WO2020133227A1

WO2020133227A1 - Handwriting data processing method, input device and handwriting system

Info

Publication number: WO2020133227A1
Application number: PCT/CN2018/124920
Authority: WO
Inventors: 李友; 周政霖
Original assignee: 深圳市柔宇科技有限公司
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-07-02
Also published as: CN113168248A

Abstract

A handwriting data processing method, an input device (10) and a handwriting system (100). The handwriting data processing method is applied to the input device (10), and the handwriting data processing method comprises: acquiring specific parameters of the input device (10) and the transmission format when carrying out data transmission between the input device (10) and a terminal device (20); determining the sampling interval of writing points according to the specific parameters and the transmission format; determining a reference point for written handwriting, collecting writing points on the written handwriting according to the sampling interval, and obtaining handwriting information of a current sampling point; calculating the relative variation between the handwriting information of the current sampling point and the handwriting information of the reference point; determining relative handwriting information of the current sampling point according to the sampling interval and the relative variation, and encoding the relative handwriting information as encoded data of the current sampling point according to the transmission format; and sending the encoded data of the current sampling point to the terminal device (20).

Description

Handwriting data processing method, input device and handwriting system

Technical field

The present application relates to the field of input devices, in particular to a handwriting data processing method, input device and handwriting system.

Background technique

The input device (such as a tablet) of the existing handwriting system collects the data of the sampling point when the user writes and sends it to the terminal device for display, but due to the transmission rate limitation of Bluetooth and other transmission methods, in some occasions such as classrooms or conferences When the room is waiting, multiple handwriting boards are simultaneously transmitted to a display terminal, so that the amount of data transmitted exceeds the transmission rate of Bluetooth and other transmission methods, resulting in data loss, which affects the display effect of the terminal device.

Summary of the invention

The embodiments of the present application provide a handwriting data processing method, an input device, and a handwriting system, which can compress the data transmitted by the handwriting system, reduce data packet loss, and ensure the display effect of the terminal device.

The present application provides a handwriting data processing method, which is applied to an input device. The handwriting data processing method includes: acquiring specific parameters of the input device and a transmission format of the input device and a terminal device during data transmission; The specific parameters and the transmission format determine the sampling point of the writing point; determine the reference point of the writing handwriting, and collect the writing point on the writing handwriting according to the sampling interval, and obtain the handwriting information of the current sampling point; calculate the current sampling The relative change amount of the handwriting information of the point and the reference point; determine the relative handwriting information of the current sampling point according to the sampling interval and the relative change amount, and encode the relative handwriting information according to the transmission format Is the encoded data of the current sampling point; and sending the encoded data of the current sampling point to the terminal device.

The present application also provides an input device. The input device includes a processor, and the processor is used to acquire specific parameters of the input device and a transmission format of the input device and the terminal device when performing data transmission. The specific parameters and the transmission format determine the sampling point of the writing point, determine the reference point of the writing handwriting, and collect the writing point on the writing handwriting according to the sampling interval, and acquire the handwriting information of the current sampling point and calculate the current sampling point The relative change amount of the handwriting information of the reference point and the handwriting information of the reference point, the relative handwriting information of the current sampling point is determined according to the sampling interval and the relative change amount, and the relative handwriting information is encoded according to the transmission format as The encoded data of the current sampling point, and sending the encoded data of the current sampling point to the terminal device.

The present application also provides a handwriting system. The handwriting system includes a terminal device and the input device of the foregoing embodiment. The terminal device is in communication connection with the input device, and the terminal device is used to receive input sent by the input device The data is displayed according to the input data.

The handwriting data processing method, input device, and handwriting system according to the embodiments of the present application compress the handwriting information through relative encoding to obtain the relative change amount of the current sampling point, and further compress the relative change amount through the sampling interval to obtain relative handwriting information , Not only reduces the amount of data transmission, so that the transmission data rate will basically not exceed the transmission rate limit of Bluetooth and other transmission methods, to prevent data packet loss, thus ensuring the display effect of the terminal device. Moreover, the relative change amount is further compressed through the sampling interval, and the coding range is dynamically expanded without increasing the relative number of encoding bits, so that the relative change of the two sampling points during writing due to the difference in user's writing habits and usage methods The problem that the amount exceeds the coding range corresponding to the relative coding mode and the sampling accuracy is affected is solved.

Additional aspects and advantages of the embodiments of the present application will be partially given in the following description, and some will become apparent from the following description, or be learned through practice of the embodiments of the present application.

BRIEF DESCRIPTION

The above and/or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

FIG. 1 is a schematic flowchart of a handwriting data processing method according to some embodiments of the present application.

2 is a schematic structural diagram of a handwriting system according to some embodiments of the present application.

FIG. 3 is a schematic diagram of a transmission format that is not processed by the handwriting data processing method.

4 is a schematic diagram of a transmission format of a current collection point in some embodiments of the present application.

5 is a schematic diagram of a transmission format of a reference point in some embodiments of the present application.

FIG. 6 is a schematic diagram of principles of a handwriting data processing method according to some embodiments of the present application.

7 to 14 are schematic flowcharts of a handwriting data processing method according to some embodiments of the present application.

detailed description

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are only used to explain the present application, and cannot be construed as limiting the present application.

1 and 2, the handwriting data processing method according to the embodiment of the present application is applied to the input device 10, and the handwriting data processing method includes the following steps:

010: Obtain the specific parameters of the input device 10 and the transmission format of the input device 10 and the terminal device 20 when performing data transmission;

020: Determine the sampling interval of writing points according to specific parameters and transmission format;

030: Determine the reference point of the writing handwriting, and collect the writing points on the writing handwriting according to the sampling interval, and obtain the handwriting information of the current sampling point;

040: Calculate the relative change between the handwriting information of the current sampling point and the reference point;

050: Determine the relative handwriting information of the current sampling point according to the sampling interval and the relative change amount, and encode the relative handwriting information as the encoded data of the current sampling point according to the transmission format; and

060: Send the encoded data of the current sampling point to the terminal device 20.

In some embodiments, the input device 10 includes a processor 16, and the processor 16 is used to obtain specific parameters of the input device 10 and the transmission format of the input device 10 and the terminal device 20 during data transmission, according to the specific parameters and the transmission format Determine the sampling interval of the writing point, determine the reference point of the handwriting, and collect the writing point on the writing handwriting according to the sampling interval, and obtain the handwriting information of the current sampling point, calculate the relative of the handwriting information of the current sampling point and the reference point The change amount, the relative handwriting information of the current sampling point is determined according to the sampling interval and the relative change amount, the relative handwriting information is encoded according to the transmission format as the encoded data of the current sampling point, and the encoded data of the current sampling point is sent to the terminal device 20.

The input device 10 may be a tablet 12, a stylus 14, etc. It can be understood that the input device 10 may also be other devices such as a touch screen of the terminal device 20, which is not limited herein. In the embodiment of the present application, the input device 10 12 for the tablet.

That is to say, step 010, step 020, step 030, step 040, step 050, and step 060 may be executed by the tablet 12.

Specifically, the processor 16 of the tablet 12 first obtains the specific parameters of the tablet 12 itself (such as resolution, size and other parameter information) and the transmission format for data transmission with the terminal device 20. When handwriting information is encoded, in order to ensure that all handwriting information can be accurately encoded, the transmission format of the absolute encoding method is generally shown in FIG. 3, where the handwriting information includes position information, pressure information, and time information. The position information refers to It is the coordinate value of the collection point in the input area of the tablet 12.

Please refer to FIG. 3, which is a schematic diagram of a transmission format in the prior art. The transmission bit number required for position information S1 is 32 bits, the transmission bit number for pressure information S2 is 16 bits, and the transmission bit number for time information S3 It is 32 bits. If handwriting information is transmitted using the transmission format of FIG. 3, in a scenario where multiple people write and display at the same time in a meeting or classroom teaching, assuming 40 people, an average of 300 sampling point pairs are collected every 300ms at the sampling rate. One word is collected and counted according to the frequency of Chinese characters. The average of each word is about 7.3 strokes. In theory, a bandwidth of nearly 3.2Mbps is required to write smoothly. That is to say, when using the transmission format of Figure 3 for data transmission, the number of coding bits required for each collection point is large, and in some scenarios such as conferences or classroom teaching, it will occupy too much bandwidth and easily exceed Bluetooth and other transmission methods. The transmission rate limitation of ， results in data packet loss, which in turn affects the display effect of the terminal device 20.

However, the real writing area only occupies a very small part of the tablet 12. When the user writes, the tablet 12 samples according to the sampling interval to obtain the first sampling point and use it as a reference point. For each writing, the next The sampling point has only a small change in position and pressure relative to the reference point, and the change in the time interval from the previous sampling point is also small. Therefore, the handwriting board 12 according to the embodiment of the present application may use a relative encoding method to compress the handwriting information. After the handwriting information is compressed using the relative encoding method, there is no need to transmit the handwriting information with a larger number of transmission bits required during transmission. Instead, it is sufficient to transmit the relative handwriting information with a smaller transmission bit number.

Please refer to FIG. 4, which is a schematic diagram of a transmission format in a relative encoding format provided by one embodiment of this application. In this embodiment, the number of transmission bits required for position information S1 is 16 bits, the number of transmission bits required for pressure information S2 is 8 bits, and the number of transmission bits required for time information S3 is 8 bits. Similarly, if the handwriting information is transmitted using the transmission format of FIG. 4, in a scenario where multiple people write and display at the same time in a meeting or classroom teaching, assuming 40 people, an average of 300 sampling points are collected every 300ms at the sampling rate Collecting a word, and according to the frequency of Chinese character usage, each word averages about 7.3 strokes. In theory, only 1.3Mbps of bandwidth can be used to write smoothly, and the data compression ratio can reach nearly 40%. Of course, as shown in the transmission format of the reference point shown in FIG. 5, the transmission bit number required for the position information S1 is 32 bits, the transmission bit number required for the pressure information S2 is 16 bits, and the transmission bit number required for the time information S3 is 8 bits. In order to ensure the accuracy of the handwriting information of the reference point, when the handwriting information of the reference point is transmitted, the transmission is performed according to a larger number of transmission bits to ensure that the handwriting information of the reference point can be accurately encoded. It can be understood that although the reference point is transmitted with a larger number of transmission bits, since the reference point only occupies a very small part of the entire handwriting, it basically has no effect on the final transmission bandwidth, so the handwriting information is encoded using a relative encoding method After that, the data compression ratio can still be close to 40%.

When the handwriting information is compressed using a relative coding method, as shown in FIG. 6, the upper left corner of the writing area of the tablet 12 is the coordinate origin O(0,0), the short side of the tablet 12 is the X axis, and the tablet The long side of 12 establishes a coordinate system XOY (hereinafter referred to as the absolute coordinate system) for the Y axis. When the user writes in the writing area of the tablet 12, the tablet 12 samples each writing point on the writing track to form a sample The first sampling point on the writing track is used as a reference point. For example, the position information includes coordinate values. The resolution of the tablet 12 is 1080P (that is, 1920*1080). The tablet 12 collects the user’s writing track. A sampling point P1 is used as a reference point, assuming that the coordinate value of P1 is (510, 400), the relative change in the position of the collection point after P1 (ie, the relative change in coordinates) is relative to the reference point P1 in the absolute coordinate system The relative coordinate value calculated by the coordinate value of the current point, for example, the coordinate value of the current collection point P2 in the absolute coordinate system is (600, 500), then the relative change of the coordinate of the current collection point P2 relative to the reference point P1 is (90,100); If the coordinate value of the current collection point is transmitted, the encoding of the abscissa 600 in binary requires 10 digits of transmission, and the encoding of the ordinate in binary requires 9 digits of transmission, coordinate value Encoding in binary requires a total of 19 transmission digits. When the relative change amount of the coordinate is transmitted, 90 bits of the relative change amount of the abscissa is encoded in the binary system, and 7 bits of transmission are required. The quantity only needs 14 bits, and the required number of transmission bits is greatly reduced; for another example, the pressure information includes the pressure value, the pressure value of the reference point P1 is 100, and the pressure value of the current collection point P2 is 120, then the relative value of the current collection point P2 The relative change of pressure at the reference point P1 is 20. When transmitting the pressure value, coding in binary requires 7 digits, and when transmitting the relative change of pressure, coding in binary requires only 5 digits. The required transmission The number of digits is greatly reduced; for another example, the time information includes the time value, for example, the time value of the reference point P1 is 22:40:10 (because the time interval between the two acquisition points is basically impossible to differ by more than one day, so only the transmission of hours, minutes and seconds Information only), the time value of the collection point P2 is 22:41:15, the relative change in time is 0:1:5, and the number of digits required for encoding in binary when transmitting the time value is as follows: 22 Encoding in binary requires 5 bits of transmission, 41 minutes in binary requires 6 bits of transmission, 15 seconds in binary requires 4 bits of transmission, and the total value of P2 It requires 15 bits of transmission, and when the relative change of transmission time is 0, encoding 1 minute and 5 seconds in binary system only needs 5 bits of transmission, and the number of transmission bits required is greatly reduced. Therefore, the use of relative coding can greatly reduce the number of transmission bits of each sampling point, so that the transmission data rate will basically not exceed the transmission rate limit of Bluetooth and other transmission methods, preventing data loss, thereby ensuring the terminal device 20 display effect.

Although the above-mentioned relative encoding method reduces the number of encoding bits, in extreme cases, the relative change of the two sampling points during writing due to the difference in the user's writing habits and usage patterns exceeds the encoding range corresponding to the relative encoding method. As a result, the sampling accuracy is affected. Taking the encoding of the abscissa as an example, when using fewer transmission digits (for example, 8 digits), its maximum range can only support [-255, 255]. Due to the different writing habits of different users, there will be some users The actual writing range of is more than 256 pixels, and the collection points of more than 256 cannot be accurately encoded, and the maximum can only be encoded to 255, so it will cause the accuracy of the handwriting information of the sampling point to be lost. For example, the relative change of the coordinates of the current sampling point is (15, 299). When encoding, the processor 16 encodes the coordinates of the current sampling point as (15, 255), that is, beyond the scope of accurate encoding The coordinates of the boundary value of will be encoded according to the corresponding boundary value, where greater than 255 is encoded in 255, and less than -255 is encoded in -255, which causes an error in the relative change in coordinates; for example, pressure information is transmitted less When the number of digits (for example, 8 bits), the relative change in pressure at the current sampling point is 300. When encoding, the processor 16 encodes the pressure data at the current sampling point by 255, which causes an error in the pressure information; for example, When the time information uses fewer transmission bits (for example, 8 bits), it is assumed that the time occupies 1 bit, the minute occupies 1 bit, and the second occupies 6 bits. When the relative change of the current sampling point time is 2 minutes and 10 seconds, where The minute has exceeded the encoding range of the transmission digits of the minute by 1 bit [0,1]. When encoding, the processor 16 encodes the minute in the time value of the current sampling point by 1, that is, the relative change in time becomes 1 Minutes and 10 seconds, there is an error in the relative change in time.

In order to solve the problem that the relative variation of the two sampling points during writing exceeds the coding range corresponding to the relative encoding mode due to the differences in the user's writing habits and usage methods, the processor 16 is affected by the sampling accuracy. The specific parameters and the transmission format determine the sampling interval of the writing point, wherein the specific parameters of the tablet 12 may be the resolution, size, preset pressure threshold, preset time threshold and other parameters of the tablet 12, in this embodiment, the specific parameters Including resolution, preset pressure threshold, and preset time threshold. The processor 16 can calculate the sampling interval according to the specific parameters and the number of bits of the corresponding handwriting information in the transmission format, for example, the sampling interval includes the abscissa sampling interval, the ordinate sampling interval, the pressure sampling interval, and the time sampling interval, the resolution Including the number of horizontal pixels and the number of vertical pixels, the sampling interval of the horizontal coordinate can be calculated according to the number of transmission bits (such as 8 bits) corresponding to the number of horizontal pixels and the horizontal coordinate, and the sampling interval of the vertical coordinate can be corresponding to the number of vertical pixels and the vertical coordinate value The number of transmission bits (such as 8 bits) is calculated, the pressure sampling interval can be calculated according to the preset pressure threshold and the corresponding number of transmission bits (such as 8 bits), and the time sampling interval can be calculated according to the preset time threshold and time value The number of transmission bits (such as 8 bits) is calculated, so that the processor 16 can calculate the abscissa sampling interval, the ordinate sampling interval, the pressure sampling interval, and the time sampling interval, respectively.

After calculating the sampling interval, on the basis of calculating the relative change, the relative change is further compressed according to the sampling interval to obtain relative handwriting information. The relative handwriting information also includes relative position handwriting information, relative pressure handwriting information, and relative time. Handwriting information, for example, the relative change amount of coordinates includes the relative change amount of the abscissa and the relative change amount of the ordinate, the relative change amount of the abscissa is compressed according to the sampling interval of the abscissa, and the relative change amount of the ordinate is compressed according to the sampling interval of the ordinate, Compress the relative change of pressure according to the pressure sampling interval, and compress the relative change of time according to the time sampling interval. The compression method can be the relative change divided by the corresponding sampling interval. The compression method can also be other methods, which are not done here. Restrictions. In this embodiment, the compression method is the relative change amount divided by the corresponding sampling interval. Due to space limitations, the following will only take the compression of the relative change amount of the abscissa as an example according to the sampling interval of the abscissa. The relative change amount of the ordinate is compressed according to the sampling interval of the ordinate, and the relative change of pressure is compressed according to the pressure sampling interval. The principle of compressing the relative change of time according to the time sampling interval is similar to that of compressing the relative change of the abscissa according to the sampling interval of the abscissa, which will not be repeated here. For example, the relative change of the abscissa is 300, and the resolution of the tablet 12 is 1080P (that is, 1920*1080), that is, the number of horizontal pixels is 1080. When transmitting data in the transmission format as shown in FIG. 4, The number of transmission bits of the relative change of the coordinate is 8 bits, and the corresponding coding range is [-255, 255]. The sampling interval for calculating the abscissa is 1080/2 ⁸ = 5 (result integer is reserved). If compression is not performed, the abscissa When the relative change is 300, the coding range corresponding to 8-bit transmission digits has been exceeded [-255, 255], and the relative position handwriting information can be obtained by dividing the relative change of the abscissa by the sampling interval (ie, 300/5) The abscissa value 60 of the relative position handwriting information at this time, the abscissa value 60 of the relative position handwriting information is within the coding range [-255, 255] corresponding to the 8-bit transmission bit number, then the abscissa value 60 of the relative position handwriting information can be accurately encoded , That is to say, the relative change of the current collection point that was not within the coding range can be accurately encoded after the compression of the sampling interval, and the sampling interval is obtained according to specific parameters and the number of transmission bits, which can make the relative change of Even if the value reaches the maximum (for example, the relative change of the abscissa reaches the maximum value of 1080, 216 is still within the coding range [-255, 255] corresponding to the 8-bit transmission number after compression), it can be accurately encoded, so that The handwriting information of the collection points collected by the user in the entire writing area of the handwriting board 12 can be accurately encoded, and the coding range is dynamically expanded, which solves the above two samplings during writing due to the differences in the user's writing habits and usage methods The relative change amount of the point exceeds the coding range corresponding to the relative coding method, which leads to the problem that the sampling accuracy is affected.

Finally, the relative handwriting information is encoded according to the transmission format to obtain the encoded data of the current sampling point, and then the encoded data is sent to the terminal device 20 to control the terminal device 20 to display the corresponding written content.

In summary, the handwriting data processing method and handwriting board 12 of the embodiment of the present application compress the handwriting information through relative encoding to obtain the relative change of the current sampling point, and further compress the relative change through the sampling interval to obtain the relative handwriting Information, not only reduces the amount of data transmission, so that the transmission data rate will basically not exceed the transmission rate limit of Bluetooth and other transmission methods, to prevent data loss, and thus ensure the display effect of the terminal device 20. Moreover, the relative change amount is further compressed through the sampling interval, and the coding range is dynamically expanded without increasing the relative number of encoding bits, so that the relative change of the two sampling points during writing due to the difference in user's writing habits and usage methods The problem that the amount exceeds the coding range corresponding to the relative coding mode and the sampling accuracy is affected is solved.

Please refer to FIG. 2 and FIG. 7, in some embodiments, the number of transmission digits of the abscissa is N, the number of transmission ordinates is M, the number of pressure transmissions is J, and the number of time transmissions is K, N, M, J and K are all positive integers; sampling interval includes abscissa sampling interval, ordinate sampling interval, pressure sampling interval and time sampling interval; specific parameters include resolution, preset pressure threshold, and preset time threshold, step 020 include:

0202: Determine that the horizontal coordinate sampling interval is equal to the number of horizontal pixels divided by 2 to the Nth power;

0204: Determine that the ordinate sampling interval is equal to the number of vertical pixels divided by the Mth power of 2;

0206: Determine that the pressure sampling interval is equal to the preset pressure threshold divided by the power of 2; and

0208: Determine that the time sampling interval is equal to the preset time threshold divided by the power of K.

In some embodiments, the processor 16 is used to determine that the horizontal sampling interval is equal to the number of horizontal pixels divided by the Nth power of 2, the vertical sampling interval is equal to the number of vertical pixels divided by the Mth power of 2, and to determine the pressure sampling interval Is equal to the preset pressure threshold divided by the power of J; and the determined time sampling interval is equal to the preset time threshold divided by the power of K.

That is to say, step 0202, step 0204, step 0206, and step 0208 may be implemented by the processor 16.

Specifically, after the specific parameters of the tablet 12 and the transmission format for data transmission between the tablet 12 and the terminal device 20 are obtained, the sampling interval can be determined according to the specific parameters and the transmission format. The sampling interval on the abscissa is equal to the number of horizontal pixels divided by 2. Power of N, the sampling interval of the ordinate is equal to the number of vertical pixels divided by the power of M. After the relative change in the position of the collection point is compressed according to the sampling interval, even if the relative change in the horizontal coordinate reaches the same as the number of horizontal pixels, the vertical The relative coordinate change amount is the same as the number of vertical pixels, and it is also within the coding range corresponding to the transmission format after dividing by the sampling interval to obtain relative handwriting information, that is, the collection point where the user writes in any writing area of the handwriting board 12 The handwriting information can be accurately encoded. The pressure sampling interval is equal to the preset pressure threshold divided by the power of J, and the time sampling interval is equal to the preset time threshold divided by the power of K, where the preset pressure threshold can be based on the two collection points when the user writes normally The maximum pressure difference between the two is determined, and the preset time threshold can be determined according to the maximum time difference between the two collection points when the user normally writes, or the redundancy can be retained to increase the preset pressure threshold and the preset time threshold appropriately to make the collection The relative change in pressure between the two collection points will not exceed the preset pressure threshold, and the relative change in time will not exceed the preset time threshold, so as to ensure that the handwriting information of the collection point collected in the extreme writing situation of the user can also be Code accurately.

Please refer to FIGS. 2 and 8. In some embodiments, step 030 includes:

0302: Record the first point of the writing points on the writing handwriting as the reference point and obtain the handwriting information of the reference point;

0304: Encode the handwriting information of the reference point and record the encoded data of the reference point; and

0306: Send the encoded data of the reference point to the terminal device 20.

In some embodiments, the processor 16 is also used to record the first point of the writing points on the writing handwriting as a reference point and acquire the handwriting information of the reference point, encode the handwriting information of the reference point and record the encoding of the reference point The data and the encoded data of the transmission reference point are sent to the terminal device 20.

Specifically, when the user writes, the processor 16 takes the first point of the writing point of the handwriting as a reference point and collects the handwriting information of the reference point. After the reference point is determined, since the relative encoding method is adopted, the tablet 12 The handwriting information of the sampling points collected in the subsequent transmission all transmit relative handwriting information, that is, the handwriting information of other sampling points are determined based on the handwriting information of the reference point. If the handwriting information of the reference point deviates, it will Affect the accuracy of the handwriting information of all sampling points. Therefore, the reference point needs to directly transmit handwriting information instead of relative handwriting information. Since the reference point does not transmit relative handwriting information, in order to ensure that the reference point handwriting information can be accurately encoded The handwriting information of the reference point can be encoded according to the larger transmission bit number. As shown in the transmission format of the reference point shown in FIG. 5, the position information S1 occupies 32 bits, the pressure information S2 occupies 16 bits, and the time information S3 occupies 8 bits. Since the terminal device 20 only needs to know the sequence of each sampling point to connect in order to display the stroke trajectory, that is, the terminal device 20 does not know the time information of the reference point, nor will it affect the stroke trajectory, and the latter sampling The relative change in time of the point must be greater than the relative change in time of the previous sampling point, so the time information of the reference point can be encoded with 0, and then the writing order of the collection point can be determined according to the magnitude of the relative change in time. Therefore, the number of transmission bits required to transmit the handwriting information of the reference point is reduced. In addition, although the reference point is transmitted with a larger number of transmission bits, since the reference point occupies only a very small part of the entire handwriting, it basically has no effect on the transmission bandwidth of the handwriting information. Finally, after the processor 16 encodes the handwriting information of the reference point and records the encoded data, the processor 16 sends the encoded data of the reference point to the terminal device 20.

In some embodiments, please refer to FIGS. 2 and 9, after step 0306, step 030 further includes:

0307: Determine whether a confirmation signal fed back by the terminal device 20 is received within a preset time, and the confirmation signal is a signal returned to the tablet 12 after the terminal device 20 receives the encoded data of the reference point; and

0308: If the confirmation signal of the terminal device 20 is not received within the preset time, the encoded data of the reference point is retransmitted.

In some embodiments, the processor 16 is also used to determine whether a confirmation signal fed back by the terminal device 20 is received within a preset time. The confirmation signal is that the terminal device 20 receives the encoded data of the reference point and returns it to the tablet 12 Signal; and if the confirmation signal of the terminal device 20 is not received within a preset time, the encoded data of the reference point is retransmitted.

That is to say, step 0307 and step 0308 can be implemented by the processor 16.

Specifically, the terminal device 20 may control the processor 16 to start sending the encoded intermediate writing data to the terminal device 20. When the user performs a writing operation, the handwriting pad 12 may collect a sampling point and obtain the encoded intermediate writing data immediately. The intermediate writing data is sent to the terminal device 20, or the encoded intermediate writing data of multiple sampling points can be obtained and sent together, which can be determined according to the data processing capability of the terminal device 20. After sending the encoded intermediate writing data of the absolute sampling point, since the current sampling point is obtained based on the absolute sampling point, in order to ensure the accuracy of the writing data of the entire stroke, it is necessary to ensure that the terminal device 20 receives the absolute sampling point encoding The processor 16 determines whether the terminal device 20 has received the absolute sampling point encoded intermediate writing data. If it determines that the absolute sampling point encoded intermediate writing data has not been received, it controls the processor 16 to send the absolute sampling point again. After the encoded intermediate writing data is ensured, the terminal device 20 receives the absolute sampling point encoded intermediate writing data, and then controls the processor 16 to send the subsequent intermediate sampling data after encoding. Since each stroke has an absolute sampling point, each time the tablet 12 receives the encoded intermediate writing data that ends the sampling point (that is, the last sampling point of each stroke), the processor 16 will judge the terminal again Whether the device 20 receives the encoded intermediate writing data of the absolute sampling point of the next stroke, thereby ensuring that the encoded intermediate writing data of the absolute sampling point of each stroke is received by the terminal device 20.

In some embodiments, please refer to FIGS. 2 and 10, the sampling interval includes an abscissa sampling interval, an ordinate sampling interval, a pressure sampling interval, and a time sampling interval; step 030 further includes:

0309: Collect the writing points on the writing handwriting according to one of the abscissa sampling interval, the ordinate sampling interval, the pressure sampling interval, and the time sampling interval.

Specifically, the handwriting board 12 samples the handwriting according to a predetermined sampling rate, so it can only be determined according to one of the abscissa sampling interval, the ordinate sampling interval, the pressure sampling interval, and the time sampling interval The sampling rate is used to collect the writing points on the writing handwriting, where the sampling rate refers to the number of sampling points collected per second by the tablet 12, such as 300 sampling points per second. For example, the sampling rate is 300 sampling points per second, and the sampling interval of the abscissa is 5, and the sampling rate is determined according to the sampling interval of the abscissa. The sampling rate is the original sampling rate divided by the sampling interval of the abscissa, that is, the actual sampling The rate becomes 60 sampling points per second, for example, the sampling rate is 300 sampling points per second, the ordinate sampling interval is 6, and the sampling rate is determined according to the ordinate sampling interval refers to: the sampling rate is the original The sampling rate is divided by the ordinate sampling interval, that is, the actual sampling rate becomes 50 sampling points per second; for another example, the sampling rate is 300 sampling points per second, and the pressure sampling interval is 3, according to the pressure sampling interval Determining the sampling rate refers to: the sampling rate is the original sampling rate divided by the pressure sampling interval, that is, the actual sampling rate becomes 100 sampling points per second; for another example, the sampling rate is 300 sampling points per second, The time sampling interval is 3, and determining the sampling rate according to the time sampling interval refers to: the sampling rate is the original sampling rate divided by the time sampling interval, that is, the actual sampling rate becomes 100 sampling points per second. And because the resolution of the current terminal device 20 is generally higher, even if the actual sampling rate is 1/5 of the original sampling rate (that is, one sampling point is collected every 4 sampling points), when the terminal device 20 displays, Will not have a big impact on the display effect. Moreover, after reducing the sampling rate by the sampling interval, the number of sampling points required to be transmitted per second is reduced, thereby further compressing the amount of data transmitted and increasing the data compression ratio.

In some embodiments, the user can customize the sampling rate.

Specifically, according to the different needs of different users for the display effect, the user is not satisfied with the display effect obtained at the current sampling rate, and may feel that the display effect of the handwriting obtained by the small sampling rate is not delicate enough, and the user can manually adjust the sampling at this time Rate, for example, the tablet has a sampling rate adjustment knob, the user can adjust the knob to adjust the sampling rate of the tablet, or the terminal device setting interface includes the sampling rate setting, the user can adjust the sampling rate through the terminal device, the terminal device controls the tablet to The sampling rate set by the user is used for sampling.

In some embodiments, please refer to FIGS. 2 and 11, the relative change includes the position relative change, the pressure relative change and the time relative change, and step 040 includes:

0402: The difference between the coordinate value in the position information of the current sampling point and the coordinate value in the position information of the reference point is recorded as the relative change in position;

0404: The difference between the pressure value in the pressure information of the current sampling point and the pressure information in the reference point is recorded as the relative change in pressure; and

0406: The difference between the time value in the time information of the current sampling point and the time value in the time information of the reference point is recorded as the relative change in time.

In some embodiments, the processor 16 is used to record the difference between the coordinate value in the position information of the current sampling point and the coordinate value in the position information of the reference point as the relative change in position, and the pressure information of the current sampling point The difference between the pressure value in the pressure value and the pressure information in the reference point is recorded as the relative change in pressure, and the difference between the time value in the time information of the current sampling point and the time value in the time information of the reference point is recorded as the time relative The amount of change.

That is to say, step 0402, step 0404, and step 0406 may be implemented by the processor 16.

Specifically, after determining the reference point, the processor 16 calculates the relative change amount of the handwriting information of the current collection point and the handwriting information of the reference point, where the relative position change amount is the coordinate value and the reference point in the position information of the current sampling point The difference of the coordinate value in the position information of the relative pressure is the difference between the pressure value in the pressure information of the current sampling point and the pressure value in the pressure information of the reference point, and the relative time change is the time information of the current sampling point The difference between the time value of the time and the time value of the time information of the reference point, that is to say, the processor 16 obtains the relative change by calculating the difference between the handwriting information of the current collection point and the handwriting information of the reference point. accurate.

In some embodiments, please refer to FIGS. 2 and 12, the handwriting data processing method further includes:

021: Send the specific parameters and sampling interval of the input device 10 to the terminal device 20 communicatively connected to the input device 10.

In some embodiments, the processor 16 is used to send the specific parameters and sampling interval of the input device 10 to the terminal device 20 that is in communication connection with the input device 10.

That is to say, step 021 can be implemented by the processor 16.

Specifically, when writing, the tablet 12 needs to communicate with the terminal device 20 before data can be transmitted. The tablet 12 first establishes a communication connection with the terminal device 20. The communication connection can be either a wired connection or a wireless connection. Wired connection such as USB connection, etc., wireless connection such as Bluetooth connection, etc. Then, after the tablet 12 communicates with the terminal device 20, the processor 16 sends the specific parameters and sampling interval of the tablet 12 to the terminal device 20. Among them, specific parameters such as the resolution of the tablet 12 are sent to the terminal device 20, and the terminal device 20 can zoom or enlarge the writing content on the tablet 12 according to the resolution of the tablet 12 and its own resolution, so as not to The written content becomes too small or too large when displayed on the terminal device 20 to ensure the display effect. The terminal device 20 may be determined according to the ratio of the relative change in pressure at the current sampling point to the preset pressure threshold and/or the ratio of the relative change in time to the preset time threshold according to the preset pressure threshold and the preset time threshold in the specific parameter The thickness, transparency and other attributes of the handwriting can more accurately adjust the display effect of the handwriting.

The sending sampling interval is because the relative handwriting information is obtained by compressing the relative position change, pressure relative change and time relative change respectively according to the corresponding sampling interval, so the terminal device 20 acquires the encoded relative handwriting information to In order to restore the relative handwriting information to the corresponding relative change in the generated encoded data, the terminal device 20 decodes the obtained relative handwriting information after acquiring the encoded data, and then corresponds the relative change in position, the relative change in pressure and the relative change in time The relative handwriting information is restored at the corresponding sampling intervals to obtain the relative position change, pressure relative change and time relative change before compression, thereby ensuring the accuracy of the sampling points acquired by the terminal device 20. For example, the relative change amount of the abscissa of the sampling point is 510, and the relative handwriting information of the abscissa is obtained after being compressed according to the sampling interval of the abscissa (such as the sampling interval of the abscissa is 2) 510/2=255, and the terminal device 20 obtains the abscissa The relative handwriting information of 510/2=255 is restored at the sampling interval of the abscissa to obtain the relative change of the abscissa 255*2=510, which can not only compress the data during transmission to ensure the transmission efficiency, but also accurately restore the data before compression Handwriting information. The compression and reduction of the relative change of the ordinate, the relative change of pressure and the relative change of time are the same as the compression and reduction of the relative change of the abscissa and will not be repeated here.

In some embodiments, please refer to FIG. 2 and FIG. 13, the relative position change includes the relative change of the abscissa and the relative change of the ordinate, and the relative handwriting information includes relative position handwriting information, relative pressure handwriting information and relative time handwriting information ; Step 050 includes:

0502: The value of dividing the relative change amount of the abscissa by the sampling interval of the abscissa and the value of the relative change amount of the ordinate by the sampling interval of the ordinate is recorded as relative position handwriting information.

0504: The value of the relative pressure change divided by the pressure sampling interval is recorded as relative pressure handwriting information; and

0506: The value of the relative change in time divided by the time sampling interval is recorded as relative time handwriting information.

In some embodiments, the processor 16 is used to divide the relative change of the abscissa by the value of the sampling interval of the abscissa and the value of the relative change of the ordinate to the sampling interval of the ordinate as the relative position handwriting information, the pressure The value of the relative change amount divided by the pressure sampling interval is recorded as relative pressure handwriting information, and the value of the time relative change amount divided by the time sampling interval is recorded as relative time handwriting information.

That is to say, step 0502, step 0504, and step 0506 may be implemented by the processor 16.

Specifically, after calculating the relative change amount of the current sampling point, in order to further compress the handwriting information of the current sampling point and dynamically expand the encoding range, the relative change amount of the abscissa is divided by the value of the sampling interval of the abscissa and the ordinate The value of the relative change divided by the ordinate sampling interval is recorded as relative position handwriting information, the value of the relative change in pressure divided by the pressure sampling interval is recorded as relative pressure handwriting information, and the value of the relative time change is divided by the time sampling interval Recorded as relative time handwriting information, the relative change of the abscissa, the relative change of the ordinate, the relative change of pressure and the relative change of time are divided by the corresponding sampling interval, and the sampling interval is based on the specific parameters of the tablet 12 and the tablet 12 The number of transmission bits during data transmission with the terminal device 20 is obtained. After the handwriting information of the current sampling point is compressed according to the sampling interval, not only can the coding range be dynamically expanded, but also the data compression ratio can be further improved. Among them, the dynamic expansion of the coding range refers to: the number of transmission digits of the tablet 12 during actual data transmission does not increase, but the relative handwriting information is compressed according to the sampling interval before transmission, and after transmission, according to the sampling interval The relative handwriting information is restored, so as to dynamically expand the coding range, that is, the coding range of the handwriting information becomes larger, but the actual number of transmission bits remains unchanged.

In some embodiments, referring to FIG. 2 and FIG. 14, the input device 10 (handwriting board 12) includes a memory 122, and after step 050, the handwriting data processing method further includes:

070: Cache the encoded data of the current sampling point into the memory 122 of the input device 10.

In some embodiments, the processor 16 is also used to cache the encoded data of the current sampling point into the memory 122 of the input device 10.

That is to say, step 070 may be implemented by the processor 16.

Specifically, after the processor 16 encodes the relative handwriting information to obtain the encoded data, the encoded data is cached in the memory 122. For example, the processor 16 may collect the encoded data of the collection point after the tablet 12 collects an acquisition point Cache to the memory 122 and then send to the terminal device 20; for another example, the processor 16 also caches the encoded data of the multiple collection points in the memory 122 after collecting multiple collection points on the tablet 12 and then collectively sends multiple collections together The encoded data of the point is given to the terminal device 20; the encoded data of the collected point is buffered through the memory 122, and can be easily taken out when needed.

In some embodiments, the sampling point further includes an end sampling point, and the end sampling point is a sampling point whose pressure data is less than a preset pressure value.

Specifically, the user writing is generally based on strokes, so the pressure of the sampling point collected at the end of a stroke written by the user is generally less than or equal to the preset pressure value (for example, the preset pressure value is 0), so the tablet When the pressure data is less than or equal to the preset pressure value, the point will be marked as the end sampling point, that is, the last sampling point of a stroke, the sampling is also in stroke units, so the reference point is each stroke when the user writes The first sampling point or the first sampling point collected after the end of the sampling point. In this way, the pen tablet can accurately break the pen to ensure the accuracy of the writing data of each stroke transmitted to the terminal device.

In some embodiments, when the relative change in the abscissa, the relative change in the ordinate, the relative change in pressure, or the relative change in time is outside the coding range corresponding to the relative coding method, the current sampling point is recorded As a reference point.

Specifically, in the relative encoding mode, taking the number of encoded bits corresponding to position information, pressure information and time information as 16, 8, and 8 respectively, the handwriting board collects the handwriting information of the sampling point to obtain the relative change and judges Whether the relative change of the abscissa, the relative change of the ordinate, the relative change of the pressure or the relative change of the time of the current sampling point are within the corresponding coding range, for example, the relative change of position includes the relative change of the abscissa and the relative change of the ordinate Amount, the relative change of the abscissa, the relative change of the ordinate, the relative change of pressure and the relative change of time all correspond to the 8-bit coded digits (ie, the coding range [-255, 255]); when the relative change of the abscissa is 280 indicates that the relative change of the abscissa is outside the coding range [-255,255], and the relative change of the abscissa cannot be accurately coded according to the current 8-bit coding digits. Similarly, when the relative change and pressure of the ordinate The relative change or time relative change is outside the coding range [-255,255], and it is no longer possible to accurately encode the relative change in ordinate, the relative change in pressure, or the relative change in time according to the current 8-bit coding digits, thus Affect the accuracy of the handwriting information acquired by the terminal device. Therefore, when the relative change amount of the abscissa, the relative change amount of the ordinate, the relative change amount of pressure, or the relative change of time of the current sampling point is outside the corresponding coding range, the current sampling point is transmitted as the reference point, and the current sampling point is transmitted The handwriting information without transmitting the relative handwriting information, thereby preventing the deterioration of the accuracy of the written data caused by some extreme situations, and because the probability of extreme situations is small, the number of reference points will not become too much. The effect of compression ratio is small.

Please refer to FIG. 2 again. The handwriting system 100 according to an embodiment of the present application includes a terminal device 20 and the input device 10 of any of the foregoing embodiments. The terminal device 20 is communicatively connected to the input device 10, and the terminal device 20 is used to receive input data sent by the input device 10 and display it according to the input data.

The handwriting system 100 of the embodiment of the present application compresses the handwriting information through relative encoding to obtain the relative change amount of the current sampling point, and further compresses the relative change amount through the sampling interval to obtain relative handwriting information, which not only reduces the data transmission The amount of data, so that the transmission data rate will basically not exceed the transmission rate limit of Bluetooth and other transmission methods, to prevent data packet loss, thereby ensuring the display effect of the terminal device. Moreover, the relative change is further compressed through the sampling interval, and the coding range is dynamically expanded without increasing the relative number of encoding bits, so that the relative change of the two sampling points during writing due to the difference in user's writing habits and usage methods The problem that the amount exceeds the coding range corresponding to the relative coding mode and the sampling accuracy is affected is solved. Moreover, the terminal device 20 can restore the relative handwriting information according to the sampling interval to ensure the accuracy of the handwriting information of the sampling point.

In some embodiments, please continue to refer to FIG. 2, the handwriting system 100 further includes a stylus 14, and the handwriting board 12 is used to receive the writing operation of the stylus 14 to form writing data. The user can restore the real writing experience by holding the stylus 14 for writing operation.

In some embodiments, please continue to refer to FIG. 2. The stylus 14 includes a pressure sensor 142. The pressure sensor 142 is disposed at the position of the pen tip. The pressure sensor 142 can collect pressure data when the stylus 14 performs a writing operation on the tablet 12. The handwriting board 12 can calculate the pressure value of the sampling point according to the correspondence between the pressure data and the sampling point. When the stylus 14 detects the pressure, it is only necessary to detect the pressure of the component (ie, the pen tip) that the stylus 14 is in contact with the tablet 12. Compared with detecting the pressure of the entire writing area through the tablet 12, the detection accuracy is higher.

Although the embodiments of the present application have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be construed as limitations to the present application. Those of ordinary skill in the art can The embodiments are changed, modified, replaced, and modified, and the scope of the present application is defined by the claims and their equivalents.

Claims

A handwriting data processing method applied to an input device, characterized in that the handwriting data processing method includes:

Obtain the specific parameters of the input device and the transmission format of the input device and the terminal device during data transmission;

Determine the sampling interval of the writing point according to the specific parameter and the transmission format;

Determine the reference point of the writing handwriting, and collect the writing point on the writing handwriting according to the sampling interval, and obtain the handwriting information of the current sampling point;

Calculating the relative change of the handwriting information of the current sampling point and the reference point;

Determining the relative handwriting information of the current sampling point according to the sampling interval and the relative change amount, and encoding the relative handwriting information as the encoded data of the current sampling point according to the transmission format; and

Sending the encoded data of the current sampling point to the terminal device.
The handwriting data processing method according to claim 1, wherein the handwriting information includes position information, pressure information, and time information.
The handwriting data processing method according to claim 2, wherein the relative change includes a relative change in position, a relative change in pressure and a relative change in time, and the calculation of the handwriting information of the current sampling point and the The relative change of the handwriting information of the reference point includes:

Record the difference between the coordinate value in the position information of the current sampling point and the coordinate value in the position information of the reference point as the relative change in position;

Recording the difference between the pressure value in the pressure information at the current sampling point and the pressure value in the pressure information at the reference point as the relative change in pressure; and

The difference between the time value in the time information of the current sampling point and the time value in the time information of the reference point is recorded as the relative change in time.
The handwriting data processing method according to claim 1, wherein the determination of the reference point of the handwriting further comprises:

Record the first point of the writing points on the writing handwriting as the reference point and obtain handwriting information of the reference point;

Encode the handwriting information of the reference point and record the encoded data of the reference point; and

Sending the encoded data of the reference point to the terminal device.
The handwriting data processing method according to claim 4, wherein after the sending the encoded data of the reference point to the terminal device, further comprising:

Judging whether a confirmation signal fed back by the terminal device is received within a preset time, and the confirmation signal is a signal returned to the handwriting board after the terminal device receives the encoded data of the reference point; and

If the confirmation signal of the terminal device is not received within the preset time, the encoded data of the reference point is retransmitted.
The handwriting data processing method according to claim 1, wherein the sampling interval includes an abscissa sampling interval, an ordinate sampling interval, a pressure sampling interval, and a time sampling interval; and the writing handwriting is collected according to the sampling interval The writing point of includes collecting the writing point on the writing handwriting according to one of the abscissa sampling interval, the ordinate sampling interval, the pressure sampling interval and the time sampling interval.
The handwriting data processing method according to claim 3, characterized in that, in the transmission format, the number of transmission digits of the abscissa is N, the number of transmission digits of the ordinate is M, and N and M are positive integers; the specific parameters include all The resolution of the input device, the resolution includes the number of horizontal pixels and the number of vertical pixels; the sampling interval includes the horizontal coordinate sampling interval and the vertical coordinate sampling interval; and the writing point is determined according to the specific parameter and the transmission format Sampling interval, including:

Determining that the horizontal coordinate sampling interval is equal to the number of horizontal pixels divided by the Nth power of 2; and

It is determined that the ordinate sampling interval is equal to the number of longitudinal pixels divided by the Mth power of 2.
The handwriting data processing method according to claim 7, wherein the relative change amount of the position includes the relative change amount of the abscissa and the relative change amount of the ordinate, the relative handwriting information includes the relative position handwriting information; The sampling interval and the relative amount of change determine the relative handwriting information of the current sampling point, including:

The value of dividing the relative change amount of the abscissa by the sampling interval of the abscissa and the value of the relative change amount of the ordinate by the sampling interval of the ordinate is recorded as relative position handwriting information.
The handwriting data processing method according to claim 3, wherein the number of pressure transmission digits in the transmission format is J, the number of time transmission digits is K, and J and K are positive integers; the specific parameter includes a preset pressure A threshold and a preset time threshold; the sampling interval includes a pressure sampling interval and a time sampling interval; and the sampling interval for determining a writing point according to the specific parameter and the transmission format includes:

Determining that the pressure sampling interval is equal to the preset pressure threshold divided by a power of 2; and

It is determined that the time sampling interval is equal to the preset time threshold divided by a power of two.
The handwriting data processing method according to claim 9, wherein the relative handwriting information includes relative pressure handwriting information and relative time handwriting information; and the current sampling is determined according to the sampling interval and the relative change amount Relative handwriting information of points, including:

Dividing the relative change in pressure by the pressure sampling interval as relative pressure handwriting information; and

The value of the relative change in time divided by the time sampling interval is recorded as relative time handwriting information.
The handwriting data processing method according to claim 1, wherein after the step of encoding the relative handwriting information as the encoded data of the current sampling point according to the transmission format, further comprising:

Cache the encoded data of the current sampling point into the memory of the input device.
The handwriting data processing method according to claim 1, wherein the handwriting data processing method further comprises:

Sending the specific parameter of the input device and the sampling interval to the terminal device communicatively connected to the input device.
An input device, the input device includes a processor, characterized in that the processor is used to obtain specific parameters of the input device and the transmission format of the input device and the terminal device during data transmission; according to the The specific parameters and the transmission format determine the sampling interval of the writing point; determine the reference point of the writing handwriting, and collect the writing point on the writing handwriting according to the sampling interval, and obtain the handwriting information of the current sampling point and calculate the current sampling point The relative change amount of the handwriting information of the reference point and the handwriting information of the reference point; determine the relative handwriting information of the current sampling point according to the sampling interval and the relative change amount, and encode the relative handwriting information according to the transmission format as The encoded data of the current sampling point; and sending the encoded data of the current sampling point to the terminal device.
The input device according to claim 13, wherein the handwriting information includes position information, pressure information, and time information.
The input device according to claim 14, wherein the relative change includes a relative change in position, a relative change in pressure and a relative change in time, and the processor is further configured to convert the position of the current sampling point The difference between the coordinate value in the information and the coordinate value in the position information of the reference point is recorded as the relative change in position, and the pressure value in the pressure information of the current sampling point and the pressure information in the reference point are The difference between the pressure values is recorded as the relative change in pressure, and the difference between the time value in the time information of the current sampling point and the time value in the time information of the reference point is recorded as the relative change in time .
The input device according to claim 13, wherein the processor is further configured to record the first point of the writing points on the writing handwriting as the reference point and acquire the handwriting of the reference point Information, handwriting information encoding the reference point and recording the encoded data of the reference point, and sending the encoded data of the reference point to the terminal device.
The input device according to claim 16, wherein the processor is further configured to determine whether a confirmation signal fed back by the terminal device is received within a preset time, and the confirmation signal is received by the terminal device The signal returned to the input device after the encoded data to the reference point, and if the confirmation signal of the terminal device is not received within the preset time, re-transmit the encoded data of the reference point .
The input device according to claim 13, wherein the sampling interval includes an abscissa sampling interval, an ordinate sampling interval, a pressure sampling interval, and a time sampling interval; the processor is further configured to sample according to the abscissa One of the interval, the ordinate sampling interval, the pressure sampling interval and the time sampling interval collects the writing points on the writing handwriting.
The input device according to claim 15, wherein in the transmission format, the number of transmission digits on the abscissa is N, the number of transmission digits on the ordinate is M, and N and M are positive integers; the specific parameter includes the input The resolution of the device, the resolution includes the number of horizontal pixels and the number of vertical pixels; the sampling interval includes an abscissa sampling interval and an ordinate sampling interval; the processor is further configured to determine that the abscissa sampling interval is equal to the The number of horizontal pixels is divided by the Nth power of 2, and it is determined that the ordinate sampling interval is equal to the number of vertical pixels divided by the Mth power of 2.
The input device according to claim 19, wherein the relative change amount of the position includes the relative change amount of the abscissa and the relative change amount of the ordinate, and the relative handwriting information includes relative position handwriting information; the processor further uses For dividing the relative change amount of the abscissa by the value of the sampling interval of the abscissa and dividing the relative change amount of the ordinate by the sampling interval of the ordinate, the relative position handwriting information is recorded.
The input device according to claim 15, wherein the number of pressure transmission digits in the transmission format is J, the number of time transmission digits is K, and J and K are positive integers; the specific parameters include a preset pressure threshold and A preset time threshold; the sampling interval includes a pressure sampling interval and a time sampling interval; the processor is further used to determine that the pressure sampling interval is equal to the preset pressure threshold divided by a power of 2 J, and the time The sampling interval is equal to the preset time threshold divided by 2 to the power of K.
The input device according to claim 21, wherein the relative handwriting information includes relative pressure handwriting information and relative time handwriting information; the processor is further configured to divide the relative change in pressure by the pressure sampling The value of the interval is recorded as relative pressure handwriting information, and the value of the relative change in time divided by the time sampling interval is recorded as relative time handwriting information.
The input device according to claim 13, wherein the input device includes a memory, and the processor is further configured to cache the encoded data of the current sampling point into the memory.
The input device according to claim 13, wherein the processor is further configured to send specific parameters of the input device and the sampling interval to the terminal device communicatively connected to the input device.
A handwriting system, characterized in that the handwriting system includes the input device and the terminal device according to any one of claims 13-24, the terminal device is in communication connection with the input device, and the terminal device is used for receiving The input data sent by the input device is displayed according to the input data.