JP3278465B2 - Television signal processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter for transmitting a television signal for a landscape screen having an aspect ratio different from that of a current television signal while maintaining compatibility so that a current receiver can reproduce an image. The present invention relates to an encoder and a television signal processing device used for a reception-side decoder corresponding to the encoder.

[0002]

2. Description of the Related Art Television signals are obtained by scanning a screen. For example, in the NTSC system, 1
The screen is scanned by 480 lines. The effective scanning line for one screen is referred to as 480 [lines / frame].

[0003] When an image is taken by a landscape screen camera having an aspect ratio of 16: 9 and displayed on a display having an aspect ratio of 4: 3, the circularity is not maintained, and a circular subject becomes a vertically long elliptical shape. That is, compatibility between the landscape screen broadcast and the current receiver broadcast cannot be obtained as it is. 4: 3 aspect ratio without losing landscape screen
In order to display a circle as a circle on the display, the horizontal screen signal must be compressed to 3/4 in the vertical direction. As described above, the encoding method of displaying a landscape screen camera signal with a current receiver having an aspect ratio of 4: 3 while maintaining the roundness involves a non-image portion above and below the display (there are black bars above and below the screen, (Image is displayed in the center)
For this reason, it is called the letterbox system. In the letterbox method, the effective scanning line number of the original image is 480 lines / line.
In the case of [frame], the number of scanning lines is converted to 360 [lines / frame], thereby realizing a compression of 3/4 in the vertical direction, and processing of making upper and lower 120 [lines / frame] non-image portions is performed. . On the other hand, if the signal of the letterbox system is displayed as it is on a display having the same horizontal aspect ratio of 16: 9 as that of the camera, a circular subject becomes a horizontal elliptical shape. Therefore, in order to decode the signal transmitted with compatibility with the current receiver to the original landscape screen, it is necessary to perform 4/3 expansion processing vertically and convert it to 480 [books / frame]. become.

As described above, in the letterbox system, compression / expansion in the vertical direction is necessary, and a scanning line number conversion technique is indispensable. The scanning line number conversion technique is known as an application of a sample point conversion technique using an interpolation filter, and is a method that has no problem in principle.

However, an important problem arises when handling interlaced television signals which are generally widely used. In the interlaced scanning signal, one image (hereinafter, referred to as a frame) is composed of two field images. The field image is composed of half a scanning line of the frame image, and has a mutually offset scanning line positional relationship between consecutive fields. At present, the field accumulation type is mainly used in interlaced scanning cameras. That is, actually, an image is sampled in the time direction for each field. Therefore, in the case of a still image, a correct frame image can be obtained by superimposing the first and second continuous two fields, but in the case of a moving image, a correct frame image cannot be obtained due to image misalignment between fields. .

[0006] Under such circumstances, in the conventional scanning line conversion technique of inputting an interlaced scanning signal, a still image is processed as a frame (between fields), and a moving image is processed in a field where no image shift occurs. Motion adaptation processing is being performed. As an example of such inter-field / intra-field motion adaptation, FIG. 10 is reprinted with the drawing of the embodiment shown in Japanese Patent Publication No. 4-3151, in which an interlaced scanning signal is input and sequentially converted to a scanning signal. The input signal is input to the field memory 315 via the field memory 314. The input signal and the output of the field memory 315 are input to a subtractor 319. A motion detection signal is obtained from the subtractor 319,
21 and 322 are controlled. The output of the field memory 314 is input to the line memory 316 and the adder 3
17 is input. The adder 317 is a line memory 316
And the output of the field memory 314 are added,
It is input to a 1/2 coefficient unit 318. The output of the coefficient unit 318 is an interpolation signal in the field, and is input to the adder 323 via the coefficient unit 321 in the case of a moving image. The adder 323 includes a coefficient unit 321 and a coefficient unit 3 that outputs a still image signal.
22 are added and input to the time compression circuit 325.
The output of the time compression circuit 325 is input to the switch 326. The switch 326 has the field memory 31
The signal (original signal) obtained by compressing the output of No. 4 by the time compression circuit 324 is also input, and the original signal and the interpolation signal are alternately selected and derived.

In the above system, the input to the coefficient unit 321 is an intra-field processing signal, and the input to the coefficient unit 322 is an inter-field processing signal.
20 controls the coefficient units 321 and 322. In the intra-field processing, the scanning lines constituting the field are only の of the frame, so in principle, only half the vertical resolution can be realized as compared with the frame processing (between the fields). At the same time, if a vertical high-frequency component exceeding the representable vertical resolution is included in the input signal, aliasing occurs and the image quality is significantly degraded. In the letterbox method, the number of scanning lines is further reduced by the vertical compression process, so that the problem of the fundamental image quality deterioration due to the reduction in the resolution of the interlaced scanning and the aliasing distortion is more serious. In particular, the current NTS
When configuring the system based on the C system, 180 lines in the field (or 180 lines in 180 lines)
However, it is an area where deterioration is most easily detected, which is very inconvenient in terms of visual characteristics. For example, 1
In a 125 [line / frame] HDTV, the number of scanning lines in a field is about twice that of NTSC, so that there is no serious deterioration.

In the case of the NTSC system, since 240 scanning lines are converted into 180 scanning lines in the in-field processing of a moving image, the vertical resolution can be realized only 180 [lines / screen height] or less. 180 of the input signal
Vertical high frequency components equal to or higher than [book / screen height] become aliasing distortion.

As described above, since interlaced scanning in scanning line conversion has a fundamental problem, sufficient performance can be obtained in letterbox processing in which a progressive scanning signal is input. However, letterbox processing in which an interlaced scanning signal is input is obtained. There was no proposal that sufficient performance could be obtained by processing. The progressive scanning has twice the amount of information as the interlaced scanning. As a general theory, if a progressive scanning signal is considered, a good image quality can be expected, but the cost must be high. As described above, from the viewpoint of cost performance, a hierarchical system configuration capable of appropriately responding to the progressive scanning signal and the interlaced scanning signal in accordance with the image quality required for each image program is desirable. In addition, economical difficulty is expected as a practical problem in introducing a high-cost progressive scanning system at a time. Therefore, if the above-described hierarchical system configuration is possible, it is preferable that a low-cost interlaced scanning compatible system coexist at the initial stage of introduction.

[0010]

As described above, although an encoder and a decoder capable of responding to the sequential scanning signal in the letterbox system have been obtained, there is no encoder or decoder capable of responding to the interlaced scanning signal.
However, from the viewpoint of the video camera, a system that creates a low-cost interlaced scanning signal is more cost-effective than a video camera that creates a progressive scanning signal.

[0011]

[0012] Therefore this invention, in the case of converting the number of scanning lines by a scanning signal is inputted interlaced, to provide a television signal processing apparatus for obtaining a resolution of improvement and aliasing distortion mitigation in the current receiver Aim.

[0013]

[0014]

[0015]

(1) Encoding processing at the time of interlaced scanning signal input

The signal is converted into a 480 [line / frame] progressive scanning signal having a frame frequency equal to the frame frequency F of the input signal by frame synthesis, and signals of a vertical low-frequency component and a vertical high-frequency component are extracted by vertical LPF and HPF. Each signal is converted into a letter box type scanning line number of 360 [lines / frame] in the form of a sequential scanning signal, reconfigured into interlaced scanning and transmitted as a letter box type main screen, and the vertical high frequency band is transmitted. The component signals are multiplexed and transmitted to the upper and lower non-image portions. (2) Encoding processing at the time of progressive scanning signal input

A temporal low-frequency component and a high-frequency component are separated by a sum process and a difference process between frames, and each frame is decimated to perform 480 [line / frame] of a frame frequency F which is 1/2 of a frame frequency 2F of an input signal. Is converted to a sequential scanning signal.

In a still picture, vertical low-pass and vertical high-pass components are extracted from a temporal low-pass component signal by vertical LPF and HPF, and each signal is sequentially scanned in the form of a scanning signal by letterbox scanning. 360 lines / line
The number of scanning lines is converted into a frame, the image is reconfigured into interlaced scanning, and transmitted as a main screen of the letterbox system. The signal of the vertical high-frequency component is multiplexed and transmitted to upper and lower non-image portions.

In the case of a moving image, a vertical low-pass component is extracted from a signal of a temporal low-pass component by a vertical LPF, and the number of scanning lines in a letter box system is 360 in the form of a sequential scanning signal.
The number of scanning lines is converted to [lines / frame], and at the same time, the band of the signal of the temporal high-frequency component is band-limited by the vertical LPF. The number of scanning lines is further converted to 360 [lines / frame], and the temporal low-frequency component signal is converted. It is added to the scan line converted signal, reconstructed into interlaced scanning and transmitted as the main screen of the letterbox system, and the signal obtained by band-limiting the signal of the temporal high-frequency component by the vertical LPF to upper and lower non-image portions. Transmit by multiplexing. At the time of sequential scanning and scanning input, a motion is detected by a motion detection circuit, and the processing of the still image / moving image is appropriately switched. (3) Decoding processing at the time of interlaced scanning signal output

Regardless of whether the original input of the encoding signal is sequential scanning or interlaced scanning, the interlaced scanning encoded signal is converted into a 360 [line / frame] progressive scanning signal having a frame frequency equal to the frame frequency F of the input signal by frame synthesis from the interlaced scanning encoded signal. After subtracting the signal converted to 360 lines / frame from the signal transmitted in the upper and lower non-image portions, 48
After the number of scanning lines has been converted to 0 [lines / frame], a signal which has been separately converted to 480 [lines / frame] from the signals transmitted in the upper and lower non-image portions is added, and reconfigured for interlaced scanning and output. I do. (4) Decoding process at the time of sequential scanning signal output

Regardless of whether the original input of the encoded signal is sequential scanning or interlaced scanning, the interlaced scanning encoded signal is converted to a 360 [line / frame] progressive scanning signal having a frame frequency equal to the frame frequency F of the input signal by frame synthesis from the interlaced scanning encoded signal. After subtracting the signal converted to 360 lines / frame from the signal transmitted in the upper and lower non-image portions, 48
After the number of scanning lines is converted to 0 [lines / frame], it is converted to a frame frequency 2F by repeating the frame. A signal which is separately converted to a scan line of 480 [lines / frame] from a signal transmitted in the upper and lower non-image portions is frequency-shifted to a temporal high frequency by repeating frame inversion for a moving image, and to a vertical high frequency in a still image. The frequency is shifted and the frame is repeated, added to the 480 [line / frame] signal where the frame is repeated, and output as a sequential scan at a frame frequency of 2F.

[0022]

[Function] (1) Encoding processing at the time of interlaced scanning signal input

The input signal is converted into a 480 [line / frame] progressive scanning signal having a frame frequency F by frame synthesis. Subsequent processing is performed by sequential scanning. Therefore, there is no reduction in resolution and no aliasing when the interlaced scanning is performed in the field. The components extracted by the vertical LPF are components that contribute to the vertical sharpness, and the filter parameters are set to 36
If it is set to about 0 [book / screen height], visually sufficient characteristics can be obtained. Since this signal is a progressive scanning signal whose band is limited to 360 [lines / screen height] or less, the scanning line can be converted to 360 [lines / frame]. The signal of the vertical high frequency component by the HPF is a temporal high frequency component representing movement in a frame (between fields) in a moving image, and a vertical high frequency component in a still image. In the interlaced scanning, whether it is a vertical high frequency band or a temporal high frequency band depends on the image content, and it is not always possible to determine it. Since the signal converted to 360 [books / frame] lacks motion information, the signal of the vertical high frequency component by the HPF is 36
It is converted to 0 [book / frame] and motion information is added. Since this signal is reconstructed into an interlaced scan and transmitted as a main screen of the letterbox system, compatibility is maintained even when the signal is received by a current receiver. Further, the signal of the vertical high frequency component by the HPF is multiplexed and transmitted to the upper and lower non-image portions, and becomes an auxiliary signal when decoding to the original 480 [lines / frame] on the receiving side. (2) Encoding processing at the time of progressive scanning signal input

A temporal low-frequency component and a high-frequency component are separated by a sum process and a difference process between frames, and each frame is decimated to perform 480 [line / frame] of a frame frequency F which is a half of a frame frequency 2F of an input signal. It is converted into a progressive scanning signal. Although this signal has a frame frequency of が, it is two signals of a sum and a difference of the original signals, so that there is no loss of information.

In a still picture, since a temporal high frequency component does not occur, only a signal of a temporal low frequency component is used. 3 that can be transmitted by the letterbox method with vertical LPF
The band is limited to 60 [line / screen height], the difference signal between the original signal and the vertical low-frequency component is obtained by the HPF, multiplexed and transmitted to upper and lower non-image parts, and used as a vertical reinforcement signal on the receiving side. Since these signals are sequentially scanned, they can be easily converted to 360 [books / frame]. Further, since the frame frequency is F, if the scanning lines are rearranged so as to have an offset relationship between the fields, the scanning lines can be converted to the interlaced scanning, and the main screen signal is compatible with the current receiver.

In a moving image, a vertical low-pass component is extracted from a signal of a temporal low-pass component by a vertical LPF, and the number of scanning lines of a letter box system is 360 in the form of a sequential scanning signal.
The number of scanning lines is converted to [book / frame]. This signal lacks motion information in the frame. The band of the temporal high frequency component signal is limited by the vertical LPF, and the number of scanning lines is 3
The number of scanning lines is converted to 60 [lines / frame], added to the signal converted from the temporal low-frequency component signal to the scanning lines, motion information is added, and interlaced scanning is reconfigured to form a letterbox main screen. To be transmitted. The signal obtained by band-limiting the signal of the temporal high-frequency component by the vertical LPF is multiplexed and transmitted to upper and lower non-image portions, and is used as a reinforcement signal of motion information on the receiving side. At the time of progressive scanning input, a motion is detected by a motion detection circuit, and the processing of the still image / moving image is appropriately switched. (3) Decoding processing at the time of interlaced scanning signal output

Regardless of whether the original input of the encode signal is a sequential scan or an interlaced scan, the transmitted signal is an interlaced scan encode signal. Therefore, by frame synthesis, 360 [lines / frame] having a frame frequency equal to the frame frequency F of the input signal is obtained. ] Is converted into a progressive scanning signal, motion information is extracted from the signal transmitted in the upper and lower non-image portions, and this is extracted as 360
Subtraction is performed from the signal obtained by performing the scan line conversion to [book / frame], thereby canceling the aliasing component of the main screen transmitted by interlaced scanning. The 360 [line / frame] sequential scanning signal from which the aliasing component has been removed can be easily converted to 480 by the scanning line conversion circuit.
The number of scanning lines can be converted to [book / frame]. The signal which is separately scanned and converted to 480 [lines / frame] from the signal transmitted in the upper and lower non-image portions is a temporal high frequency component for a moving image and a vertical high frequency component for a still image. The signal is added as a reinforcement signal, reconstructed as an interlaced scan, and output. (4) Decoding process at the time of sequential scanning signal output

Regardless of whether the original input of the encoded signal is sequential scanning or interlaced scanning, the transmitted signal is an interlaced scanning encoded signal. Therefore, by frame synthesis, a frame frequency of 360 [lines / frame] equal to the frame frequency F of the input signal is obtained. 360] converting the signal into a progressive scanning signal, extracting the temporal high-frequency signal from the signal transmitted in the upper and lower non-image portions,
The subtraction is performed using the signal converted to [book / frame] by the scanning line, thereby canceling the aliasing component of the main screen transmitted by the interlaced scanning. The 360 [line / frame] sequential scanning signal from which the aliasing component has been removed can be easily converted to 480 by the scanning line conversion circuit.
The number of scanning lines can be converted to [book / frame]. It is converted to a frame frequency 2F by frame repetition. This signal lacks motion information in the frame. A signal which is separately subjected to scan line conversion to 480 [lines / frame] from a signal transmitted in the upper and lower non-image portions is converted into a temporal high-frequency component for a moving image and added to the frame repetition signal. In the case of a still image, since it is a vertical high frequency component, it is shifted in frequency to the vertical high frequency, added in the same manner, and output as a sequential scan at the frame frequency 2F.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

(1) FIG. 1 shows a first embodiment of the present invention, and is a processing block diagram of a letter box type encoder for inputting an interlaced scanning signal. Further, for explanation of the operation, the vertical spatial frequency fv [LPV] and the temporal spatial frequency ft [H
z] are shown in FIGS. 8 and 9.

The input terminal 1 has an effective scanning line number of 480 lines / frame having the spectrum shown in FIG. 8A and a 2: 1 jump of a frame frequency of 30 Hz (field frequency of 60 Hz). A scanning signal is input. The signals in the hatched areas A and B in FIG. 8A are characteristic in interlaced scanning. The vertical high frequency component and the temporal high frequency component overlap due to the aliasing of the interlaced scanning, and cannot be distinguished on the signal. For example, in a picture having a vertical high-frequency component in a still image, a flicker called an interline flicker, that is, a temporal high-frequency component occurs as aliasing. In addition, even if a picture has only a vertical low-frequency component, if the picture moves, it appears to be folded back in the vertical high-frequency range. In interlaced scanning, areas A and B in FIG. 8A have the same information and cannot be distinguished. In the frame synthesizing circuit 2, the first and second fields are synthesized to obtain the spectrum shown in FIG. 8 (1b). That is,
It is converted into a progressive scanning signal having a frame frequency of 30 [Hz]. Interlace scanning between the same frame frequencies can be easily performed by sequentially rearranging the scanning line signals in the first field and the scanning line signals in the second field using the buffer memory and outputting the same frame signal. realizable. The output of the frame synthesizing circuit 2 is input to a vertical low-pass filter (V-LPF) 4 and band-limited to the spectrum shown in FIG. Further, the data is converted into 360 [books / frame] by the 4 → 3 scanning line conversion circuit 11 and is converted into the data shown in FIG.
The spectrum becomes d).

The input / output signal of the V-LPF 4 is input to the subtractor 5 to perform a difference operation, and the output of the subtracter 5 is as shown in FIG.
The spectrum of g) is obtained. This signal has an important meaning as information indicating a motion in a moving image. The output of the subtractor 5 is horizontally and vertically band-limited by a horizontal and vertical filter (HV-LPF) 6. This signal is eventually multiplexed and transmitted in the upper and lower non-image area as described later,
As an area for transmitting the data, the transmission capacity is only 120 [lines / frame], which is 1/3 of the main screen 360 [lines / frame]. Therefore, the amount of information must be reduced to 1/3, and components with low visual contribution are deleted in advance. For this reason, HV-LPF6 has been inserted. An example of the characteristics of the HV-LPF 6 is shown in FIG.
This is shown in (1i). The output of the HV-LPF 6 is converted by the vertical frequency shift circuit 7 into the spectrum shown in FIG.
This vertical frequency shift can be easily realized by inverting the polarity for each scanning line. The output of the vertical frequency shift circuit 7 is
It is supplied to the 4 → 3 converter 8 and the 4 → 2 converter 14 and divided into two systems. One system is for improving the resolution of a moving image when the main signal is reproduced by the current receiver, and the other system is for using the same for reproducing the original signal.

The output of the vertical frequency shift circuit 7 is converted into a 360 [line / frame] sequential scanning signal by the 4 → 3 converter 8 of one system, and is converted by the 4 → 2 converter 14 into 24 signals.
It is converted into a 0 [line / frame] progressive scanning signal. 4 →
The output of the 3 converter 8 is supplied to the vertical frequency shift circuit 9 as shown in FIG.
It is converted to the spectrum of a). The output of the vertical frequency shift circuit 9 is multiplied by K (K = 0 to 1) by a multiplier 10. K
Is given by the output of the motion detection circuit 3, and for a still image, K =
0, K = 1 for moving images. Therefore, FIG.
Adder 1 when the signal having the spectrum of (2a) is a moving image
FIG. 8 (1) which is the output of the 4 → 3 conversion circuit 11 by 2
8) is added to the signal having the spectrum of FIG.
Signal having the spectrum

The output of the adder 12 is a progressive scan signal having a frame frequency of 30 [Hz] of 360 [lines / frame]. The progressive scan → interlaced scan conversion circuit 13 outputs a frame frequency of 30 [Hz] (field frequency of 60 [Hz]). H
z]) is converted to a 2: 1 interlaced scanning signal. As in the frame synthesizing circuit 2 described above, in the sequential scanning of the same frame frequency → interlaced scanning conversion, a scanning line signal in a frame is alternately output as a first field signal and a second field signal for each scanning line using a buffer memory. It can be easily realized. The spectrum of the output of the progressive scan → interlaced scan converter 13 is shown in FIG. 8 (1f). As shown by the hatched portion, information indicating the motion of the moving image is stored as a 360 [line / frame] interlaced scan signal. Therefore, compatibility with the current receiver of the letter box system is ensured.

On the other hand, the output of the 4 → 2 scanning line converter 14 is 2
40 [lines / frame], 1/3, 2/3 for each scanning line
Is compressed by the data rearranging circuit 16 to
The signal is converted into a signal of [book / frame] interlaced scanning and becomes a multiplex signal at the top and bottom of the screen. The main screen signal and the screen upper / lower part signal are switched by the switch 17 and become a 480 [book / frame] interlaced scanning signal of the letter box system, which is output from the output terminal 18.

(2) FIG. 2 shows a second embodiment, and is a processing block diagram of a letter box type encoder which receives an interlaced scanning signal and a sequential scanning as inputs. Portions having the same functions as in the first embodiment are denoted by the same reference numerals as in FIG.

The input terminal 20 receives a 1: 1 sequential scanning signal having an effective scanning line number of 480 lines / frame and a frame frequency of 60 Hz. The input terminal 1 has an effective scanning line number of 480 lines / frame and a frame frequency of 30.
A 2: 1 interlaced scanning signal of [Hz] (field frequency 60 [Hz]) is input.

As described above, in the interlaced scanning, FIG.
The signal areas indicated by the hatched areas A and B in (1a) cannot be distinguished, and the vertical high frequency component and the temporal high frequency component are overlapped by the aliasing of the interlaced scanning, and cannot be distinguished on the signal. However, in the progressive scanning, FIG. 9 (2b)
, And there is no aliasing as in the case of interlaced scanning, and the vertical high frequency component and the temporal high frequency component can be clearly distinguished.

When switching the system mode, the switches 31, 32, 33, and 34 switch the processing mode between the input of the interlaced scanning signal and the input of the sequential scanning signal. Switches 31, 32, 3 shown in the figure
The states 3 and 34 indicate the mode at the time of inputting the sequential scanning signal. [When progressive scanning signal is input]

The switches 31, 32, 33, and 34 are all closed to the sequential scanning signal input mode. A 1: 1 sequential scanning signal having an effective scanning line number of 480 lines / frame and a frame frequency of 60 Hz is input to the input terminal 20. As described above, in the interlaced scanning, FIG.
The signal areas indicated by the hatched areas A and B cannot be distinguished from each other, and the vertical high frequency component and the temporal high frequency component are overlapped due to the aliasing of the interlaced scanning and cannot be distinguished on the signal. However, the sequential scanning has the spectrum structure shown in FIG. 9 (2b), and there is no aliasing as in the interlaced scanning, and the vertical high frequency component and the temporal high frequency component can be clearly distinguished. The sum and difference of the input / output signals of the 1/60 second delay unit 21 are calculated by the adder 22 and the subtractor 23, respectively.
It is multiplied by で with the 係数 coefficient multipliers 24 and 25. The outputs of the 1/2 coefficient units 24 and 25 become the sum average and difference average output between frames, respectively, and output a temporal low-frequency component and a temporal high-frequency component, respectively. The outputs of the 1/2 coefficient units 24 and 25 are thinned out by the switches 26 and 27, respectively, and are converted into a progressive scanning signal of 480 [lines / frame] and a frame frequency of 30 [Hz]. These two signals are half of the input frame frequency, but are each defined as a sum and difference, and there is no information missing from the input. The spectra of the output signals of the switches 26 and 27 are shown in FIG.
b) (difference component). The output signal of the switch 26 is input to the V-LPF 4 and the subtractor 5 through the switch 31.

The output of the subtractor 5 has the spectrum shown in FIG. 8 (1g). In this case, it clearly means the vertical high frequency component of the input. The horizontal and vertical bands of this signal are limited by the HV-LPF 6, and the vertical frequency shift circuit 7 has the spectrum shown in FIG. 8 (1 h). Multiplier 4
3 is controlled by a value obtained by calculating 1−K by the subtractor 41 from the output K (K = 0 to 1) of the motion detection circuit 28. The motion detection circuit 28 detects an image motion of the signal of the input terminal 20.

The fact that the multiplier 43 is controlled by 1-K means that the output of the vertical frequency shift circuit 7 which is a temporal low-frequency component and a vertical high-frequency component is an adder 4 at the time of a still image.
2. It is sent to the 4 → 2 scanning line converter 14 through the switch 34.

On the other hand, the output of the switch 27, which is a temporal high-frequency component, is converted by the temporal frequency shift circuit (T-shift) 46 into the spectrum shown in FIG.
The HV-LPF 40 having the same characteristics as the V-LPF 6 is subjected to horizontal and vertical band limitation, is input to the multiplier 44, passes through the switch 33, and is converted to 3 by the 4 → 3 scanning line number converter 8.
It is converted to 60 [lines / frame], converted to the spectrum of FIG. 9 (2a) by the vertical frequency conversion circuit 9 and input to the multiplier 10. The output of the motion detection circuit 28 is input to the multiplier 10 through the switch 32, and K = 1 is given for a moving image. Therefore, the temporal high-frequency component, which is motion information, is output from the multiplier 10 in the case of a moving image, and the temporal low-frequency component is converted by the adder 12 into the 4 → 3 scanning line number converter 11.
Is added to the signal converted to 360 [books / frame]. The output of the adder 12 is sequentially scanned by the progressive scan → interlaced scan converter 13 → frame frequency 30 [Hz] (field frequency 60 [H] by the interlaced scan converter 13).
z]) is converted to a 2: 1 interlaced scanning signal.

The HV, which is the temporal high frequency component, is used.
The output of LPF 40 is applied to adder 42 through multiplier 44; The multiplier 43 has a gain of 1 for a still image and a gain of 0 for a moving image. On the other hand, the multiplier 44 has a gain of 0 for a still image and a gain of 1 for a moving image. Therefore, in the case of a moving image, the temporal high-frequency component is further converted to a screen upper / lower multiplex signal described later via the multiplier 44. That is, the output of the adder 42 passes through the switch 34, is sequentially processed by the 4 → 2 scanning line number converter 12, the time compression circuit 15, and the data rearrangement circuit 10, and becomes a screen upper and lower multiplexed signal. The main screen signal and the screen upper / lower part signal are switched by the switch 17 and become a 480 [book / frame] interlaced scanning signal of the letter box system, which is output from the output terminal 18. [At the time of interlaced scanning signal input] Next, the operation at the time of interlaced scanning input will be described. The switches 31, 32, 33, and 34 are all assumed to be closed to the interlaced scanning input mode.

The input terminal 1 has a spectrum shown in FIG. 8 (1a), the number of effective scanning lines is 480 [lines / frame], and the frame frequency is 30 [Hz] (field frequency 60 [Hz]), 2: 1. A scanning signal is input. Assuming that the switches 31, 32, 33, and 34 are all closed to the interlaced scanning input mode, the configuration pattern is exactly the same as that of the first embodiment described with reference to FIG. 1, and the same operation is performed. Therefore, detailed description is omitted.

(3) FIG. 3 shows a third embodiment.
FIG. 11 is a processing block diagram of a decoder that receives a signal encoded in the letterbox system described in the second embodiment and outputs an interlaced scanning signal.

The encode signal is input to the input terminal 50. The received signal is converted into an interlaced scanning signal regardless of whether the original signal is interlaced scanning or progressive scanning. Switch 5
In step 1, the main screen signal is taken into the frame synthesizing circuit 52, and the upper and lower screen multiplexed signals are taken into the rearranging circuit 53. The frame synthesizing circuit 52 converts the main screen signal from an interlaced scanning signal of 360 [lines / frame] to a progressive scanning signal of 360 [lines / frame] at a frame frequency of 30 [Hz], and the spectrum of FIG. can get. The signals multiplexed in the upper and lower portions of the screen are reproduced by the rearrangement circuit 53 and the time expansion circuit 54 into the same signal as the output signal of the 4 → 2 scanning line converter 14 described in the first and second embodiments. The output of the time expansion circuit 54 is input to a 2 → 3 scanning line converter 55 of one system and a 2 → 4 scanning line converter 60 of the other system.

The output of the 2 → 3 scanning line converter 55 is 360
In the case of [book / frame], it is converted to the sequential scanning of the frame frequency 30 [Hz], and the vertical frequency shift circuit 5
The spectrum is converted into the spectrum shown in FIG.
Is input to The output K of the motion detection circuit 64 is input to the other input terminal of the multiplier 57, and K = 1 is output for a moving image. Therefore, in the case of a moving image, the output of the vertical frequency shift circuit 56 is added to the subtractor 58 through the multiplier 57, and
The vertical / temporal aliasing component included in the 0 [line / frame] interlaced scanning is removed to obtain the spectrum shown in FIG. 8 (1d). Frame frequency 30 at 360 [books / frame] where aliasing components have been removed and cleaned
The progressive scanning signal of [Hz] is 480 [lines / frame] by the 3 → 4 scanning line converter 59 and has a frame frequency of 30.
The signal is converted into a progressive scanning signal of [Hz], becomes a spectrum of FIG. 8 (1c), and is sent to the adder 62. Also, 2 → 4
The signal converted by the scanning line converter 60 into a sequential scanning signal having a frame frequency of 30 [Hz] at 480 [lines / frame] is converted into a spectrum shown in FIG. 8 (1g) by the vertical frequency shift circuit 61 and transmitted to the adder 62. Can be Adder 62
As a result, the output of the 3 → 4 scanning line converter 59 and the output of the vertical frequency shift circuit 61 are added, and the spectrum shown in FIG. The output of the adder 62 is a sequential scanning signal having a frame frequency of 30 [Hz] of 480 [lines / frame].
z]) is converted to a 2: 1 interlaced scanning signal. As described in the first embodiment, in the sequential scanning → interlaced scanning conversion between the same frame frequencies, the scanning line signals in the frame are alternately output as the first field signal and the second field signal for each scanning line using the buffer memory. It can be easily realized.

(4) FIG. 4 shows a fourth embodiment.
FIG. 13 is a processing block diagram of a decoder that receives a signal encoded in the letterbox system in the second embodiment and outputs a progressive scanning signal. The same reference numerals are given to the same functional units as those in the embodiment of FIG.

The encode signal is input to the input terminal 50. A main screen signal is converted by a switch 51 into a frame synthesis circuit 52.
And the upper and lower screen signals are received by the rearrangement circuit 53. The main screen signal is changed to 360 by the frame synthesis circuit 52.
360 [book / frame] from the interlaced scanning signal of [book / frame]
The frame is converted into a progressive scan having a frame frequency of 30 [Hz], and the spectrum shown in FIG. 8 (1e) is obtained. The signals multiplexed in the upper and lower portions of the screen are processed by the rearrangement circuit 53 and the time expansion circuit 54 as described in the first and second embodiments.
The reproduced signal is the same as the output signal of the two-scan line converter 14. The output of the time expansion circuit 54 is a 2 → 3 scanning line converter 5
5 and 2 → 4 are input to the scanning line converter 60. The output of the 2 → 3 scanning line converter 55 is converted into a progressive scanning signal having a frame frequency of 30 [Hz] at 360 [lines / frame], and is converted by the vertical frequency shift circuit 56 into the spectrum of FIG. Is input to the device 57. The output K of the motion detection circuit 64 is input to the other input terminal of the multiplier 57, and K = 1 is output for a moving image. Therefore, in the case of a moving image, the output of the vertical frequency shift circuit 56 passes through the multiplier 57 and
8 and the vertical / temporal aliasing component included in the 360 [line / frame] interlaced scanning is removed to obtain the spectrum shown in FIG. 8 (1d). A progressive scanning signal having a frame frequency of 30 [Hz] at 360 [lines / frame], which has become clean by removing aliasing components, has a frame frequency of 30 [Hz] at 480 [lines / frame] by the 3 → 4 scanning line converter 59. It is converted into a progressive scanning signal, and FIG.
The spectrum becomes (1c) and is sent to the adders 77 and 78.

The output of the time expansion circuit 54 is 2 → 4
The scanning line converter 60 converts the signal into a sequential scanning signal having a frame frequency of 30 [Hz] at 480 [lines / frame], and the signal is multiplied through a vertical frequency shift circuit 61, a multiplier 72-1 and a polarity inversion circuit 76. Is input to the device 72-2.

The vertical frequency shift circuit 61 shown in FIG.
The signal having the spectrum of (1g) is a multiplier 73-1,
It is sent to 73-2. The output K of the motion detection circuit 64 is input to the multipliers 72-1 and 72-2, and the subtracter 7
The signal is converted into 1-K by 4 and input to multipliers 73-1 and 73-2. In the case of a moving image, K = 1, and the multiplier 72-1,
72-2 is turned on, and the multipliers 73-1 and 73-2 are turned off. The situation is reversed for a still image. The outputs of the multipliers 72-1 and 73-1 are added by an adder 75-1, and the outputs of the multipliers 72-2 and 73-1 are added to an adder 75-2.
Is added. Outputs of the adders 75-1 and 75-2 are input to adders 77 and 78. The output of the 3 → 4 scanning line converter 59 is also input to the adders 77 and 78. Adder 7
The processing circuits 7 and 78 and the processing circuit that supplies the outputs of the adders 75-1 and 75-2 to the adders 77 and 78 perform double frame conversion processing in the still image mode and moving image by performing frame repetition. This is a circuit that performs double frame conversion processing of the mode.

The output of the adder 77 is 1
/ 2 is time-compressed and input to the switch 82. The output of the adder 78 is delayed by 1/60 second by the delay circuit 79 and time-compressed to 1/2 by the time compression circuit 81.
Connected to. The switch 82 is switched every 1/60 second, and a sequential scanning signal having a frame frequency of 60 [Hz] is output from the output terminal 83 at 480 [lines / frame].

With regard to the above-mentioned signals in the case of the moving image of the 2 → 4 scanning line converter 60, the same frame signal is reduced to 1/60 second by a series of operations of the polarity inversion circuit 76, the delay circuit 79, and the switch 83. The polarity is inverted at intervals and the repetition is repeated. This means that the temporal frequency shift has been performed, and the spectrum is as shown in FIG. 9 (2g). Also, 3 →
Output of 4-scanning line converter 59 and vertical frequency shift circuit 61
Is the same frame signal repeated at 1/60 second intervals. (5) FIG. 5 shows a fifth embodiment, and is a processing block diagram of a letter box type encoder that inputs an interlaced scanning signal and a sequential scanning signal.

Since the second embodiment is basically the same as the second embodiment shown in FIG. 2, only the differences will be described. In the second embodiment, the input / output signal of the V-LPF 4 is connected as the input of the subtractor 5, but in the fifth embodiment, the 3 → 4 scanning line converter 11 is used.
a is added, and the input of the V-LPF 4 and 3 → 4
The output of the scanning line converter 11a is input. In the second embodiment, the output of the switch 33 is connected to the vertical frequency shift circuit 9 through the 4 → 3 scan line converter 8, but in the fifth embodiment, the output of the switch 33 is connected to the 4 → 2 scan line converter 8.
a, and is input to the vertical frequency shift circuit 9 through the 2 → 3 scanning line converter 8b.

In the fifth embodiment, the same processing as that of the decoder described in the third and fourth embodiments is performed on the encoder side, and the deterioration factor caused by the filter characteristics on the decoder side can be corrected on the encoder side in advance. .

(6) FIG. 6 shows a sixth embodiment, which is a decoder which receives a signal encoded in the letterbox system or a signal of the current system in the first or second embodiment and outputs an interlaced scanning signal. The processing block diagram of FIG.

Since the sixth embodiment is based on the third embodiment, only the addition will be described. The signal at the input terminal 50 is input to the switch 101 and the multiplex detection circuit 100, and the output of the multiplex detection circuit 100 is
1 is switched and controlled. The multiplex detection circuit 100 determines the multiplex-transmitted signal as in the first, second, and third embodiments, and when a multiplex signal is included, switches the switch 101 to the sequential scanning → interlaced scan conversion circuit 63 side. If it is determined to be a signal, it is switched to the input terminal 50 side. When a control signal for identifying multiplex transmission is included in the vertical blanking period or the like, the multiplex detection circuit 100 performs an operation of detecting the control signal.

(7) FIG. 7 shows a seventh embodiment.
FIG. 11 is a processing block diagram of a decoder that receives a signal encoded by the letter box method or a signal of the current method in the second embodiment and outputs a sequential scanning signal.

Since the seventh embodiment is based on the fourth embodiment, only the additional components will be described. Interlaced scanning from the input terminal 50 → sequential scanning conversion circuit 102 (interlaced scanning with a frame frequency of 30 Hz → frame frequency of 60 Hz)
Scanning). The output of the switch 82 and the interlaced scan → sequential scan conversion circuit 102 is supplied to the switch 103 and selectively output. The switch 103 is switched and controlled by the output of the multiplex detection circuit 100. When the multiplexing detection circuit 100 determines that the signal is a multiplexed signal as in the first, second, and third embodiments, the switch 103 is switched to selectively derive the output of the switch 82 and is determined to be the current signal. In this case, switching is performed so that the output of the interlaced scanning → sequential scanning conversion circuit 102 is selectively derived. As described in the sixth embodiment, when a multiplex identification signal is separately multiplexed and transmitted, the multiplex detection circuit 100 performs an operation of detecting the identification signal.

[0061]

According to the present invention, since the interlaced scanning input is combined with the sequential scanning in the encoder and the processing is performed, 240 [lines /
Screen height], and the resolution is improved . In the encoder of the sequential scan input performs the same process, but it is processed in high performance by for motion information and vertical high frequency information of the moving image can be clearly discriminated.

[0062]

[0063]

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment as an encoder for interlaced scanning signal input according to the present invention.

FIG. 2 is a diagram showing a second embodiment as an encoder for inputting interlaced scanning signals and sequential scanning signals according to the present invention.

FIG. 3 is a diagram showing a third embodiment as a decoder for interlaced scanning signal output according to the present invention.

FIG. 4 is a diagram showing a fourth embodiment as a decoder for outputting progressive scanning signals according to the present invention.

FIG. 5 is a diagram showing a fifth embodiment as an encoder for interlaced scanning and sequential scanning signal input according to the present invention.

FIG. 6 is a diagram showing a sixth embodiment as a decoder for interlaced scanning signal output according to the present invention.

FIG. 7 is a diagram showing a seventh embodiment as a decoder for inputting a progressive scanning signal according to the present invention.

FIG. 8 is a diagram showing a two-dimensional spectrum in a vertical / temporal spatial frequency domain for explaining the operation of the present invention.

FIG. 9 is a diagram showing a two-dimensional spectrum in a vertical / temporal spatial frequency domain for explaining the operation of the present invention.

FIG. 10 is a diagram showing a scanning line interpolation circuit of a conventional television signal processing circuit.

[Explanation of symbols]

2 ... frame synthesis circuit, 3 ... motion detection circuit, 4 ... vertical low-pass filter (V-LPF), 5 ... subtractor, 6 ... horizontal / vertical low-pass filter (HV-LPF) 7, 9 ... vertical frequency Shift circuit, 8, 11 ... 4 → 3 scanning line converter, 1
0: Multiplier, 12: Adder, 13: Sequential scan to interlaced scan conversion circuit, 14: 4 to 2 scan line converter, 15: Time compression circuit, 16: Rearrangement circuit, 17: Switch, 21
... 1/60 second delay unit, 22, 42 ... adder, 23, 41
... Subtractors, 24, 25 ... 1/2 coefficient units, 26, 27, 3
1 to 34: switch, 28: motion detection circuit, 40: horizontal / vertical low-pass filter, 43, 44: multiplier, 46:
Temporal frequency shift circuit, 52: frame synthesis circuit, 53: rearrangement circuit, 54: time expansion circuit, 55:
2 → 3 scanning line converter, 56, 61: vertical frequency shift circuit, 57: multiplier, 58: subtractor, 59: 3 → 4 scanning line converter, 60 ... 2 → 4 scanning line converter, 62: addition Bowl, 6
3: sequential scanning → interlaced scanning conversion circuit, 64: motion detection circuit, 72-1, 72-2, 73-1, 73-2: multiplier, 74, 75-1, 75-2, 77, 78: addition vessel,
79 ... 1/60 second delay device, 80, 81 ... 1/2 time compression circuit.

Claims (1)

(57) [Claims] A frame synthesizing means for receiving an interlaced scanning signal as an input and synthesizing a signal of a first field and a second field (or a second field and a first field) of the signal into a frame signal; Output is high frequency component of vertical spatial frequency .
Min and a separating means for separating into a low-frequency component, converts the number of scanning lines of the low-frequency component separated by said separating means
A first scanning line number conversion unit, and the high frequency component separated by the separation unit is shifted to a vertical low frequency band.
First converting means for converting the number of scanning lines of the output of the first converting means.
A scanning line number conversion means, shifting the vertical high-output of the second scanning line number conversion means
A second conversion means for converting the number of scanning lines , and an output of the second conversion means.
Adding means for adding to the output of the stage; and a first interlaced scanning of the frame signal from the adding means.
A television signal processing apparatus comprising: reconstructing means for separating and configuring a signal form of a field and a second field (or a second field and a first field).