting points relative to the blackboard.
Further, the step of storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals and generating handwriting files further comprises the steps of:
and sampling the handwriting points according to a preset frequency, recording the related information of the handwriting points, and storing according to the sampling sequence.
An on-board handwriting recording device for realizing the above-mentioned on-board handwriting recording method, comprising:
the handwriting signal source is used for sending handwriting signals along with a writing track when writing on a blackboard;
the induction module is used for capturing handwriting signals in real time to obtain an blackboard writing track image and a blackboard image;
the acquisition processing module is used for controlling the acquisition action of the induction module and carrying out relevant processing on the acquired data to obtain relevant information of handwriting points;
and the sampling storage module is used for sampling and storing the relevant information of the handwriting points to generate a handwriting file.
Further, the handwriting signal source includes:
an optical signal transmitter for transmitting an optical signal indicative of handwriting;
the writing pen fixing unit is used for fixing the writing pen;
the pressure sensing unit is used for controlling the switch of the optical signal transmitter according to pressure sensing;
and the power supply unit is used for providing a working power supply for the handwriting signal source.
The beneficial effects of the invention are as follows: according to the writing on board handwriting recording method and device, the writing on board track is obtained by capturing the handwriting signals sent out along with the writing focus, and the handwriting signals are sampled and stored to obtain the handwriting files.
Drawings
FIG. 1 is a flow chart of a method of an embodiment of the present invention;
FIG. 2 is a flow chart of a handwriting point acquisition process in accordance with an embodiment of the present invention;
FIG. 3 is a block diagram of an apparatus according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of further device module relationships according to an embodiment of the present invention;
fig. 5 is an example of a distorted image of an embodiment of the present invention;
FIG. 6 is an example of an image after image distortion correction in accordance with an embodiment of the present invention;
fig. 7 is an example of an image received by the image acquisition unit after light filtering according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. The method and the device for writing on blackboard are suitable for writing on blackboard for classroom teaching.
Referring to fig. 1 to 7, an apparatus for writing handwriting recording according to the present invention, as shown in fig. 3, includes:
the handwriting signal source is used for sending handwriting signals along with a writing track when writing on a blackboard;
the induction module is used for capturing handwriting signals in real time to obtain an blackboard writing track image and a blackboard image;
the acquisition processing module is used for controlling the acquisition action of the induction module and carrying out relevant processing on the acquired data to obtain relevant information of handwriting points;
and the sampling storage module is used for sampling and storing the relevant information of the handwriting points to generate a handwriting file.
Further specific means are shown in FIG. 4, specifically, the handwriting signal source comprises an optical signal emitter, a writing pen fixing unit, a pressure sensing unit and a power supply unit;
the optical signal transmitter is arranged at the tip of the writing tool pen and is used for transmitting an optical signal for indicating handwriting; the optical signal can adopt laser, infrared light or visible light in a specific frequency band; here, a narrow-band infrared LED is used as the optical signal emitter; in order to accurately acquire the writing track of the blackboard writing, a switch of the optical signal emitter is triggered through the pressure sensing unit, when writing is performed, the pressure sensing unit detects the pressure between the writing pen and the blackboard, the optical signal emitter is triggered to emit optical signals of a specific frequency band, when writing is not performed, no pressure is generated between the writing pen and the blackboard, and the optical signal emitter does not emit optical signals, so that the optical signals can reflect the writing track; the writing pen can be a special pen body integrated with the optical signal transmitter, the writing pen fixing unit, the pressure sensing unit and the power supply unit, or can be a common chalk or other writing pens which are independently arranged and can be used together with the optical signal transmitter, the writing pen fixing unit, the pressure sensing unit and the power supply unit; in order to be widely applicable, a writing pen fixing unit is used for fixing a common chalk as a writing tool, and when a chalk nib is in contact extrusion with a blackboard, the tail end of the chalk is extruded to a pressure sensing unit so as to trigger an optical signal transmitter to work; the power consumption of handwriting signal source is provided by a battery, and the battery adopts a rechargeable battery for environmental protection and recycling.
Specifically, the sensing module comprises a light filtering unit and an image acquisition unit;
the image acquisition unit is a camera, adopts a near-focus and wide-angle lens, can even adopt a distorted wide-angle lens according to the requirement, and is fixed in the upper front of the blackboard; when the induction module starts to work, the image acquisition unit firstly acquires the image of the blackboard and acquires the position of the blackboard; when handwriting signals are collected, in order to prevent other light from interfering, the handwriting signals are clearer, a light filtering unit is arranged in front of an image collecting unit lens, when blackboard images are collected, the light filtering unit is in a closed state and is opened when the handwriting signals are collected, only specific frequency band light signals emitted by a light signal emitter pass through the light filtering unit, the image collecting unit only collects the handwriting signals, and the handwriting signals received by the image collecting unit after light filtering are shown in fig. 7.
Specifically, the acquisition processing module comprises an acquisition control unit, a distortion correction unit and a coordinate conversion unit;
the acquisition control unit controls the image acquisition unit to shoot handwriting images at high frequency, controls the light filtering unit to remove interference information in the images, and rapidly and accurately identifies handwriting point image coordinates of the blackboard writing handwriting; because the image acquisition unit is fixed in front of the blackboard, the shot image can be big and small up, and the shot image can also generate distortion by adopting a near-focus and wide-angle lens, one distortion example is shown in fig. 5, so that the obtained handwriting point image coordinates of the handwriting point are deviated from the actual positions, the shot blackboard image and the handwriting image need to be sent to the distortion correction unit for further correction processing, and the corrected image is shown in fig. 6; the image shot by the image acquisition unit is not only an area of the blackboard, but also an area outside the blackboard, so that the image coordinates of the handwriting points need to be subjected to coordinate system conversion to obtain the relative coordinates of the handwriting points relative to the blackboard, and the relative coordinates represent the actual positions of the handwriting points on the blackboard.
Specifically, the sampling storage module samples relevant information of handwriting points according to a certain frequency, wherein 20 handwriting points are sampled every second, the sampling information of each handwriting point comprises a start-stop sign, relative time and relative coordinates of the handwriting point relative to a blackboard, the sampling information of each handwriting point is a storage unit, the occupied space is only 6 bytes, and all the handwriting points are sequentially stored according to the relative time to obtain a complete handwriting file; assuming that a class is 1 hour and the writing is always on board, sampling 20 handwriting points per second, the handwriting file only occupies about 0.41MB of storage space, and compared with the class recorded video, the file size is greatly reduced; the handwriting file can be decoded and played through the corresponding blackboard writing handwriting reader, and when the handwriting file is played, the writing tracks are sequentially displayed according to the relative time, so that the whole process and the whole details of the blackboard writing in a class can be restored.
The method for writing on the blackboard is shown in fig. 1, and comprises the following steps: a handwriting signal is sent out along a writing track; acquiring a blackboard image; capturing and processing handwriting signals in real time to generate handwriting point image coordinates; converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard; and storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals, and generating a handwriting file.
The specific process flow of handwriting point collection is shown in fig. 2, wherein, in order to accurately capture the writing track of the blackboard writing, the handwriting signal is triggered by pressure induction, and a specific frequency band optical signal emitted from the pen tip of the writing tool is used as the handwriting signal.
Specifically, the step of capturing and processing the handwriting signal in real time and generating the handwriting point image coordinates includes: filtering out optical signals except handwriting signals; capturing the filtered handwriting signals in real time to obtain handwriting images; and establishing a first coordinate system for the handwriting image to obtain the image coordinates of the handwriting point.
Specifically, before the coordinates of the handwriting point image are converted to obtain the relative coordinates of the handwriting point relative to the blackboard, the method further comprises the following steps: detecting whether the blackboard image has distortion or not; and if the blackboard image has distortion, correcting the image distortion of the blackboard image.
Specifically, the step of converting coordinates of the image coordinates of the handwriting point to obtain relative coordinates of the handwriting point relative to the blackboard comprises the following steps: establishing a second coordinate system according to the blackboard position; and carrying out coordinate conversion on the image coordinates of the handwriting points according to the coordinate relation of the image distortion correction to obtain the relative coordinates of the handwriting points relative to the blackboard.
Specifically, the step of storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals and generating handwriting files further comprises the following steps: and sampling the handwriting points according to a preset frequency, recording the related information of the handwriting points, and storing according to the sampling sequence.
The present invention is not limited to the above embodiments, and the present invention can be achieved by the same means. Various modifications and variations are possible in the technical solution and/or in the embodiments within the scope of the invention.
Claims (5)
1. The writing recording method is characterized by comprising the following steps:
a handwriting signal is sent out along a writing track, wherein the handwriting signal is an optical signal of a preset frequency band;
acquiring a blackboard image;
capturing and processing handwriting signals in real time through a camera to generate handwriting point image coordinates;
the step of capturing and processing the handwriting signal in real time and generating handwriting point image coordinates comprises the following steps: filtering out optical signals except for handwriting signals, capturing the filtered handwriting signals in real time to obtain handwriting images, and establishing a first coordinate system for the handwriting images to obtain handwriting point image coordinates;
converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard;
storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals, generating handwriting files, decoding and playing the handwriting files through corresponding blackboard writing handwriting readers, and sequentially displaying writing tracks according to the relative time during playing;
storing relative coordinates of handwriting points according to the time sequence of capturing handwriting signals, and generating a handwriting file, and further comprising the steps of: and sampling the handwriting points according to a preset frequency, recording the related information of the handwriting points, and storing according to the sampling sequence.
2. An blackboard writing recording method according to claim 1, characterized in that: the writing signal is emitted from the nib end of the writing instrument.
3. An blackboard writing recording method according to claim 1, characterized in that: the handwriting signal is triggered by pressure induction.
4. An blackboard writing recording method according to claim 1, characterized in that: the step of converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard further comprises the following steps:
detecting whether the blackboard image has distortion or not;
and if the blackboard image has distortion, correcting the image distortion of the blackboard image.
5. An blackboard writing recording method according to claim 4, characterized in that: the step of converting the coordinates of the handwriting point image to obtain the relative coordinates of the handwriting point relative to the blackboard comprises the following steps:
establishing a second coordinate system according to the blackboard position;
and carrying out coordinate conversion on the image coordinates of the handwriting points according to the coordinate relation of the image distortion correction to obtain the relative coordinates of the handwriting points relative to the blackboard.
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| CN201810782439.2A CN108805108B (en) | 2018-07-17 | 2018-07-17 | Method for recording handwriting of blackboard |
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| CN201810782439.2A CN108805108B (en) | 2018-07-17 | 2018-07-17 | Method for recording handwriting of blackboard |
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| CN108805108B true CN108805108B (en) | 2024-03-12 |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2020133108A1 (en) * | 2018-12-27 | 2020-07-02 | 深圳市柔宇科技有限公司 | Handwriting acquisition method, handwriting transmission method and apparatus, and graphics tablet and system therefor |
| CN111930249B (en) * | 2020-07-21 | 2021-08-17 | 深圳市鹰硕教育服务有限公司 | Intelligent pen image processing method and device and electronic equipment |
| CN111949145A (en) * | 2020-07-21 | 2020-11-17 | 深圳市鹰硕教育服务股份有限公司 | Intelligent pen image processing method and device and electronic equipment |
| CN111881904A (en) * | 2020-07-31 | 2020-11-03 | 城云科技（中国）有限公司 | Blackboard writing recording method and system |
| CN114407561B (en) * | 2021-12-23 | 2023-02-24 | 湖南铁道职业技术学院 | Blackboard erasing method based on AIoT technology and intelligent blackboard eraser assembly |
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