JP3565193B2 - Video magnifier - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a video signal of a letter box type, a Vista size, a cinema size or the like having a screen lacking at the top and bottom can be expanded to a video display device having an aspect ratio of 16: 9, and the position of a subtitle of a movie or the like can be changed. This is related to the image enlargement device.
[0002]
[Prior art]
In recent years, the enlargement of the screen of the television has been firmly established, and it is considered that the screen will shift to a wider aspect.
[0003]
In addition, video software (especially movie software) has been enhanced, and a video signal of a letter box type, a Vista size, a cinema size, or the like, which lacks a screen above and below, has a wide aspect ratio (for example, an aspect ratio of 16: 9). An image enlargement device for enlarging an image on the screen of (1) is commercialized. At this time, since subtitles are missing in a movie or the like, subtitles are extracted in advance, and subtitle processing is performed such that the extracted subtitles are moved to an arbitrary position in the video and synthesized after the video is enlarged.
[0004]
Hereinafter, an example of a video enlarging apparatus having a conventionally used subtitle processing function will be described with reference to the drawings.
[0005]
FIG. 10 is a block diagram of a conventional video enlarging apparatus having a subtitle processing function. In FIG. 10, 1 is a video signal input terminal, 2 is an AD conversion circuit, 3 is a luminance signal / color signal separation circuit, 4 is a motion detection circuit, 39 is a scanning line number conversion circuit, 40 is a subtitle processing circuit, 10 is a subtitle processing circuit. A switch for synthesizing the caption and the enlarged video in accordance with the output of the caption processing control signal from the processing circuit 40, a DA converter 11 and an output terminal 14 for a luminance signal subjected to the caption processing and the video enlargement. The operation of the video enlarging device configured as described above will be described below. The subtitle processing circuit 40 first extracts a subtitle portion from the luminance signal separated by the luminance signal / color signal separation circuit 3, and then moves the extracted subtitle to a position where the user decides to combine the subtitle. Here, the switch 10 combines the moved subtitle and the luminance signal enlarged by the scanning line number conversion circuit 39 in accordance with the subtitle control signal of the subtitle processing circuit 40. The synthesized signal is DA-converted by the DA converter 11 and output from the luminance signal output terminal 14.
[0006]
FIG. 9 shows an example of scanning line number conversion when the number of scanning lines is tripled. Hereinafter, FIG. 9 will be described.
[0007]
In FIG. 9, ○ indicates a scanning line, the levels of the scanning lines before conversion of the number of scanning lines are A1 and A2, and the levels of the scanning lines after conversion of the number of scanning lines are C1 to C4. Here, C1 to C4 are calculated by weighting the distance between the scanning lines A1 and A2 (see FIG. 9). As described above, in the present invention, image enlargement is performed by increasing the number of scanning lines.
[0008]
FIG. 7 shows a block diagram of the above-described subtitle processing circuit 40. In FIG. 7, reference numeral 24 denotes an input terminal of a luminance signal separated from a video signal by the luminance / color signal separation circuit 3, 25 denotes a field memory used to extract and move subtitles, and 30 controls a field memory. A field memory control signal generating circuit, 31 is a subtitle extraction start line input terminal, 32 is a subtitle extraction end line input terminal, 33 is a subtitle moving destination line input terminal, 34 is a subtitle threshold input terminal, and 27 is a post-movement. , A comparator for judging the magnitude relationship between the caption and the caption threshold, 35 is a caption processing ON / OFF signal input terminal, and 28 switches the output of the comparator 27 and a constant value 1 in accordance with the caption processing ON / OFF signal. A switch 29 is a subtitle processing control signal output terminal, and 26 is an output terminal of a subtitle processing signal of a luminance signal.
[0009]
Hereinafter, the operation of the caption processing circuit 40 of FIG. 7 will be described. In the field memory control signal generating circuit 30, first, a write enable pulse (hereinafter, referred to as a WE signal), which is a write control pulse for the field memory 25, based on the subtitle extraction start line and the subtitle extraction end line input by the user. ) And a write reset pulse (hereinafter, referred to as a WR signal). Next, a read enable pulse (hereinafter, referred to as an RE signal) and a read reset pulse (hereinafter, referred to as an RR signal), which are read pulses of the field memory 25, based on the caption destination line input by the user. To be described). With the above memory control pulse, only the subtitle portion of the luminance signal is written in the field memory 25, only the subtitle is read out at the moving line destination designated by the user, and output from the output terminal 26 of the subtitle processing signal. You.
[0010]
The comparator 27 discriminates the character portion and the background portion of the caption, and outputs 0 in the character portion and 1 in the background portion. The switch 28 controls subtitle processing ON / OFF. When the subtitle processing is ON, the output of the comparator 27 is selected. When the subtitle processing is OFF, 1 is selected and output from the subtitle processing control signal output terminal. .
[0011]
[Problems to be solved by the invention]
However, by simply reading the subtitles recorded in the field memory from the field memory when moving the subtitles with the above configuration, for example, the subtitles are recorded and read between different fields as shown in FIG. When a subtitle is moved between different fields), the vertical relationship of the scanning lines is reversed, and there is a problem that the subtitle characters are deteriorated.
[0012]
The present invention has been made in view of the above problems, and provides an image enlargement device that improves the image quality of an enlarged image when converting the number of scanning lines, improves the image quality of characters when moving subtitles, and improves operability when moving subtitles. Things.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, a video enlarging device according to the present invention includes a video signal input terminal, an A / D converter connected to the video signal input terminal for converting an analog signal into a digital signal, and an A / D converter connected to an output terminal of the A / D converter. A motion detection circuit for detecting the motion of the video signal; a luminance signal / color signal separation circuit connected to an output terminal of the AD converter and an output of the motion detection circuit for separating a luminance signal from the video signal; It is connected to the pulse input terminal, current field and the odd / even field determination circuit for controlling the subtitle processing circuit to determine the phase of the horizontal pulse and vertical pulse the odd field or even field, the odd / even field determination circuit and extraction of the caption signal on the basis of the connected odd / even field determination result to the output terminal and the first output terminal of the luminance signal / color signal separation circuit (luminance signal) And a scanning line number conversion circuit connected to the first output terminal (for the luminance signal) of the luminance signal / color signal separation circuit for converting the number of scanning lines, and a subtitle processing circuit of the above subtitle processing circuit. A synthesizing circuit connected to the first output terminal (for subtitle signal), the second output terminal (for subtitle control signal), and the output terminal of the scanning line number conversion circuit, and for synthesizing the subtitle signal and the video signal with the subtitle control signal; A D / A converter connected to the output terminal of the synthesizing circuit and converting a digital signal into an analog signal; and a video signal output terminal connected to the output terminal of the D / A converter.
[0014]
According to the above configuration, when a subtitle is moved, the scanning line generated at the time of the subtitle movement pointed out in the problem is determined by determining whether the field of the subtitle is extracted or the field of the destination of the subtitle is an odd / even field. Can be prevented from deteriorating the image quality of characters due to the upside-down inversion.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an image enlargement device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an image enlargement apparatus according to an embodiment of the first invention of the present invention.
[0016]
In FIG. 1, 1 is a video signal input terminal, 2 is an AD converter, 3 is a luminance signal / color signal separation circuit, 4 is a motion detection circuit, 6 is a scanning line interpolation circuit, 7 is a scanning line number conversion circuit, and 40 is A subtitle processing circuit, 10 is a switch, 11 is a DA converter, 12 is a horizontal pulse input terminal, 13 is a vertical pulse input terminal, and 14 is a luminance signal output terminal.
[0017]
The operation of the image enlargement device configured as described above will be described below. A video signal input from a video signal input terminal 1 is first converted into digital data by an AD converter 2, and then a luminance signal / chrominance signal separation circuit 3 separates a luminance signal from a video signal, and is separated. The luminance signal is subjected to scanning line interpolation by the scanning line interpolation circuit 6 to output an interpolation signal and a current signal. The luminance signal / color signal separation processing and the scanning line interpolation processing are performed using the motion detection signal detected by the motion detection circuit 4. (Reference: "Development of a high-definition image processing method for clear vision": Samukawa, Torai, Ishizu, Imai, Fujita 1990 TV Conference Annual Meeting) The current signal and the interpolation signal output from the scanning line interpolation circuit 6 are the number of scanning lines. The number of scanning lines is converted by the conversion circuit 7, and the image is enlarged by this processing. Here, the reason why the scan line number conversion is performed after the scan line interpolation will be described with reference to FIG.
[0018]
In FIG. 5, (a) shows an odd field and an even field of the NTSC system, where ○ indicates a white scanning line, and ● indicates a black scanning line. Here, when the number of scanning lines is converted for each field by the method described with reference to FIG. 9, the result is as shown in FIG. 9B. On the screen of the television, the scanning lines are as shown in FIG. Grayish gray (marked by ◎ in FIG. 5 is a gray scanning line), and image quality is degraded by image enlargement.
[0019]
On the other hand, in the present invention, the scanning line interpolation is first performed to generate the current line and the interpolation line. FIG. 5C shows an example of a scanning line interpolation result when a still image is targeted for simplicity. FIG. 5D shows a signal obtained by converting the number of scanning lines of the signal shown in FIG. 5C. On the screen of the television, a white-white-white-gray-black-gray-gray-white-white-white image is obtained in a region (b). It can be seen that the image quality has been improved.
[0020]
FIG. 2 is a block diagram showing one embodiment of the video enlarging apparatus according to the second aspect of the present invention.
[0021]
In FIG. 2, 1 is a video signal input terminal, 2 is an AD converter, 3 is a luminance signal / color signal separation circuit, 4 is a motion detection circuit, 5 is a switch, 39 is a scanning line number conversion circuit, and 8 is a subtitle processing circuit. Reference numeral 10 denotes a switch, 11 denotes a DA converter, and 14 denotes a luminance signal output terminal. The operation of the image enlargement device configured as described above will be described below.
[0022]
The basic operation is the same as that of the conventional video enlarging apparatus described above. However, in the present invention, the subtitle is masked with a certain luminance value after extracting the subtitle by providing the switch 5, so that the subtitle is synthesized after the subtitle is synthesized. I try not to get two. The switch 5 is controlled based on a caption mask control signal from the caption processing circuit 8.
[0023]
FIG. 3 is a block diagram showing one embodiment of the video enlarging apparatus according to the third aspect of the present invention.
[0024]
3, reference numeral 1 denotes a video signal input terminal, 2 denotes an AD converter, 3 denotes a luminance signal / color signal separation circuit, 4 denotes a motion detection circuit, 39 denotes a scanning line number conversion circuit, 8 denotes a subtitle processing circuit, and 9 denotes an odd caption. / Even field discriminating circuit, 10 is a switch, 11 is a DA converter, 14 is a luminance signal output terminal, 12 is a horizontal pulse input terminal, and 13 is a vertical pulse input terminal.
[0025]
The operation of the image enlargement device configured as described above will be described below. The basic operation is the same as that of the conventional image enlarging apparatus described above, but the present invention addresses the following problem by providing an odd / even field discriminating circuit 9.
[0026]
In the subtitle processing, a subtitle signal is extracted from the video signal, and only the extracted subtitle characters are moved to an arbitrary position of the enlarged video and synthesized (see FIG. 6). At this time, there is no problem in moving the subtitle into the same field (see FIG. 6B, n is an odd number), but moving to a different field (see FIG. Since the relationship is reversed, the characters of the subtitles are degraded jaggedly.
[0027]
Therefore, in the present invention, when the odd / even field discriminating circuit 9 discriminates the odd / even of the current field and moves the caption between different fields , the caption is moved by one even field. The number is increased by the number of scanning lines (the read pulse of the field memory in the even field is delayed by 1H (one horizontal period)). This operation eliminates the reversal of the vertical relationship of the scanning lines as shown in FIG.
[0028]
The odd / even field discriminating circuit 9 discriminates odd / even fields based on the phases of the horizontal pulse and the vertical pulse.
[0029]
FIG. 8 shows a block diagram of the caption processing circuit 8. In the subtitle processing circuit 8, the subtitle processing circuit 40 described above has a subtitle mask signal output terminal 44, an odd / even discrimination signal input terminal 45, and a field memory added with the function of performing the field memory control described in the third embodiment of the present invention. The configuration is such that a control signal generation circuit 50 is added.
[0030]
FIG. 4 is a block diagram showing an embodiment of an image enlarging apparatus for enlarging an image of a color signal according to the fourth aspect of the present invention.
[0031]
In FIG. 4, 1 is a video signal input terminal, 2 is an AD converter, 3 is a luminance signal / color signal separation circuit, 4 is a motion detection circuit, 15 is a switch, 17 is a scanning line number conversion circuit, 18 is a switch, and 19 Is a DA converter, 20 is a color signal output terminal, 21 is a color signal level input terminal, 22 is a subtitle control signal input terminal, 23 is a subtitle mask signal input terminal, and 51 is a clamp level detection circuit.
[0032]
The operation of the color signal video enlarging device configured as described above will be described below.
[0033]
The luminance signal / color signal separation circuit 3 separates a color signal from a video signal. As in the case of the luminance signal, the subtitle portion of the video signal is masked by the switch 15 with the value detected by the clamp level detection circuit 51, and the image is enlarged by the scanning line number conversion circuit 17. The switch 18 combines the enlarged color signal and the caption based on the caption control signal obtained from the luminance signal. Here, as the level of the subtitle color signal, a value input from the color signal level input terminal 21 is used. The synthesized color signal is converted into an analog signal by the DA converter 19.
[0034]
Also, the subtitle signal is not always present on the video signal, and if there is no subtitle signal, subtitle processing cannot be performed. Therefore, in the fifth invention of the present invention, the caption signal is stopped, so that the caption processing can be performed even when the caption does not appear on the video signal, and the operability is improved.
[0035]
【The invention's effect】
As described above, according to the first aspect of the present invention, the video enlarging apparatus includes a video signal input terminal, an AD converter connected to the video signal input terminal, which converts an analog signal into a digital signal, and an output terminal of the AD converter. A motion detection circuit connected to the A / D converter for detecting a motion of the video signal; a luminance signal / color signal separation circuit connected to an output terminal of the AD converter and an output of the motion detection circuit for separating a luminance signal from the video signal; is connected to the terminal and the vertical pulse input terminal, and an odd / even field determination circuit current field to control the discriminated subtitle processing circuit in the phase of the horizontal pulse and vertical pulse the odd field or even field, odd / even field extraction of the output terminal and the luminance signal / color signal first is connected to the output terminal (luminance signal) caption signal based on the odd / even field determination result of the separation circuit of the determination circuit Subtitle processing circuit that performs the scanning and moving, a scanning line number conversion circuit that is connected to the first output terminal (for the luminance signal) of the luminance signal / color signal separation circuit, and converts the number of scanning lines, and the above subtitle processing circuit A synthesizing circuit connected to the first output terminal (for subtitle signals), the second output terminal (for subtitle control signals), and the output terminal for the above-described conversion of the number of scanning lines, and for synthesizing subtitle signals and video signals with subtitle control signals; A D / A converter connected to the output terminal of the synthesizing circuit and converting a digital signal into an analog signal; and a video signal output terminal connected to the output terminal of the D / A converter.
[0036]
With the above configuration, it is possible to improve the image quality of the characters of the caption of the enlarged video as compared with the conventional method.
[Brief description of the drawings]
FIG. 1 is a block diagram of an apparatus for enlarging an image of a luminance signal according to a first embodiment of the present invention; FIG. 2 is a block diagram of an apparatus for enlarging an image of a luminance signal according to a second embodiment of the present invention; FIG. 4 is a block diagram of an apparatus for enlarging an image of a luminance signal according to a third embodiment of the present invention. FIG. 4 is a block diagram of an apparatus for enlarging an image of a color signal according to a fourth embodiment of the present invention. FIG. 6 is an explanatory diagram of an embodiment of a caption moving method according to the present invention. FIG. 7 is a block diagram showing a specific example of a caption processing circuit. FIG. 8 is a block diagram showing a specific example of a caption processing circuit. 9: Principle of the scanning line number conversion method [FIG. 10] Block diagram of a conventional image enlarging device [Description of symbols]
Reference Signs List 1 video signal input terminal 2 AD conversion circuit 3 luminance signal / color signal separation circuit 4 motion detection circuit 5, 10, 15, 18, 28 switch 6 scanning line interpolation circuit 7, 17, 39 number of scanning line conversion circuit 8, 40 subtitle Processing circuits 11 and 19 DA conversion circuit 9 Odd / even field discriminating circuit 12 Horizontal pulse input terminal 13 Vertical pulse input terminal 14 Luminance signal output terminal 20 Color signal output terminal 21 Color signal level input terminal 22 Subtitle control signal input terminal 23 Subtitle mask control signal input terminal 24 Luminance signal input terminal 25 Field memory 26 Subtitle processing signal output terminal 27 Comparator 29 Subtitle processing control signal output terminal 30, 50 Field memory control signal generation circuit 31 Subtitle extraction start line input terminal 32 Caption extraction end line input terminal 33 Caption destination line input terminal 34 Caption threshold input terminal 35 characters Curtain processing ON / OFF signal input terminal 44 Subtitle mask signal output terminal 45 Odd / even field discrimination signal input terminal 46 Constant value input terminal 51 Clamp level detection circuit

Claims (1)

A video signal input terminal, an A / D converter connected to the video signal input terminal for converting an analog signal into a digital signal, a motion detection circuit connected to an output terminal of the A / D converter and detecting a motion of the video signal; A luminance signal / color signal separation circuit connected to an output terminal of the AD converter and an output of the motion detection circuit for separating a luminance signal from the video signal; a horizontal pulse input terminal and a vertical pulse input terminal; An odd / even field discriminating circuit for discriminating whether the field is an odd field or an even field based on the phase of the horizontal pulse and the vertical pulse, and controlling a caption processing circuit; an output terminal of the odd / even field discriminating circuit; and the luminance signal / color signal first perform the movement and the extraction of the caption signal on the basis of the connected odd / even field determination result to the output terminal (luminance signal) of the separation circuit, a different fee A subtitle processing circuit that increases the subtitle movement by one scanning line when performing subtitle movement between nodes, and the number of scanning lines connected to the first output terminal (for the luminance signal) of the luminance signal / color signal separation circuit. Is connected to a first output terminal (for a subtitle signal), a second output terminal (for a subtitle control signal) of the subtitle processing circuit, and an output terminal of the scanning line number conversion circuit. A combining circuit for combining a caption signal and a video signal with a caption control signal, a DA converter connected to an output terminal of the combining circuit to convert a digital signal into an analog signal, and a video connected to an output terminal of the DA converter A video enlargement device comprising a signal output terminal.

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