JPH10191208A - Video signal processor and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device executing double speed line processing and zooming processing on the video signal of a PALplus system, executing sequential scanning conversion, reducing the number of scanning lines and displaying data on a liquid crystal display, for example, with less memories. SOLUTION: In an inputted video signal, a horizontal frequency is doubled at the time of outputting it from a memory 10 and the number of lines is reduced. The signal is supplied to a still image filter 12, it is delayed by one field in a memory 13 and it is supplied to the filter 12 and a dynamic image filter 17. In the filter 12, an interpolation processing is executed by synthesizing the lines with a prescribed coefficient between the supplied signals and the number of the scanning lines is reduced. In the filter 17, the interpolation processing is executed only with the output of the memory 13 by considering that motion exists in the signal. A movement calculation part 16 calculates movement amount from the difference between the frames of the signals and previous movement amount by one field. A dynamic/still image logic part 18 switches the outputs of the filters 12 and 17 based on the movement amount of they are mixed and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a video signal processing apparatus and method for converting an image transmitted in an interlace format into a progressive scan and displaying the converted image on, for example, a flat panel display.

[0002]

2. Description of the Related Art In recent years, with the remarkable development of telecommunication technology, wireless and wired new media have appeared one after another. For example, in television broadcasting, high image quality and a wide screen are achieved in a frequency band of one channel, for example, 6 MHz, while maintaining compatibility with current broadcasting. This means that the aspect ratio (the ratio of the length and width of the screen) is (16: 9) with respect to the current broadcasting system.
It is a big feature that the screen is wide and wide. For example, in Europe, PAL (Pha
As a next-generation television broadcasting system, broadcasting by the PALplus system is about to reach a practical stage through experimental broadcasting, as opposed to the se-alternation-by-line system.

FIG. 17 shows an example of an image received by the PALplus system. FIG. 17A shows a PALpl in a television receiver having a screen with a current aspect ratio of (4: 3).
It is a state in which a video broadcast in the us format is projected. In a current television receiver not equipped with a PALplus decoder and having an aspect ratio of 4: 3, FIG.
As shown in the figure, the screen has a non-image portion above and below the main image portion. This is because signals are transmitted in the letterbox format in the PALplus system. This video is PA
When displayed on a television receiver provided with a decoder compatible with Lplus, the image becomes as shown in FIG. 17B, and a wide screen can be enjoyed.

The signal format of the PALplus signal source is a 625/50/2: 1, 4: 2: 2 digital component signal. The sampling frequency is 1
3.5 MHz. The main image portion converts 625 pixels (576 effective scanning lines) of sequentially scanned pixels into signals of 432 effective scanning lines by 4-3 scanning line conversion, performs predetermined vertical low-pass filtering, and performs interlaced scanning. Is converted to At this time, the vertical resolution is deteriorated due to the 4-3 conversion. Therefore, a vertical resolution enhancement signal is transmitted in order to reinforce the deteriorated vertical resolution. As will be described later, a signal obtained by demodulating the vertical resolution enhancement signal on the receiving side is called a helper signal.

In the PALplus system, there are two types of signal processing modes, depending on the type of signal source, a "camera mode" for handling television camera images and the like and a "film mode" for handling movie film images and the like. The camera mode has 50 fields per second, and the film mode has 25 fields per second. Therefore, in the camera mode, signal processing is performed in units of fields, and in the film mode, since an image does not move between two fields forming one frame, signal processing is performed in units of frames.

[0006] This PALplus system is based on the following 3
All conditions must be met.

The first condition is to execute vertical conversion to letterbox format. An original image having an aspect ratio of 16: 9 with 576 effective scanning lines is converted into a 16: 9 letterbox format with 432 scanning lines. At this time, QMF (Q
uadrature Mirror Filter) conversion is performed to obtain a vertical resolution enhancement signal of the luminance signal Y. The vertical resolution enhancement signal of the luminance signal Y is multiplexed and transmitted to the upper and lower non-image portions. This vertical conversion is performed in units of fields in the above-described camera mode, and is performed in units of frames in the film mode.

[0008] The second condition is transmission of a helper signal. The chrominance subcarrier is modulated with the vertical resolution enhancement signal obtained by the QMF conversion. At the time of this modulation, a level limitation and a band limitation are performed on the vertical resolution augmentation signal. Also, the level is restricted at the time of transmission. FIG.
Shows an example of the vertical resolution reinforcement signal (helper signal) and the signal of the letter box.

The third condition is a motion adaptive color plus process. This is MACP (Motion Adaptive Color Plu
s), which is an encoding process performed to suppress crosstalk interference between the luminance signal Y and the chrominance signal C and to improve the horizontal resolution of the luminance signal. In camera mode, the area where the color signal is moving on the screen (moving area)
And the stationary area are determined. In the PALplus signal, the luminance signal Y has a bandwidth of 3.5 MHz,
In the motion domain, this bandwidth is band-limited to 3 MHz,
In the stationary region, the entire band of 3.5 MHz is transmitted. On the receiving side, processing is switched based on the determination of the moving area and the stationary area. In the film mode in which the processing is performed in units of one frame, since the image does not move between the fields constituting one frame, the processing for the still area in the camera mode is fixedly performed.

FIG. 19 schematically shows scanning line interpolation by the PALplus method. As shown in FIG. 19A, a broadcast signal according to the PALplus method (hereinafter referred to as PALplus)
The plus image signal) includes a main image portion X and non-image portions W arranged above and below the main image portion X. The helper signal H is superimposed on the non-image portion W. In a television receiver compatible with the PALplus system, an interleave process using a memory is performed to demodulate the PALplus signal having such a configuration.

That is, as shown in FIG. 19B, for a screen having an aspect ratio of 4: 3, after the scanning lines of the main image portion X are output as the first to third lines and three lines, One scanning line on which the helper signal H is superimposed is inserted. Thereafter, similarly, an interleaving process is performed in which three scanning lines of the main image portion X and scanning lines on which the helper signal H is superimposed are alternately inserted. Therefore, at this stage, as shown in this figure, the original image is a vertically elongated image.

The image subjected to the interleave processing is filtered by the vertical filter. By this filtering process, as shown in FIG. 19C, a wide image having an aspect ratio of 16: 9 is reproduced, and the helper signal H is extracted. That is,
In a television receiver compatible with a wide screen having an aspect ratio of 16: 9, a wide image having an aspect ratio of 16: 9 can be reproduced by the above-described processing.
On the other hand, a conventional screen television receiver having an aspect ratio of 4: 3 is reproduced as it is with a conventional image having an aspect ratio of 4: 3 as shown in FIG. 19A.

FIG. 20 shows the details of the frame structure according to the PALplus system. The first field is 216
It is composed of a main image portion X composed of lines, and a non-image portion H formed above and below the main image portion X and composed of 36 lines. The 23rd line in the invalid screen includes a PALplus signal, the above-described mode signal, and a WSS (Wide Screen Signa) which is an identification control signal for detecting the presence / absence of three-dimensional precombing.
ling) is interpolated. In the main picture portion X of the PALplus signal, a composite video signal having an aspect ratio of 16: 9 and having 216 scanning lines per field is transmitted. A helper signal is transmitted in a non-image portion H composed of 36 scanning lines arranged above and below the main image portion X. The second field has the same configuration as the first field.

In a television receiver compatible with the PALplus system, interpolation processing is performed at the time of reproducing a PALplus signal, so that a higher quality image can be obtained.
That is, from a signal of a total of 287 lines of the luminance signal (216 lines / field) of the main image portion X and the helper signal H (upper and lower 72 lines / field), a 16: 9 image composed of 287 scanning lines per field is obtained. obtain. Regarding the color difference signal, the color difference signal (216 lines /
Field) alone, a 16: 9 image consisting of 287 scanning lines per field is obtained.

Such an interpolation process is performed on a frame basis in principle. At this time, the first in one frame
In the case of a moving image in the above-described camera mode in which a field (hereinafter, referred to as “A field”) and a second field (hereinafter, referred to as “B field”) have greatly different images, processing is performed in frame units. And the image quality is greatly impaired. Therefore, in the PALplus system, a 1-bit mode signal indicating the correlation between these two fields is multiplexed on the WSS, and the camera mode and the above-described film mode are distinguished from each other, whereby reliable interpolation processing is performed. That is, in the film mode, since the images of the A field and the B field are the same, intra-frame interpolation is performed using the images of the A field and the B field in the same frame. In the camera mode, intra-field interpolation is performed using a video signal of one field.

FIG. 21A shows a signal spectrum of a luminance signal Y and a carrier chrominance signal C according to the PALplus system. For the Y signal, the color subcarrier frequency 4.43 MHz
Are modulated in frequency multiplex. FIG. 21B shows the signal spectrum of the helper signal. This signal is also modulated at a color subcarrier frequency of 4.43 MHz and has a band from about 0.5 to 5 MHz.

On the other hand, in recent years, flat display technology has been developed, and television receivers using the flat display technology are being developed. A flat panel display used in such a television receiver includes, for example, a liquid crystal panel (LC
D) and a plasma display. In such a flat panel display, the number of scanning lines that can be displayed is fixed due to the structure of the panel. For example,
In the computer screen display, the number of effective scanning lines is 4
Eighty VGA (Video Graphic Array) standards have become de facto standards. Also, the number of effective scanning lines of a television signal according to the NTSC system is 480. Therefore, a flat panel display having 480 effective scanning lines is becoming standard.

Therefore, in order to display an image according to the above-described PALplus method on such a flat panel display, the number of effective scanning lines of the image signal supplied to the display is, for example, from 576 to 48.
It is necessary to convert to zero.

As a conversion method, for example, for a demodulated PALplus signal having 576 effective scanning lines, a format conversion is further performed so that the number of effective scanning lines becomes 480, or a scanning by the PALplus signal is performed. There is a method of displaying the main image portion of the letter box format without performing the line interpolation process (in this case, the number of effective scanning lines is 432).

FIG. 22 shows an example of the configuration of a video apparatus which demodulates this PALplus signal and projects the PALplus signal on a display element based on the VGA standard. Input terminal 300
From PALplus composite video signal C
VBS is supplied. The signal CVBS is supplied to the color decoder 301 and the timing generator 302.

The signal C supplied to the color decoder 301
For example, a band including a color carrier is extracted from the VBS by a band-pass filter, color demodulated, and used as a color difference signal UV. This color difference signal UV is a line-sequential C
Including _R and C _B component. It is difficult to completely separate the band of the luminance signal Y from the band including the chrominance carrier by the bandpass filter. Therefore, a component of the luminance signal Y is mixed as a cross color component into the color difference signal UV subjected to color demodulation. The color difference signal UV and the signal CVBS containing the cross color component are supplied from the color decoder 301 to the three-dimensional Y / C separation unit 303.

The timing generator 302 generates various timing signals based on, for example, a horizontal synchronization signal included in the supplied signal CVBS. Although not shown, this timing signal is supplied to each unit in this configuration.

On the other hand, signal CVBS supplied from input terminal 300 is also supplied to a mode decoder and a helper signal processing unit (not shown). In the mode decoder, the WSS multiplexed on the 23rd line of the supplied signal CVBS is extracted. The extracted WSS is
The information is decoded, and in this configuration, the information based on the WSS is sent to the necessary parts. For example, the identification information for identifying the camera mode and the film mode included in the WSS includes a helper signal processing unit, a timing generator 301, a three-dimensional Y / C separation unit 303, a line double speed processing unit 304, and a format conversion unit. 305
Supplied to

In the helper signal processing section, the vertical resolution augmentation signal, which is modulated and transmitted by the color carrier signal in the upper and lower non-image portions of the supplied signal CVBS, is demodulated and the amplitude is adjusted. Signal H is set. The helper signal H is supplied to a line double speed processing unit 304 and a format conversion unit 305 for scanning line interpolation.

In the three-dimensional Y / C separating section 303, the supplied signal CVBS is subjected to a filtering process by a three-dimensional filter using a field memory corresponding to the three-dimensional precombing characteristic on the transmitting side, and a luminance signal is output. Y is taken out. A similar filtering process is performed on the supplied color difference signal UV, so that the mixed cross color component is removed. The luminance signal Y and the color difference signal UV are
It is supplied to the line double speed processing unit 304.

In the line double speed processing unit 304, interlaced signals are converted into progressively scanned image signals mainly by motion adaptive signal processing. The converted signal is supplied to the format conversion unit 305. In the format conversion unit 305, the supplied luminance signal Y _H and color difference signal UV _F, format conversion is performed the number of scanning lines is converted by a predetermined method. 576 per field
The number of scanning lines of the luminance signal Y _H and the color difference signal UV _F having line scanning lines and having an aspect ratio of 16: 9 is converted into, for example, 504 image signals per field. By this conversion, the number of scanning lines is 480
It is suitable for projecting on a VGA standard flat panel display which is a line. The processing in the line double speed processing unit 304 and the format conversion unit 305 will be described later.

The signals obtained by converting the number of scanning lines into a luminance signal 2Y _H and a color difference signal 2UV _F are supplied to a matrix unit 306. In the matrix section 306,
Luminance signal 2Y _H and the color difference signals 2 UV _F is the display element 30
7, the image is converted into a format suitable for displaying an image, for example, three primary color signals 2R, 2G, and 2B. These signals 2
Each of R, 2G, and 2B is supplied to and displayed on a display element 307 including, for example, a liquid crystal display (LCD) and its driving unit.

FIG. 23 shows the line double speed processing unit 304 described above.
An example of the configuration of the format conversion unit 305 will be described in detail. It should be noted that the processing for the luminance signal Y _F and the color difference signal UV _F is substantially the same, and thus the luminance signal Y _F and the color difference signal UV _F will be described as image signals.

The image signal supplied from the input terminal 350 is input to the insertion line determination logic unit 351 from the terminal F4. At the same time, the image signal is supplied to the field memory 352, delayed by one field, and read out. The read signal is further delayed by one field in subsequent field memories 353 and 354. The signals read from the field memories 352, 353, and 354 are supplied to the terminals F3, F2, and F1 of the insertion line determination logic unit 351 respectively.

The insertion line determination logic unit 351 determines whether the supplied image signal is a still image or a moving image. This determination is made based on, for example, the signals supplied to the terminals F4 and F2 and the terminals F3 and F1.
This can be done by calculating an inter-frame difference between the signals supplied to the first and second signals. If it is determined that the supplied image signal is a still image, the image signals supplied to the terminals F4 and F3 are superimposed by a method described later, and the interlace signal is sequentially converted to a scanning signal. If it is determined that the image is a moving image, an image of a portion that has not been transmitted is generated and output by interlace scanning only from the image signal supplied to the terminal F3.

In an actual image in which a still image portion and a moving image portion are mixed, the still image process and the moving image process are switched (or mixed) for each pixel in accordance with the amount of motion detected by the above method. And output it.

Based on the judgment by the insertion line determination logic 351 described above, the image signal supplied from a predetermined terminal is converted into an image signal of an even line and an odd line, and is output. The image signals of these even and odd lines are supplied to line memories 355a and 355b, respectively.
Then, the image signals supplied to these line memories 355a and 355b are read at twice the horizontal frequency. By switching these outputs for each line by the switch circuit 356, a sequentially scanned image signal can be obtained.

The image signals sequentially scanned are supplied to an image scaling memory 357. Memory 3
At 57, 360 in the central part of the supplied image signal
Dummy data is output at a ratio of 3: 1 for one scanning line. As a result, the image signal is converted into 480 scanning lines. With this processing, temporary zooming is performed on the image signal. Since the amount of image data per field is doubled by the above-described line double speed processing, the memory 357 needs twice the capacity of the field memories 352, 353, and 354, for example.

The zoomed image data is supplied to a vertical filter 358. This vertical filter 358
Thus, the scanning line data of the dummy portion inserted at the time of the above-described zooming is created, and the scanning line data by the dummy and the original image signal are mixed at a ratio of 3: 1.
As a result, the continuity of the lost image is adjusted, and scanning line interpolation is performed.

FIG. 24 shows an example of a configuration for performing the above-described scanning line interpolation processing. FIG. 25 schematically shows the interpolation processing by this configuration. It should be noted that this scanning line interpolation is performed by substantially the same processing for the luminance signal Y and the color difference signal UV. Therefore, the processing for the luminance signal Y will be described here, and the description for the color difference signal UV will be omitted. For this configuration, an identification signal based on WSS is supplied from the mode decoder described above. This identification signal includes identification information indicating whether the signal CVBS is in the film mode or the camera mode. In this configuration, the operation is switched between these two modes based on the identification signal.

In the film mode, the luminance signal Y + H from the input section 360 is delayed by one field by a field memory 361 composed of, for example, a FIFO memory.
The data is written to the A field RAM 362 and also written to the B field RAM 363. Note that these A
Field RAM 362 and B field RAM 36
For example, a dual-port RAM, which can perform reading in parallel with writing, is used for 3.

The A-field RAM 362 and the B-field RAM 363 perform the above-described interleave processing when reading data. FIG. 25A
Indicates the definition of the input line number used in the following description. As described above, in the following description, the helper signals of the upper non-picture part are H1, H2,..., H36 from the top, and the helper signals of the lower non-picture part are LH1, LH from the top.
2,..., LH36. The main image portion is simply referred to as a first line to a 216th line.

Of the digital luminance signals Y + H written in the RAMs 362 and 363, the luminance signal Y allocated to the main image portion is the 216th digital signal sequentially from the first line of the main image portion.
Data is read out to the line. In parallel with this, as shown by the dotted line in FIG. 25B, the helper signal H multiplexed in the upper non-picture portion is read out in order from H1 to H36, and then the helper signal H multiplexed in the lower non-picture portion. The signal H is sequentially read from LH1 to LH36. FIG. 25C shows an enlarged view of the above-mentioned circle in FIG. 25B. As shown, the first, second, and third lines of the luminance signal Y are read, and H1 of the helper signal H is read.
Subsequently, the fourth, fifth, and sixth lines of the signal Y are read, and H2 of the helper signal H is read. In this way, the helper signal H of one line is incorporated into the luminance signal Y of three lines, and the interleave processing is performed. This process is common to the A field RAM 362 and the B field RAM 363.

FIG. 26 shows the memory control in the film mode in the A field RAM 362 and the B field RAM 363.
A method for writing and reading the luminance signal Y + H will be described. FIG. 26A shows an example in which the input unit 360 inputs the B field RA
5 shows a luminance signal Y + H supplied to M363. As shown in the figure, the signal of the A field (first field) of the first frame first arrives at the B field RAM 363, and then the signal of the B field (second field) of the same frame is received. To come. Similarly, next, the A field and the B field of the second frame, the third frame,...
Arriving at 3. At this time, the data of each field includes the upper helper signals H1 to H36, the first to 216th lines of the luminance signal Y of the main picture area, and the lower helper signals LH1 to LH1.
They arrive in the order of LH36.

FIG. 26A shows a luminance signal Y + H output from the field memory 361 and written into the A field RAM 362. The timing of the luminance signal Y + H is delayed by one field by the field memory 361. Therefore, the above-mentioned B field RAM3
At the timing when the B field of the first frame arrives at 63, the A field of the first frame arrives at the A field RAM 362. Hereinafter, the B field of the first frame, the A field of the second frame,.
As described above, the luminance signal Y + H arrives at the A field RAM 362 with the timing shifted by one field from the arrival at the B field RAM 363. At this time, the data of each field arrives in the order of the upper helper signal H, the luminance signal Y of the main picture area, and the lower helper signal H.

The helper signal H and the luminance signal Y are the signals of the A field and the B field of the same frame.
Field RAM 362 and B field RAM 36
Only when the data arrives at the same time, the A field RAM 362 and the B field RAM 363 are written. An example of the write timing is shown by hatching in the figure. Thus, 1
A-field RA from which a field-delayed signal arrives
The signal of the A field is written in M362, and the signal of the B field is written in the B field RAM 363.

The signals of the A field and the B field are supplied to the A field RAM 362 and the B field RA
When the data is read from M363, the above-described interleave processing is performed. At this time, the same contents are read out continuously for two fields. This is shown in FIG. 26B. That is, from the A field RAM 362, the luminance signal Y of the main image portion is read out in the order of the first to 216th lines, and the helper signal H of the upper and lower non-image portions is read out for one line of the luminance signal Y of the three lines. .

In the case of the film mode, the contents of the scan lines of both the input A field and the input B field are required to obtain the A field output and the B field output. Therefore, the same contents are read from the A field RAM 362 and the B field RAM 363 over two fields. The signals read from the A field RAM 362 and the B field RAM 363 are supplied to the vertical filtering processing unit 364, respectively.

[0044] In the vertical filtering processing unit 364, by performing vertical filtering process on the supplied two fields of the signal to obtain a necessary luminance signal Y _H. The resulting luminance signal Y _H is derived to an output terminal 365.

On the other hand, in the camera mode, the luminance signal Y + H from the input section 360 is supplied and written only to the B field RAM 363 according to the C branch in FIG. Then, the supplied luminance signal Y + H
Interleave processing is performed in the field RAM 363 and the data is read. The read signal is supplied to the vertical filtering processing unit 364, is set as a necessary luminance signal Y _H, and is derived to the output terminal 365.

As described above, in this configuration, the field memory 361, the A field RAM 3
A total of three field memories are required, i.e., 62 and B field RAM 363.

In the above description, the configuration is adopted in which the image is scaled after performing the sequential scan conversion.
This is because there is a problem that the image quality is degraded when the image is scaled only by the image information in the field. For this, refer to the well-known document "A Consideration on Scanning Line Conversion" (Television Society Journal Vol. 44, No. 6, pp. 774-7
The details are described in (78), and the description is omitted here.

FIG. 27 schematically shows an example of the configuration of the above-described color plus processing and three-dimensional Y / C separation section 303. The composite video signal CVBS is supplied to the input terminal 400. This signal CVBS is supplied from the input terminal 400 to both the field memory 401 and the B-field band division filter 402. The field memory 401
The supplied signal CVBS is output after being delayed by 312 lines. As is well known, in the PAL / PALplus system, one frame includes 6 frames including a vertical blanking period.
It consists of 25 lines. Therefore, the signal CVBS
Are delayed by exactly one field in the field memory 401. The output of the field memory 401 is supplied to the A field band division filter 403.

The B field band division filter 402
For example, a signal CVBS that has a low-pass filter and a high-pass filter and is band-divided by the band division filter 402 has a low-frequency region (low-frequency luminance signal) not including a color carrier signal and a high-frequency region (high-frequency region) including a color carrier signal. Luminance signal). In the case of a PAL / PALplus composite video signal, the boundary between the low-frequency band and the high-frequency band is, for example, 3 MHz.

On the other hand, the signal CVBS delayed by 312 lines in the field memory 401 is supplied to the A field band division filter 403 having the same characteristics as the B field band division filter 402 described above, and outputs the low band luminance signal and the high band luminance signal. Area luminance signal.

The A-field low-band luminance signal divided by the A-field band dividing filter 403 is added to the adder 405.
Is supplied to one of the input terminals. Similarly, the B-field low-band luminance signal band-divided by the B-field band division filter 402 is supplied to one input terminal of an adder 406.

On the other hand, these band division filters 402 and 4
The B-field high-band luminance signal and the A-field high-band luminance signal, each of which has been band-divided in 03, are supplied to one and the other input terminals of the adder 404, respectively, and added. The nth line delayed by 312 lines in the A field and the (n + 3) th line in the B field
The 12 lines are adjacent lines when one frame is composed of the A and B fields. In the PALplus film mode, since the A and B fields are the same image, the correlation of the luminance signal between these lines is high. On the other hand, in the PAL / PALplus system,
The phases of the color carrier signals in the lines separated by 312 lines are different by 180 °. Therefore, this adder 404
, The color carrier signals included on the high frequency side of the signal CVBS when supplied to the input terminal 400 cancel each other. Thereby, Y / C separation is performed.

The average intra-frame luminance signal Y _ADD output from the adder 404 is supplied to a coefficient unit 407. The coefficient unit 407 multiplies the supplied signal by a predetermined coefficient k to limit the level and amplitude of the signal. If the composite video signal CVBS supplied to the input terminal 400 is based on a rapidly moving image, an interference component leaks from the average high-frequency luminance component in the frame obtained by the addition. In order to reduce the visibility of the image disturbance due to the disturbing component, the coefficient unit 407 supplies a signal Y _ADD supplied with a coefficient k according to the amount of motion sent from a motion detection unit 428 described later.
And the amplitude of the signal Y _ADD is attenuated.

The signal Y _ADD adjusted by the coefficient unit 407 to have an amplitude corresponding to the amount of movement of the luminance signal is supplied to the aliasing removal filter 408. In the color plus processing and three-dimensional Y / C separation unit 303, the same high-frequency luminance signal is used for two fields in the supplied signal CVBS, and the continuity of oblique lines is not smooth. In the aliasing removal filter 408, this is alleviated.

The signal Y _ADD output from the aliasing removal filter 408 is supplied to both the other input terminal of the adder 405 and the other input terminal of the adder 406. Adder 4
At 05, the signal Y _ADD and the above-described B-field low-frequency luminance signal are added to generate a B-field luminance signal. Similarly, in adder 405, this signal Y
_ADD and the above-mentioned A-field low-frequency luminance signal are added to form an A-field luminance signal.

The A field luminance signal is supplied to the switch circuit 4
10 is directly supplied to one input terminal. On the other hand, the B field luminance signal output from the adder 405 is delayed by one field by the field memory 409 and supplied to the other input terminal of the switch circuit 410. The switch circuit 410 can switch an input terminal for each field by a control signal generated by the timing generator 302. Therefore, a luminance signal that is sequentially scanned is derived to the output terminal 411.

Next, the color plus processing and the processing for the color difference signal UV in the three-dimensional Y / C separation section 303 will be described. The color difference signal UV is supplied to the input terminal 420. The supplied color difference signal UV is supplied to one input terminal of the field memory 421, one adder 422, and the input terminal 423a of the color difference output switch 423.
This color difference output switch 423 has three inputs and two outputs,
Based on a color difference switching signal sent according to the amount of motion from a motion detection unit 428 described later, two out of three inputs
Select output.

As in the case of the composite video signal CVBS described above, the
The signal delayed by the line is used as an A-field color difference signal, and is directly transmitted to the color difference output switch 423 and the adder 42.
2 is used as a B field color difference signal.
The A field color difference signal output from the field memory 421 is supplied to the input terminal 423c of the color difference output switch 423 and is also supplied to the other input terminal of the adder 422.

In the adder 422, the A-field color difference signal and the B-field color difference signal are added to obtain an intra-frame average color difference signal _CIFA . In this manner, by adding the color difference signals of the A field and the B field in the film mode, it is possible to remove the luminance component mixed in the chrominance signal as in the case of the above-described average intra-frame high-frequency luminance signal Y _ADD. It becomes possible. Adder 42
The signal C _IFA output from the color difference output switch 42 is
3 input terminal 423b.

In the color difference output switch 423, in the case of a normal image in which the movement is not so intense, the input terminal 423 a based on the color difference switching signal supplied from the motion detection unit 408.
And the input terminal 423c are selected. Accordingly, a B field color difference signal is output from the output terminal 423d of the color difference output switch 423, and an A field color difference signal is output from the output terminal 423e.

On the other hand, when the supplied color difference signal UV is a video with a sharp movement, an interference component is generated as in the case of the signal _YADD . Therefore, in this case, the color difference output switch 423 causes the input terminal 423b
Is selected for both of the two outputs. Therefore, the output terminals 423d and 423e of the color difference output switch 423
Output a signal _CIFA .

The output terminal 423d of the color difference output switch 423
Is delayed by one field by the field memory 424 and supplied to one input terminal of the switch circuit 425. The output of the output terminal 423e is connected to the switch circuit 4
25 is directly supplied to the other input terminal. This switch circuit 425 is similar to the switch circuit 410 described above.
The input terminal can be switched for each field by the control signal generated by the timing generator 302. Therefore, a color difference signal scanned sequentially is derived to the output terminal 426.

Next, the quantification of the amount of motion in the motion detector 428 will be described. Adder 42
Intraframe average color difference signal C _IFA output from 2 is supplied to one input terminal of the motion detection unit 428, it is supplied to a frame delay 427. Then, the signal _CIFA delayed by one frame by the one-frame delay 427 is supplied to the other input terminal of the motion detection unit 428.

[0064] In the motion detection unit 428, it is supplied to one input terminal to the supplied signal C _IFA, and the other input terminal, by using the one-frame delayed signal C _IFA, PALplus system specifications The attenuation coefficient k for the above-mentioned signal Y _ADD is calculated based on the algorithm defined in
Further, a color difference switching signal for the color difference output switch 423 is generated.

FIG. 28 shows the color plus processing and 3
6 shows a time chart of color plus signal processing in the dimensional Y / C separation unit 303. Here, processing of a luminance signal will be described as an example. FIG. 28A shows the processing in adders 405 and 406, and FIG.
04 shows the process. Further, in this example, the luminance signals are A field (1A), B field (1B) in the first frame, A field (2A) in the second frame, and B field.
Field (2B), A field (3
A), B field (3B),...

As described above, the A field high band luminance signal is delayed by one field by the field memory 401 (FIG. 28E). Therefore, FIG.
As shown in D, the B field high band luminance signal shown in FIG. 28C and the B field in the B field high band luminance signal of the B field high band luminance signal shown in FIG. A in the frame
28D, the signal Y is output every other field as indicated by hatching in FIG. 28D.
_ADD will be obtained.

As shown in FIGS. 28A and 28B, adders 405 and 406 have valid signal Y _ADD
Is obtained, a B-field low-frequency luminance signal and an A-field luminance signal in the same frame as the signal Y _ADD arrive. Then, in adders 405 and 406, signal Y _ADD is added to the B-field low-frequency luminance signal and the A-field low-frequency luminance signal, respectively, to obtain a B-field luminance signal and an A-field luminance signal of the same frame. Can be That is, as indicated by hatching in FIGS. 28A and 28B, a B field luminance signal and an A field luminance signal of the same frame are obtained every other field.

As described above, in the three-dimensional Y / C separation processing utilizing the correlation between fields, a two-field memory is required. That is, the field memory 40
1 and 421, field memories 409 and 424
And can be used in combination,
It is counted when a total of two field memories are used.

[0069]

As described above, the conventional apparatus has a problem that a very large number of field memories are required in the entire system, and the cost of the apparatus is increased. For example, in the above example, three are used for the scanning line interpolation processing, and two are used for the three-dimensional Y / C separation processing.
A total of five field memories were required.

Even in the prior art, if the system performs the scanning line interpolation processing in the field, the number of field memories can be reduced, but in this case, there is a problem that the image quality after the processing is poor. .

Further, in the above-mentioned prior art, the process of increasing the number of scanning lines, for example, from 360 to 480, could be performed, but the process of reducing the number of scanning lines could not be performed. there were. For example, in the related art, a process of displaying a video signal having 576 scanning lines on a display having 480 scanning lines as in the PAL system cannot be performed.

Accordingly, an object of the present invention is to provide a system which performs line double speed processing and zooming processing on a video signal by using a small number of field memories, for example, only one field memory, and performing various scans including reduction. It is an object of the present invention to provide a video signal processing apparatus and method capable of converting an image into the number of lines.

[0073]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a display device, such as a liquid crystal display, which has a fixed number of pixels and performs display by sequential scanning. A first memory means for converting the number of scanning lines of a video signal input in an interlaced manner, and a second memory means for delaying an output from the first memory means by one field Third memory means for further delaying the output from the second memory means by one field, fourth memory means for delaying the motion amount calculated based on the video signal by one field, and first memory Output from the means and the third
An inter-frame difference comprising the output from the memory means of
Performing a vertical filtering process on the output from the first memory unit and the output from the third memory unit by referring to the output from the fourth memory unit and calculating the motion amount; A first filter for generating a still image, a second filter for performing a vertical filtering process on an output from the third memory to generate a moving image, and a still image and a moving image. And a means for adaptively switching or mixing based on the calculation result of the motion calculation means.

Further, according to the present invention, in order to solve the above-mentioned problems, a video signal processing for displaying a display element such as a liquid crystal display having a fixed number of pixels and performing display by sequential scanning is performed. A first memory means for converting the number of scanning lines of an input video signal in an interlaced manner; a second memory means for delaying an output from the first memory means by one field; A third memory means for delaying the output from the memory means for one more field, a fourth memory means for delaying the motion amount calculated for the video signal by one field, and a third memory means. A motion calculation step of calculating a motion amount by referring to an inter-frame difference composed of the output and the output from the third memory means and the output from the fourth memory means; Performing a vertical filtering process on the output from the memory unit and the output from the third memory unit to generate a still image, and performing a first filtering process on the output from the third memory unit. To perform vertical filtering and create video images
And a step of adaptively switching or mixing a still image and a moving image based on the calculation result of the motion calculation means.

[0075]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. First, in order to facilitate understanding of the present invention, FIG. 1 shows an example of a configuration of a video apparatus to which the present invention can be applied. The video device shown in this figure
The PALplus signal is demodulated and projected on a display element based on the VGA standard. Note that this is an example of a case where the processing by the helper signal H is not performed even in the PALplus system. Therefore, this example is applicable to the PAL system.

In FIG. 1, a block 8 surrounded by a broken line is
A block 9 according to the first and third embodiments of the present invention, and a block 9 surrounded by an alternate long and short dash line is a portion according to the second embodiment of the present invention. From input terminal 1,
For example, a composite video signal CVBS according to the PALplus method is supplied. The signal CVBS is supplied to the color decoder 2 and the timing generator 3.

The signal CVB supplied to the color decoder 2
In S, for example, a band including the color carrier is extracted by a band-pass filter, color demodulation is performed, and the color difference signal UV
It is said. The color difference signal UV includes line-sequentialized C _R and C _B components. It is difficult to completely separate the band of the luminance signal Y from the band including the chrominance carrier by the bandpass filter. Therefore, a component of the luminance signal Y is mixed as a cross color component into the color difference signal UV subjected to color demodulation. The color difference signal UV and the signal CVBS including the cross color component are supplied from the color decoder 2 to the three-dimensional Y / C separation unit 4, respectively.

The timing generator 3 generates various timing signals based on, for example, a horizontal synchronizing signal included in the supplied signal CVBS. Although not shown, this timing signal is supplied to each unit in this configuration.

When this device supports the vertical resolution enhancement by the helper signal H, the signal CVBS supplied from the input terminal 1 is also supplied to a mode decoder and a helper signal processing unit (not shown). In the mode decoder, the WSS multiplexed on the 23rd line of the supplied signal CVBS is extracted. WS extracted
The S is decoded and sent to each unit where information based on this WSS is required in this configuration. For example, WS
The identification information included in S for identifying the camera mode and the film mode is supplied to the helper signal processing unit, the timing generator 3, the three-dimensional Y / C separation unit 4, and the scanning line conversion processing unit 5. In the helper signal processing unit, demodulation and amplitude adjustment of the vertical resolution reinforcement signal, which is modulated by the color carrier signal and transmitted in the upper and lower non-image portions of the supplied signal CVBS, are performed, and the above-mentioned helper signal H is obtained. . This helper signal H is supplied to the scanning line conversion processing unit 5 for scanning line interpolation.

In the three-dimensional Y / C separation section 4, the supplied signal CVBS is subjected to a filtering process by a three-dimensional filter using a field memory corresponding to the three-dimensional precombing characteristic on the transmitting side, and a luminance signal is output. Y is taken out. A similar filtering process is performed on the supplied color difference signal UV, so that the mixed cross color component is removed. The luminance signal Y and the color difference signal UV are supplied to the scanning line conversion processing unit 5.

The scanning line conversion processing unit 5 performs line double speed processing and scanning line number conversion processing. Details of these processes in the scanning line conversion processing unit 5 will be described later. Predetermined processing is to be preferred to cause out movies in a flat panel display made is VGA standard by the processing unit 5, a signal with the luminance signal 2Y _H and the color difference signals 2 UV _F is supplied to the matrix section 6, respectively. This matrix section 6
In the above, the luminance signal 2Y _H and the color difference signal 2UV _F are in a format suitable for displaying an image on the display element 7, for example,
The signals are converted into primary color signals 2R, 2G, and 2B. These signals 2
Each of R, RG, and 2B is supplied to and displayed on a display element 7 including, for example, a liquid crystal display (LCD) and its driving unit.

In this example, the display element 7 is an LCD, but the present invention is not limited to this example. That is, as the display element 7, another display element that performs display by sequential scanning, such as a plasma display or an EL (Electric Luminescence) display element, can be used.

Next, a first embodiment of the present invention will be described. FIG. 2 shows an example of the configuration of the scanning line number conversion processing unit 5 according to the first embodiment. Note that the processing in the processing unit 5 includes the luminance signal Y and the color difference signal UV.
Since the same processing can be performed by using the luminance signal Y
Of the color difference signal UV will be omitted.

The luminance signal Y is supplied to the field memory 10. When the luminance signal Y is read from the field memory 10, it is subjected to a scan line number conversion process and a line double speed process, and is passed through a noise reducer 11 to one input terminal of a still image filter 12 and a field memory 1.
3 and the first input of the motion calculator 16. The luminance signal Y supplied to the field memory 13 is
The signal is supplied to the field memory 14 after being delayed by one field, and is also supplied to the other input terminal of the still image filter 12 and the moving image filter 17.

The luminance signal Y supplied to the field memory 14 is delayed by one field and
6 and a second input terminal of the noise reducer 11. The noise reducer 11 performs a noise reducer process on the luminance signal Y delayed by a total of one frame via the field memories 13 and 14 and the luminance signal Y supplied from the field memory 10 and outputs the result. Noise of the luminance signal Y is reduced.

The coefficient k corresponding to the amount of motion is output from the motion calculator 16. The coefficient k is supplied to the moving image / still image logic unit 18 while being supplied to the field memory 15. The coefficient k supplied to the field memory 15 is delayed by one field and supplied to the third input terminal of the motion calculation unit 16 and supplied to the other input terminal of the moving image / still image logic unit 18. The motion calculator 16 calculates a motion amount of the luminance signal Y for each pixel based on the signal supplied to the third input terminal and the signals supplied to the first and second input terminals. The above-described coefficient k is output.

Still picture filter 12 and moving picture filter 1
In 7, the supplied luminance signal Y is subjected to vertical filtering, and the processed luminance signal Y is supplied to the moving image / still image logic unit 18. The output of the moving image / still image logic unit 18 is output as the output of the scanning line number conversion processing unit 5.

Although the configuration has been described here as being composed of a combination of individual processing units and memories, in practice, this configuration may be, for example, a single integrated device such as a DSP (digital signal processor). It can be realized by:

In such a configuration, first, the scanning line number conversion processing and the line double speed processing in the field memory 10 will be described. The luminance signal Y supplied to the field memory 10 is converted into a Y / C signal by the three-dimensional Y / C separation unit 4.
This is a digital signal having a data width of, for example, 8 bits after being subjected to the separation processing. This luminance signal Y is PAL
In the system, the vertical frequency is 50 Hz and the vertical resolution is 62.
There are five lines, which are 2: 1 interlace signals.

When the luminance signal Y written in the field memory 10 is read, the horizontal frequency is doubled and the number of lines is converted. FIG. 3 shows this field memory 1
0 schematically illustrates the signal processing at 0. In this example, the number of effective scanning lines per frame of a signal is changed from 576 lines to 504 lines. In this figure,
The number assigned to each line indicates the original line number when the luminance signal Y is supplied to the field memory 10.
This notation is similar in similar figures below.

FIG. 3A schematically shows a state in which the luminance signal Y is written in the field memory 10. At this time, since the luminance signal Y is a 2: 1 interlace signal, 288 signals are written per field. One field after the luminance signal Y is written in the memory 10 in this way, as shown in FIG. 3B, reading is performed at a double frequency. In addition, line double-speed reading is performed by reading out the signal of one line twice, and here, the signal of one line is read out once every three times. As a result, the number of scanning lines is changed from 288 to 4
It is converted to 80.

Conventionally, when 576 signals are converted into 480 signals per frame, it is necessary to perform thinning in the preprocessing stage because the number of lines is reduced. As a result, the scanning lines are lost, and the image quality is degraded. However, according to the method of the present invention, since the number of scanning lines is converted at the same time as the line double-speed conversion, by performing the line double-speed reading by the method described above, the total number of scanning lines is substantially reduced. Can be done.

The luminance signal Y read from the field memory 10 is supplied to one input terminal of the noise reducer 11. Further, as described above, the luminance signal Y delayed by one frame is supplied to the other input terminal of the noise reducer 11 via the field memories 13 and 14. The noise reducer 11 performs a noise reduction process by multiplying a luminance signal Y having a difference of one frame and supplied to one and the other input terminals, for example, by an appropriate coefficient and taking an averaging result. The noise reducer processing is well-known as described in, for example, a publicly-known document “Nikkan Kogyo Shimbun, Takahiko Fukinuki, Digital Signal Processing of Images”, and will be described in detail here. Is omitted.

Here, the noise reducer 11
Described that processing is performed using a signal delayed by one field, but this is not limited to this example. For example,
The output of the field memory 13 may be supplied to the other input terminal of the noise reducer 11, and the processing may be performed by a signal delayed by one field.

On the other hand, when the luminance signal Y supplied to the field memory 10 is a signal of the PALplus system, the scanning using the helper signal H superimposed on the non-image portion is performed in the subsequent vertical filter processing. Line interpolation processing is performed. In the scanning line interpolation process using the helper signal H, the helper signal H is inserted at a ratio of 3: 1 as shown in the above-mentioned conventional example, and the helper signal H and the luminance signal Y are subjected to the vertical filter processing. Is performed. Therefore, when reading the signal from the field memory 10, a dummy signal is inserted at a predetermined position.

FIG. 4 schematically shows signal processing in the field memory when the dummy signal is inserted. The luminance signal Y supplied to the memory 10 is composed of 216 scanning lines per field excluding the non-picture part of the letter box shown in FIG. 4A. This is written to the memory 10 as shown in FIG. 4B. When the signal Y is read from the memory 10, as shown in FIG. 4C, each line is read twice, and two dummy signals are inserted every three lines. As the dummy signal, for example, a pedestal level signal is used. By doing so, it is possible to convert the signal of the PALplus system into the number of scanning lines suitable for the scanning line interpolation processing.

The field memory 13 or 14
Is required to correspond to the number of lines converted in the field memory 10. For example, in the example shown in FIG. 3, a capacity sufficient to write data for 504 scanning lines is originally required. On the other hand, as described above, data of almost all lines are read twice from the field memory 10. Therefore, in the present invention, the data of the line read out redundantly is
Write to the field memory 13 every time. When data is read from the field memory 13, the read data is shaped in the same manner as in the case of the field memory 10 described above.

FIG. 5 schematically shows access control in the field memory 13. Field memory 10
5A, the data of the same line is written to the same address in the field memory 13 as shown in FIG. 5B.
This is performed, for example, by associating the line numbers with the address numbers of the memory 13. Then, when this data is read from the memory 13, the redundantly supplied line is read twice so as to restore the state when supplied.

By performing such access control in the field memory 13, the memory capacity of the field memory 13 is sufficient with a smaller capacity, for example, about half the capacity for writing 504 scanning lines. . Further, by performing the same control in the field memory 14, the required memory capacity can be reduced.

The still image filter 12 stores the luminance signal Y output from the noise reducer 11 and the field memory 1.
3 is supplied with the luminance signal Y read. In the still image filter 12, an interpolation filtering process is performed between these supplied signals on the assumption that the image has no motion. FIG. 6 schematically shows the filtering process in the still image filter 12.

As shown in FIG. 6A, the luminance signal Y (referred to as signal YN) supplied from the noise reducer 11 corresponds to the luminance signal Y supplied from the field memory 13 (referred to as signal YF). It has a delay of the field. Each of these two signals is multiplied by a predetermined coefficient as shown in FIG. 6B and synthesized. In this example, the coefficients are set to circulate every five lines of lines A, B, C, D, and E. That is, the signals YN and YF are alternately applied to the term in which the coefficient decreases and the term in which the coefficient increases, sequentially from the first read line.

FIG. 7 schematically shows the spatial arrangement of interpolation filters used in this interpolation processing. As described above, in the still image interpolation filter 12, by performing the above-described filter processing, the three lines in which the overlap of the signal YN shown in FIG. 7A is considered and the overlap of the signal YF are considered. As shown in FIG. 7B, three lines are assigned to five lines A to E by interpolation calculation. By such an interpolation process, the interval between scanning lines is substantially increased to 5/6 times, and the number of scanning lines is reduced.

In this example, the interpolation processing is performed using two lines. However, the present invention is not limited to this example, and the interpolation processing may be performed using three or more lines. Can also be.

On the other hand, the luminance signal Y output from the field memory 13 is supplied to the moving image filter 17. In the moving image filter 17, unlike the above-described still image filter 12, interpolation processing is performed on the assumption that an image has motion between the output of the noise reducer 11 and the output of the field memory 13. FIG. 8 schematically shows the filtering process in the moving image filter 17. The moving image filter 17 does not use the output from the noise reducer 11 and uses the luminance signal Y supplied from the field memory 13.
Interpolation calculation is performed based on the scanning line (referred to as signal YM).

That is, the scanning lines adjacent to the signal YM are synthesized by multiplying them by a predetermined coefficient as shown in FIG. 8B. In this example, the coefficients are set to circulate every five lines of output, and the first line is output as is. The second line is multiplied by a coefficient at a ratio of 4: 6 with the third line, and the third line is multiplied by a coefficient at a ratio of 8: 2 with the fourth line. The fourth line is multiplied by a coefficient at a ratio of 2: 8 with the fifth line, and the fifth line is multiplied by a coefficient at a ratio of 6: 4 with the sixth line. Then, the coefficient is returned to the beginning on the sixth line, and the sixth line is output as it is. Note that the line numbers and filter coefficients described here are examples, and are not limited to the values shown here.

FIG. 9 schematically shows the spatial arrangement of interpolation filters used in this interpolation processing. As described above, in the moving image filter 17, by performing the above-described filter processing, three lines in which the overlap of the signal YM shown in FIG. 9A is taken into account by interpolation calculation as shown in FIG. 9B. It is assigned to five lines A to E. By such an interpolation process, the interval between scanning lines is substantially made 6/10 times (= 3/5 times), and spatial matching with the above-described still image filter 12 is achieved.

In the motion calculation section 16, the signal supplied from the noise reducer 11 and the field memory 13
And a signal supplied after being delayed by one frame via the signal 14 and the inter-frame difference of the luminance signal Y, and output as a motion amount from the motion calculator 16 and supplied via the field memory 15. , The motion amount of the previous field is referred to, the motion amount of the luminance signal Y is calculated, and is output as a coefficient k. The moving image / still image logic unit 18 switches or mixes the supplied output of the still image filter 12 and the output of the moving image filter 17 based on the coefficient k. The method of switching or mixing moving images / still images performed here is widely known as motion adaptation processing, and thus description thereof is omitted here.

The luminance signal Y output from the moving image / still image logic section 18 is supplied to the matrix section 6 as the luminance signal 2Y because the line double speed processing has been performed as described above. As described above, the scanning line conversion processing unit 5
The same process is performed on the color difference signal UV supplied to the matrix unit 6 to generate a color difference signal 2UV, which is supplied to the matrix unit 6.

Next, a second embodiment of the present invention will be described. The second embodiment relates to the block 9 in FIG. 1 described above, and FIG. 10 shows an example of the configuration of the block 9. Note that, in FIG. 10, the same parts as those in FIG. 2 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the three-dimensional Y / C separation processing based on the above-described color plus processing is performed by a line interpolation logic, that is, a still picture filter 12, a moving picture filter 17, and a moving picture / still picture logic section. This is performed before the step 18.

In this configuration, the three-dimensional Y / C separation unit 20
Then, using the correlation between two adjacent fields, Y /
By performing C separation, a current field luminance signal CF, which is an output temporally identical to the output from the field memory 13, is obtained. Further, from the three-dimensional Y / C separation unit 20, a previous field luminance signal PF, which is an output temporally identical to the output from the noise reducer 11, is obtained.

FIG. 11 shows an example of the configuration of the three-dimensional Y / C separation section 20. This is, in principle, equivalent to the configuration of the color plus processing and three-dimensional Y / C separation unit 303 shown in FIG. The B field luminance signal output from the noise reducer 11 is input to an input terminal 21 and the A field output from the field memory 13 is
A field luminance signal is supplied to each of the input terminals 22. The A field luminance signal is supplied to the A field band division filter 24, and the B field luminance signal is supplied to the B field band division filter 23. These filters 23 and 24 include, for example, a low-pass filter and a high-pass filter. The luminance signal divided into bands by these filters 23 and 24 has a band boundary of 3 MHz in the PAL / PALplus system, for example.
It is divided into a low-frequency area (low-frequency luminance signal) not including a color carrier signal and a high-frequency area (high-frequency luminance signal) including a color carrier signal.

The A-field low-frequency luminance signal band-divided by the A-field band division filter 24 is supplied to one input terminal of an adder 27. Similarly, the B-field low-band luminance signal band-divided by the B-field band division filter 23 is supplied to one input terminal of the adder 26.

On the other hand, these band division filters 23 and 24
The B-field high-band luminance signal and the A-field high-band luminance signal, each of which is band-divided, are supplied to one and the other input terminals of the adder 25, respectively, and are added. The nth line delayed by 312 lines in the A field and the (n + 312) th line in the B field become adjacent lines when one frame is formed by the A and B fields. In the film mode, A,
Since the B field is the same image, the correlation of the luminance signal between these lines is high. On the other hand, PAL / PAL
In the plus method, the phases of the color carrier signals on the lines separated by 312 lines differ by 180 °. Therefore, by the addition in the adder 25, the chrominance carrier signals included in the high frequency side of the luminance signal are canceled each other at the time of supply to the input terminal 21 or 22, and the Y / C separation is performed.

The in-frame average high band luminance signal Y _ADD output from the adder 25 is supplied to a coefficient unit 28. The coefficient unit 28 determines a predetermined coefficient k for the supplied signal.
To limit the level and amplitude of the signal.
B supplied to the input terminals 21 and 22, respectively,
If the A-field luminance signal is based on a rapidly moving image, an interference component leaks out of the average intra-frame high-frequency luminance component obtained by this addition. In order to reduce the visibility of the image disturbance due to the interference component, in the coefficient unit 28, the coefficient k supplied from the motion calculation unit 16 is multiplied by the supplied signal Y _ADD and the signal Y _{ADD is} multiplied.
The amplitude of _ADD is attenuated.

The signal Y _ADD adjusted to have an amplitude corresponding to the amount of movement of the luminance signal by the coefficient unit 28 is _supplied to the aliasing removal filter 2.
9 to smooth the continuity of the oblique lines. The signal Y output from the aliasing removal filter 29
_ADD is supplied to the other input terminals of the adders 26 and 27, respectively.

In the adder 26, the signal Y _ADD and the above-described B-field low-frequency luminance signal are added to form a B-field luminance signal. This B field luminance signal is used as the previous field luminance signal PF and is led out to the output terminal 30. Similarly, in the adder 27, this signal Y _ADD and
The above-described A-field low-band luminance signal is added to obtain an A-field luminance signal. This A field luminance signal is
The current field luminance signal CF is output to the output terminal 31.

Next, the processing for the color difference signal UV in the three-dimensional Y / C separation section 20 will be described. The B field color difference signal output from the noise reducer 11 is supplied to an input terminal 41, and the A field color difference signal output from the field memory 13 is supplied to an input terminal 42. The B field color difference signal is supplied to one input terminal of an adder 43 and an input terminal 44 a of a color difference output switch 44. Similarly, the a-field color difference signal is supplied to the other input terminal of the adder 43 and the input terminal 44 of the color difference output switch 44.
c.

The color difference output switch 44 has three inputs and two outputs, and selects two outputs from these three inputs based on a color difference switching signal corresponding to the motion of the image. This color difference switching signal is calculated by using the coefficient k supplied from the motion calculation unit 16.
In the threshold circuit 45 at a predetermined threshold value.
This is a signal obtained by binarization.

In the adder 43, the A-field color difference signal and the B-field color difference signal are added to obtain an intra-frame average color difference signal _CIFA . In this manner, by adding the color difference signals of the A field and the B field in the film mode, it is possible to remove the luminance component mixed in the chrominance signal as in the case of the above-described average intra-frame high-frequency luminance signal Y _ADD. It becomes possible. The signal _CIFA output from the adder 43 is supplied to the input terminal 44b of the color difference output switch 44.

In the color difference output switch 44, the input terminals 44a and 44c are selected based on the above-mentioned color difference switching signal in the case of a normal image in which the movement is not so intense.
Accordingly, a B field color difference signal is output from the output terminal 44d of the color difference output switch 44, and an A field color difference signal is output from the output terminal 44e. These output signals are output to the output terminals 46 and 47 as a previous field color difference signal and a current field color difference signal so as to correspond to the above-described signals PF and CF, respectively.

On the other hand, when the supplied color difference signal is based on a video with a sharp movement, an interference component is generated as in the case of the signal _YADD . Therefore, in this case, based on the color difference switching signal, the color difference output switch 44
, The input terminal 44b is selected for both the output terminals 44d and 44e. Therefore, from the output terminals 44d and 44e of the color difference output switch 44, the signal C
_IFA is output.

As described above, the previous field luminance signal PF (and the previous field color difference signal) output from the three-dimensional Y / C separation section 20 is supplied to the still image filter 12.
On the other hand, the current field luminance signal (and the current field color difference signal) are supplied to the still image filter 12 and the moving image filter 17.
And supplied to. The following signal processing is the first of the above-described embodiments.
This is the same as the embodiment. That is, scanning line interpolation is performed in the still image filter 12 and the moving image filter 17 by a predetermined method. The signals subjected to the interpolation processing are supplied to the moving image / still image logic unit 18 and the motion calculation unit 16
The moving image / still image is adaptively switched or mixed based on the coefficient k supplied from, and is converted into a luminance signal 2Y and a color difference signal 2UV.

Here, as the three-dimensional Y / C separation processing, a method utilizing the inter-field correlation of the same frame based on the color plus processing is used, but this is not limited to this example. The present invention is also applicable to the case where the three-dimensional Y / C separation processing is performed by a method utilizing the correlation between fields.

Although the configuration has been described here as being composed of a combination of individual processing units and memories, in practice, this configuration is similar to that of the first embodiment described above. Signal processor)
For example, it can be realized by one integrated element.

Next, a third embodiment of the present invention will be described. The third embodiment relates to the block 8 in FIG. 1 described above, and FIG. 12 shows an example of the configuration of the block 8. 12, the same parts as those in FIG. 2 described above are denoted by the same reference numerals, and detailed description thereof will be omitted. In this configuration, since the same processing is performed on the luminance signal Y and the color difference signal UV,
Here, only the luminance signal Y will be described.

In the third embodiment, PALplu
It has a PALplusQMF50, which is a vertical interpolation filter for performing a linear interpolation process by QMF, which supports the s system. In this PALplusQMF50, PA
Scan line interpolation in the Lplus camera mode is performed simultaneously. Note that whether the signal is in the film mode or the camera mode is determined based on the WSS extracted by the timing generator 3.

That is, in the above-described conventional technique, FIG.
As described with reference to FIG. 25 and FIG. 25, in the PALplus system, an interleave process using a helper signal H is performed. In this configuration, when a signal is read from the field memory 10, the interleave processing is performed by reading the main screen signal and the helper signal H line by line at a ratio of 3: 1. PAL
In the plus QMF 50, a scanning line interpolation vertical filtering process by the PALplus method is performed as the intra-field process on the luminance signal Y + H into which the helper signal H is inserted at a ratio of 3: 1.

If the supplied video signal is a film mode signal, the PALplus QMF5
0 is in the through state, and the scanning line interpolation processing is not performed here.

The luminance signal Y + H interpolated by the PALplus QMF 50 is converted to a noise reducer 11.
It is supplied to the following configuration. That is, the luminance signal Y + H
Is the still image filter 1 via the noise reducer 11
2, the field memory 13 and the motion calculator 16.

The video signal output from the PALplus QMF 50 is an interlaced scanning signal having 576 effective scanning lines. Therefore, in order to display this signal on a liquid crystal display having 480 scanning lines, for example, a format conversion process for further reducing the number of scanning lines is required. PALplu
The processing in the camera mode in the s system is optimized to convert to 576 scanning lines by intra-field interpolation. Therefore, in order to perform conversion to another number of scanning lines, if conversion is performed to sequential scanning and then format conversion is performed, a favorable result in image quality can be obtained.

In the camera mode, since the scanning line interpolation processing has already been completed as described above, the still image filter 12, the moving image filter 17, and the moving image / still image logic unit 18 are set to the through state. Therefore, the luminance signal Y + H is supplied to the reduction filter 51. Note that a plurality of signals are supplied to the still image filter 12. Here, a signal from, for example, the field memory 13 selected by a predetermined method is supplied to the reduction filter 51.

FIG. 13 schematically shows the filtering process performed by the reducing filter 51. As shown in FIG. 13A, with respect to adjacent signal output equivalent to the luminance signal Y from the field memory 13 (referred to as signal YFM _2),
Each is multiplied by a predetermined coefficient as shown in FIG. 13B. In this example, the coefficients are lines A, B, C,
It is set so as to circulate every five lines of D and E. That is, the signal YFM ₂ corresponding to the line and the adjacent signal YFM ₂ are sequentially applied to the term in which the coefficient decreases and the term in which the coefficient increases sequentially from the first read line.
Is assigned to each.

In this example, as shown in FIG. 13B, one out of five dummy signals are output. That is, for example, the signal on the sixth line of the signal YFM ₂ is
The fifth line of the output is synthesized with the signal of the fifth line, and the sixth line of the output is only the dummy signal.

FIG. 14 schematically shows the spatial arrangement of interpolation filters used in this interpolation processing. As described above, in the reduction filter 51, the signal of six lines is generated by performing the above-described filter processing.
As shown in FIG.
Assigned to a line. By such an interpolation process, the interval between scanning lines is substantially increased to 5/6 times, and the number of scanning lines is reduced.

In the scaling memory 52, the writing is controlled so that the dummy line shown in FIG. 14A is not written. In the reading, the lines A, B, C, D, and E shown in FIG. It is controlled so that one field is continuously read.

Signal Y output from reduction filter 51
The number of dummy lines inserted into FM _{2 at} a rate of one out of every six lines is 96 lines per frame (576 lines / 6 =
96), so that in order to absorb the difference between the number of input lines and the number of output lines, 96
Line capacity is required.

In FIG. 15, the solid line shows the progress of the address when writing to the memory 52, and the broken line shows the progress of the address when reading from the memory 52. First, the first 96 lines of the frame are written to the memory 52.
At this time, the writing of the dummy line is skipped. For this reason, the ratio of the gradient of the address progress of writing and reading is 6: 5. The written line is read out after a period of 96 lines has elapsed. In parallel with the reading, writing of the next 96 lines is performed. By repeating this five times, the reading of one frame is completed.

Here, it is necessary that the read address from the memory 52 does not exceed the write address, but this condition is satisfied by these five readings. That is, as shown in the figure, the read and write addresses come into contact at the end of the fifth read. Therefore, the scaling memory 52 only needs to have a capacity of 96 lines.

FIG. 16 shows the PA in this third embodiment.
The process in the Lplus film mode is schematically shown. As described above, the still image filter 12 includes one signal such as a signal supplied from the field memory 10 via the noise reducer 11, a signal supplied from the field memory 13, and a signal supplied from the field memory 14. Three signals that are shifted by the field are supplied. Here, these signals are respectively converted into signals YF
M ₁ , signal YFM ₂ and signal YFM ₃ .

In the PALplus method, as described above, the A field and the B field of the same frame have the same temporal content of the image, and therefore no motion adaptation processing is performed. In the film mode, the still image filter 12 combines the signal YFM ₁ , the signal YFM ₂ , and the signal YFM ₃ with, for example, two signals in the same frame around the signal YFM _2, thereby performing a still image interpolation process. Perform

Although the configuration has been described here as comprising a combination of individual processing units and memories, in practice, this configuration is similar to the first and second embodiments described above. DSP (Digital Signal Processor)
And the like, for example, can be realized by one integrated device.

In the above description, the first, second, and third embodiments are independent from each other, but this is not limited to this example. That is, each of these configurations can be realized by, for example, one DSP.
They can be switched to each other.

In the above description, the present invention has been described as being adapted to the PAL and PALplus systems.
This is not limited to this example. For example, the present invention can be applied to a video signal according to the NTSC system.

[0145]

As described above, according to the present invention, when a video signal of, for example, the PAL or PALplus method is displayed on a display element such as a liquid crystal display, which is displayed by sequential scanning, the conventional method is used. There is an effect that the progressive scan conversion and the scaling processing, which have been processed in stages, can be performed at once by one system.

Further, according to the present invention, since the line information is not discarded in the progressive scan conversion processing accompanied by image reduction, there is an effect that high quality can be obtained in the converted image.

Further, according to the present invention, since the structure of the memory and the method of controlling the memory are devised, it is possible to perform a scaling process for reducing the number of scanning lines, and a scaling process adapted to the number of pixels of the display. There is an effect that becomes possible.

According to the first embodiment of the present invention, the memory conventionally required for 5 fields for the progressive scan conversion processing and the scaling processing can be reduced to 3 fields. According to the second embodiment of the present invention, conventionally, two fields for three-dimensional Y / C separation processing and five fields for progressive scan conversion processing and scaling processing, for a total of seven fields. The required memory can be reduced to three fields. Further, according to the third embodiment of the present invention, the conventional PA
The memory required for one field to perform the camera mode processing of the Lplus system and five fields for the progressive scan conversion processing and the scaling processing, that is, a total of six fields, is now reduced to three fields. As described above, by using the present invention, there is an effect that the field memory can be significantly reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a video device to which the present invention can be applied.

FIG. 2 is a block diagram illustrating an example of a configuration of a scanning line number conversion processing unit according to the first embodiment.

FIG. 3 is a diagram schematically showing signal processing in a field memory.

FIG. 4 is a diagram schematically showing signal processing in a field memory when a dummy signal is inserted.

FIG. 5 is a diagram schematically showing access control in a field memory.

FIG. 6 is a diagram schematically illustrating a filtering process in a still image filter.

FIG. 7 is a diagram schematically illustrating a spatial arrangement of an interpolation filter used for interpolation processing in a still image filter.

FIG. 8 is a diagram schematically showing a filtering process in a moving image filter.

FIG. 9 is a diagram schematically showing a spatial arrangement of interpolation filters used for interpolation processing in a moving image filter.

FIG. 10 is a diagram illustrating an example of a block configuration according to a second embodiment;

FIG. 11 is a block diagram illustrating an example of a configuration of a three-dimensional Y / C separation unit according to the second embodiment.

FIG. 12 is a block diagram illustrating an example of a configuration of a scanning line number conversion processing unit according to a third embodiment.

FIG. 13 is a diagram schematically showing filter processing by a reduction filter.

FIG. 14 is a diagram schematically showing a spatial arrangement of interpolation filters used for interpolation processing in a reduction filter.

FIG. 15 is a schematic diagram showing access control in a scaling memory.

FIG. 16 is a schematic diagram illustrating a process in a film mode of the PALplus system according to the third embodiment.

FIG. 17 is a schematic diagram illustrating an example of an image received by the PALplus method.

FIG. 18 is a schematic diagram illustrating an example of a vertical resolution reinforcement signal (helper signal) and a letter box signal.

FIG. 19 is a diagram schematically showing scanning line interpolation by the PALplus method.

FIG. 20 is a diagram illustrating details of a frame configuration according to the PALplus scheme.

FIG. 21 is a schematic diagram illustrating a signal according to the PALplus method.

FIG. 22 is a block diagram illustrating an example of a configuration of a video apparatus that demodulates a PALplus signal and projects the PALplus signal on a display element based on the VGA standard.

FIG. 23 is a block diagram illustrating in detail an example of the configuration of a line double speed processing unit and a format conversion unit.

FIG. 24 is a block diagram illustrating an example of a configuration for performing a scanning line interpolation process.

FIG. 25 is a schematic diagram schematically showing scanning line interpolation processing.

FIG. 26 shows an A field RAM and a B field RA
FIG. 9 is a schematic diagram showing memory control in a film mode in M.

FIG. 27 is a block diagram illustrating an example of a configuration of a color plus process and a three-dimensional Y / C separation unit.

FIG. 28 is a time chart of color plus processing and color plus signal processing in a three-dimensional Y / C separation unit.

[Explanation of symbols]

4 3D Y / C separation unit, 5 scanning line conversion processing unit, 7 display element, 10, 13, 14 ... field memory, 11 ... noise reducer, 12 ...・
Still image filter, 16: motion calculation unit, 17: video filter, 18: video / still image logic unit, 20
... 3D Y / C separation unit, 23 ... B field band division filter, 24 ... A field band division filter, 28 ... coefficient unit, 44 ... color difference output switch, 50 ... PALplusQMF, 51: Filter for reduction, 52: Scaling memory

Claims (8)

[Claims] 1. A video signal processing apparatus for displaying a video signal on a display element such as a liquid crystal display, which has a fixed number of pixels and performs display by sequential scanning, is input in an interlaced manner. A first memory means for converting the number of scanning lines of the obtained video signal, a second memory means for delaying the output from the first memory means by one field, and an output from the second memory means. Third memory means for further delaying by one field, fourth memory means for delaying the motion amount calculated based on the video signal by one field, output from the first memory means, and A motion calculating means for calculating the motion amount by referring to an inter-frame difference composed of an output from the memory means and an output from the fourth memory means; A first filtering means for performing a vertical filtering process on an output from the memory means and an output from the third memory means to create a still image, and an output from the third memory means. A second filtering unit that performs a vertical filtering process to create a moving image, and a unit that adaptively switches or mixes the still image and the moving image based on the calculation result of the motion calculating unit. A video signal processing device. 2. The three-dimensional Y signal according to claim 1, wherein an output from said first memory means and an output from said second memory means are used and a correlation between fields is used. And a three-dimensional Y / C separation unit for performing a / C separation process. 3. The video signal processing apparatus according to claim 2, further comprising a vertical resolution enhancement processing means for performing a vertical resolution enhancement process compatible with a PALplus system. 4. The video signal processing apparatus according to claim 1, wherein a field or a noise reduction process is performed on the basis of an output from said first memory means and an output from said second or third memory means. A video signal processing apparatus further comprising a frame cyclic noise reducer, wherein an output of the noise reducer is an output from the first memory means. 5. The method according to claim 1, 2 or 3.
3. The video signal processing device according to claim 1, wherein the first memory means, the second memory means, the third memory means, the fourth memory means, the motion calculation means, the first filter means, The second filter means, the switching or mixing means, the three-dimensional Y
The video signal processing apparatus, wherein the / C separation means and the vertical resolution enhancement processing means are constituted by a digital signal processor. 6. A video signal processing method for displaying a video signal on a display element, such as a liquid crystal display, having a fixed number of pixels and performing display by sequential scanning, comprising: A first memory means for converting the number of scanning lines of the obtained video signal, a second memory means for delaying the output from the first memory means by one field, and an output from the second memory means. Third memory means for further delaying by one field, fourth memory means for delaying the motion amount calculated based on the video signal by one field, output from the first memory means, and A motion calculating step of calculating the motion amount by referring to an inter-frame difference composed of an output from the memory means and an output from the fourth memory means; Performing a vertical filtering process on the output from the first memory device and the output from the third memory device to generate a still image, and performing a first filtering process on the output from the third memory device. Performing a vertical filtering process on the output of step (a) to create a moving image, and adaptively switching the still image and the moving image based on the calculation result of the motion calculating means. Mixing the video signal. 7. The video signal processing method according to claim 6, wherein an output from said first memory means and an output from said second memory means are used, and three-dimensional Y using correlation between fields is used. Performing a / C separation process. 8. The video signal processing method according to claim 7, further comprising the step of performing a vertical resolution enhancement process corresponding to a PALplus system.