JP2010146026A - Display control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the trouble that it is difficult to view drawing data of characters, drawn lines, etc., displayed on a color display device. <P>SOLUTION: The display control device for displaying drawing data of characters, drawn lines, etc., on the color display device includes: a size switching means for switching a size of drawing data to display the drawing data; and a background image decision means for inspecting a spatial frequency distribution of a background image in a region for display of drawing data to determine whether the background image has many high spatial frequency components. When the background image decision means determines that the background image has many high spatial frequency components, the size of drawing data is switched by the size switching means to display the drawing data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display control device that displays drawing data such as characters and drawing lines on a color display device.

  In an information input / output system represented by an electronic blackboard system, conventionally, a color palette is displayed on a display device, and a writing color and a background color can be selected. In this case, for example, in a system in which three types of line types can be registered as line types to be drawn in the line type selection menu, the writing color is the first unless the user performs a line color setting operation. Is a color complementary to the background color (the color on the opposite side of the hue circle and becomes gray when mixed), the second line is red, and the third line is blue. The first line automatically sets a complementary color for the background color. However, if the background color is green, if the complementary color is reddish purple, the color combination is used in business situations. In consideration of the possibility of discomfort that does not match, the line color is white.

  By the way, in recent years, when a presentation or the like is performed, an opportunity to use an information input / output system or the like equipped with a projector and a large screen display has increased. When such a display screen is a large screen, it is desired that graphics such as characters and lines are easy to see for many people.

  However, in a document creation apparatus such as a PC that creates presentation materials used in an information input / output system or the like, the user decides and sets the color of graphics such as characters and lines to be emphasized. Depending on the combination of the set color and the background color of the display screen, the portion to be emphasized may not necessarily be highlighted with respect to the other portions.

  In particular, in a type that projects and displays on a large screen like a projector, this phenomenon becomes significant when the amount of projection light is insufficient. This phenomenon becomes prominent in the type of projecting and displaying in this way. For example, when the background is blue and the normal character color is white, if the character to be emphasized is red, the display connected to the document creation device Even if you can see it with emphasis, if you project it on a large screen through a projector and display it on a large screen, the brightness of each color will be reduced if the amount of projected light is not enough. The color difference between blue and blue looks small. That is, when the character set in red for the purpose of emphasis is projected and displayed via the projector, it is difficult to see the character.

  Therefore, in order to eliminate such problems, in the color display device and the electronic blackboard system described in Patent Document 1, the color of characters (fonts) and the writing drawing color are similar to their background colors. A method of changing the color of the character (font) and the writing drawing color.

  However, according to the technology disclosed in Patent Document 1, when the character (font) color and the writing drawing color are one color, it can be dealt with by setting a complementary color for the background color. There is a problem that it is not possible to cope with a plurality of colors and writing drawing colors.

  Also, when the cursor is displayed on the display screen, if the color is similar to the background color, the characters displayed around the cursor, or the color of the writing line, the cursor is not noticeable. There is also a problem that it is difficult to see.

  Furthermore, the color selection in the color display device and the electronic blackboard system described in Patent Document 1 is based on the colors around and behind the area where the display device (large screen display) is installed, or the area projected by the projector. Therefore, depending on the combination of the displayed color and the back and surroundings where the display device is installed or the surrounding color of the area projected by the projector, the color tone may not be good.

  Furthermore, the background of characters (fonts) and writing lines may not be a single color, but may be a pattern or a still image composed of a plurality of colors, and a moving image. In the color display device and the electronic blackboard system, the writing drawing color corresponding to the color evaluation value evaluated based on the average appearance frequency of the background color is shown. However, when it is difficult to select the color of the conspicuous character (font) and the writing drawing color when the background is a still image in which various colors are mixed or a moving image in which the appearance frequency of each color changes with time There is.

  In addition, if the characters (fonts) and writing lines are thin, there is a problem that these characters and writing lines are very difficult to see.

  An object of the present invention is to prevent a problem that drawing data such as characters and drawing lines displayed on a color display device is difficult to see.

  In order to solve the above-described problems and achieve the object, the present invention provides a display control device for displaying drawing data such as characters and drawing lines on a color display device, and switching the size of the drawing data for switching. And background image determination means for examining a spatial frequency distribution of a background image in a region for displaying the drawing data and determining whether or not the background image has a high spatial frequency component. When the image is determined to be an image with many higher spatial frequency components, the size of the drawing data is switched and displayed by the size switching means.

  Further, the present invention provides a display control device for displaying drawing data such as characters and drawing lines on a color display device, comprising size switching means for switching the size of the drawing data and displaying the drawing data. When the background image is a still image or a moving image, the size switching means switches the size of the drawing data for display.

  According to the present invention, it is possible to prevent the drawing data such as characters and drawing lines displayed on the color display device from being difficult to see.

  According to the first aspect of the present invention, the background of the drawing data such as characters and drawing lines displayed on the color display device is not a single color but a pattern, a still image or a moving image composed of a plurality of colors, and a high space. When there are many frequency components, it is possible to prevent the drawing data from becoming difficult to see by switching the drawing data size to a larger size and displaying it.

  According to the second aspect of the present invention, since borders are added to drawing data such as characters and drawing lines displayed on the color display device, it is possible to prevent the drawing data from becoming difficult to see.

  According to the third aspect of the present invention, when the background of drawing data such as characters and drawing lines displayed on the color display device is a still image or a moving image, the size of the drawing data is increased. By switching and displaying, it is possible to prevent the drawing data from becoming difficult to see.

  According to the fourth aspect of the present invention, since borders are added to drawing data such as characters and drawing lines displayed on the color display device, it is possible to prevent the drawing data from becoming difficult to see.

FIG. 1 is a system configuration diagram schematically showing an information input / output system according to a first embodiment of this invention. FIG. 2 is a block diagram showing the electrical connection of each part built in the control device. FIG. 3 is a block diagram showing the electrical connection of each part built in the display controller. FIG. 4 is an explanatory diagram showing an arrangement state of each electronic camera of the information input / output device. FIG. 5 is an enlarged view showing the vicinity of the wide-angle lens and the CMOS image sensor of the electronic camera. FIG. 6 is an explanatory diagram showing several pixel positions on the image of the edge portion. FIG. 7 is an explanatory diagram illustrating an example of the image of the writing member and the rotation of the reference line. FIG. 8 is an explanatory diagram showing a method for calculating the distance between the imaging position of the contact point and the imaging position of the optical axis of the wide-angle lens. FIG. 9 is a plan view showing an example of a pull-down menu when the “drawing line” icon is selected. FIG. 10 is a plan view showing a display example of the “line setting” window. FIG. 11 is a flowchart showing the operation of the control device when the display color of the drawing line is changed in accordance with the change of the background color. FIG. 12 is a plan view showing an example of a pull-down menu when the “drawing line” icon is selected when there is an “emphasized” line to be visually emphasized. FIG. 13 is a plan view showing a display example of a “line setting” window when there is an “emphasized” line to be visually emphasized. FIG. 14 is a plan view showing an example of a pull-down menu when the “drawing line” icon is selected when a plurality of combinations of line colors are prepared for one background color. FIG. 15 is a flowchart showing the operation of the control device when the display color of the drawing line is changed in accordance with the change of the background color when a plurality of combinations of line colors are prepared for one background color. FIG. 16 is a flowchart showing the operation of the control device when changing the display color of the cursor in accordance with the change of the background color and the display color of the drawing line. FIG. 17 is a flowchart illustrating the operation of the control device when setting the background color and the display color of the drawing line in accordance with the setting of the environment color. FIG. 18 is a plan view showing a display example of a “color setting” window for selecting a combination of background color and drawing line color. FIG. 19 is a flowchart showing the operation of the control device when a combination of the background color and the drawing line color is selected in accordance with the setting of the environment color. FIG. 20 is a plan view showing an example of a pull-down menu when the “character” icon is selected in the information input / output system according to the second embodiment of this invention. FIG. 21 is a plan view showing a display example of the “character setting” window. FIG. 22 is a flowchart showing the operation of the control device when the display color of characters is changed in accordance with the change of the background color. FIG. 23 is a plan view showing a display example of a “character setting” window when there is a character color of “emphasis” to be visually emphasized. FIG. 24 is a flowchart showing the operation of the control device when the display color of the “emphasized” character to be visually emphasized is changed. FIG. 25 is a plan view showing a display example of a “character setting” window for selecting a combination of a background color and a character color. FIG. 26 is a plan view showing a display example of the “display color combination” window. FIG. 27 is a flowchart showing the operation of the control device when the display color of a character is changed in accordance with the change of the background color when a plurality of combinations of character colors are prepared for one background color. FIG. 28 is a flowchart showing the operation of the control device when the display color of the cursor is changed in accordance with the change of the background color and the character display color. FIG. 29 is a flowchart showing the operation of the control device when setting the background color and the display color of characters in accordance with the setting of the environment color. FIG. 30 is a plan view showing a display example of a “display color combination” window for selecting a combination of a background color and a character color. FIG. 31 is a flowchart showing the operation of the control device when selecting a combination of the background color and the character color in accordance with the setting of the environment color. FIG. 32 is a flowchart illustrating the operation of the spatial frequency check unit of the control device in the information input / output system according to the second embodiment of this invention. FIG. 33 is a flowchart showing the operation of the control device when setting the color of the drawing line and the color of the character based on the feature color of the image. FIG. 34 is a flowchart illustrating the operation of the control device when the thickness of the drawing line or character is increased. FIG. 35 is a flowchart showing the operation of the control device when displaying a drawing line or character with an edge added.

  A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a large screen PDP (Plasma Display Panel) is used as a color display device as an information input / output system, and electronic cameras are attached to the upper right and upper left of the display surface, respectively. This is an example in which an electronic blackboard system that obtains contact position coordinates of an object that contacts a display surface based on image information input from a camera is applied.

  FIG. 1 shows a system configuration diagram of the information input / output system 100 of the present embodiment. The information input / output system 100 includes an information input / output device 1 and a display control device (hereinafter referred to as a control device) 2. The information input / output device 1 includes two electronic cameras 10, 11 and a color display device. 12 and two speakers 13 and 14 are provided.

  When the electronic camera 10 and the electronic camera 11 are displayed on the color display device 12 with a high pixel type XGA (1024 × 768 pixels), the pixels are high enough to allow menu selection and writing operations to be performed without any problem. The output frame rate of the image signal is large, and a two-dimensional imaging device capable of independently outputting a photoelectrically converted signal for each pixel is provided. As this two-dimensional image sensor, there is, for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor. These electronic cameras A / D (Analog / Digital) convert the electrical signal photoelectrically converted by the image sensor and output digital image data. Further, the optical axis of each electronic camera is attached so as to be parallel to the plane of the color display device 12. The lenses of these electronic cameras are wide-angle lenses having an angle of view of 90 degrees or more, and can capture a predetermined coordinate input object that touches the entire area of the color display device 12.

  As described above, the color display device 12 is a large screen PDP (Plasma Display Panel). Further, the speaker 13 and the speaker 14 are built in the information input / output device 1 and output an audio signal input from the control device 2 as sound.

  Next, the electrical connection of each part built in the control apparatus 2 is shown in FIG. In the figure, a CPU (Central Processing Unit) 20, a main memory 21, a clock 22, a bus controller 23, a ROM (Read Only Memory) 24, a PCI (Peripheral Component Interconnect) bridge 25, a cache memory 26, a hard disk 27, an HD (Hard Disk). ) Controller 28, image processing circuit (1) 29, image processing circuit (2) 30, display controller 31, MPEG (Moving Picture Experts Group) decoder 32, LAN (Local Area Network) controller 43, LAN I / F (Interface) 44 FD (Floppy (registered trademark) Disk) controller 33, FD drive 34, DVD-RAM (Digital Video Disc Random Access Memory) controller 35, DVD-RAM drive 36, keyboard controller 37, mouse I / F 38, RTC (Real Time) Clock) 39, CPU bus 40, PCI bus 1, X bus (internal bus) 42 is mounted on the control unit 2.

  A program for starting up the system at power-on and controlling various devices is written in the ROM 24 in advance, and the CPU 20 reads the control processing program stored in the ROM 24 from the hard disk 27 to the main memory 21. Executes and processes the operating system (OS) and various application programs. The main memory 21 is composed of a DRAM (Dynamic Random Access Memory) and is used in a work area of the CPU 20 or the like. The clock 22 is composed of a crystal oscillator and a frequency dividing circuit, and generates a clock for controlling the operation timing of the CPU 20 and the bus controller 23. The bus controller 23 controls data transfer through the CPU bus 40 and the X bus 42.

  The PCI bridge 25 uses the cache memory 26 to perform data transfer between the PCI bus 41 and the CPU 20. The cache memory 26 is composed of a DRAM and is used by the PCI bridge 25.

  The hard disk 27 stores system software, various application programs, a lot of user data, and the like. The HD controller 28 has, for example, an IDE (Integrated Device Electronics) interface as an interface with the hard disk 27, and performs high-speed data transfer with the hard disk 27.

  The image processing circuit (1) 29 inputs digital image data output from the electronic camera 10 of the information input / output device 1 via a digital I / F (not shown) such as RS-422, and from the image data. Object extraction processing, object shape recognition processing, and the like are performed. Further, the image processing circuit (1) 29 outputs a clock and an image transfer pulse given to the electronic camera 10 via a digital I / F (not shown) such as RS-422. The image processing circuit (2) 30 is the same hardware as the image processing circuit (1) 29. The image processing circuit (2) 30 inputs digital image data output from the electronic camera 11 of the information input / output device 1, and the image processing circuit (1) 29 A similar operation is performed. Note that clocks and image transfer pulses supplied from the image processing circuit (1) 29 and the image processing circuit (2) 30 to the electronic camera 10 and the electronic camera 11, respectively, are synchronized.

  The display controller 31 performs D / A (Digital / Analog) conversion of character data, graphic data, and the like, and performs control for displaying these data on the color display device 12 of the information input / output device 1. The internal configuration and operation of the display controller 31 will be described in detail later.

  The MPEG decoder 32 decodes the MPEG file stored in the DVD-RAM (data is read by the DVD-RAM drive 36) or the hard disk 27, and the decoded YUV (Y: U: V = 4: 2: 2). The video data is output to the display controller 31, and the decoded audio data is D / A converted and output to the speakers 13 and 14. Here, Y is a luminance component, U and V are color difference (chroma) components, and U = B (blue) -Y and V = R (red) -Y.

  The LAN controller 43 executes a communication protocol compliant with, for example, the IEEE (Institute of Electrical and Electronics Engineers) 802.3 standard, and communicates with other devices connected to the Ethernet (registered trademark) via the LAN I / F 44. To control.

  The FD controller 33 performs data transfer with the FD drive 34. The DVD-RAM controller 35 has, for example, a SCSI-2 (Small Computer System Interface-2) interface as an interface with the DVD-RAM drive 36, and performs data transfer with the DVD-RAM drive 36.

  The keyboard controller 37 performs conversion from serial data input from the keyboard 3 to parallel data. The mouse I / F 38 has a mouse port and is controlled by a mouse driver (control program). Since the information input / output device 1 is an input device of the control device 2, it is not necessary to connect the keyboard 3 and the mouse 4 except during maintenance work.

  The RTC 39 is a date clock and is backed up by a battery (not shown).

  Next, the internal configuration and operation of the display controller 31 will be described in detail. FIG. 3 shows an electrical connection of each part built in the display controller 31. The display controller 31 includes a graphic controller 60, a graphic video memory 61, a graphic data conversion unit 62, a display data generation unit 63, a DAC (Digital to Analog Converter) 64, a video decoder 65, a video / still image video memory 66, and video data. A conversion unit 67, a video data superimposing unit 68, and a spatial frequency check unit 69 are included.

  The graphic controller 60 manages a plurality of drawing planes (user planes) accessed from the CPU 20, for example, background drawing data (first plane) and graphic drawing data (second drawing) such as characters and drawing lines. Are managed by separate user planes. Then, drawing data for display is generated in accordance with the character (font) data or graphic data drawing command received from the CPU 20. In addition, when a fill command for the designated area is received from the CPU 20, drawing data of a designated color is generated for all the pixels in the designated area. In these drawing data, one pixel is represented by one bit of each of R (red), G (green), B (blue), and I (Intensity). The graphic controller 60 also performs drawing data superimposition (superimposition between user planes), for example, superimposition processing of a background and characters and lines. The graphic video memory 61 is a VRAM (Video Random Access Memory), and has R, G, B, and I bit planes.

  The graphic data conversion unit 62 reads data from the graphic video memory 61 every 8 pixels, that is, 32 bits, and converts the data into 8 bits per pixel using a built-in color palette. The display data generation unit 63 reads data from the graphic data conversion unit 62 pixel by pixel, that is, by 8 bits, and displays 6 bits each for R, G, and B using a built-in color lookup table. Generate data. When the video data of a moving image or a still image is displayed in a superimposed manner, this data is output to the video data superimposing unit 68. Otherwise, it is output to the DAC 64. The DAC 64 converts each digital data of R, G, B into an analog video signal and outputs it to the color display device 12 of the information input / output device 1.

  The video decoder 65 receives YUV video data input from the MPEG decoder 32 or YUV video data of a still image (for example, JPEG decompressed image) decompressed by software by the CPU 20 per pixel (16 bits). Each B is converted into 8-bit data. It should be noted that YUV video data is input from the spatial frequency check unit 69 when the process of checking the spatial frequency of moving images or still images is executed.

  The moving image / still image video memory 66 is a VRAM and has R, G, and B bit planes. The video data conversion unit 67 converts each 8-bit data of R, G, and B into 6-bit data using a built-in conversion table. The video data superimposing unit 68 overwrites the R, G, B data input from the video data converting unit 67 with the R, G, B data input from the display data generating unit 63, or These data are ORed for each bit (transparent display of drawing data) and output to the DAC 64. The spatial frequency check unit 69 checks the distribution of the spatial frequency of the luminance component from the Y signal in the YUV video data input from the MPEG decoder 32 or the YUV video data of the still image expanded by software in the CPU 20, or Processing for obtaining the average value of the luminance components is performed.

  In the following, the flow of a moving image or still image signal in the display controller 31 is shown separately for each case.

<1. Video>
-With spatial frequency check MPEG decoder 32-> spatial frequency check unit 69-> video decoder 65-> moving picture / still image video memory 66-> video data conversion unit 67-> video data superimposing unit 68-> DAC 64-> color display device 12
No spatial frequency check MPEG decoder 32 → video decoder 65 → video / still image video memory 66 → video data converter 67 → video data superimposing unit 68 → DAC 64 → color display device 12
The above is the signal flow in the case of a moving image.

<2. Still image>
-With spatial frequency check PCI bus 41-> spatial frequency check unit 69-> video decoder 65-> moving picture / still image video memory 66-> video data conversion unit 67-> video data superimposing unit 68-> DAC 64-> color display device 12
No spatial frequency check PCI bus 41 → video decoder 65 → video / still image video memory 66 → video data converter 67 → video data superimposing unit 68 → DAC 64 → color display device 12
The above is the signal flow in the case of a still image.

  Next, a method for geometrically obtaining the contact position when the writing member contacts the color display device 12 of the information input / output device 1 will be described. As shown in FIG. 4, the electronic camera 10 of the information input / output device 1 includes a wide-angle lens 50 and a CMOS image sensor 51, and the electronic camera 11 includes a wide-angle lens 52 and a CMOS image sensor 53. The optical axis of the light is parallel to the plane of the color display device 12 of the information input / output device 1, and each electronic camera is arranged so as to be able to image a coordinate input object that makes contact with the entire area of the color display device 12. Yes.

  Here, the distance between the wide-angle lens 50 and the wide-angle lens 52 is L, the contact point of a writing member such as a finger or a pen on the plane of the color display device 12 is A, the position coordinates of the point A are (x, y), and the wide-angle lens. X-Line is a straight line connecting 50 and the wide-angle lens 52, β1 is an angle between the direction of the contact point A in the wide-angle lens 50 and the X-Line, and the direction of the contact point A in the wide-angle lens 52 is X-Line. Let the angle be β2.

An enlarged view of the vicinity of the wide-angle lens 50 and the CMOS image sensor 51 of the electronic camera 10 is shown in FIG. In FIG. 5, f is a distance between the wide-angle lens 50 and the CMOS image sensor 51, and h is a distance between the imaging position of the optical axis of the wide-angle lens 50 and the imaging position of the contact point A in the CMOS image sensor 51. (Distance in a direction parallel to the plane of the color display device 12), α is an angle formed by the optical axis of the wide-angle lens 50 and the X-Line, and θ is a line connecting the contact point A and its imaging point and the wide-angle lens 50. This is the angle formed by the optical axis. With these,
θ = arctan (h / f) (1)
β1 = α−θ (2)
The following two expressions hold. Here, since the angle α is known in advance as an assembly specification, the angle β1 can be obtained from these two equations. Similarly, the angle β2 can be obtained for the electronic camera 11 as well.

When the angle β1 and the angle β2 are obtained in this way, the position coordinates (x, y) of the contact point A can be calculated by the principle of triangulation: x = Ltanβ2 / (tanβ1 + tanβ2) (3)
y = xtanβ1 (4)
Is calculated as

  Next, the relationship between the image (straight line) of the edge portion corresponding to the plane of the color display device 12 imaged on the CMOS image sensor 51 and the CMOS image sensor 53 and the pixel arrangement of the CMOS image sensors 51 and 53 will be described. To do. The CMOS image sensor 51 and the CMOS image sensor 53 have a two-dimensional pixel arrangement, but when the number of pixels is different between the vertical direction and the horizontal direction, the direction with the smaller number of pixels is the X-axis direction, and the direction with the larger number of pixels is the Y-axis. As the direction, the electronic camera 10 and the electronic camera 11 are assembled so that the Y-axis direction is as parallel as possible to the plane of the color display device 12. If the number of pixels in the vertical and horizontal directions is the same, either direction is taken as the Y-axis direction.

Here, when the image (straight line) of the edge portion corresponding to the plane of the color display device 12 imaged on the CMOS image sensors 51 and 53 does not coincide with the Y-axis direction of the pixel array, the color display device 12 An angle δ formed by the image (straight line) of the edge portion corresponding to the plane and the Y-axis direction of the pixel array is obtained. This angle δ can be obtained by examining several pixel positions on the image (straight line) of the edge portion. A diagram for this explanation is shown in FIG. Using the end point of the image (straight line) of the edge portion in FIG. 6 as a reference pixel position, the number of pixels x in the X-axis direction and the number of pixels y in the Y-axis direction at arbitrary points A, B, and C on the straight line are examined. In each of these points,
tanδ * = x / y (5)
Δ * is obtained by the above, and the average value of these values is taken as the angle δ.

When the distance between the plane of the color display device 12 and the object (writing member) is obtained from the image data captured by the CMOS image sensors 51 and 53, the image (straight line) of the edge corresponding to the plane of the color display device 12 is obtained. It is more convenient to use the Y axis of the image data coordinate system. Therefore, when the distance between the plane of the color display device 12 and the object (writing member) is obtained using image data, the coordinate value of the image data is rotated by the angle δ obtained above and processed. As shown in FIG. 6, when the image (straight line) of the edge portion is tilted to the right, the image is rotated to the left, and conversely, when it is tilted to the left, the image is rotated to the right. The coordinates (x ′, y ′) after the rotation are the coordinates before the rotation (x, y),
x ′ = x × cosδ−y × sinδ (6)
y ′ = x × sin δ + y × cos δ (7)
It is calculated | required by two Formulas. When δ is a positive value, it rotates clockwise, and when it is negative, it rotates counterclockwise.

  Next, a method for determining contact between the writing member and the plane of the color display device 12 from image data captured by the electronic camera 10 and the electronic camera 11 will be described. The electronic camera 10 of the information input / output device 1 limits the pixels that output image signals in the imaging region of the CMOS image sensor 51 in the direction perpendicular to the plane of the color display device 12. That is, control is performed so that an image signal is output only for pixels that are imaging a range from the plane of the color display device 12 to a predetermined distance. The image signal is A / D converted and the digital image data is output to the image processing circuit (1) 29 of the control device 2. The image processing circuit (1) 29 performs a process of extracting the contour line of the object from the inputted image data for one frame. Extraction of the contour line of such an object includes, for example, a method of determining a density gradient between pixels by differentiation and determining the contour line from the direction and size. One of these methods is disclosed in Japanese Patent Publication No. 8-16931.

  When the contour line is extracted in this way, it is determined whether or not the object is a writing member based on the shape of the contour line. This shape determination is performed using an image recognition technique. As the shape recognition method, for example, first, the center of gravity of the object is obtained, the distance between the center of gravity and the contour line is sequentially obtained around the center of gravity (360 °), and the shape of the contour line is specified from the relationship between the angle and the distance. There is a method (see JP-A-8-315152).

  The data regarding the shape of the contour line thus obtained is compared with data stored in advance in the ROM 24 or the hard disk 27 as the shape of the writing member, thereby determining whether or not the object having the shape is a writing member. At the time of writing operation, since the inclination of the writing member with respect to the writing surface is not constant, the reference line (0 ° position) connecting the center of gravity of the object and the contour line is rotated within a certain angle range and stored in advance Compare. An example of this writing member image and reference line rotation is shown in FIG. A plurality of types of data relating to the shape of the writing member may be prepared, and all of these may be used during the shape determination process.

Next, when it is determined by the above determination processing that the member is a writing member, it is determined whether or not the writing member is in contact with the writing surface. Here, the writing surface corresponds to one side of the imaging region as shown in FIG. Therefore, it may be determined whether the image of the writing member is in contact with the side corresponding to the writing surface. When it is determined that the writing member is in contact with the writing surface, the distance h between the imaging position of the contact point and the imaging position of the optical axis of the wide-angle lens 50 is obtained. In the example of FIG. 8, h is the imaging position of the optical axis of the wide-angle lens 50 and h1 is the imaging position of the contact point.
h = h0-h1
Is required. Note that h0 and h1 are obtained from the number of pixels from the reference side in the vertical direction of the CMOS image sensor 51 and the distance between the pixels (pixel pitch).

  When the distance h is obtained in this way, the angle β1 is obtained using f and α having known values from the equations (1) and (2).

  In the image processing circuit (2) 30, the angle β2 can be obtained by performing the same processing as described above.

  Using these β1, β2 and L having a known value, the coordinates (x, y) of the contact point on the writing surface can be obtained from the equations (3) and (4).

  Next, among the processes executed in the information input / output system 100 of the present embodiment, the description of the same processes as those performed by the conventional information input / output system is omitted, and the information input / output system 100 is omitted. The processing for realizing the characteristic functions provided by will be described below. Here, a characteristic function executed by the CPU 20 of the control device 2 based on a program will be described.

In this embodiment, since a moving image or a still image is not used, the signal flow in the display controller 31 is
PCI bus 41-> graphic controller 60-> graphic video memory 61-> graphic data conversion unit 62-> display data generation unit 63-> DAC 64-> color display device 12
It becomes only. The graphic controller 60 executes the overlay process of the background, the drawing data, and the cursor data.

  As shown in the display example of FIG. 9, the color display device 12 displays icons for setting the color of a drawing line (handwritten line) and the background color of a writing area (blackboard). When this is touched, a pull-down menu is displayed, and this menu operation allows the drawing line and background color to be set and changed as appropriate. When the “drawing line” (pencil mark) icon is selected, attributes for two types of lines are displayed. The line “line 1” has a black color and a thickness of 1.5 pt (points), and the line “line 2” has a red color and a thickness of 2 pt. Each line is displayed in that color. Each line is set to an automatic mode in which the color setting is automatically determined from the background color. The display example of FIG. 9 shows a case where the background color is white. A combination data table of the background color, the line color of “Line 1”, and the line color of “Line 2” is stored in advance in the ROM 24 of the control device 2, and the two line colors are uniquely defined according to the set background color. It is decided.

  When “line setting” is selected from the pull-down menu shown in FIG. 9, a window for performing “line setting” is displayed. A display example of this “line setting” window is shown in FIG. FIG. 10 shows the attribute of the line “line 2”. When the “automatic” check box is unchecked, the line color automatic setting mode is cancelled. In addition to the solid line, the line type can be selected from a dotted line, an alternate long and short dash line, and the like. When the line color automatic setting mode is cancelled, the line color can be selected from a 40 color palette. When “Line 1” is selected, the line attribute of “Line 1” is displayed.

  The user can select the “background color” icon to open the “background color setting” window and set (change) the color using the color palette in this window. A display example of this window is omitted. If the background color is changed when both line colors are in the automatic setting mode, the combination data table of the background color and the two line colors stored in the ROM 24 is referred to. The line color and the line color of “Line 2” are changed. This change is a change in line attribute information (stored in the main memory 21 or the hard disk 27) and a change in display data on the color display device 12. For example, when the background color is changed from white to green, “line 1” is changed to white and “line 2” is changed to pink. Note that the green background color and the pink color of “Line 2” have a complementary color relationship, and the “Line 2” line is conspicuous. When the background color is changed, the CPU 20 fills the background user plane number and the color information (green) after the change, the line drawing user plane number of “Line 1”, and the color information of the line after the change. The drawing color changing command including (white), the drawing color changing command including the line drawing user plane number of “Line 2” and the color information (pink) of the changed line are passed to the graphic controller 60. Then, the display screen of the color display device 12 is updated according to each changed color. FIG. 11 shows an operation flow of the control device 2 that realizes the first display color setting means.

  When only one of the “Line 1” line and the “Line 2” line is in the automatic setting mode, the color of the target line is set based on the background color and the color of the line not in the automatic setting mode. It may be changed. In this case, there is a method of preparing a plurality of combinations of two line colors for one background color (stored in a table in the ROM 24) and adaptively selecting them. This detailed description is omitted.

  Next, in addition to the two types of lines “line 1” and “line 2”, a case where there is a line of “emphasis” to be further visually emphasized will be described. Similar to the case where there are only two types of lines, “Line 1” and “Line 2”, when the “drawing line” (pencil mark) icon is selected, attributes for the three types of lines are displayed. . An example of this display is shown in FIG. The “enhanced” line has a red color and a thickness of 2 pt. The “line 1” line has a black color and a thickness of 1.5 pt. The “line 2” line has a blue color and a thick color. Is 1.5pt. Each line is set to an automatic mode in which the color setting is automatically determined from the background color. The case where the background color is white is shown. A combination data table of the background color and the line color of “emphasis” and the line color of “line 1” and “line 2” is stored in the ROM 24 of the control device 2 in advance, and the three line colors are set according to the set background color. Is uniquely determined.

  When “line setting” is selected from the pull-down menu shown in FIG. 12, a window for performing “line setting” is displayed. A display example of this “line setting” window is shown in FIG. FIG. 13 displays the attribute of the “highlight” line. The functions of the displayed menus are the same as those in FIG.

  If the background color is changed when all three line colors are in the automatic setting mode, the three line colors are selected by referring to the combination data table of the background color and the three line colors stored in the ROM 24. Change each one. For example, when the background color is changed from white to green, the “emphasis” line is changed to pink, “line 1” is changed to white, and “line 2” is changed to light blue. Note that the background color green and the “highlight” line color pink are in a complementary relationship, and the “highlight” line is conspicuous. Then, the display screen of the color display device 12 is updated according to the changed colors.

  If all lines of “emphasis”, “line 1”, and “line 2” are not in the automatic setting mode, the color of the target line is changed based on the background color and the line color that is not in the automatic setting mode. You may make it do. In this case, there is a method in which a plurality of combinations of three line colors with respect to one background color are prepared (stored in a table in the ROM 24) and adaptively selected from them. This detailed description is omitted.

  Subsequently, when the background color is changed when all the drawing line colors are in the automatic setting mode, not all line colors are uniquely determined according to the background color, but a combination of all the line colors is selected. A case will be described in which a plurality of background colors are prepared for the user to select from these. Here, a case will be described where there are three types of drawing lines: “emphasis”, “line 1”, and “line 2”.

  When the “drawing line” icon is selected by the user, attributes for three types of lines are displayed. An example of this display is shown in FIG. Here, it is assumed that the background color is green, the “emphasized” line is pink, “line 1” is white, and “line 2” is light blue.

  When “next” at the bottom of the pull-down menu shown in FIG. 14 is selected, the color of one or more lines among the three types is changed. For example, only the “emphasis” line is changed to yellow. These three combinations of line colors are stored in a table in the ROM 24 in a visually preferred order for one background color, and when the next combination is selected by the user, The line attribute (color) is changed with reference to the combination. When the “drawing line” icon is selected while the pull-down menu is displayed, the attribute of the line displayed at that time is set as valid data. FIG. 15 shows an operation flow of the control device 2 for realizing the display color selection means.

  It should be noted that the priority of the combination of line colors with respect to one background color can be operated so as to change depending on the application in which the present system is used. For example, when used for business purposes, pink is not suitable for business, so the combination of lines using pink is set with a low priority. This usage setting can be set in the maintenance mode when the apparatus is installed, for example. And the priority order of the combination of the usage and each line color is stored in the ROM 24.

  Incidentally, the color display device 12 displays an icon for setting the color of the “cursor” in addition to the icon for setting the color of the drawing line and the background color of the writing area (FIG. 9). If the user touches this, a “cursor color setting” window is opened, and a color palette in this window can be used to set (change) the color. A display example of this window is omitted. Here, a case where there are two types of drawing lines will be described as an example.

  A combination data table of the background color and the color of “cursor”, the line color of “line 1”, and the line color of “line 2” is stored in the ROM 24 of the control device 2 in advance, and the cursor color is changed according to the set background color. Color and two line colors are uniquely determined. For example, when the background color is white, “cursor” is green, “line 1” is black, “line 2” is red, and when the background color is changed from white to green, “cursor” is light blue, “Line 1” is changed to white, and “Line 2” is changed to pink. FIG. 16 shows an operation flow of the control device 2 for realizing the cursor display color setting means.

  Next, when a color close to the background or surrounding color (environment color) where the information input / output system 100 is installed is set, and the background color of the writing area and the color of the drawing line are automatically set based on this color Will be described. The environmental color is set in the maintenance mode.

  When “environment color setting” is selected in the maintenance mode, a color palette similar to that shown in FIG. 10 is displayed on the color display device 12. A combination data table of the environment color, the background color of the writing area and the color of the drawing line is stored in advance in the ROM 24 of the control device 2, and the back of the information input / output system 100 installed from the color palette displayed by the user. Alternatively, when a color close to the surrounding color is selected, the background color of the writing area and the color of the drawing line are uniquely determined according to the selected environmental color. For example, if there are two types of drawing lines, “Line 1” and “Line 2”, and the environment color is set to light brown (beige), the background color is light yellow, “Line 1” is black, Set line 2 "to red. When pink is set as the environmental color, the background color is set to light red, “Line 1” is set to blue, and “Line 2” is set to yellow. FIG. 17 shows an operation flow of the control device 2 for realizing the environmental color registration means.

  Next, a case will be described in which a plurality of combinations of background colors and drawing line colors are prepared for one environmental color and the user is allowed to select from these.

  When “environment color setting” is selected in the maintenance mode, a color palette is displayed on the color display device 12, and the user can select a color close to the color behind or around where the information input / output system 100 is installed. When selected, a “color setting” window for selecting a combination of background color and drawing line color is displayed. A display example of this “color setting” window is shown in FIG. Now, light brown is set as the environmental color, the background color is light yellow, “Line 1” is black, and “Line 2” is red. When the “Next” button in the window shown in FIG. 18 is selected, the background color is displayed as light brown, “Line 1” is displayed in black, and “Line 2” is displayed in blue. Here, when the “setting” button is selected, the background color and the color of each line are fixed to the currently displayed color. FIG. 19 shows an operation flow of the control device 2 that realizes the combination selection means.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same part as 1st Embodiment mentioned above is shown with the same code | symbol, and abbreviate | omits description. In the first embodiment, the function for appropriately setting and changing the color of the drawing line and the background has been described as a characteristic function provided in the information input / output system 100. However, in this embodiment, the character and background A description will be given of the function of appropriately setting and changing the color.

In this embodiment as well, since no moving image or still image is used, the signal flow in the display controller 31 is
PCI bus 41-> graphic controller 60-> graphic video memory 61-> graphic data conversion unit 62-> display data generation unit 63-> DAC 64-> color display device 12
It becomes only. The graphic controller 60 executes the overlay process of the background, the drawing data, and the cursor data.

  As shown in the display example of FIG. 20, the color display device 12 displays icons for setting the color of characters and setting the background color. By selecting these icons, characters and backgrounds are displayed. The color can be set and changed as appropriate.

  When the “character” icon is selected by the user, a window for performing “character setting” is displayed. A display example of the “character setting” window is shown in FIG. In FIG. 21, “Font” is a font type such as “Mincho”, “Gothic”, “Size” is a character size, “Style” is a character style such as “Bold”, “Italic”, etc. Can be changed respectively. The text color can be selected from a 40-color palette. When “change color” in this window is selected, colors that are conspicuous with respect to the background color are automatically selected from the color palette of 40 colors other than the color of characters already displayed. For one background color, the color of the character displayed on the background color is stored in advance in the ROM 24 as a data table, for example, in the order of conspicuous colors, and this data table is displayed when “change color” is selected. The character color may be selected in the order of the conspicuous colors with reference to FIG. For example, when “color change” is selected when the background color is white and the current character color is only black, the character color input from the keyboard 3 thereafter is displayed in red. To change the color of text that is already displayed, select the text you want to change the color of, then select the “Text” icon to open the “Text Settings” window and change the color. The color of the specified character string can be changed.

  When the “background color” icon shown in FIG. 20 is selected, a window for performing “background color setting” is displayed. In this window, the same 40-color palette as shown in FIG. 21 (“character setting” window) is displayed. The background color can be set (changed) using this color palette. A display example of this window is omitted.

  Next, a case where the character display color is changed when the background color is changed will be described. If the background color is white and the text color is black and red, and the background color is changed to green, the black text color is changed to white and the red text color is changed to pink. Note that the background color green and the peach color, which is a character color, have a complementary relationship, and characters of this color are conspicuous. When the background color is changed, the CPU 20 performs a fill command including the background user plane number and the color information (green) after the change, and the character display user plane number and the black character color are white, and the red character color. Passes to the graphic controller 60 a display color change command for changing to pink. Then, the display screen of the color display device 12 is updated according to each changed color. The combination data table of the background color and the corresponding character color is stored in the ROM 24 in advance, and two or more character colors are uniquely determined according to the set background color. Yes. FIG. 22 shows an operation flow of the control device 2 that realizes the first display color setting means.

  In the above description, the character color is changed. However, a conspicuous color with respect to the background color can be automatically selected for graphics such as filling in the closed region (in the figure). This detailed description is omitted.

  Next, a case where there is a character color of “emphasis” to be visually emphasized in addition to the two character colors will be described. As in the case of the two character colors described above, when the “character” icon is selected, the “character setting” window is displayed. An example of this display is shown in FIG. In FIG. 23, an “emphasized color” menu is added to FIG. When “highlight color” is selected here, the color of characters input from the keyboard 3 thereafter is displayed in the most prominent color with respect to the background color. As the most prominent color, a complementary color with respect to the background color may be selected. When “highlight color” is selected in a state where a character string to be changed to the highlight color is designated, the designated character string is displayed in a color that is most conspicuous with respect to the background color. If a character with the same color as the emphasized color already exists when the “emphasized color” selection operation is performed, the color of the existing character is changed to another color. A combination data table of the background color, the corresponding emphasis color, and each character color is stored in advance in the ROM 24, and these character colors are uniquely determined according to the set background color. For example, if “emphasis color” is selected while white and pink characters are displayed in green, the existing pink characters are changed to light blue, and characters that are input from the keyboard 3 thereafter. Is displayed in pink. The operation flow of the control device 2 is shown in FIG.

  In the above description, the character color is changed. However, it is possible to automatically select the most conspicuous color with respect to the background color for graphics such as filling in the closed region (in the figure). This detailed description is omitted.

  Subsequently, when the background color is changed, a plurality of character colors are not uniquely determined according to the background color, but a plurality of combinations of the character colors are prepared for one background color. A case where the user makes a selection will be described. Here, a case will be described in which there are three types of character colors: “emphasized color”, “character color 1”, and “character color 2”.

  When the “character” icon is selected by the user, a “character setting” window is displayed. An example of this display is shown in FIG. FIG. 25 is obtained by changing the “emphasis color” menu in FIG. 23 to a “color combination” menu.

  When “color combination” is selected here, a “display color combination” window is displayed. This display example is shown in FIG. In FIG. 26, the number of display character colors can be variably set. Currently, 3 is set. Three types of colors are actually displayed corresponding to the number of displayed character colors ("emphasized color" is pink, "character color 1" is white, and "character color 2" is light blue). Here, the first color is a highlight color. When the number of display character colors is set to 4 or more, the character colors “Character color 3”, “Character color 4”,... Are added to the right blank area in the “Display color combination” window. Is displayed. When the “next” menu in this “display color combination” window is selected, one or more of the three character colors are changed. For example, only “highlight color” is changed to yellow. A plurality of combinations of these three character colors are stored in a table in the ROM 24 in a visually preferred order for one background color. When the next combination is selected by the user, the next combination of the data table is displayed. The display color is changed with reference to the combination. FIG. 27 shows an operation flow of the control device 2 that realizes the combination selection means.

  It should be noted that the priority order of the combination of the character colors with respect to one background color can be operated so as to change depending on the application in which the present system is used. For example, when used for business purposes, pink is not suitable for business, so the combination of colors using pink is set with a low priority. This usage setting can be set in the maintenance mode when the apparatus is installed, for example. The priority order of the combination of usage and each character color is stored in the ROM 24.

  By the way, the color display device 12 displays an icon for setting the color of the “cursor” in addition to icons for setting the color of characters and setting the background color (see FIG. 20). Touching this opens the “Set Cursor Color” window, where you can use the color palette in this window to set (change) the color. A display example of this window is omitted.

  A combination data table of the background color, a plurality of character colors corresponding to the background color, and the color of the “cursor” is stored in advance in the ROM 24 of the control device 2, and the cursor color and the plurality of character colors are determined according to the set background color. It is decided uniquely. For example, when the background color is white, the “cursor” is green, the first character color is black, the second character color is red, and when the background color is changed from white to green, the “cursor” is light blue The first character color is changed to white and the second character color is changed to pink. FIG. 28 shows an operation flow of the control device 2 for realizing the cursor display color setting means.

  Next, a case will be described in which a color close to the background or surrounding color (environment color) where the information input / output system 100 is installed is set, and the background color and character color are automatically set based on this color. The environmental color is set in the maintenance mode.

  When “environment color setting” is selected in the maintenance mode, a color palette similar to that shown in FIG. 21 is displayed on the color display device 12. A combination data table of environmental colors, background colors, and a plurality of character colors is stored in the ROM 24 in advance, and a color close to the background or surrounding color where the information input / output system 100 is placed from the color palette displayed by the user. When is selected, the background color and the colors of a plurality of characters are uniquely determined according to the selected environmental color. For example, when light brown (beige) is set as the environmental color, the background color is set to light yellow, the first character color is set to black, and the second character color is set to red. When the environment color is pink, the background color is set to light red, the first character color is set to blue, and the second character color is set to yellow. FIG. 29 shows an operation flow of the control device 2 for realizing the environmental color registration means.

  Next, a case will be described in which a plurality of combinations of background colors and character colors are prepared for one environmental color and the user is allowed to select from these.

  When “environment color setting” is selected in the maintenance mode, a color palette is displayed on the color display device 12, and the user can select a color close to the color behind or around where the information input / output system 100 is installed. Upon selection, a “display color combination” window for selecting a combination of background color and character color is displayed. A display example of the “display color combination” window is shown in FIG. When the environment color is set to light brown, the background color is light yellow, the first character color is black, and the second character color is red, the “Next” button in this window Is selected, the background color is light brown, the first character color is black, and the second character color is blue. Here, when the “set” button is selected, the background color and the color of each character are changed to the colors currently displayed in the “display color combination” window. FIG. 31 shows an operation flow of the control device 2 that realizes the combination selection means.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the same part as 1st embodiment mentioned above and 2nd embodiment is shown with the same code | symbol, and description is also abbreviate | omitted. Unlike the first embodiment and the second embodiment described above in which the background of the writing area is a single color, the present embodiment uses a still image or a moving image as the background of the writing area. This is a case where

In this embodiment, since a moving image or a still image is used, the flow of the graphic data signal in the display controller 31 is as follows.
PCI bus 41-> graphic controller 60-> graphic video memory 61-> graphic data conversion unit 62-> display data generation unit 63-> video data superimposition unit 68-> DAC 64-> color display device 12
It becomes.

  In the YUV video signal, most of the information is concentrated on the luminance (Y). Therefore, the characteristics of the image can be determined by examining the spatial frequency distribution of the luminance component of the image. In the present embodiment, still image data and moving image data pass through the spatial frequency check unit 69, where the spatial frequency distribution is examined. The spatial frequency check unit 69 divides the YUV video data input from the MPEG decoder 32 or the YUV video data of the still image expanded by software by the CPU 20 into blocks each having 8 × 8 pixels, and the luminance for each block. The spatial frequency distribution is examined for the component (Y).

  As this method, for example, a two-dimensional discrete cosine transform (DCT) is used. The two-dimensional discrete cosine transform is expressed by the following equation.

  In Expression (8), N is the number of pixels in the horizontal and vertical directions of the block, and here N = 8. f (i, j) is a luminance value of each pixel input to the spatial frequency check unit 69, and F (u, v) is a DCT coefficient at the spatial frequency u in the horizontal direction and the spatial frequency v in the vertical direction. The spatial frequency distribution can be determined from the relationship between the spatial frequency u, v and the DCT coefficient F (u, v). That is, if the value of F (u, v) is larger than the larger values of u and v, it can be determined that the image has many high spatial frequency components.

  In this way, it is determined whether or not each block has an image with many high spatial frequency components (background image determination means), and the number of blocks determined to be an image with many high spatial frequency components is the number of all blocks. When the ratio is greater than or equal to a predetermined ratio with respect to the number, the entire image is regarded as an image having a high spatial frequency component. If it is determined that the entire image is an image having a high spatial frequency component, the average of the luminance components (Y) of all the pixels is obtained.

  When this average value is larger than a predetermined value (luminance value determination means), the spatial frequency check unit 69 notifies the CPU 20 that the image has a high spatial frequency component and has a high luminance. Upon receiving this notification, the CPU 20 sets the color of the drawing line to black (display color second setting means). When there are a plurality of drawing lines, all the lines are set to a low (dark) color. In addition, upon receiving this notification, the CPU 20 sets the color of all characters to black. Note that the character color may not be all black, but may be set to a color in which the lightness is lowered (darkened) for each character color.

  On the other hand, when it is determined that the entire image is an image having a high spatial frequency component and the average of the luminance components (Y) of all the pixels is smaller than a predetermined value, the spatial frequency check unit 69 determines the high spatial frequency component. The CPU 20 is notified that the image has a large amount and a low luminance. Upon receiving this notification, the CPU 20 sets the color of the drawing line to white (display color second setting means). In addition, when there are a plurality of drawing lines, all the lines are set to a bright (bright) color. In addition, upon receiving this notification, the CPU 20 sets the color of all characters to white. Note that the character color may not be all white, but may be set to a color with increased (lightened) brightness for each character color.

  Thereafter, when the user inputs writing, the corresponding drawing lines and characters are displayed in a set color on the still image or moving image.

  In the case of a moving image, the spatial frequency check unit 69 may check the spatial frequency distribution at predetermined time intervals, for example, at 10 second intervals.

  The operation flow of the spatial frequency check unit 69 is shown in FIG. In the above operation flow, the case where the entire background image of the writing area is determined is shown. However, the background image is divided into a plurality of areas, the spatial frequency distribution is checked for each divided area, the luminance is Thus, the drawing line color and the character color setting can be made more adaptive. This detailed description is omitted.

  Next, a case where a still image or moving image with a small high spatial frequency component is the background image of the writing area will be described. In this case, the drawing line color and the character color are set to stand out from the background image.

  The spatial frequency distribution is checked by a method using the two-dimensional discrete cosine transform as described above in the spatial frequency check unit 69. When it is determined that the entire image is an image with a high spatial frequency component and a small amount of spatial frequency components, R, G output from the spatial frequency check unit 69 and input to the video / still image video memory 66 through the video decoder 65. From the B data, the most frequently used color (characteristic color of the image) in the entire image is examined. As this method, for example, the colors may be grouped into several representative colors for each pixel based on the degree of color similarity, and the most representative colors may be specified. Then, the color of the drawing line or the color of the character is set to a color that is conspicuous with respect to the specified representative color, for example, a color that has a complementary color relationship (display color third setting means). When there are a plurality of drawing line colors and character colors, a combination of a plurality of line colors for one background color is prepared in a table in the ROM 24, and this table is used with the specified representative color as the background color. Refer to and set the drawing line color and text color. The operation flow of the control device 2 is shown in FIG.

  Next, an operation of increasing the thickness of the drawing line or character so that the drawing line or character is conspicuous when a still image or moving image having a high spatial frequency component is the background image of the writing area will be described.

  The spatial frequency distribution is checked by a method using the two-dimensional discrete cosine transform as described above in the spatial frequency check unit 69. When it is determined that the entire image is an image having a high spatial frequency component, the CPU 20 is notified of this information. Upon receiving this notification, the CPU 20 checks the thickness of the current drawing line or character, and if it is thinner than the predetermined thickness, sets the drawing line or character to the predetermined thickness (size switching means). . In addition, when there are a plurality of thicknesses of drawing lines and characters, the thickness may be changed according to the thickness of each drawing line or character. For example, when “Line 1” is 1.5 pt and “Line 2” is 2 pt, the length is changed to 3 pt and 4 pt, respectively. The operation flow of the control device 2 is shown in FIG.

  Next, description will be made of an operation of adding a border to a drawing line or character so that the drawing line or character is conspicuous when a still image or moving image having a high spatial frequency component is a background image of a writing area.

  The spatial frequency distribution is checked by a method using the two-dimensional discrete cosine transform as described above in the spatial frequency check unit 69. When it is determined that the entire image is an image having a high spatial frequency component, the CPU 20 is notified of this information. Upon receiving this notification, the CPU 20 passes to the graphic controller 60 a drawing command for adding an edge including a color corresponding to the color of the drawing line and a drawing command for adding an edge including a color corresponding to the color of the character. Upon receiving this drawing command, the graphic controller 60 generates a drawing line or character of a color specified by the drawing command that is thicker than the current drawing line or larger than the current character, and this newly generated drawing line or character. Overlay existing drawing lines and text on top. In this way, the part of the newly generated drawing line or character where the existing drawing line or character does not overlap is the edge of the line. The drawn drawing lines and characters with the edges are superimposed on a still image or a moving image and displayed on the color display device 12. The drawing line or character color and the edge color added thereto are stored in association with the ROM 24, and the CPU 20 refers to this information to identify the edge color to be added. The operation flow of the control device 2 is shown in FIG.

  If the still image or video is the background image of the writing area, increase the thickness of the line and / or add an edge to the line so that the drawing lines and characters stand out. It may be displayed. This operation is executed if the background image is a still image or a moving image, and there is no need to check the spatial frequency of the image.

  In each embodiment, the electronic blackboard system which is the information input / output system 100 including the information input / output device 1 including the color display device 12 and the display control device 2 is applied. However, the present invention is not limited to this. It may be configured by the color display device 12 and the display control device 2.

1 Information Input / Output Device 2 Display Control Device 12 Color Display Device 100 Information Input / Output System

Japanese Patent Laid-Open No. 11-327789

Claims (4)

In a display control device that displays drawing data such as characters and drawing lines on a color display device,
Size switching means for switching and displaying the size of the drawing data;
A background image determination unit that examines a spatial frequency distribution of a background image of an area in which the drawing data is displayed, and determines whether the background image has many high spatial frequency components;
When the background image determining unit determines that the image has many high spatial frequency components, the size switching unit displays the drawing data by switching the size of the drawing data.   2. The background image is displayed by adding an edge to the drawing data when the background image determining means determines that the background image of the area for displaying the drawing data is an image having a high spatial frequency component. The display control apparatus described. In a display control device that displays drawing data such as characters and drawing lines on a color display device,
Comprising size switching means for switching and displaying the size of the drawing data;
When the background image of the area where the drawing data is displayed is a still image or a moving image, the size switching means displays the drawing data by switching the size of the drawing data.   4. The display control apparatus according to claim 3, wherein when the background image of the area where the drawing data is displayed is a still image or a moving image, an edge is added to the drawing data.

Images