KR101258910B1 - Method of writing on screen by laser pointer in presentation system - Google Patents

Abstract

PURPOSE: A method for writing an image by using a laser pointer in a presentation system is provided to maximize convenience for a speaker by continuously displaying a character or a picture indicated by the speaker on a presentation image. CONSTITUTION: A camera photographs a screen at regular intervals to capture a frame. When a laser point is detected from an image of a current frame, a position of the laser point is recognized to be stored in a coordinate set(S3). If the laser point is detected from the image of the current frame, the number of unrecognized frames is counted(S6). When the laser point disappears, the number of specific frames is passed, and the number of stored coordinates is more than a specific number, a major axis length and a minor axis length are calculated through ellipse fitting(S9). If the proportion of the major axis length and the minor axis length is greater than a specific value, an ellipse is determined(S10). When the ellipse is determined, the ellipse is displayed on a screen as a calculated value with a beam projector. [Reference numerals] (AA) Start; (BB,EE,FF,HH,JJ,LL) No; (CC,DD,GG,II,KK,MM) Yes; (NN) End; (S1) Initializing a coordinate set; (S10) Drawing an ellipse on a screen; (S11) Straight line-fitting the coordinate set; (S12) Calculating the start and end points of a straight line to be drawn on the screen; (S13) Drawing the straight line on the screen; (S14) Finishing the program?; (S2) Laser pointer position recognized?; (S3) Adding to the coordinate set; (S4) Accumulating the number of unrecognized frames; (S5,S7) Number of unrecognized frames < A ?; (S6) Number of coordinates > B ?; (S8) Ellipse-fitting the coordinate set; (S9) Minor axis/major axis < C ?;

Description

Image writing method using laser pointer in presentation system {METHOD OF WRITING ON SCREEN BY LASER POINTER IN PRESENTATION SYSTEM}

The present invention relates to an image writing method for displaying a character or a picture on the screen as an image in a presentation system. More particularly, the present invention automatically reads a character or picture intended by a presenter by reading a trajectory of a position indicated by a laser pointer. An image writing method using a laser pointer of a presentation system for displaying an image on a screen.

When the presenter makes a presentation using a user terminal such as a beam projector and a laptop, the presenter uses a laser pointer to irradiate a laser beam on the screen and instructs the underline, triangle, square, It may be indicated by a circle or the like and may simply be indicated by text.

In the presentation, however, the laser pointer only points to the presenter's current point (called the laser point) when turned on, but cannot be displayed continuously in the presentation image. It has the drawback of having a temporary property that disappears in.

In order to solve this drawback, when generating the data for the presentation image, the shapes such as underline, triangle, square, circle, etc. to be input by the laser pointer are sequentially inputted in advance, but this takes much time for data generation. Has disadvantages.

Accordingly, in the technical field, the presenter implements a seamlessly indicated shape such as an underline, a triangle, a square, and a circle indicated by the laser pointer together with the presentation image, so that the presenter can improve the delivery power during the presentation. The technology has been patented by the applicant and registered under the registration number 10-122543.

[Related Technical Literature]

1. Presentation system using a Laser-pointer mouse (Patent Application No. 10-2000-0016712)

2. Input apparatus using a raser pointer and system foroffering presentation using the apparatus (Patent Application No. 10-2005-0109878)

3. Application Method to Presentation Image by Extracting Laser Pointer Image (Patent Registration No. 10-1222543)

Patent No. 10-1222543, pre-registered by the present applicant, extracts and stores the trajectory of the laser pointer, compares it with a preset figure, and applies the image of the most similar figure to the corresponding position of the presentation image to indicate the position of the laser pointer. The figure is displayed continuously in the presentation image. Therefore, the registered patent No. 10-1222543 has a problem in that the writing function of displaying characters on an image is insufficient.

The present invention has been proposed to solve the above problems, and an object of the present invention is to quickly read the trajectory of the position indicated by the laser pointer to automatically present a character or picture intended by the presenter on the screen as a presentation It is to provide an image writing method using a laser pointer of the system.

In order to achieve the above object, the method of the present invention provides a presentation in which a beam projector displays a presentation image provided from a user terminal, a laser pointer scans a laser point on the screen, and a camera shoots the screen. A presentation system, comprising: capturing a frame by capturing the screen at regular intervals by the camera; Detecting a laser point in an image of a current frame captured by the camera; When the laser point is detected in the image of the current frame, recognizing a position of the laser point and storing the laser point in a coordinate set; Counting the number of unrecognized frames if the laser point is not detected in the image of the current frame; Calculating a long axis length and a short axis length by performing an elliptic fitting if the laser point disappears from the screen, the specific frame number A passes, and the stored coordinates are equal to or greater than the specific number B; Judging by a straight line when the ratio between the short axis length and the long axis length is less than or equal to the specific value C, and determining an ellipse if it is greater than or equal to the specific value; Displaying an ellipse with a calculated value on a screen of a screen through a beam projector when determining an ellipse; And a straight line fitting of the stored coordinate set when judged to be a straight line, calculating a start point and an end point of the straight line from the stored coordinate set, and displaying a straight line on the screen screen through the beam projector. It is characterized by displaying the image on the screen by the beam projector.

In the image writing method, the area of the screen obtained varies depending on the position of the camera, so that the corner points are found in the acquired image by scanning a white screen on the screen to match the position of the laser point with the position of the screen. The method may further include matching a corner point of the terminal screen.

In addition, the camera is a camera that recognizes the light of the laser pointer or infrared light according to the type of laser pointer, and can adjust the exposure, brightness, contrast, and white balance so that the laser pointer recognizes the laser point indicated on the screen. It is.

In the image writing method using the laser pointer of the presentation system according to the present invention, the coordinates of the position indicated by the laser pointer while accumulating the screen at a predetermined frame interval are quickly stored in a line or ellipse according to a predetermined writing algorithm. Recognizing) and immediately displaying on the screen has the advantage of maximizing the convenience of the presenter by continuously displaying the characters or pictures indicated by the presenter on the presentation video.

In addition, the method of the present invention matches and utilizes the position value extraction for the laser image using the laser pointer and the extraction for the closest image, thereby accurately matching the position indicated by the presenter in the presentation image to best match the intention of the presenter. There is an effect that can simply display a straight line, a figure, a character, and the like.

1 is a schematic diagram showing the overall configuration of a typical presentation system to which the present invention can be applied;
FIG. 2 is a block diagram showing the configuration of the camera in FIG. 1; FIG.
3 is a block diagram showing a configuration of a user terminal in FIG. 1;
4 is a flowchart illustrating a procedure of writing an image using a laser pointer in a presentation system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the present specification, when one component 'transmits' data or a signal to another component, the component may directly transmit the data or signal to another component, and through at least one other component. This means that data or signals can be transmitted to other components.

1 is a schematic diagram showing the overall configuration of a typical presentation system to which the present invention can be applied. Referring to FIG. 1, the presentation system according to the present invention includes a beam projector 100, a screen 200, a laser pointer 300, a camera 400, a user terminal 500, and an IP network 600. . Here, the IP network 600 is a communication network capable of a large capacity, long distance voice and data service, and may be, for example, the Internet. In addition, the IP network may be a next-generation wired or wireless network for providing high-speed multimedia services based on ALL IP (Internet Protocol).

In addition, the camera 400 may be a camera or an infrared camera that recognizes the light of the laser pointer according to the type of the laser pointer 300, and the laser pointer 300 may recognize the laser point indicated on the screen 200 most brightly. Exposure, brightness, contrast, white balance, etc. can be adjusted so that the beam projector 100 captures the screen 200 to scan. At this time, since the area of the screen obtained is different according to the position of the camera 400, the position of the laser point is different from the position of the screen. It finds each corner point and transforms it using homography and perspective transform so that each corner point becomes an edge point of the user terminal screen.

FIG. 2 is a diagram illustrating a configuration of the camera 400 in FIG. 1. Referring to FIG. 2, the camera 400 includes a CMOS module 410, a micro controller unit (MCU) 420, a laser imaging module 430, a first storage unit 440, a first transmission and reception terminal 450, and a first transmission unit 450. 1 I / O interface 460, the laser imaging module 430 includes a laser imaging means 431 and a laser position value extraction means 432.

In this specification, a module may mean a functional and structural combination of hardware for carrying out the technical idea of the present invention and software for driving the hardware. For example, the module may mean a logical unit of a predetermined code and a hardware resource for performing the predetermined code, and means a physically connected code or does not necessarily mean one kind of hardware. It can be easily inferred by the average expert in the art.

The MCU 420 connects the data session with the user terminal 500 by controlling the first transmission / reception terminal 450 or the first I / O interface 460, and then connects the data session with the user terminal 500. The CMOS module 410 is driven to enter a photographing standby mode by receiving a photographing command for the screen 200 and each position value set by the user terminal 500. At this time, the MCU 420 stores the received position values in the first storage unit 440. That is, the MCU 420 controls the first transmitting and receiving terminal 450 when connecting the data session through the user terminal 500 and the IP network 600, and the data session with the user terminal 500 through the direct data cable. When connected, the first I / O interface 460 is controlled.

The laser is irradiated from the laser pointer 300 carried by the user to one of the position values set on the screen 200 by the user terminal 500 on the screen 200 through the CMOS module 410. The detected MCU 420 wakes up the laser imaging module 430. Accordingly, the laser photographing means 431 of the laser photographing module 430 photographs the laser image during the continuous irradiation time of the laser output from the laser pointer 300 and then stores the laser image in the first storage unit 440. At the same time, the laser position value extracting means 432 of the laser photographing module 430 extracts the position value of the laser continuously irradiated with respect to the laser image photographed by the laser photographing means 431 at a predetermined time interval and then stores the first value. Stored in the unit 440. That is, the laser photographing module 430 irradiates a laser beam to the screen 200 by using the laser pointer 300 when the user makes a presentation. The laser photographing module 430 underlines a certain area with the laser pointer 300. In the case of designating triangles, squares, circles, etc., the shape of one underline, triangle, square, circle, etc. may be recognized as one continuous laser irradiation.

In this case, the laser photographing means 431 photographs a laser image during a continuous irradiation time output from the laser pointer on the screen 200 when the laser image is photographed. The range is preferably set to 1/100 to 1/2 second.

In addition, the first storage unit 440 and the second storage unit 550 to be described later are non-volatile memory (NVM). Even though power is not supplied, the first storage unit 440 maintains the stored data and does not delete the flash memory. Memory), magnetic random access memory (MRAM), phase-change random access memory (PRAM), ferroelectric RAM (FRAM), and the like.

The MCU 420 may be configured to transmit the laser image during the continuous irradiation time taken through the data session connected with the user terminal 500 and the extracted position value according to a preset time interval of the laser image to the user terminal 500. The first transceiver 450 and the first I / O interface 460 are controlled.

3 is a diagram illustrating a configuration of the user terminal 500 in FIG. 1. Referring to FIG. 3, the user terminal 500 includes a second transceiver 510, a second I / O interface 520, a central controller 530, a presentation image implementation module 540, and a second storage unit ( 550, an input / output unit 560, and a laser pointer writing module 570. The central controller 530 includes a camera / beam projector control module 531, and the presentation image implementing module 540 includes screen position value setting means 541, laser image extracting means 542, and image converting means ( 543). On the other hand, the user terminal 500 stores a presentation program such as PowerPoint in the second storage unit 550, the central control unit 530 is loaded on the system memory in response to a user's request through the input and output unit 560 do.

The camera / beam projector control module 531 of the central controller 530 connects the second transceiver 510 or the second I / O interface 520 so that the beam projector 100 and the camera 400 connect data sessions. To control. Thereafter, the camera / beam projector control module 531 controls the presentation image to be implemented by the beam projector 100 through the connected data session, and then wakes up the presentation image implementation module 540.

Accordingly, the screen position value setting means 541 of the presentation image implementation module 540 has a horizontal direction (X) and a vertical direction (X) for the screen 200 on which the presentation image output from the beam projector 100 is implemented. Each position value by the combination of Y) is set and stored in the second storage unit 550. The position value may be set to a pixel value or a coordinate value, and may be set to various numerical values according to the resolution of the presentation image implemented by the beam projector 100.

The laser image extraction unit 542 of the presentation image implementation module 540 compares the received laser image with a plurality of images stored in the second storage unit 550 and extracts an image having the closest shape.

The image conversion means 543 of the presentation image implementation module 540 divides the shape of the nearest image extracted by the laser image extraction means 542 at a predetermined time interval, and then extracts the image of the divided shape. The presentation matching laser image is generated by matching the extracted position values at predetermined time intervals of the laser image, and then stored in the second storage unit 550.

The camera / beam projector control module 531 synchronizes the presentation matching laser image generated by the presentation image implementing module 540 with the presentation image being output to the beam projector 100 according to the passage of time. Control the beam projector 100 to be.

On the other hand, the laser pointer writing module 570 uses an elliptic fitting and a linear fitting to track the movement of the laser pointer 300 when writing on the screen 200 using the laser pointer 300. Or it calculates in a straight line and displays various colors on the screen. That is, when the laser pointer 300 operates and is exposed to the screen 200, the camera 400 acquires it, stores it in the coordinate system of the monitor, and continuously stores the laser pointer 300 when the laser pointer 300 continuously operates. When the laser pointer 300 does not exist on the screen, if a specific number of frames (A) passes and the stored coordinates are more than a certain number (B), elliptic fitting is performed to find a long axis length, a short axis length, a principal axis angle, a center point, and the like. If it is approximate to the horizontal and the short axis length / long axis length is less than or equal to the specific value C, it is determined as a straight line, and if it is greater than or equal to the specific value, it is determined to be an ellipse. Draw an ellipse with the calculated value on the screen when judging as an ellipse, and straight-fit the stored coordinates when judging with a straight line, calculate the start and end points of the straight line to draw using the left and right coordinates of the stored coordinates, and draw a straight line on the screen. This process is repeated in a loop until the end of the program.

4 is a flowchart illustrating a procedure of writing an image using a laser pointer in a presentation system according to the present invention.

First, the writing algorithm according to the present invention focuses on the fact that most characters (particularly, Hangul) or figures can be represented by straight lines and ellipses (circles), so that the presenter writes on the screen 200 using the laser pointer 300. The trajectory of the laser point is judged as an ellipse or a straight line through elliptic fitting and linear fitting, and a continuous image is written at the corresponding position on the screen. Such a laser pointer writing algorithm of the present invention is executed as a program in the user terminal 500. Through a series of simulations, it is determined that a series of scanning is completed because no laser point is detected in a frame captured by the camera 400. Set the number of frames (A) and the specific number (B) determined that the coordinates stored in the coordinate set are sufficient for writing, and perform an elliptic fitting to determine the ratio between the short axis length and the long axis length ( Set C) in advance. In addition, in order to match (synchronize) the image frame according to the position on the screen with the position of the monitor screen of the user terminal 500 and the position of the camera, a series of synchronization procedures are performed to scan the white screen on the screen to match the edges. The frame 400 sets a frame period for capturing (shooting) the screen 200 to obtain frame data capturing the screen 200 at a set period interval.

Referring to FIG. 4, first, a coordinate set for storing trajectory coordinates of a laser point is initialized (S1). Thereafter, the camera 400 receives image data of the current frame capturing the screen, determines whether there is a laser point in the current frame, and if there is a laser point, recognizes the coordinates of the laser point and adds the coordinates to the coordinate set (S2, S3).

If there is no laser point in the current frame and the recognition fails, the number of unrecognized frames is accumulated and it is determined whether the accumulated count value exceeds a preset A value. If the A value is not exceeded, the process returns to step S2 and repeats. If the value A is exceeded, the process returns to step S1 to initialize the coordinate set (S4, S5).

If the number of coordinates stored in the coordinate set exceeds the preset value of B, it is determined whether the number of unrecognized frames exceeds the value of A. If the number of coordinates is exceeded, the coordinate set is elliptically fitted to calculate shortened length and long axis length (S6). ~ S8). If the number of unrecognized frames is less than the A value, the process returns to step S2 and repeats (S7).

Subsequently, if the ratio (short axis / long axis) value of the short axis length and the long axis length obtained through the wave fitting exceeds the preset C value, the ellipse is displayed on the screen 200 through the beam projector 100 (S9). S10).

If the ratio of the short axis length to the long axis length (short axis / long axis) obtained through the wave fitting is less than the preset C value, it is judged as a straight line, and the linear set of coordinates is fitted. To display a straight line on the screen screen through the beam projector (S11 ~ S13). At this time, the color of the ellipse or the straight line may be preset or selected or randomly determined by manipulation.

When such a laser pointer writing program is continuously executed, the screen screen continuously displays and outputs a character or a picture written by the presenter using the radar pointer 300 as an image. When the clear button is input, the writing is written on the screen 200. One image is erased and the coordinate set is initialized to start writing again (S14).

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored.

Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device and the like, and also implemented in the form of a carrier wave (for example, transmission over the Internet) .

In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. And functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers skilled in the art to which the present invention pertains.

As described above, preferred embodiments of the present invention have been disclosed in the present specification and drawings, and although specific terms have been used, they have been used only in a general sense to easily describe the technical contents of the present invention and to facilitate understanding of the invention , And are not intended to limit the scope of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: beam projector 200: screen
300: laser pointer 400: camera
500: user terminal 600: IP network

Claims (3)

In a presentation system in which a beam projector displays a presentation image provided from a user terminal on a screen, a laser pointer scans a laser point on the screen, and a camera shoots the screen.
Capturing a frame by capturing the screen at regular intervals by the camera;
Detecting a laser point in an image of a current frame captured by the camera;
When the laser point is detected in the image of the current frame, recognizing a position of the laser point and storing the laser point in a coordinate set;
Counting the number of unrecognized frames if the laser point is not detected in the image of the current frame;
Calculating a long axis length and a short axis length by performing an elliptic fitting if the laser point disappears from the screen, the specific frame number A passes, and the stored coordinates are equal to or greater than the specific number B;
Judging by a straight line when the ratio between the short axis length and the long axis length is less than or equal to the specific value C, and determining an ellipse if it is greater than or equal to the specific value;
Displaying an ellipse with a calculated value on a screen of a screen through a beam projector when determining an ellipse; And
In case of judging by a straight line, after fitting the stored coordinate set in a straight line, calculating the start point and end point of the straight line in the stored coordinate set, and displaying a straight line on the screen screen through the beam projector. An image writing method using a laser pointer of a presentation system, characterized by displaying an image on a screen by a beam projector.
The method of claim 1, wherein the image writing method is
Since the area of the screen is different depending on the position of the camera, the white screen is scanned on the screen to match the position of the laser point with the position of the screen. The image writing method using a laser pointer of the presentation system further comprising the step of matching as possible.
The method of claim 1, wherein the camera
It is a camera that recognizes the laser pointer light or infrared rays according to the type of laser pointer, and adjusts exposure, brightness, contrast, and white balance so that the laser pointer can recognize the laser point indicated on the screen. Image writing method using laser pointer of presentation system.

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