JPS6051092A - Band compression transmitting system of wide band picture signal - Google Patents

Abstract

PURPOSE:To limit the deterioration of picture quality of a part of still picture to a minimum and perform highly efficient band compression by changing the rate of compression of a signal band responding to the movement of the picture. CONSTITUTION:The picture signal 2 from the input terminal 1 of a trensmission side is band limited by an LPF6 to add a narrow band signal YL to a switch 7, and to add to a signal mixer 9 through a vertical direction LPF8. The signal 2 is delayed by 1 frame by a frame memory 3, and added by an adder 5, and added to a mixer 9 from an attenuator 10-a. On the other hand, the 1 frame delayed signal is added to a movement detecting circuit 11, and movement of the picture is detected from differential signal between the signal 2. The mixing rate of an attenuation sum output picture signal and a vertical direction LPF output picture signal is controlled by the detected moving area signal 12. The mixed output picture signal 13 is processed by a subtracter 14, LPF 15, an adder 17, a time axis compression circuit 20 etc. to limit the deterioration of picture quality of still picture part to a minimum and to perform highly efficient band compression.

Description

[Detailed description of the invention]

Technical Field The present invention relates to a wideband image signal band compression transmission method for compressing the signal band of a wideband image signal and transmitting the compressed signal band through a narrowband transmission path, and in particular, a method for compressing the signal band of a wideband image signal and transmitting the compressed signal band through a narrowband transmission path. It is designed to enable highly efficient bandwidth and compressed transmission. Conventional technology This kind of wideband image signal band compression transmission method is used as a transmission method that is less susceptible to cross-color interference that tends to occur with signal band compression and to the differential gain characteristics and differential phase characteristics of the transmission system. A transmission method for time-division multiplexing signals, for example, a time-axis compression multiplexing+Tc1t method is known. In conventional time-division multiplexing band compression transmission systems such as this 'I'CI system, in order to increase the compression ratio of the signal band, the transmission bandwidth of the luminance signal is For a certain scan line, the entire required signal band is set,
As for the next scanning line, the signal band is limited by a low-pass p-wave filter and narrow band transmission is performed, and wideband transmission and narrowband transmission are performed alternately on the scanning line. Such FIG.
In the conventional transmission method shown in a), the transmittable band in the horizontal and vertical two-dimensional spatial frequency domain of the image signal is the area shown in Figure 1 (bl), and the high frequency B signal and component are not transmitted. Therefore, this high frequency region B is a high frequency region common to the horizontal and vertical rain spatial frequency regions, and is a signal region that is related to the definition of the diagonal direction in the image. It is said that even if the signal components in the high frequency range are not transmitted, the image quality will not deteriorate significantly.However, in order to increase the band compression rate, the high frequency range B that is not transmitted is set too large, and the band limit is set too high. If the passband of the low-pass p-wave filter for the purpose of In this case, the passband width of the low-pass p-wave filter for band limiting can be made to be less than 4% of the required signal band. In Fig. 1(b), an example is shown in which region B is set to less than the total region. In addition, in the TOI transmission method mentioned above, the low-pass p
For example, the image signal band-limited by the wave transmitter is
As shown in Figure (0), time-division transmission is performed by alternately providing scanning line periods for transmitting wideband signals on the normal time axis and scanning line periods for compressing the time axis and transmitting narrowband signals. , If noise is mixed in the transmission system, the signal-to-noise ratio of the narrowband signal restored by extending the time axis on the receiving side will be different from that of the narrowband signal after transmitting the image signal of the entire signal band as it is. The signal-to-noise ratio is lower than that obtained when band-limiting is performed in the same way using the same low-pass p-wave generator used to form the signal-to-noise ratio.・The larger the expansion ratio is, the larger it becomes. especially,
In the case of FM transmission of such a TOI signal, the above-mentioned reduction in the signal-to-noise ratio becomes significant due to the characteristics of FM transmission. Therefore, in terms of such a reduction in the signal-to-noise ratio, there is a limit to the limitation of the signal band by the low-pass p-wave device, and the band compression ratio cannot be made very large. Furthermore, it is said that the deterioration in image quality is not visually noticeable in moving parts of the image, and for image signals in moving parts, the deterioration in image quality is not noticeable even if band compression is performed to a large extent. If band compression is applied uniformly across the screen, image quality degradation will be noticeable for static image parts, so as long as band compression is applied uniformly across the entire screen, there will be no image quality degradation for moving images. Conventional band compression transmission systems of this type have been subject to various drawbacks, such as the inability to achieve a sufficiently large band compression ratio, even if the band compression ratio is not noticeable. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to efficiently perform band compression transmission by compressing the moving image portion at a sufficiently high rate without causing image quality deterioration in the still image portion. It is an object of the present invention to provide a wideband image signal band compression transmission system that enables the transmission of wideband image signals. In other words, in the band compression transmission method of the present invention, if the compression rate of the signal band is changed according to the amount of image movement, there will be no image quality deterioration at all for the still image portion, and image quality deterioration for the moving image portion will be minimized. This method was developed based on the fact that it is possible to perform highly efficient band compression while suppressing In band-compressing transmission of an image signal, on the transmitting side, a first wideband image signal component consisting of an input wideband image signal with no band limitation applied in the vertical spatial frequency domain and the horizontal spatial frequency domain, and a first wideband image signal component in the high range of the horizontal spatial frequency domain are transmitted. a second wideband image signal component consisting of the input wideband image signal subjected to band limitation only in the high frequency region of the vertical spatial frequency domain, and the amount of motion of the image detected between adjacent frames is the same as the first wideband image signal component. When the amount of motion of the image does not exceed the predetermined level, the first wideband image signal component is used as the transmission wideband image signal component, and when the amount of motion of the image exceeds the first predetermined level, the amount of motion of the image is determined according to the motion of the image. An image signal component formed by weighted addition of the first wideband image signal component and the second wideband image signal component at a first ratio determined by At the receiving end, a transmission image signal is transmitted in which the transmission broadband image signal component is transmitted only during one of the corresponding horizontal scanning periods, and the received transmission image signal is transmitted at the receiving side. From the image signals of two adjacent frames in the signal, an eighth wideband image signal component with no band limitation applied in the vertical spatial frequency domain and the horizontal spatial frequency domain and a high frequency domain in the vertical spatial frequency domain in the high range of the horizontal spatial frequency domain are obtained. and a fourth wideband image signal component in which the band is limited only in the area, and when the amount of image movement detected between the image signals of the two adjacent frames does not exceed a second predetermined level, the fourth wideband image signal component is 8 is replaced with the narrowband image signal component in the transmission image signal, and the amount of motion of the image is
When the predetermined level is exceeded, the first ratio G determined according to the amount of movement of the image is formed by weighted addition of the eighth wideband image signal component and the fourth wideband image signal component. The present invention is characterized in that a wideband image signal is restored by replacing an image signal component with a narrowband image signal component in the transmission image signal. EXAMPLES The present invention will be described in detail below with reference to the drawings. Therefore, prior to a detailed explanation of the present invention, the conventional TOI transmission method mentioned above will be briefly explained. In other words, in the conventional TOI transmission method, it is necessary to restore the narrowband transmitted image signal component to the wideband image signal component by some method. It is necessary to perform interpolation using wideband transmission signal components of scan line periods adjacent to . If such interpolation were to be performed perfectly, it would be possible to easily restore and reproduce the image signal components transmitted with band compression in various formats, but in general, such interpolation should be performed completely. This is difficult, and in an incompletely reproduced image, the scan lines visually appear to be flowing up and down. In order to avoid the visual flow of overlapping scan lines, in the conventional TOI transmission system, as shown in FIG. 1. i+s,--
−, scanning line periods i+1 and 1+8 in which a wideband signal was also transmitted in the next +1 frame, and a narrowband signal YL was transmitted in the second frame. -m-, the narrowband signal is also transmitted in the next +1 frame. That is, N T SO
The number of scanning lines that make up one frame is 52 in the image signal of the high-definition television system or the so-called high-definition television system.
Since the number of lines is an odd number such as 5 lines or 1125 lines, unless special measures are taken, when a wideband signal is transmitted in one frame during corresponding scanning line periods between adjacent frames, In the other frame, the wideband signal and the narrowband signal to be transmitted alternately on the scanning lines are transmitted. Therefore, as mentioned above, in any frame, in the corresponding scanning line period,
At any given time, so-called frame reset processing was used to transmit only either a wideband signal or a narrowband signal. In other words, in the conventional TOI transmission method,
In order to avoid the image quality deterioration caused by the visual flow of scanning lines mentioned above, measures such as frame reset are taken to prevent the two
It was necessary to match the signals transmitted during corresponding scanning line periods between frames to be broadband signals or narrowband signals. In contrast, in the transmission system of the present invention, one transmission of both wideband and narrowband signals is performed in the manner shown in FIG. 2, for example, without requesting any special measures such as frame reset. That is, in the transmission mode shown in the second figure, the scanning line period i in the frame is first. i+2. --First, transmit a wideband signal, and scan line period i
+ 1 , 1+ 8 + --- When a narrowband signal is transmitted, in the +1 frame following this first frame, the scanning line period for transmitting the wideband signal and the narrowband signal, respectively, is as follows. First, it is completely opposite to the scanning line period in a frame. That is, the scanning line mark jllji in the +1 frame. 1+2. --- transmits a narrow band signal, and also scans, line period i+], sat+8. --- transmits a wideband signal. Furthermore, in the transmission method of the present invention, when forming a wideband signal, the image signal of the current frame and the image signal of the previous frame are combined at a ratio corresponding to the magnitude of image movement detected between adjacent frames. The high frequency component of the image signal formed by weighted addition of the sum signal and the low frequency signal component in the vertical spatial frequency domain of the image signal of the current frame is added to the narrowband image signal in the image signal transmitted to the current frame. The image is restored to a wideband image signal. therefore,
In a still image without movement, the image signal component formed according to the magnitude of the movement described above becomes zero and does not contribute to image signal transmission at all. On the other hand, on the receiving side of the transmission system of the present invention, in the transmission mode shown in FIG. The high-frequency signal component yH included in the wideband signals YI and +H transmitted during the scanning line period i+2 of the first frame, i.e., the scanning line period i+2 of the first frame, recorded in a storage device such as a frame memory is extracted, and the above-mentioned First, it is added to the narrowband signal YL transmitted during the scanning line period i+2 in the +1 frame. When there is movement in the image, the narrowband signal is restored to the wideband signal in substantially the same manner as in the conventional TOI transmission method for the portion of the moving image where the movement of the image is detected. That is, in the transmission mode shown in the second figure, in restoring the narrowband signal YL transmitted in the scanning line period 1,01 of the frame into a wideband signal, the wideband signal YL transmitted in the adjacent scanning line periods 1itli, i+2, etc. A high frequency signal component YH in the signal YL+H is extracted and added to the narrowband signal YL to restore the form of the wideband signal YL+H. As described above, in the transmission system of the present invention, still image signals are transmitted in both regions A and B in the signal transmission band shown in FIG. 1(b), resulting in image quality degradation. does not occur at all. Furthermore, in the transmission system of the present invention, only the band-limited area A shown in FIG. Visual image quality deterioration due to the restriction will hardly occur.In other words, even if a moving image signal is transmitted only through transmission area A and subjected to band restriction, the image quality deterioration will not be visually noticeable.Therefore, the present invention Even if band compression transmission is performed using this method, there will be no substantial image quality deterioration in the wideband image signal, and a significant improvement in image quality will be achieved compared to the conventional method.Next, in the transmission method of the present invention, The specific configuration of the transmission device provided on the transmitting side and the receiving side will be explained.First, an example of the configuration of the transmitting side device in the transmission method of the present invention is shown in FIG. A case of band compression transmission of an image signal will be explained. In the illustrated configuration, the image signal 2 supplied to the input terminal 1 is converted into a narrowband image signal YL by limiting the signal band by a low-pass p-wave filter 6. Then, it is led to one terminal 6 of the changeover switch 7, and at the same time is led to the signal mixer 9 via the vertical low-pass p-wave converter 8.The signal mixer 9 has this vertical low-pass signal. 6 (iB attenuator 10-a The input image signal 2 and the one-frame delayed image signal 4 described above are also guided to the motion detection circuit 11, and are detected by the difference in image signal components between the two image signals with a one-frame difference. [Moving area signal that represents the magnitude of image movement]
form 2. Specifically, the moving area signal 12 is a signal indicating a moving part of the image, and is formed based on the difference image signal between two adjacent frames as described above. Nao, if only the interframe difference signal is used, there will be a difference in the image signal between frames even for still images due to noise mixed in during imaging and transmission, and jitter of the clock signal used during sampling. When this occurs, it may be erroneously determined that the image is a moving image based on the difference. Therefore, in order to make decisions regarding dynamic area signals without error, the inter-frame difference signals should not be used as they are, but must be guided to a coring circuit, an isolated point removal circuit, etc., and subjected to shaping processing before forming a dynamic area signal. do. In addition, in that case, 37927
The coring level used in the circuit is appropriately set, such as by controlling it based on the magnitude of noise contained in the image signal and the steepness of the rise of the image signal in the horizontal direction. Further, the formation of such a motion area signal is described in detail in Japanese Patent Application Nos. 57-88018 and 57-155788, which were proposed by the present inventors, so a detailed explanation will be omitted. . Therefore, in the above-mentioned motion detection circuit 11, the signal band of the image signal targeted for motion detection is made equal to the narrowband transmission bandwidth, and the motion of the image is detected based on the interframe difference of the narrowband image signal. Then, the detection output signal 12 from the motion detection is applied to the signal mixer 9, and the output image signal is attenuated by 6 dB according to the magnitude of the moving area signal in the detection output signal 12. The mixing ratio with the directional low-frequency P wave output image signal 8a is changed as follows. In other words, when the magnitude of the moving area signal 12 is k, the magnitude k is '1' for a still image, approximately '0' for a moving image with extremely large movement, and the intermediate G value. In this case, the value is set between 0 and 1 II depending on the amount of movement of the image. That is, in the signal mixer 9 in the configuration shown in FIG. 8, the magnitude of the 6 dB attenuated sum output image signal 10a is
, and when the magnitude of the vertical low-frequency p-wave output image signal 8a is 08, the magnitude of the mixed output image signal 18 is C6.
The surface input image signals 10a and 8a are mixed in such a way that the following equation holds. e -, -e + (1-k) e8 5 The image signal mixing operation according to the amount of movement of the image is such that only the 6 dB attenuation sum output image signal 10a is mixed into the output image in the still image signal. This is a mixing operation in which the proportion of the vertical low-frequency p-wave output image signal 8a mixed into the mixed output image signal 18 gradually increases as the amount of image movement increases. Such a mixed output image signal 18 is subtracted by a subtracter]4 and a low-pass p
At the same time, the p-wave output image signal of the low-pass p-wave generator 15 is also supplied to the subtracter 14 and subtracted from the mixed output image signal 18. Therefore, the combination of the low-pass p-wave filter 5 and the subtracter 14 acts as a high-pass p-wave filter for the mixed output image signal 18, and the output image signal of the subtractor 14 is teeth,
This becomes the high frequency signal component YH in the mixed output image signal 13. In addition, according to the equally simple high-pass p-wave device having such a configuration, the pass characteristic when the high-pass p-wave output and the low-pass p-wave output are added must be strictly °゛1'''. Therefore, there is an advantage that the overall transmission characteristics do not deteriorate at all. Therefore, the p-wave output high-frequency signal from the subtracter 14, the component element YH) 16, is led to the adder ]4. Low-pass p-wave device 6
The narrowband image signal (YL+Hl 19) is added to the wideband image signal I (YL+Hl 1
8 and lead it to the other terminal a of the changeover switch 7. One terminal of this changeover switch has a low-pass p
A narrowband image signal (YL, +19) is introduced from the transducer 6 and is switched at the scanning line period. When the narrowband image signal YL is extracted during the line period, the wideband image signal YL+H is extracted during the next scanning line period.The switching output signal of the switch 7 is sent to the time axis compression circuit 2.
0, and the time axes, which were equal for each signal YL+H1YL before time axis compression as shown in FIG. 5 1al, are compressed only for the narrowband image signal YL, as shown in FIG. 6 1bl. The time axis compression ratio at that time is as follows, assuming that the signal band ratio of the narrow/wide band image signal YL and YL+H is α:1.
For example, if the signal band ratio is 1:4, the time axis compression ratio is ξ, and both signal bands become equal after time axis compression. As a result of such time axis compression, Fig. 5 (b
As shown in 1, of the two scanning line (2H) periods during which the wide/narrow band image signals YL+H and YL were transmitted on the original time axis, the -H period is a blank period, and other information signals are not transmitted in a time-sharing manner. 5 (as shown in C1, the wide/narrow band image signal YL+ accommodated in the 11/4H period after time-axis compression), or by time-axis expanding the entire YL to the full 2H period. , the required transmission bandwidth can be compressed to (1'/4)/2 or %. Here, to supplementarily explain the high-frequency signal component Y■ contained in the wideband image signal YL+H, the single-wave output high-frequency signal component (YH) 16 in the configuration shown in FIG. , the addition output sum signal of the input wideband image signal 2 and its one-frame delayed signal 4, that is, the low # and P waves in the time axis direction are applied. In this state, if there is movement in the image, the high-frequency signal component YH will be significantly attenuated, making it impossible to transmit detailed information about the image. Therefore, for the moving image portion, the high frequency image signal component yH is formed only from the input wideband image signal 2 and used for subsequent signal processing. However, as mentioned above, since the high-frequency image signal component YH is transmitted only during every other scanning line period, a high-pass p-wavelength filter is used to convert the wide-band image signal 2 for transmission into its horizontal direction. If high-frequency signal components are simply extracted, the high-frequency components in the vertical spatial frequency domain become aliasing distortion and fall within the desired signal band, causing interference. Therefore, a vertical low-pass p-wave filter is used to prevent the generation of disturbances due to such aliasing distortion. Next, FIG. 6 shows a configuration example of a receiving side device in the transmission system of the present invention. In the illustrated configuration, the time-division multiplexed image signal of the form shown in FIG. 5 la is supplied to the input terminal 22 after one demodulation. The input image signal having the signal form shown in FIG. 5 1c) is first led to the time axis converter 28, and
The time axis is restored by converting the original signal form shown in FIG. . Next, the converted output image signal 24 of the time axis conversion circuit 28 is supplied to the frame memory 25, the motion detection circuit 27, and the vertical low-pass p-wave converter 80, and is also supplied to one terminal of the changeover switch 38 and the adder. It is also supplied to one terminal of a7. On the other hand, the one-frame delayed image signal 26 from the frame memory 25 and the p-wave output image signal 81 from the vertical low-pass p-wave generator 80 are supplied to the signal mixer 29, and the frames are interleaved in the same manner as on the transmitting side. Under the control of the motion area signal 28 from the motion detection circuit 27, which detects the amount of image movement from the difference, like the sending side, at a ratio according to the amount of image movement,
The one-frame delayed image signal 26 and the vertical low-frequency p-wave output image signal 81 are mixed. Next, the mixed output image signal 82 of the signal mixer 29 is guided to a high-pass p-wave circuit consisting of a low-pass p-wave filter 88 and a subtracter 85, as on the transmission side, and the mixed output image signal 82 is The high frequency image, signal component (YH) 86 is extracted and supplied to the other terminal of the adder 87, and the narrowband image signal YL in the time axis conversion output time division multiplexed image signal 24 is
is added to the scan line period. The addition output broadband image signal (YL+H) of the adder 37 is guided to the other terminal a of the changeover switch 88. This changeover switch 38 directs the signal as it is to the output terminal during the scanning line period of the wideband image signal YL+H in the time-axis converted output time-division multiplexed image signal 24 supplied to one terminal, and controls the scanning of the narrowband image signal YL. During the line period,
Addition output broadband image signal YL+ supplied to the other terminal a
It is switched at the scanning line period so as to lead H to the output terminal. As a result, as the switching output signal 39 of the changeover switch 88, the broadband image signal component Y is output in all sequential scanning line periods.
The wideband image signal restored by arranging L+H is sent to output terminal 4.
Extracted from 0. The operating principle and basic configuration of the transmitting/receiving device of the broadband image signal band compression transmission method of the present invention are as described above, but by developing the operating principle and basic configuration, band compression transmission is performed with an even better signal-to-noise ratio. The present invention will be described in further detail with reference to an example in which it is possible to perform the following. First, FIG. 7 shows another configuration example in which the transmitting side apparatus having the configuration shown in FIG. 8 is improved as described above. To explain only the differences between the configuration example shown in Figure 7 and the configuration shown in Figure 3, in the configuration shown in Figure 8, the wideband image signal YL+)l used as the transmission output is narrower than the low-frequency E wave output. Although the band image signal (YL) 19 is formed by adding the high frequency signal component YH of the mixed output wide band image signal 18, in the configuration example shown in FIG. dB reduced attenuation frame summation output image signal 10;
When the input image signal is a motion image signal, the vertical wideband image signal I YL+Hl 41 and the signal mixer 9
Under the control of the motion area signal 12 from the motion detection circuit 1, the two signals are appropriately mixed by weighted addition at a ratio according to the amount of motion of the image, and the mixed output signal 42 is output. wide-band image signal component YL+H and narrow-band side image signal component I (YL) whose band is limited by the low-pass p-wave device 6.
19 are alternately switched by the scanning line period inversion operation of the changeover switch 7 and supplied to the time axis compression circuit 20, thereby obtaining a time division multiplexed image signal for band compression transmission similar to that in the configuration shown in FIG. There is. By performing the image signal processing described above with reference to FIG.
Since the inter-frame output image signal is used as the output image signal, the signal-to-noise ratio is 8.
This will result in a dB improvement. Note that the output image signal for transmission of the transmitting side device with the configuration shown in FIG. 7 has the same signal form as that with the configuration shown in FIG.
It goes without saying that the time-division multiplexed image signal for transmission with the configuration shown in the figure can be received by the receiving side device with the configuration shown in the sixth figure described above and restored to the original wideband image signal. However, similar to the transmitting device with the configuration shown in FIG. 7, a better signal-to-noise ratio can be obtained.1. FIG. 8 shows another example of the configuration of the receiving side device when the configuration shown in Figure e is improved. That is, in the time division multiplexed image signal for transmission in which the signal form shown in FIG. Therefore, the noise power mixed in the transmission system is limited to the narrowband image signal Y.
It has the same magnitude for L and wideband image signal YL+H. However, in the receiving device, the time axis of the narrowband image signal YI, with respect to the wideband image signal YL+H, is
Since the restoration is performed by expanding at a ratio opposite to that in the transmitting device, that is, at a ratio of 200 nm, the noise power per unit frequency contained in the narrowband image signal yL after such time axis expansion is: If the noise spectrum characteristics are flat, the noise will be twice as large when mixed in the transmission system. Therefore, the signal-to-noise ratio between the narrowband image signal YI and the wideband image signal YL+H in the frequency domain within the signal band of the narrowband image signal YL after time-axis expansion described above is that the narrowband image signal YL is α as a result, the overall signal-to-noise ratio in this frequency domain is +10/)/
It will decrease by 2. In particular, in the case of FM transmission of such a time-division multiplexed band compressed image signal, the noise mixed into the transmission signal becomes so-called triangular noise, so the degree of deterioration of the overall signal-to-noise ratio on the receiving side described above further increases. . The receiving side device having the configuration shown in FIG. 8 in the transmission system of the present invention is designed to eliminate the above-described drawback of the conventional signal-to-noise ratio deterioration. The configuration and operation of the receiving side device shown in FIG.
Only the differences compared to the illustrated receiving side device will be described. That is, in the conventional device shown in FIG. 6, the narrowband image signal Y is used for both still images and moving images.
A wideband image signal YL is obtained by adding the high frequency signal component YH to L.
+H, whereas in the receiving device according to the present invention shown in FIG. Wideband image signal (YL+H) in which all signal bands were transmitted during the relevant scanning line period before the system period.
26 is taken out from the frame memory 25 and used.
Similarly to the conventional device shown in FIG. The image signal L YL+H) 4'8 is not used when reproducing a still image, but is used only when reproducing a moving image in which the broadband image signal YL+H of one frame period before cannot be used instead. As a result, the deterioration of the signal-to-noise ratio that conventionally occurs in reproduced image signals during time-division multiplex transmission that performs time-axis compression and expansion is limited to only moving images where such deterioration of the signal-to-noise ratio is not noticeable. For still images in which deterioration in the signal-to-noise ratio is easily noticeable, the cause of such deterioration in the signal-to-noise ratio can be completely eliminated. The operating principle and transmitter/receiver of band compression transmission according to the present invention have been described above for a black and white image signal corresponding to a luminance signal component.Next, the case of performing band compression transmission of a color image signal will be described. The operating principle of color image signal transmission according to the method of the present invention is to perform signal processing similar to the signal processing based on the operating principle described above for monochrome image signals on the luminance signal Y and two color signals al, which constitute the color image signal. The purpose is to do something about O. However, color signal a1. Regarding a, there is no deterioration in image quality even if the vertical resolution is reduced to half the vertical resolution of the luminance signal Y. Therefore, in order to reduce the color signal transmission band, the color signal is thinned out every other scanning line. Transmit. That is, regarding the luminance signal Y in the color image signal,
9th. As shown in Figure Ta), alternately transmitting the wideband signal component YL+H and the narrowband signal component YL in each successive frame consisting of odd and even fields in the scanning line is effective for the black-and-white image described above with reference to Figure 2. The operating principle of signal transmission is the same, but for color signals C, ,C, two color signals are transmitted in each successive frame consisting of odd and even fields, as shown in Figure 9Tb). Both color signal components C□I, +H, OIL, and OgL+H are transmitted alternately in the scanning lines so that C□ and C9 are transmitted alternately in the scanning lines, and the wideband signal components L+H and the narrowband signal components are also transmitted alternately in the scanning lines. a
St+ is transmitted in combination. As mentioned above, as a transmitting/receiving device for performing signal processing based on almost the same operating principle for the luminance signal and color signal in the color image signal, the same signal processing for both signals is performed by the same circuit. FIG. 10 shows an example of the configuration of the transmitting side apparatus of the transmission system of the present invention in the case where the time division multiplexed color image signal having the signal form as described above is transmitted in a band compressed manner. In the transmitting side device having the configuration shown in the figure, a luminance signal Y and two color signals C+, , C9 are input to input terminals 45 and 46.
．． 47 and 47, respectively. Note that the color signal is 0. ,
The signal band of O, is generally b of the signal band of the luminance signal Y.
If there is a certain degree, it is sufficient in terms of image quality. The chrominance signals C□, C8 in the signal band are passed through a vertical low-pass p wave filter 49.
50, band limitation is applied to each vertical spatial frequency region to prevent so-called aliasing distortion components from occurring when line-sequential transmission is performed. The p-wave output signals of the vertical low-pass p-wave generators 49 and 50 are switched alternately between the scanning lines by the switch 5 to form a line-sequential color signal 52, and this line-sequential color signal 52 and the input luminance signal (Y )4
8 to the time division multiplexing circuit 58, and
A time division multiplexed image signal 54 having a signal form as shown in FIG. The time-division multiplexed image signal 54 is subjected to signal processing similar to that in the configuration shown in FIG. Since there are some differences between the two, in order to switch the circuit configuration or circuit operation for each transmission period, the changeover switches 64, 72 and the open/close switch 78 are operated at the timings shown in FIG. 12. . FIG. 12 is a time chart showing the operation processes of the switches 4fl, 72 and 78 in comparison with each other. As is clear from the switching operation mode of each switch shown in the figure, the eighth
Signal processing exactly similar to that described above is performed for the illustrated configuration to form a narrowband luminance signal YL and a wideband luminance signal YL+H. On the other hand, regarding the color signal transmission period, almost the same signal processing is performed in the switching operation mode of each switch shown in the figure, but since the two color signals C, , C, are transmitted line sequentially, The switching operation mode is set with this point in mind. In connection with such switching operation,
The configuration of the vertical low-pass p-wave filter 61 will be explained with reference to FIG. 18. In the vertical low-pass filter having the configuration shown in FIG. 18, the time division multiplexed color image signal to be transmitted is transmitted as shown in FIG.
a), (For BL, as mentioned above, since the wideband signal component and the narrowband signal component are transmitted alternately on the scanning lines, the central point a of the IH memory rows connected in cascade as shown in the figure At the moment when the narrowband luminance signal YL appears! Well, the other points b, b', d, in the cascade
A broadband luminance signal YL+H appears at d'. Therefore, points b and b' are connected to the coefficient multiplier 80 via an adder q8b, and points d and d' are connected to a coefficient multiplier 79 via an adder 78d, and multiplied by appropriate coefficients. By performing weighting, it is possible to construct a low-pass p-wave filter in the duty direction for the high-band luminance signal component yH. . On the other hand, regarding color signals, when one narrowband color signal OIL appears at the midpoint a of the IH memory column, the same wideband color signal 01L+H appears at the other point C1C'' of that IH memory column. The other broadband color signal 0stb+H appears at point b', the other narrowband color signal CZL appears at point d'', and the other narrowband color signal CZL appears at midpoint a. At the time when C2L appears, the other broadband color signal OgL+H appears at points c and c'. Therefore, point 0. By connecting C' to the coefficient multiplier 81 via the adder 780 and weighting it by multiplying it by an appropriate coefficient, a vertical low-pass p-wave filter for the high-frequency color signal component CH can be constructed. I can do it. Therefore, each switch as described above is 64°72! ,
By the switching operation of 78, a time-division multiplexed color image signal in a signal form including a blank period as shown in FIG. 11+bl is obtained on the output side of the open/close switch 73 in the configuration shown in FIG. If the signal is supplied to the time axis conversion circuit 74 and the time axis of the entire signal is expanded appropriately,
As shown in FIG. 1, a time-division multiplexed color image signal having a signal form in which the blank period is closed is obtained. Next, FIG. 14 shows an example of the configuration of a receiving side device in the transmission system of the present invention, which receives a time-division multiplexed color image signal having the signal format shown in FIG. 11(C) and restores a wideband color image signal. Shown below. In the structure of the chart, the 11th
After the time-division multiplexed color image signal in the signal form shown in FIG. 01 is supplied to the time axis converter 87 and converted into the signal form shown in FIG. Similarly, the luminance signal and the line-sequentially transmitted color signal are processed. FIG. 15 shows a time chart of switching operation modes of the switches 92, 98, and 101 corresponding to each transmission period of the luminance signal and color signal in this case. Further, the vertical low-pass p-wavelength filter 91.9g can be constructed in substantially the same manner as shown in FIG. As described above, a time-division multiplexed color image signal consisting of a wideband luminance signal YL+H and two types of wideband color signals O□L+H and O1L+H is obtained on the switching output side of the changeover switch 98, but the two types of color signals are Since the line-sequential transmission is carried out alternately, it is necessary to restore the normal mode of simultaneous transmission of each scanning line. A vertical low-pass p-wave converter 99 performs the function of restoring the signal form, and its configuration is as shown in FIG.
fi: These are connected in cascade, and the adder 108 adds and extracts the color signals separated by 2H periods at the input and output terminals, and also extracts them from the midpoint of the cascade connection. Therefore, in the end, a time-division multiplexed color image signal having the signal form shown in FIG. 11(a) is obtained on the output side of the changeover switch 101 in the configuration shown in FIG. led, brightness 108 and 2
Color signals 104 and 105 of each type are taken out. Next, FIG. 17 shows an example of the configuration of the receiving side device when a scan conversion circuit for converting interlaced scanning to sequential scanning is added to the configuration shown in FIG. 14 to further improve image quality. show. The illustrated configuration is a changeover switch in a part of the configuration shown in Figure 14, which is partitioned by dotted lines]0
1 switching output signal 110 and the detection output signal 111 of the motion detection circuit 90 are extracted, and the time division multiplexed color image signal 1 is obtained.
10 and the l-field delayed signal 121 from the field memory 112 are added and combined by an adder 115 via vertical low-pass p-wave devices 118 and 114, respectively, which are controlled by the motion detection output signal 111.
6 is processed by the YO separation time axis conversion circuit 117,
It converts interlaced scanning to sequential scanning,
The details can be based on the descriptions of Japanese Patent Applications No. 57-88018 and No. 57-155788 [Adaptive Space-Time Interpolation Filter] proposed by the present inventors. , Therefore, the interpolated signal 116 obtained by the above-mentioned addition synthesis
and the original signal 110 to the YO separation/time axis conversion circuit [7], and by the combination of the [H memory and changeover switch as shown in Fig. 18], the IH4 extended signal is converted according to the time chart shown in Fig. 19. By appropriately combining them, it is possible to separate the time-division multiplexed luminance signal Y and chrominance signal C, and at the same time obtain a progressive scanning chrominance signal in which the horizontal scanning period is set to 1 of the original period. As described above, the YO separation of the time-division multiplexed color image signal and the time axis compression for progressive scan conversion are performed by switching each signal component at the timing shown in FIG. 19 using the configuration shown in FIG. 18. However, among the 12 memory read signals in the time chart shown in Figure 19, for the color signal, each signal marked with 11H) is used as the reference signal, and for the luminance signal W, the OH delay and 2H delay are used. , that is, the output luminance signals 189a and 1a90 in the configuration shown in FIG. 18 are also read out, and these luminance signals are used for vertical edge and contour correction. As mentioned above, FIG. 20 shows an example of the circuit configuration when vertical contour correction is performed using each of the OH-delayed, IH-delayed, and 2H-delayed luminance signals. In the illustrated configuration FfL, each delay signal 160.1f of OH, 21 (and IH)
11 and 162, adder 168, -6dB attenuator 16
4. The subtracter 166, the attenuator 167, and the adder 168 are used to appropriately combine the vertical contour correction signal]69, but since this circuit configuration is widely used in cameras and the like, the details thereof will be explained below. Further explanation will be omitted. Therefore, in the YO separation/time axis conversion circuit 117 having the configuration shown in FIG. For YO separation of time-division multiplexed color image signals, time axis compression for progressive scan conversion, and vertical contour correction (DOH, IH, 2H delayed signals 189
The simultaneous formation of a, 1181890 is its great advantage. , Therefore, in the receiving side device having the configuration shown in FIG.
- Since the field memory 112 is used to obtain the delayed signal, the frame/mo IJ 89 in the configuration shown in FIG.
Together with this, a memory device for 1.5 frames is used. In contrast, the configuration shown in Figure 17

[FIG. 21 shows an example of the configuration of the receiving side device in the case where a one-field delayed signal is obtained without adding a field memory. In the illustrated configuration, two cascaded field memories 89a and 89b are used in place of the frame memory 89 in the configuration illustrated in FIG.
A one-field delayed signal is taken out from the midpoint of the cascade. However, simply replacing the frame memory with two cascade-connected field memories will result in a wideband luminance signal component YL+H and a narrowband luminance signal component YL for each scanning line period. In addition, as for the color signal, the broadband color signal component OL+H and the narrowband color signal component OL of the line sequential signal consisting of 1 and g types of color signals appear alternately. (It is not possible to use the 1-field delayed signal as is.) Therefore, the converted output time division multiplexed color image signal 88 of the time axis converter 87 is not used as the input signal of the field memory 89a, but the switching output image signal of the switching switch 98 is used as the input signal of the vertical low-pass p-wave converter. 99 and changeover switch 101
The color signals are supplied to the field memory 89a through a line-sequential color signal interpolation circuit. Since the memory input image signal includes the luminance signal Y and the two types of color signals cl and O, both of which are broadband signal components L+H, the one-field delayed signal obtained at the output side of the field memory 89a is as follows.
It is always possible to use a wideband signal of L+H, which is sufficient for progressive scan conversion. However, in the transmission system of the present invention, as explained above, since both the transmitting side device and the receiving side device have a frame memory, the noise reducer function is added using the frame memory of this invention. be able to. FIG. 22 shows an example of the configuration of a transmitting side device to which such a noise reducer function is added. In the configuration shown in the figure, the time-division multiplexed color image signal 54 formed in the same manner as in the configuration shown in FIG. The signal mixer 60 generates the domain signals 70 and 70a.
and 60a, respectively. The signal mixer 60a converts the time-division multiplexed color image signal 54 supplied to the motion detection circuit 57 and the one-frame delayed signal 55a into a motion area signal 70 representing the magnitude of motion.
a, the output voltage eoutl of the mixed output signal 69b, the voltage of the one-frame delayed signal 55a from the frame memory 55 is e□, and the voltage of the input time division multiplexed color image signal is e, and further, if the size of the moving area signal 70a is 0, then eoutl-
1-e1+ (x-kl)e. becomes. Therefore, if the size of the moving area signal @70a is set to 01, when the motion of the image is large, it is set to °゛0'', and when it is a still image, it is set to a value in the range of 0<kl<1, then the moving area Since there is a relationship between the value of the signal 70a of 1 and the degree of improvement in the signal-to-noise (SN) ratio, the magnitude of the dynamic area signal 70a is set to 0 so as to obtain the desired degree of improvement in the SN ratio. However, the size □ is continuously changed depending on the amount of image movement to prevent blurring of the image due to movement.The above signal processing allows the mixed output of the signal mixer 69a to be For the signal o9b, in the case of a still image or an image with small movement, a color image signal with an unimproved signal-to-noise ratio is obtained.
The circuit operation according to the illustrated configuration is the same as that in the tenth illustrated configuration, and the relationship between the magnitude of the other detection output signal 70 of the motion detection circuit 5 and the magnitude of the image motion is
10 is the same as in the configuration shown in FIG. Next, the circuit operation for improving the SN ratio using a frame memory in the receiving side apparatus will be explained.The circuit configuration is as shown in FIG. 28, and operates as follows. That is, in the illustrated configuration, as in the configuration shown in FIG. 21, the input time-division multiplexed color image signal is converted by the time axis converter 87 into a time-division multiplexed color image signal having the signal form shown in FIG. After transforming each narrowband signal component YL. For the transmission period of CIL, OH, there are a vertical low-pass p-wave converter 91, a changeover switch 92, a horizontal low-pass p-wave converter 98. A circuit consisting of a subtracter 94 and an adder 95 adds each high frequency signal component HlCIH and %H, respectively. The changeover switch 98 provided at the output end of such a circuit falls to the terminal (a) side during the transmission period of each wideband signal component YL+H"IL+)t"2L+H in the input time-division multiplexed color image signal, and During the transmission period of the band signal component YL I CIL 101L, the terminal (b
) side, 1 As mentioned above, the G high frequency signal component YH'
OIH, 011) I is added to extract each signal component that has been made broadband. The switching output signal of the switch 98 is guided to a color signal interpolation circuit consisting of a vertical low-pass p-wave device 9g and a changeover switch 100, and two types of color signals C□ and C2 that have been alternately transmitted line-by-line are output. Interpolation is performed in the form of simultaneous transmission signals for each scanning line. Such color signal interpolation output signal 150
is supplied to the motion detection circuit 90 and stored in the field memory 89.
The motion of the image is detected based on the result of comparison with the one-frame delayed signal [54] from the frame memory device consisting of the continuous connection of signals a and 89b. Input signal 150 of motion detection circuit 90
and 154 also supplies the signal mixer 97a, and the wideband signal component YH+L + in the color signal interpolation output signal 150.
CIL++H" 11L+H transmission period, the changeover switch 158 is turned to the terminal lal side, and signal mixing is performed at a ratio corresponding to the magnitude of the motion area signal 152 from the motion detection circuit 90, and the signal mixer 97a Obtain the output voltage e.utg eouts-, -e8+11-, le. 3, where eB is ] frame delayed signal 154
, and e is the color signal interpolation output signal 15
It has a size of 0. Note that the value of 2 for the large size of the moving area signal 152 is appropriately set so as to obtain the required degree of improvement of the SN ratio, as in the case of the noise reducer in the transmitting side device, and the value of 2 is set appropriately so that the required degree of improvement of the SN ratio can be obtained. As it grows, the size increases to 8
is made smaller toward °"0"°. On the other hand, the color signal wIrIIJ output signal 159 contains GtZ+narrowband signal component YL r 011. +o2L transmission period, the signal mixer 97a operates in the same manner as described above, but during these transmission periods, the changeover switch 1
58 to the terminal fbl side, signal mixing is performed at a ratio corresponding to 1 to the magnitude of the motion area signal 151 from the motion detection circuit go. In this case, the magnitude of 51 is 1, as the motion of the image increases, II Q I
Set so that it becomes smaller toward I. Through this signal processing, the mixed output signal 155 of the signal mixer 97a becomes a time-division multiplexed color image signal with an improved S/N ratio for a still image. Next, we will explain the formation of a high frequency signal component in the horizontal spatial frequency domain that should be added to the narrowband image signal reproduced by the receiving device to widen the band.In each of the configuration examples of the receiving device described above, For moving images, the required high-frequency signal components are formed from the narrowband image signal and other image information within the same field. That is, the second
8 In the configuration shown, the vertical low-pass p-wave filter 9]
, a changeover switch 92, a horizontal low-pass p-wave unit 98, and a subtracter 94 form a high-frequency signal component.
In the receiving side device having the configuration shown in FIG. 4, in addition to forming the high frequency signal component in the same manner as described above, the image signal 161 which precedes the narrowband image signal to which the high frequency signal component is to be added by one frame period is used. is read from the frame memory 89a, and -H
Via memory 156, IH memory 57, adder] 58
and 6 d13 attenuator 159 to perform vertical band limiting.
The wave output signal 162 is supplied to one input terminal of the signal adder 160, and the switching output image signal of the changeover switch 92 is supplied to the other input terminal. In this signal adder 160, according to the magnitude of the detection output signal of the motion detection circuit 90, that is, the motion area signal, if there is no motion of the image or there is little motion, the above-mentioned p
Uniweighted mixing is performed in such a manner that the wave output image signal 162 is mainly output, and when the movement of the image is large, the switching output image signal of the switch 92 is mainly output. The operation of the other circuit parts in the configuration shown in FIG. 24 is the same as in the configuration shown in FIG. However, the converted output image signal 88 of the time axis conversion circuit 87
is used as one input signal of the motion detection circuit 90, and the field memo IJ forming the frame memory is used as the other input signal so as to temporally precede the converted output image signal 88 by one frame period. 89 a, 8
9. Make the delay amount of b slightly shorter than one field period. Further, the delay circuit 168 is connected to the second signal mixing circuit 97a.
This is for adjusting the delay amount of one of the input signals so that the human input signals have a time difference of exactly one frame. In the configuration examples of the transmitting/receiving device shown in FIGS. 22 and 28, the frame memory used in each transmitting/receiving device of the transmission method of the present invention is used to perform the noise reducer function, so that the transmission side and The signal-to-noise ratio can be improved on both the receiving side, and in the receiving side device with the configuration shown in Figure 24, even if there is movement in the image, signal processing can be performed simply using the image signal of the previous frame period. A reproduced image signal with higher resolution can be obtained than when the above method is used. Note that among this type of image signal band compression transmission method, there is a transmission method that increases the compression rate of the image signal band by combining a frame memory and a high-order dot interlace scanning method; When transmitting analog image signals, it is necessary to accurately match the phase of resampling at the receiving device with the phase of sampling at the transmitting side, maintain the waveform transmission characteristics of the transmission system well, and It is necessary to give sufficient consideration to gain characteristics, differential phase characteristics, etc. On the other hand, the transmission system of the present invention does not use dot interlace scanning, so not only does resampling to reproduce the sample points be unnecessary, but the characteristics of the transmission system are also It has the advantage that wideband color image signals can be sufficiently transmitted with transmission characteristics necessary for monochrome image signal transmission. Effects As is clear from the above explanation, according to the present invention, image quality deterioration during still image transmission, which conventionally occurred in a transmission method in which wideband signal components and narrowband signal components were time-division multiplexed, can be avoided. By using frame memory, it is possible to completely eliminate this problem and to compress the bandwidth of a wideband high-quality image signal. The resolution is reduced only in the part of the moving image where the image is blurred due to the accumulation effect, so that the detection limit or tolerance limit for visually degraded image quality degradation is met, and no substantial image quality degradation occurs. You can avoid it. In general, according to the present invention, in order to improve the image quality during moving image transmission, the horizontal resolution of the moving image area is not simply lowered, but high-frequency signal components related to both horizontal and vertical resolution are That is, it is possible to achieve band compression transmission by suppressing the transmission of only the signal component that visually has the least influence on image quality deterioration as a high-resolution component in the diagonal direction. Further, according to the present invention, by transmitting the inter-frame sum signal component for the still image portion, it is possible to improve the S/N ratio of the camera image output image signal by 8 dB, and further improve the reception speed. When playing back a narrowband transmission image signal in a still image area by widebanding it on the side, avoid adding high frequency signal components to the narrowband transmission image signal whose S/N ratio has decreased due to time axis conversion. SN of
By replacing it with a broadband transmission signal with a good ratio, the overall SN ratio can be improved. Furthermore, according to the present invention, even when transmitting color image signals, the color signals are transmitted line-sequentially and alternately, and the same signal processing is applied to the luminance signal, thereby realizing a significant compression of the color signal band. In addition, the signal processing of luminance and chrominance signals can be efficiently performed by time-division use of the same circuit. Y
The same circuit can also be used for signal processing for time axis conversion during C separation, so that the signal processing can be performed efficiently and the circuit configuration can be simplified. In addition, the circuit size can be greatly reduced by efficiently performing YO separation of the time-division multiplexed color image signal, time axis conversion for progressive scan conversion, and signal delay for vertical contour correction by using the same circuit. It is possible to achieve various remarkable effects, such as being able to reduce the amount of memory and making the receiving side apparatus more economical by using both the frame memory and the field memory.

[Brief explanation of the drawing]

Figure 1 is a diagram and signal waveform diagram showing the aspects of wide and narrow band signal transmission in the conventional time-base compression transmission system, respectively. FIG. 3 is a block diagram showing an example of the configuration of a transmitting side device in the transmission system of the present invention; FIG. 4 is a diagram showing an example of the configuration of a transmission side device in the transmission system of the present invention; FIG. Figures 5(C) and 5(C) are signal waveform diagrams sequentially showing aspects of time axis conversion in wide and narrow band signal time division multiplex transmission, and Figure 6 is a signal waveform diagram showing an example of the aspect of transmission according to the present invention. FIG. 7 is a block diagram showing another configuration example of the transmitting device in the transmission method of the present invention; FIG. 8 is a block diagram showing an example of the configuration of the receiving device in the transmission method of the present invention. Figures 9 fa) and [b], which are block diagrams showing other configuration examples, respectively show aspects of time-division multiplexing transmission of both wide and narrow band signal components of luminance signals and color signals during color image transmission in the transmission system of the present invention. 10 is a block diagram showing still another configuration example of the transmitting side device in the transmission system of the present invention, and FIG. 11(a) to (C
) is a signal waveform diagram sequentially showing an example of signal conversion for time division multiplex transmission of luminance/color image signals in the configuration of the transmitting device, and FIG. 12 is a signal switching diagram of each part in the configuration of the transmitting device. FIG. 13 is a block diagram showing an example of the configuration of the vertical low-pass p-wave device in the configuration of the transmitting device, and FIG. 14 is the timing chart showing the timing of the receiving device in the transmission system of the present invention. A block diagram showing another configuration example, FIG. 15 is a time 1,000 yard diagram showing the timing of signal switching of each part in the same configuration of the receiving side device, and FIG. 16 is a configuration example of the frame memory in the same configuration of the receiving side device. FIG. 17 is a block diagram showing an example of the configuration of a circuit section added to the configuration of the receiving device, and FIG. 18 is a block diagram showing the configuration of the receiving device. A block diagram showing an example of the configuration of the conversion circuit, FIG. 19 is a time chart showing the operation timing of each memory device in the configuration of the receiving device, and FIG. 20 is a vertical contour correction in the configuration of the receiving device. FIG. 21 is a block diagram showing an example of the configuration of the circuit; FIG. 21 is a block diagram showing still another example of the configuration of the receiving device in the transmission system of the present invention; FIG. 22 is a block diagram showing still another example of the transmitting device in the transmission system of the present invention. FIG. 28 is a block diagram showing another example of the configuration of the receiving side device in the transmission system of the present invention; FIG. 24 is a block diagram showing still another configuration of the receiving side device in the transmission system of the present invention. FIG. 2 is a block diagram illustrating an example. 1, 22.45.46.47.76, 88.106.
IP'2. ]J8--Input terminal 8, 25.55.811--Frame memory 5, 17
．． 87.56.66, 78.911+, 108.11
5.158°160, 1 (18,168...adder 6
, 15. L3.58.98...low-pass p-wave unit 7,
+118.51.6L 92.98.100a, 1
01.186a, 186b. 186C, 187, 138, IIJ...Switch 8,
80.49.50.61.91.99.118.114
...Vertical low-pass p-wave unit 9, 29.69.97...Signal mixer] Oa, e8
．． 159.164.167 --- Attenuator] 1.27.5
7.90...Motion detection circuit 14, 1.60.94.1
86...Subtractor 20...Time axis compression circuit 21, +0.82.8L 108.104.105.
]09a, ]09b,... Output terminal 28, 87... Time axis converter 58... Time division multiplex circuit 77, 107.124.125.126.1BB,
130.131.182゜184, 157...IH
Memories 79, 80.81...Coefficient units 89a, 89b, 112...Feel Fme% I
J102...YO separation circuit 117...YO separation/time axis conversion circuit Patent applicant: Japan Broadcasting Association Patent attorney Kosaku Sugimura, 11□゛′″::・・
・,j ;・1,・4・− Figure 1 (a) Figure 1 (b) Water frequency (bandwidth) Figure 1 (C) Figure 1 (d) iIs2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 9 Figure 54 Figure 16 Figure 17 Figure 21

Claims (1)

[Claims] L When transmitting a wideband image signal component for transmission and a narrowband image signal component for transmission alternately in each horizontal scanning period to perform band compression transmission of the wideband image signal, on the transmitting side, the vertical spatial frequency [2] consisting of an input wideband image signal with no band limitation applied to the domain and horizontal spatial frequency domain, and band limitation applied only to the high range of the vertical spatial frequency domain in the high range of the horizontal spatial frequency domain. The amount of movement of the image detected between adjacent frames forming the second wideband image signal component consisting of the input wideband image signal is the first
When the amount of motion of the image does not exceed the predetermined level, the first wideband image signal component is used as the broadband image signal component for transmission, and when the amount of motion of the image exceeds the first predetermined level, the amount of motion of the image is determined. An image signal component formed by weighted addition of the first wideband image signal component and the second wideband image signal component at a ratio of A transmission image signal is transmitted in which the transmission wideband image signal component is transmitted only during one of the corresponding horizontal scanning periods, and the receiving side transmits a transmission image signal that is compatible with the received transmission image signal. From the image signals of two adjacent frames,
An eighth wideband image signal component in which band-limiting is not applied to the vertical spatial frequency domain and the horizontal spatial frequency domain, and a fourth wideband image in which band-limiting is applied only to the high band in the vertical spatial frequency domain in the high band in the horizontal spatial frequency domain. and when the amount of image motion detected between the image signals of two adjacent frames does not exceed a second predetermined level, the eighth wideband image signal component is added to the image signal for transmission. and when the amount of movement of the image exceeds the second predetermined level, the eighth wideband image is replaced with the narrowband image signal component of the image at the first ratio determined according to the amount of movement of the image. The wideband image signal is restored by replacing the narrowband image signal component in the transmission image signal with an image signal component formed by weighted addition of the signal component and the fourth wideband image signal component. Wideband image signal band compression transmission method. λ The transmission method according to claim 1, wherein the first wideband image signal component is a sum signal between two adjacent frames in the input wideband image signal. Signal band compression transmission method. & Wideband image signal band compression in the transmission system according to claim 1, characterized in that the input wideband image signal whose signal-to-noise ratio has been improved by a noise reducer is used as the wideband image signal component of [1]. Transmission method. Table 1. In the transmission system according to claim 1, the narrowband image signal component having a predetermined band formed from the input wideband image signal via a low-pass p-wave filter having a predetermined passband is input to the narrowband image signal component having a predetermined band. A wideband image signal band characterized in that the first wideband image signal component is an image signal component formed by adding high frequency components of sum signals between image signals of two adjacent frames in the wideband image signal. Compressed transmission method. & In the transmission system according to claim 1, a low-pass p-wave filter having a predetermined passband from the input wideband image signal or the input wideband image signal whose signal-to-noise ratio has been improved by a noise reducer. The vertical spatial frequency in the high range of the horizontal spatial frequency domain of the input wideband image signal or the input wideband image signal whose signal-to-noise ratio has been improved by the noise reducer is added to the narrowband image signal component having a predetermined band formed through the input wideband image signal. A wideband image signal band compression transmission system, characterized in that the second wideband image signal component is an image signal component formed by adding low-frequency components of regions. a In the transmission system according to claim 1, a broadband image signal component in a preceding frame among two adjacent frames in the received transmission image signal is used as the eighth broadband image signal component. A wideband image signal band compression transmission method characterized by the following. 7. In the transmission method according to claim 1,
A wideband image signal component in the received image signal for transmission and an image signal component replaced with the narrowband image signal component are weighted and added at the first ratio determined according to the amount of movement of the image to produce the image. Broadband image signal band compression transmission system characterized by forming signal components 1. '8. In the transmission system according to claim 1, the high-frequency component of the wideband image signal component in the preceding frame of two adjacent frames in the transmission image signal is used as the narrowband image in the subsequent frame. A wideband image signal band compression transmission system characterized in that an image signal component formed by adding to a signal component is used as the eighth wideband image signal component. 9. In the transmission system according to claim 1, a high-frequency component of a wideband image signal component that is close to the narrowband image signal component in the transmission image signal and the narrowband image signal component in the same field is provided. A high frequency component in a wideband image signal component near the narrowband image signal component among the image signal components replaced in the field one field before the band image signal component is used as the amount of motion of the image. The second determined according to
Wideband image signal band compression characterized in that the fourth wideband image signal component is an image signal component formed by adding an image signal component formed by weighted addition to the narrowband image signal component at a ratio of Transmission method. 10. In the transmission method according to any one of claims 1 to 9, two color signals in the input wideband image signal are transmitted through a vertical low-pass p-wavelength filter, respectively, and A wideband image signal band compression transmission system characterized in that the input wideband image signal is replaced with a time division multiplexed image signal formed by sequentially and alternately time division multiplexing a luminance signal. 1t In the transmission system according to claim 10, the time-division multiplexed image signal is delayed for one field period via a field memory, and the time-division multiplexed luminance signal and the color signal are separated and progressively scan converted. 1. A wideband image signal band compression transmission system characterized in that interlaced scanning can be converted to sequential scanning by simultaneously performing time axis compression. 1t- In the transmission system according to claim 11, a frame memory formed by cascading two field memories is used to transfer a one-field delayed signal necessary for scan conversion from a frame memory used for other signal processing. 1. A wideband image signal band compression transmission system characterized by being able to form a wideband image signal. 1 & Claim 12 In the transmission system, a wideband image signal whose bandwidth has been restored for both the luminance signal and the color signal is supplied to the cascade-connected two-information field memory, and the wideband image signal for each line is restored. A wideband image signal band compression transmission system characterized in that a luminance signal and two line-sequentially alternating wideband color signals are obtained. −. Story: In the transmission method according to any one of claims 10 to 18, the Y of the time division multiplexed image signal is
Broadband image signal band compression characterized in that a delayed signal for vertical contour correction, a delayed signal for one horizontal scanning period, and a delayed signal for two horizontal scanning periods are simultaneously extracted in addition to time axis compression for O separation and progressive scan conversion. Transmission method.