JP2004135009A - On-screen display unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display a character string in a high grade with visual effect where the background becomes translucent. <P>SOLUTION: A character background image generation section 45 replaces a pixel having 100% concentration of a pseudo half tone pattern b2 outputted from a pseudo half tone pattern memory 44 with the color of color data b1 outputted from a color pallet 43 for outputting to a synthesis processing section 47 as a background image b5. The synthesis processing section 47 replaces a pixel, where a pixel at the same position in font data b3 becomes a character color pixel in the pixels of the background image b5, with the character color pixel, replaces a pixel, where the pixel at the same position of the font data in pixels of 0% concentration of the background image B5, with the value of the pixel of a picture indicated by a source picture signal b4 at the same position as the pixel, generates a superimpose image b6 for outputting to an RGB decoder 2, and achieves superimpose display. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an on-screen display (OSD) device for superimposing and displaying a character string such as a character string on a video.
[0002]
[Prior art]
As an on-screen display technology in an on-screen display device that superimposes a character string such as a character string on a video, a normal rectangular character display area for a superimpose is provided in a part of a video display area. A technique for displaying a character string in a predetermined display color in this character display area is known (for example, Japanese Patent Application Laid-Open No. 2002-14646). In addition, a technique is known in which the luminance of the relevant portion of the video is reduced and displayed in a portion other than the character shape of the character display area, that is, in the background portion of the character string. In this technique, an input video signal is branched and attenuated to generate a video signal, and the attenuated video signal is used to generate a video with reduced luminance serving as a background of a character display area, and a synchronization signal. Is included in the video signal, the character display area and the display position of the character string are controlled based on the synchronization signal included in the attenuated video signal.
[0003]
According to such a technique, it is possible to obtain a visual effect in which a character display area provided on an image is translucent (a lower image can be seen through).
[0004]
Prior art document information related to the invention of this application includes the following.
[0005]
[Patent Document 1]
JP 2002-14646 A
[Problems to be solved by the invention]
According to the above-described on-screen display technology, when the input video signal is, for example, a composite signal of a luminance signal, a chrominance signal, and a synchronization signal, a character display area or a character string is displayed based on the attenuated synchronization signal. The display position will be controlled. Since it is difficult to strictly synchronize with the video depending on the attenuated synchronization signal, the control of the character string and the display position of the character display area based on the attenuated synchronization signal sharpens the edge portion of the character. May not be able to be expressed. Also, in order to use a video whose brightness is greatly reduced as the background of the character display area, if the degree of attenuation of the video signal is increased, synchronization is disturbed, and the display of the character string or the character display area is disturbed. It can be lost.
[0007]
Therefore, an object of the present invention is to provide an on-screen display device capable of performing high-quality spur imposition display with a visual effect as if the character display area is translucent.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to an on-screen display device that displays one or more characters in a form of an on-screen display in a character display area set on a video, and overlaps the character display area of the video. Detecting means for detecting the dominant hue of the area, and selecting a hue detected by the detecting means or a color of a hue similar to the hue as a background color, and selecting the color of the character in the character display area with the selected background color. Character background drawing means for drawing a background. According to such an on-screen display device, the background color of the character in the character display area is changed to the same system color as the color of the area corresponding to the character display area represented by the video without reducing the luminance of the video signal. By doing so, it is possible to visually generate the character display area so that the background portion of the character is recognized as being translucent or the video below the character can be seen through the background portion.
[0009]
In order to achieve the above object, the present invention provides an on-screen display device which displays one or a plurality of characters in a form of an on-screen display in a character display area set on a video, As an on-screen display method of giving a visual effect to the background, a pixel of a predetermined background color of an image of a background area of the character display area serving as the background of the character, and a pixel of the video at the same position as the own pixel An on-screen display method, comprising the steps of: generating by combining a pixel having the same color as the image; and displaying an image representing a character with the generated image of the background area as a background in the character display area. I will provide a.
[0010]
According to such an on-screen display method, the background of the character display area is set to the predetermined background color and the color of the image below the character display area, without reducing the brightness of the video signal. The character display area can be generated so that the background portion of the character is recognized as being translucent or the image below can be seen through the background portion of the character.
[0011]
Here, such an on-screen display method is specifically applied to, for example, an on-screen display device that displays one or a plurality of characters in a form of an on-screen display in a character display area set on a video. A pixel pattern memory storing a pixel matrix pattern in which pixels of a background color and pixels of a predetermined value representing a non-background color are arranged in combination, and an image obtained by arranging the pixel matrix pattern in the character display area, A character background to be rendered as a background of the character in the character display area, the background image being a pixel other than the pixel representing the character and having the pixel of the predetermined value as a color of a pixel of the video at a position overlapping the pixel. This can be implemented by providing a drawing unit.
[0012]
Alternatively, in an on-screen display device, a pixel pattern memory storing a pixel matrix pattern in which significant value pixels and insignificant value pixels are arranged in combination, and an image obtained by arranging the pseudo pixel matrix pattern in the character display area The pixel of the significant value pixel other than the pixel representing the character is set as the predetermined background color, and the color of the insignificant pixel other than the pixel representing the character is the pixel of the image at the position overlapping the pixel. This can be implemented by providing character background drawing means for drawing a background image in the color of a pixel as a background of the character in the character display area. In this case, the pixel matrix pattern is a pseudo halftone pattern for expressing a predetermined density image by a combination of 100% density pixels and 0% density pixels. The pixel having the 0% density may correspond to the pixel having the insignificant value for the pixel having the significant value. Still further, in the pixel pattern memory, a plurality of pseudo halftone patterns respectively corresponding to images of different densities are stored, and in the character background drawing means, as the pseudo halftone pattern applied to the character display area, By selectively using one pseudo halftone pattern among the plurality of pseudo halftone patterns stored in the pseudo halftone pattern memory, a visual effect that allows translucent or lower images to be seen through is provided. The degree may be selectively controlled. Alternatively, detecting means for detecting a dominant hue of an area overlapping the character display area of the image is provided, and the character background drawing means sets the hue detected by the detecting means or a hue color similar to the hue to the hue. By selecting the background color as a predetermined background color, an effect that is visually less unnatural may be realized.
[0013]
In the above-described on-screen display device or on-screen display method, it is preferable to select, as the background color used for the background of the character string, a color having a brightness equal to or less than an intermediate value in the brightness range of the video. Desirable for obtaining a natural visual effect.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows a configuration of an on-screen display device according to the present embodiment. Hereinafter, as an example, a case where the source video, which is a video input to the on-screen display device, is a composite signal that is a composite signal of a luminance / color signal such as Y and C and a vertical and horizontal synchronization signal. An example is described.
[0015]
As shown in the figure, an on-screen display device selects a source image from a plurality of input source images and outputs the selected source image. The selector 1 converts the source image output by the selector 1 into RGB signals and outputs the RGB signals. A decoder 2; an RGB input display 3 for displaying an image based on an RGB signal output from the RGB decoder 2; an OSD processing unit 4 for superimposing a character string of characters such as characters, numbers, and symbols on the source image; And a control unit 5 that performs the control.
[0016]
In such a configuration, the control unit 5 controls the operation of the selector 1 for selecting the source video. Further, the control unit 5 outputs to the RGB decoder 2 a signal for setting a character string to be superimposed on the source video, a display position of the character string, and a density of a background of the character string to the OSD processing unit 4.
[0017]
The OSD processing unit 4 outputs an image of the set character string with the background set to the density at a timing determined according to the set display position of the character string. On the other hand, the RGB decoder 2 outputs the video input from the OSD processing unit 4 instead of the source video at a timing determined according to the set display position of the character string. Here, the video signal of the video of the character string output by the OSD processing unit 4 may be a Y composite signal or an RGB signal. When the video signal of the video of the character string output by the OSD processing unit 4 is a composite signal, the RGB decoder 2 replaces the source video signal input from the selector 1 at a timing determined according to the set display position of the character string. The video signal input from the OSD processing unit 4 is converted into an RGB signal and output. When the video signal of the video of the character string output by the OSD processing unit 4 is an RGB signal, the RGB decoder 2 outputs the video signal input from the OSD processing unit 4 at a timing determined according to the display position of the set character string. Is output in place of the RGB signal obtained by converting the source video signal input from the selector 1.
[0018]
Hereinafter, the details of the OSD processing unit 4 will be described.
FIG. 2 shows an internal configuration of the OSD processing unit 4. In the following, for convenience of explanation, an example in which one character (alphabetic characters, numbers, symbols, etc.) is represented by 8 pixels × 8 pixels will be described.
As shown, the OSD processing unit 4 includes a synchronization signal extraction unit 41, a background color determination unit 42, a color palette 43, a pseudo halftone pattern memory 44, a character background image generation unit 45, a character memory 46, a synthesis processing unit 47, and an OSD. And a control unit 48.
[0019]
Here, in the color palette 43, for each of the representative hues of black, blue, red, yellow, green and other typical hues, the luminance of the hues is relatively low (for example, less than the intermediate value of the lightness range of the source video). The color data of the color (luminance) is stored.
In addition, as shown in FIG. 3A, a plurality of pseudo halftone patterns of 8 pixels × 8 pixels corresponding to different densities are stored in the pseudo pattern memory in advance, as shown in FIG. 3A. In the illustrated example, a1 is a pseudo halftone pattern corresponding to 25% density, a2 is a pseudo halftone pattern corresponding to 50% density, a3 is a pseudo halftone pattern corresponding to 75% density, a4 is a pseudo halftone pattern corresponding to 100% density. Further, black pixels in the pseudo halftone pattern are pixels having a color of 100% density, and white represents pixels having a density of 0%. That is, if these pseudo halftone patterns represent gray, the black pixels in each similar halftone pattern are black pixels, and white represents white pixels.
[0020]
It should be noted that such a pseudo halftone pattern corresponding to each density can be obtained for the density% by a well-known halftone screen method, pattern dither method, and error diffusion method (dither).
Next, the character memory 46 stores, for example, font data for each character that can be displayed by the OSD processing unit 4, as indicated by the character “L” in b3 of FIG. 3B. The black pixels in the figure are the character colors, and the white pixels are the background colors.
[0021]
Returning to FIG. 2, in such a configuration, the synchronization signal extraction unit 41 extracts a synchronization signal from a composite source video signal input from the selector 1, generates a horizontal / vertical display reference timing signal, and performs OSD control. Output to the section 48 and the background color determination section 42.
[0022]
The control unit 5 generates a display signal indicating the display period of the character string according to the display reference timing signal and the display position of the character string set by the control unit 5, and outputs the display signal to the background color determination unit 42. Further, during the character string display period, the font data of each character constituting the character string set by the control unit 5 is output from the character memory 46 at a timing corresponding to the display position of the pixel of the character. Processing for outputting each pixel of the pseudo halftone pattern corresponding to the density set by the control unit 5 from the pseudo halftone pattern memory 44 at the same timing as the pixel at the corresponding position of the font data to be output from the character memory 46 Is performed for each font data to be output from the character memory 46.
[0023]
On the other hand, the background color determination unit 42 analyzes the source video signal input from the selector 1 during the display period indicated by the display signal input from the control unit 5, and controls the dominant local region of the source video corresponding to the display period. The color is determined by, for example, setting the color having the largest number of pixels as the dominant color. Note that, here, an approximate hue such as blue, red, yellow, or gray is determined as the dominant color rather than strictly determining the color. That is, for example, each pixel of the partial region of the source video corresponding to the display period is classified into a predetermined hue group according to its color, and the hue of the group having the largest number of classified pixels is dominant. The color is determined. Then, the background color determination unit 42 causes the color palette 43 to output color data corresponding to the determined dominant color. That is, for example, if the hue determined as the dominant color is blue, color data with a relatively low luminance of the blue hue stored in the color palette 43 is output from the color palette 43.
[0024]
As a result of the above processing, as shown in FIG. 3B, the color data b1 selected based on the source video signal from the color palette 43, the pseudo halftone pattern b2 from the pseudo halftone pattern memory 44, and the character memory 46 from the character memory 46. Output font data b3.
[0025]
In FIG. 2, the character background image generation unit 45 converts the 100% density pixels of the pseudo halftone pattern b2 output from the pseudo halftone pattern memory 44 into the color data b1 output from the color palette 43 as shown in FIG. And outputs the background image b5 to the synthesis processing unit 47. Then, as shown in FIG. 3B, the synthesis processing unit 47 in FIG. 2 replaces, of the pixels of the background image b5, the pixels of which the pixel at the same position in the font data b3 is a character color pixel with a character color pixel. Of the 0% density pixels of the background image b5, the pixels in the font data whose pixels at the same position are the background color pixels are replaced with the values of the pixels of the image represented by the source video signal b4 at the same positions as the pixels. Replacement generates a superimposed image b6 and outputs it to the RGB decoder 2.
[0026]
However, the synthesis processing unit 47 outputs, as an intermediate image, an image obtained by replacing the pixel of the background image b5 in which the pixel at the same position in the font data b3 is a character color pixel with a character color pixel, In the RGB decoder 2, the superimposed image b5 may be generated by replacing the 0% density pixel of the intermediate image with the pixel value of the video represented by the source video signal at the same position as the pixel.
[0027]
The embodiments of the present invention have been described above.
As described above, according to the present embodiment, the background color of the character string is used in the same system as the color of the region corresponding to the character background region represented by the source video signal without using the source video signal by reducing its luminance. By using the color, the background of the character string can be visually generated so as to be recognized as translucent.
[0028]
Further, according to the present embodiment, the background of the character string is visually recognized as if it is translucent using the pseudo halftone pattern without using the luminance of the source video signal by reducing it. Can be generated as follows.
[0029]
Further, according to the present embodiment, a unique visual effect different from the conventional one can be realized by generating the background of the character string using the pseudo halftone pattern.
In the above embodiment, the 100% density pixel of the pseudo halftone pattern is replaced with the color of the color data read from the color pallet 43. However, this is always replaced with a predetermined specific color, for example, gray with low luminance. May be performed. Alternatively, 100% density pixels of the pseudo halftone pattern may be replaced with gray pixels, and the replacement with the color of the color data read from the color palette 43 may be omitted.
[0030]
Also, instead of replacing the 100% density pixels of the pseudo halftone pattern with the colors of the color data read from the color palette 43, the 100% density pixels are replaced in advance with the respective color data stored in the color palette 43 in the above embodiment. In addition, a pseudo halftone pattern for each color is prepared, and a pseudo halftone used according to the determination of the background color determination unit 42 instead of replacing 100% density pixels of the pseudo halftone pattern with the color data stored in the color palette 43. The pattern colors may be switched for use.
[0031]
Further, the above embodiments can be similarly applied to a case where the source video is not a composite signal but a video signal in another format such as an RGB signal or a Y / C signal.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an on-screen display device capable of performing spur imposition display with high quality with a visual effect as if the background of the character is translucent.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an on-screen display device according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an OSD processing unit according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating an operation of an OSD processing unit according to the embodiment of the present invention.
[Explanation of symbols]
1: selector, 2: RGB decoder, 3: display, 4: OSD processing unit, 5: control unit, 41: synchronization signal extraction unit, 42: background color determination unit, 43: color palette, 44: pseudo halftone pattern memory , 45: character background image generation unit, 46: character memory, 47: synthesis processing unit, 48: OSD control unit.

Claims (8)

An on-screen display device that displays one or more characters in a form of an on-screen display in a character display area set on a video,
Detecting means for detecting a dominant hue of an area overlapping the character display area of the video,
Character background drawing means for selecting a hue detected by the detection means or a color of a hue similar to the hue as a background color, and drawing the background of the character in the character display area with the selected background color. A featured on-screen display device. An on-screen display device that displays one or more characters in a form of an on-screen display in a character display area set on a video,
A pixel pattern memory storing a pixel matrix pattern in which pixels of a predetermined background color and pixels of a predetermined value representing a non-background color are arranged in combination;
In the image obtained by arranging the pixel matrix pattern in the character display area, the color of the pixel having the predetermined value, which is a pixel other than the pixel representing the character, of the pixel of the video at a position overlapping the pixel An on-screen display device, comprising: character background drawing means for drawing a color background image as a background of the character in the character display area. An on-screen display device that displays one or more characters in a form of an on-screen display in a character display area set on a video,
A pixel pattern memory storing a pixel matrix pattern in which significant value pixels and insignificant value pixels are arranged in combination,
In the image obtained by arranging the pseudo pixel matrix pattern in the character display area, pixels other than the pixels representing the character and having a significant value as a predetermined background color, and pixels other than the pixels representing the character Character background drawing means for drawing a background image in which the color of a pixel of an insignificant value is the color of a pixel of the video at a position overlapping with the pixel as a background of the character in the character display area, On-screen display device. The on-screen display device according to claim 3, wherein
The pixel matrix pattern is a pseudo halftone pattern for expressing an image of intermediate density by a combination of 100% density pixels and 0% density pixels, and the 100% density pixels are replaced with the significant value pixels. , Wherein the 0% density pixels correspond to the insignificant value pixels. The on-screen display device according to claim 4, wherein
The pixel pattern memory stores a plurality of pseudo halftone patterns each corresponding to a different intermediate density image,
The character background drawing means selectively selects one of the plurality of pseudo halftone patterns stored in the pseudo halftone pattern memory as a pseudo halftone pattern to be arranged in the character display area. An on-screen display device used for: The on-screen display device according to claim 3, 4 or 5, wherein
Having a detection means for detecting the dominant hue of the area overlapping the character display area of the video,
An on-screen display device, wherein the character background drawing means selects a hue detected by the detection means or a color having a hue close to the hue as the predetermined background color. An on-screen display device according to claim 1, 2, 3, 4, 5, or 6,
The on-screen display device, wherein the character background drawing means selects a color having a brightness equal to or less than an intermediate value of a brightness range of the video as the background color. In an on-screen display device for displaying one or more characters in a form of an on-screen display in a character display area set on a video, an on-screen display method for giving a visual effect to a background of the character in the character display area. hand,
Generating an image of a background area of the character display area as a background of the character by a combination of a pixel having a predetermined background color and a pixel having the same color as a pixel of the video at the same position as the own pixel; When,
Displaying an image representing a character with the generated background area image as a background in the character display area.

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