CN101877067B - Method and system for hand input based on camera device - Google Patents

Abstract

The invention discloses a method for handwriting input based on an imaging device. The method comprises: setting up an imaging device in advance, and the imaging device displays image information captured by the imaging device through a display device connected thereto; The information determines the input area of the handwriting input; in the current frame captured by the camera device, the first display coordinate and the second display coordinate of the input terminal of the input device and the projection of the input terminal in the input area are acquired; when the first display coordinate and When the second display coordinates are equal, obtain and record the real coordinates of the input terminal in the input area according to the first display coordinates or the second display coordinates, and reset the current frame; when the acquired first display coordinates and the second display coordinates are not equal , the handwriting of the handwriting input is obtained according to the recorded real coordinates of the input terminal in the input area. The invention also discloses a camera-based handwriting input system. By using the above method and system, handwriting input can also be realized without using a traditional handwriting input device.

Description

Method and system for handwriting input based on camera device

technical field

The invention relates to the technical field of handwriting input, in particular to a camera-based handwriting input method and system.

Background technique

In the prior art, when the user wishes to input required input content into the computer through handwriting input (not through keyboard and other input devices), it is generally necessary to use an additional handwriting input device. When using a traditional handwriting input device, the user first needs to connect the handwriting input device used to the computer, and install the software or driver related to the handwriting input device in the connected computer, and then use a specific input tool (for example, stylus), and carry out handwriting input on specific input board, just can input the content that needs input in the computer. During the use of the above-mentioned handwriting input device, the user's operation process is relatively complicated, and the user needs to purchase an additional handwriting input device, thereby increasing the cost of the user using the handwriting input method. For example, commonly used traditional handwriting input devices can generally be classified into three categories: resistive piezo-sensitive, electromagnetic piezo-sensitive, and capacitive piezo-sensitive. Among them, although the price of resistive piezo-sensitive and electromagnetic piezo-sensitive handwriting input devices is relatively low, they are relatively easy to damage and have low precision; although capacitive piezo-sensitive handwriting input devices can achieve high precision, they are very expensive. Expensive, thereby greatly increasing the cost of the user using the handwriting input method.

Contents of the invention

In view of this, the present invention provides a method and system for handwriting input based on a camera device, thereby improving the convenience of handwriting input and reducing user costs.

According to above-mentioned purpose, technical scheme of the present invention is achieved like this:

A method for handwriting input based on a camera, the method comprising:

A, a camera device is set, and the camera device displays the image information captured by the camera device through a display device connected to it;

B. Determine the input area for handwriting input according to the image information captured by the camera device;

C. In the current frame of the image information captured by the camera device, obtain the first display coordinate of the input terminal of the input device in the input area and the first display coordinate of the input terminal of the input device projected in the input area Two display coordinates;

D. When the obtained first display coordinates and second display coordinates are equal, according to the first display coordinates or the second display coordinates, obtain and record the real coordinates of the input end of the input device in the input area, and reset Determine the current frame, and return to step C;

When the acquired first display coordinates and second display coordinates are not equal, handwriting input handwriting is obtained according to the recorded real coordinates of the input end of the input device in the input area.

The camera device is: a camera, a probe or a monitor.

Also further include in the step A:

Adjusting the shooting angle and/or shooting distance of the camera device, so that the input area of the handwriting input is completely within the shooting range of the camera device.

Described step B comprises:

By means of a boundary recognition method, the boundary of the input area is automatically recognized from the image information captured by the camera device, and the input area of the handwriting input is determined.

Described step B comprises:

The user determines the four vertices of the input area of the handwriting input in the image information captured by the camera device through a preset confirmation method, thereby determining the input area of the handwriting input.

The method further includes:

An auxiliary light source is arranged so that when the input device is used for handwriting input, the input end of the input device is clearly projected laterally into the input area.

Described step C comprises:

In the current frame captured by the camera device, according to the position of the input terminal of the input device and the projection of the input terminal of the input device in the current frame, obtain the first display of the input terminal of the input device in the input area The coordinates and the second display coordinates of the projection of the input end of the input device in the input area.

Resetting the current frame in the step D includes:

The Nth frame after the current frame captured by the camera device is set as the current frame; the N is a natural number.

The method further includes:

The number of transmission frames of the camera is set in advance or dynamically according to the handwriting input speed.

Obtaining the handwriting of the handwriting input according to the recorded real coordinates of the input end of the input device in the input area in the step D includes:

According to the order of recording time of each real coordinate, the points indicated by each real coordinate are sequentially connected with a straight line, so as to obtain the handwriting input by the user.

Embodiments of the present invention also provide a camera-based handwriting input system, the system comprising: an input device, a camera, a display device, and a processing device;

The input device is used for handwriting input within the shooting range of the camera device;

The camera device is used to send the captured image information to the display device and the processing device;

The display device is used to display the image information sent by the camera device;

The processing device is used to determine the input area of the handwriting input according to the image information captured by the camera device; in the current frame of the image information captured by the camera device, obtain the position of the input terminal of the input device in the input area The first display coordinates and the second display coordinates of the projection of the input terminal of the input device in the input area; when the acquired first display coordinates and the second display coordinates are equal, according to the first display coordinates or the second display coordinates coordinates, acquire and record the real coordinates of the input end of the input device in the input area, and reset the current frame; when the obtained first display coordinates and second display coordinates are not equal, according to the recorded input device Each real coordinate of the input terminal in the input area obtains the handwriting of the handwriting input.

As can be seen from the above, the present invention provides a method and system for handwriting input based on a camera, because in this method and system, there is no need to use traditional handwriting input equipment, but only a camera is set in advance, and through The image information captured by the camera device is set to obtain the content of the user's handwriting input, so that the user's handwriting input can also be realized when the traditional handwriting input device is not used, thus greatly improving the convenience of handwriting input and reducing the user's effort. cost and improve user experience.

Description of drawings

FIG. 1 is a flowchart of a method for handwriting input based on a camera device in the present invention.

Fig. 2 is a schematic diagram of the input area of the handwriting input determined in the present invention.

Fig. 3 is a schematic diagram of obtaining the real coordinates of the input terminal of the input device in the input area in the present invention.

FIG. 4 is a schematic diagram of a camera-based handwriting input system in the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail by giving specific embodiments and referring to the accompanying drawings.

FIG. 1 is a flowchart of a method for handwriting input based on a camera device in the present invention. As shown in Figure 1, the method for the handwriting input based on camera among the present invention comprises the steps as follows:

In step 101, a camera device is set, and the camera device displays image information captured by the camera device through a display device connected thereto.

In this step, a camera device that can continuously capture clear image information can be preset according to actual application conditions, and the camera device can be connected to a display device so that the display device can display the image information captured by the camera device. In an embodiment of the present invention, the above-mentioned imaging device can be various imaging devices such as cameras, probes or monitors that are now commonly used; and the above-mentioned display device can be a computer with a display or other devices that can receive, process and A display device that displays image information captured by the imaging device. For example, a camera connected to a computer through a USB interface can be preset, and the computer can receive and process image information captured by the camera, and display the image information captured by the camera through a display.

In an embodiment of the present invention, the shooting angle and/or shooting distance of the above-mentioned camera device can be adjusted according to actual application conditions, so that the input area of the handwriting input determined in the subsequent steps is completely located in the shooting area of the camera device. within range. For example, when the input area of the handwriting input has not been determined, the camera can be set at the front and top of the position where the input area of the handwriting input may appear, so as to ensure that the shooting range of the camera can be completely covered in the subsequent steps. The input area for handwriting input determined in .

In addition, in order to facilitate identification or processing in subsequent steps, parameters such as the resolution and the number of transmission frames of the image information captured by the above-mentioned camera device should meet preset standards. The specific standard can be set in advance according to the actual application situation, and the specific setting method will not be repeated here.

In step 102, an input area for handwriting input is determined according to the image information captured by the camera device.

In this step, the input area of the handwriting input may be determined automatically or manually according to the image information captured by the camera device (for example, a plurality of frames captured by the camera device). For example, when the above-mentioned input area is a paper with a known aspect ratio (for example, standard A4 paper) or other sheet-like media with a specified shape (for example, rectangle) and available for user input, the common boundary identification method can be used to , from the image information (for example, a certain frame in the image information) picked up by the camera device, automatically recognize the boundary of the above-mentioned input area (for example, four sides and 4 vertices of A4 paper), thereby determining the handwriting The input field to enter. For another example, when the above-mentioned input area is paper with a known aspect ratio or other sheet-like media with a specified shape and available for user input, the user can use a preset confirmation method (for example, by mouse click, etc.) The four vertices of the input area of the handwriting input are determined in the image information captured by the camera device (for example, in a certain frame in the image information), so as to determine the input area of the handwriting input. In the embodiment of the present invention, the above boundary identification method and the method of determining the region through four vertices can use various common methods in the field, so details are not repeated here.

Fig. 2 is a schematic diagram of the input area of the handwriting input determined in the present invention. As shown in FIG. 2 , the input area 201 of the handwriting input is located in a certain frame 200 of the image information captured by the camera device, and the four vertices of the input area 201 are A, B, C and D respectively. Since the image information captured by the camera device is a two-dimensional image, and the camera device is generally arranged on the front top of the above-mentioned input area 201, the input area 201 whose actual shape is a rectangle is shown as a trapezoid in FIG. 2, that is to say , since the input area displayed in the image information is equivalent to a projection of the actual input area of handwriting input in the image information, the shape of the input area of the actual handwriting input is different from the shape of the input area displayed in the image information of.

After determining the input area of handwriting input, in the above image information (for example, in a certain frame), a selected point in the image information (for example, a certain vertex of the input area) As the origin, a display coordinate system is established in the image information, so that each point in the input area of the above-mentioned handwriting input has a definite display coordinate in the display coordinate system (that is, the position information of the point in the above-mentioned image information ). For example, as shown in FIG. 2 , in a certain frame 200 of the image information captured by the camera device, a point A can be established as the origin, with AD as the horizontal axis, and a straight line perpendicular to AD as the vertical axis. Displays the coordinate system. According to the display coordinate system established above, the display coordinates of each point in the input area of the handwriting input in the display coordinate system can be obtained. For example, the display coordinates of point A are (0, 0), the display coordinates of point B are (b1, b2), the display coordinates of point C are (c1, c2), and the display coordinates of point D are (d1, 0). etc. Correspondingly, a plane Cartesian coordinate system corresponding to the above-mentioned display coordinate system can be established in the plane where the actual handwriting input area is located, for example, corresponding to the above-mentioned display coordinate system on the image information, it can be used in actual In the plane where the input area of the handwriting input is located, a corresponding plane Cartesian coordinate system is established with the vertex A point as the origin, with AD as the horizontal axis, and the straight line perpendicular to AD (that is, the straight line passing through AB) as the vertical axis. The coordinates of a point in the rectangular coordinate system of the plane can be called the real coordinates of the point. It can be seen from this that each point in the input area of the above-mentioned handwriting input has a display coordinate and a real coordinate.

Since the shape of the input area of the handwriting input in the image information picked up by the camera device is not the same as the actual shape of the input area, the display coordinates of a point in the above-mentioned input area in the above-mentioned image information are different from the coordinates of the point in the above-mentioned image information. The real coordinates are not necessarily equal (except for special points, such as the origin), but since there is a one-to-one correspondence between the display coordinates of each point in the input area and the real coordinates of the point, according to the corresponding relationship, and By using the conversion method commonly used in the prior art, the real coordinates of a certain point can be obtained according to the displayed coordinates of the point.

In addition, after the above-mentioned input area for handwriting input is determined, by default, it can directly enter into the process of acquiring user's handwriting input handwriting as described below. And in a specific embodiment of the present invention, after the input area of the above-mentioned handwriting input is determined, the process of obtaining the user's handwriting input handwriting as described below is not immediately entered, but after the user sends a corresponding instruction (for example, The user clicks the corresponding button or directly enters an instruction), and then enters the process of obtaining the user's handwritten input handwriting as described below.

Step 103, in the current frame of the image information captured by the camera device, obtain the first display coordinates of the input terminal of the input device in the above-mentioned input area and the second display coordinates of the projection of the input terminal of the input device in the above-mentioned input area .

After the above-mentioned input area for handwriting input is determined, the user can perform handwriting input in the determined input area for handwriting input through the input device, thereby entering into the process of acquiring user's handwriting input handwriting. In the embodiment of the present invention, the input device can be any tool that is convenient for the user to input the required input content, for example, the above-mentioned input device can be various pens, or other easy-to-identify, with a pointed end object. In addition, in the embodiment of the present invention, an auxiliary light source (for example, a desk lamp, a luminous display screen, etc.) can also be pre-set, so that when the above-mentioned input device is used for handwriting input, the input end of the input device can be clearly Laterally projected into the above-mentioned input area, so as to identify the input end of the input device and the projection of the input end of the input device; The irradiation angle and/or the irradiation distance of the auxiliary light source are adjusted so that the input end of the input device and the projection of the input end of the input device can be recognized simultaneously in the subsequent process.

Generally, the image information acquired by the camera device is composed of a plurality of consecutive frames, and each frame can be regarded as a static image. Therefore, in a specific embodiment of the present invention, according to the current frame of the image information captured by the camera device, the display coordinates ( may be referred to as the first display coordinates, the same below), and the display coordinates of the projection of the input terminal of the input device (referred to as the input end projection, the same below) in the input area determined above (may be referred to as the second display coordinates, below same). Wherein, the current frame is the image frame captured by the camera device that needs to be processed currently. When step 102 is executed for the first time, the current frame is the first frame captured by the camera device after entering the process of acquiring handwriting input by the user.

Specifically, in this step, in the current frame captured by the camera device, according to the input terminal and the projected position of the input terminal in the current frame, the first display coordinates of the above-mentioned input terminal in the above-mentioned input area and the input The second display coordinates projected by the terminal in the above input area. For example, in a specific embodiment of the present invention, the above-mentioned input terminal and input terminal projection can be automatically identified from the current frame through a commonly used automatic identification method, so that the input terminal and input terminal projection can be obtained in the current frame. s position. Since the input area is completely within the shooting range of the camera, the input area must be within the current frame, that is, the display coordinates of each point in the input area must correspond to a position in the current frame. Therefore, when the position of the input terminal and the input terminal projection in the current frame is known, the input terminal and the input terminal projection can be obtained according to the position of the input terminal and the input terminal projection in the current frame. Display coordinates within the input field.

Step 104, judging whether the obtained first display coordinates and the second display coordinates are equal, if yes, execute step 105, otherwise, execute step 107;

In this step, it is first necessary to judge whether the obtained first display coordinates and the second display coordinates are equal. When the obtained first display coordinates and the second display coordinates are equal, it means that the input terminal of the input device is equal The projections of the input ends of the device overlap, and at this time the input end of the input device must have fallen into the plane where the input area of the above-mentioned handwriting input is located, so it can be judged that the user has started handwriting input. At this time, the subsequent step 105 can be performed to Obtain and record the real coordinates of the input terminal of the input device in the input area; and when the obtained first display coordinates and second display coordinates are not equal, it means that the projections of the input terminal of the input device and the input terminal of the input device do not coincide , at this time, the input end of the input device does not fall on the plane where the input area of the handwriting input is located, therefore, step 107 can be executed directly.

Step 105, according to the first display coordinates or the second display coordinates, acquire and record the real coordinates of the input end of the input device in the input area.

As can be seen from Figure 2, since the shape of the input area in the image information captured by the camera device is not the same as the actual shape of the input area, the display coordinates of each point in the input area are generally not equal to the point The actual coordinates in the input area, but there must be a one-to-one correspondence between the displayed coordinates of each point and the actual coordinates of the point. Therefore, according to the displayed coordinates of a certain point in the input area, the actual coordinates of the point in the input area must be obtained.

In this step, since the first display coordinates and the second display coordinates are known and equal, according to the above-mentioned first display coordinates or second display coordinates, by using the conversion method commonly used in the field, the input The real coordinates of the device's input terminal within the input area.

Fig. 3 is a schematic diagram of obtaining the real coordinates of the input terminal of the input device in the input area in the present invention. Taking Fig. 3 as an example, in a specific embodiment of the present invention, according to the first display coordinates or the second display coordinates, and through the conversion method described below, the input terminal of the input device can be obtained in the input area The real coordinates in .

As shown in FIG. 3 , the display coordinates of the four vertices A1, B1, C1, and D1 of the input area 201 are respectively: (X1, Y1), (X2, Y2), (X3, Y3) and (X4, Y4) , the display coordinates of auxiliary points E1, F1 are (X5, Y5) and (X6, Y6) respectively, and the display coordinates (ie the first display coordinates) of the input terminal O of the input device in the input area are (X, Y ), the real coordinates of the input terminal O of the input device in the input area are (x, y). Among them, the three points of A1, E1, and D1 are collinear, the three points of B1, F1, and C1 are collinear, and the three points of E1, O, and F1 are collinear.

Since X1, Y1, X2, Y2, X3, Y3, X4, Y4, X, and Y are all known, and X5, Y5, X6, and Y6 are all intermediate quantities, the following equations can be established:

a) $\frac{x1-x3}{Y1-Y3}=\frac{x1-x5}{Y1-Y5}$

b) $\frac{x2-x4}{Y2-Y4}=\frac{x2-x6}{Y2-Y6}$

c) $\frac{x5-x6}{Y5-Y6}=\frac{x-x6}{Y-Y6}$

d) $\frac{{(x1-x5)}^2+{(Y1-Y5)}^2}{{(x1-x3)}^2+{(Y1-Y3)}^2}=\frac{{(x2-x6)}^2+{(Y2-Y6)}^2}{{(x2-x4)}^2+{(Y2-Y4)}^2}$

According to the above equations, we can get:

$\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\frac{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; x</span>}\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Y</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Y</span>}\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; x</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Y</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Y</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; L</span>}$

Wherein, L is the actual height (or actual length) of the preset input area when determining the input area of the handwriting input, which is used to represent the accuracy of the handwriting input. For example, when the resolution of the camera is VGA (640×480), the value of L can be set to 320 according to the actual shooting range and angle of the camera, which is the actual height (or actual length) of the input area. ) is 320; and when the resolution of the camera is SXGA (1280×1024), the value of L can be set to 800, that is, the actual height (or actual length) of the input area is 800. In an embodiment of the present invention, the value of L can be determined according to the resolution of the camera device or an empirical preset value, or can be determined by the user himself, but the set value of L is not greater than the value of the camera device The height of the resolution.

Similarly, the value of another real coordinate x of the above-mentioned input terminal O can be obtained according to the same method as the above-mentioned method for obtaining the value of y, so as to obtain the real coordinate (x, y) of the input terminal O in the input area. At this time, an actual width W of the input area used to represent the handwriting input can be preset, and W can also be determined according to the resolution of the camera device or an empirical preset value, or determined by the user himself, but the set The value of W is not greater than the resolution width of the imaging device. Therefore, when the above-mentioned values of L and W are set, the size of the input area is (W×L).

The conversion method described above is only an exemplary description. In the embodiment of the present invention, other common conversion methods in the field can also be used to obtain the real coordinates of the input terminal of the input device in the input area.

Step 106, reset the current frame, and return to step 103;

In this step, the Nth frame after the current frame captured by the camera device may be directly set as the current frame, and the execution returns to step 103 . Wherein, N is a natural number, and the value of N can be preset according to actual application conditions. For example, N=1 may be set, that is, the next frame of the current frame captured by the camera device is set as the current frame.

In practical applications, the transmission frame rate of the camera device is generally 30 frames/s or 60 frames/s, and even has a higher transmission frame rate (for example, 120 frames/s), while the user's handwriting input speed is relatively slow . Therefore, in the embodiment of the present invention, the transmission frame number of the camera device can be set in advance or dynamically according to the handwriting input speed. For example, when the user's handwriting input speed is faster, the transmission frame number of the camera can be set to be larger (for example, 60 frames per second or more); and when the user's handwriting input speed is slower, the The number of transmission frames of the camera device is set relatively small (for example, 15 frames/second or less).

Step 107 , according to the recorded real coordinates of the input end of the input device in the input area, the handwriting of the handwriting input is obtained.

In an embodiment of the present invention, when the user starts to input or is continuously inputting corresponding content (for example, inputting a certain stroke), the input device used by the user must fall into the plane where the above-mentioned input area is located. The input end of the input device must coincide with the projection of the input end, that is, the obtained first display coordinates and the second display coordinates are equal; When inputting a certain stroke), the input device used by the user will leave the plane where the input area is located. At this time, the input end of the input device and the projection of the input end must not coincide, that is, the first display obtained above The coordinates and the second display coordinates are not equal.

Therefore, in the embodiment of the present invention, this step will be executed only when the obtained first display coordinates and the second display coordinates are not equal. In this step, the handwriting of the handwritten input can be obtained according to the above-mentioned recorded real coordinates by using a common processing method in the field. For example, according to the sequence of recording time of each real coordinate, the points represented by each real coordinate are sequentially connected with a straight line, and then the handwriting input by the user can be obtained. Of course, in the embodiment of the present invention, the user's handwriting input handwriting can also be obtained according to the multiple real coordinates recorded above through other commonly used handwriting acquisition methods in the field, which will not be repeated here.

In an embodiment of the present invention, when this step is performed, the number of recorded real coordinates of the input end of the input device in the input area may be 0, 1 or more. For example, when the number of recorded real coordinates is 0, it means that the user has not input the actual content, that is, the handwriting of the user's handwriting input is empty; when the number of recorded real coordinates is 1, it means The handwriting of the user's handwriting input is one point; and when the number of recorded real coordinates is multiple, it means that before step 107 is performed, the input end of the input device used by the user has continuously moved in the input area , thereby completing the input of one stroke, that is, the handwriting of the user's handwriting input is a stroke, for example, the handwriting of the user's handwriting input is a certain stroke in a certain Chinese character, number, English letter or other symbols.

It can be seen that, in the embodiment of the present invention, the content input by the user through the input device is composed of one or more strokes, for example, the user can input the number "3" by inputting a stroke "3", You can also enter the Chinese character "ten" by entering two strokes in sequence: "一" and "丨", and you can also input English capital letters by inputting three strokes "丨", "一" and "丨" in sequence The letter "H", etc., and so on.

Therefore, when the user inputs the actual content by handwriting through the input device, each stroke of the user's handwriting input can be obtained through the above-mentioned steps 103-107. And after obtaining all the strokes of the user's handwriting input, the actual content of the user's handwriting input can be judged by the judgment method commonly used in the art, for example, which Chinese character, number, English letter or other symbol is judged by the user's handwriting input wait. Since the specific judging method does not belong to the part to be protected in the technical solution of the present invention, it will not be repeated here.

It can be seen from the above that through the above steps 101 to 107, the handwriting of the user's handwriting input can be finally obtained, so as to obtain the content of the user's handwriting input. Therefore, in the above-mentioned handwriting input method based on the camera device, it is not necessary to use a traditional handwriting input device, but only a camera device needs to be set in advance, and the image information captured by the camera device can be used to obtain the user's handwriting input. input content. Moreover, the above-mentioned camera device can directly use various commonly used camera devices (such as cameras, etc.) Paper, so that the user's handwriting input can also be realized without using an additional traditional handwriting input device, thus greatly improving the convenience of handwriting input, reducing the user's cost, and improving the user's experience.

In addition, in an embodiment of the present invention, a camera-based handwriting input system is also provided. FIG. 4 is a schematic diagram of a camera-based handwriting input system in the present invention. As shown in FIG. 4 , the camera-based handwriting input system in the present invention includes: an input device 401 , a camera 402 , a display device 403 and a processing device 404 .

The input device 401 is used for handwriting input within the shooting range of the camera device;

The camera device 402 is configured to send the captured image information to the display device 403 and the processing device 404;

The display device 403 is configured to display the image information sent by the camera device 402;

The processing device 404 is used to determine the input area of the handwriting input according to the image information captured by the camera device 402; The first display coordinates in the area and the second display coordinates of the projection of the input terminal of the input device 401 in the input area; when the obtained first display coordinates and the second display coordinates are equal, according to the first display coordinates or The second display coordinates, acquire and record the real coordinates of the input terminal of the input device 401 in the input area, and reset the current frame; when the acquired first display coordinates and the second display coordinates are not equal, according to the recorded Each real coordinate of the input terminal of the input device 401 in the input area obtains handwriting input handwriting.

In summary, the present invention provides a camera-based handwriting input method and system, because in this method and system, do not need to use traditional handwriting input equipment, but only need to pre-set a camera, and through The image information captured by the camera device is set to obtain the content of the user's handwriting input, so that the user's handwriting input can be realized without using a traditional handwriting input device, thereby greatly improving the convenience of handwriting input and reducing the user's effort. cost and improve user experience.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention. within the scope of protection.

Claims (11)

1. A method for handwriting input based on camera, characterized in that the method comprises: A, a camera device is set, and the camera device displays the image information captured by the camera device through a display device connected to it; B. Determine the input area for handwriting input according to the image information captured by the camera device; C. In the current frame of the image information captured by the camera device, obtain the first display coordinate of the input terminal of the input device in the input area and the first display coordinate of the input terminal of the input device projected in the input area Two display coordinates; D. When the obtained first display coordinates and second display coordinates are equal, according to the first display coordinates or the second display coordinates, obtain and record the real coordinates of the input end of the input device in the input area, and reset Determine the current frame, and return to step C; When the acquired first display coordinates and second display coordinates are not equal, handwriting input handwriting is obtained according to the recorded real coordinates of the input end of the input device in the input area. 2. The method according to claim 1, wherein the camera device is a camera, a probe or a monitor. 3. The method according to claim 1, characterized in that, in the step A, further comprising: Adjusting the shooting angle and/or shooting distance of the camera device, so that the input area of the handwriting input is completely within the shooting range of the camera device. 4. The method according to claim 1, wherein said step B comprises: By means of a boundary recognition method, the boundary of the input area is automatically recognized from the image information captured by the camera device, and the input area of the handwriting input is determined. 5. The method according to claim 1, wherein said step B comprises: The user determines the four vertices of the input area of the handwriting input in the image information captured by the camera device through a preset confirmation method, thereby determining the input area of the handwriting input. 6. The method according to claim 1, characterized in that the method further comprises: An auxiliary light source is arranged so that when the input device is used for handwriting input, the input end of the input device is clearly projected laterally into the input area. 7. The method according to claim 1, wherein said step C comprises: In the current frame captured by the camera device, according to the position of the input terminal of the input device and the projection of the input terminal of the input device in the current frame, obtain the first display of the input terminal of the input device in the input area The coordinates and the second display coordinates of the projection of the input end of the input device in the input area. 8. The method according to claim 1, wherein resetting the current frame in the step D comprises: The Nth frame after the current frame captured by the camera device is set as the current frame; the N is a natural number. 9. The method according to claim 1, characterized in that the method further comprises: The number of transmission frames of the camera is set in advance or dynamically according to the handwriting input speed. 10. The method according to claim 1, wherein obtaining the handwriting of handwriting input according to the input end of the recorded input device in the step D in the input area includes: According to the order of recording time of each real coordinate, the points represented by each real coordinate are sequentially connected with a straight line, so as to obtain handwriting input by the user. 11. A system for handwriting input based on a camera, characterized in that the system comprises: an input device, a camera, a display device and a processing device; The input device is used for handwriting input within the shooting range of the camera device; The camera device is used to send the captured image information to the display device and the processing device; The display device is used to display the image information sent by the camera device; The processing device is used to determine the input area of the handwriting input according to the image information captured by the camera device; in the current frame of the image information captured by the camera device, obtain the position of the input terminal of the input device in the input area The first display coordinates and the second display coordinates of the projection of the input terminal of the input device in the input area; when the acquired first display coordinates and the second display coordinates are equal, according to the first display coordinates or the second display coordinates coordinates, acquire and record the real coordinates of the input end of the input device in the input area, and reset the current frame; when the obtained first display coordinates and second display coordinates are not equal, according to the recorded input device Each real coordinate of the input terminal in the input area obtains handwriting input handwriting.