JPH0462630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television signal receiving device, and more specifically, it converts an interlaced image signal, which has been subjected to band compression processing using multiple sub-Nyquist sampling, into a sequential scanning signal. This relates to a device for converting

Conventional technology A method for reducing the signal bandwidth by multiple sub-Nyquist sampling when transmitting a wideband image signal such as a high-definition television signal [Television Society technical report material, "Satellite one-channel transmission system for high-definition television" ” (MUSE)
TEBS95−2vol7No.44] has been proposed. this
The MUSE method applies an offset to the sampling phase between fields, frames, and lines, and transmits an image signal by performing processing such that the sampling phase goes around in four fields, that is, two frames. Therefore, the receiving device is equipped with a frame memory to store image signals sequentially transmitted over four fields, and combines them to restore a high-definition television image.The scanning method is known as 2: 1 interlace is used. Hereinafter, a conventional example of this MUSE type television receiving apparatus will be explained with reference to FIG.

A digitized image signal is supplied to the signal input terminal, and this signal is sent to the switch 2 via a conductor 11.
0 and is supplied to an interframe interpolation processing circuit consisting of a frame memory 30. This switch 20 receives the incoming input signal and the 1 signal fed back from the frame memory 30.
The signal from the previous frame is multiplexed, and an image signal interpolated between frames is sent to the conductor 21. On the other hand, the image signal supplied to the signal input terminal 10 is also supplied via the conductor 12 to a moving image filter 35 that performs predetermined filter processing.
The output of 5 provides a signal for the moving portion in the image via conductor 36 to a mixing circuit 40. The aforementioned conductor 2
The inter-frame interpolated image signals sent to 1 are supplied to a mixing circuit 40 and a motion detection circuit 50 via conducting wires 22 and 23, respectively. This motion detection circuit 5
0, the output of the frame memory 30 is supplied to other inputs via the conductor 31, detects a moving part using the frame correlation of the image, and supplies a motion control signal to the mixing circuit 40 via the image guide 51. do.

Mixing circuit 40 is therefore responsive to the motion control signal supplied via conductor 51, and receives the signal from conductor 22 for pixels in the still image portion, and the signal from conductor 36 for pixels in the moving image portion. are mixed or switched at a predetermined ratio and output. The output of the mixing circuit 40 is supplied via a conductor 41 to one input of the field memory 60 and an interpolation filter 70 that performs interpolation processing between fields. By means of a motion control signal supplied via a conductor 52, interpolation processing between fields is performed only on pixels of the still image portion, and a restored high-definition television image is sent to a signal output terminal 100.

Problems to be Solved by the Invention Since the television signal transmitted in the above-mentioned receiving device is in the form of 2:1 interlaced transmission, a scan conversion device is required to supply the signal to a display device having a different scanning mechanism. Must be placed independently. For example, field frequency _V (Hz), number of scanning lines N (lines), 2:1 interlace scanning method.
To convert a high-definition television signal based on the MUSE method into a progressive scanning method signal with a field frequency _V (Hz) and a number of scanning lines N (lines), a field memory for conversion is arranged, and two adjacent fields are By compressing the time of one scanning line in half and transmitting the signals alternately, it is possible to convert something such as a still image well. However, in the case of moving images, image quality deterioration such as image duplication occurs, so it is better to generate a scanning line interpolation signal from a single field signal and use this signal. Such devices not only require additional motion detection circuitry to detect moving and static parts of the image, but in this case also process every pixel of the restored high-definition television image. This poses problems, such as making the device extremely expensive.

Means for Solving the Problems The receiving device according to the present invention receives an interlaced scanning television signal that has been subjected to band compression processing using multiple sub-Nyquist sampling, and performs first signal processing that performs interframe interpolation processing. a second signal processing circuit that performs spatial interpolation processing on the received current field signal; a third signal processing circuit that detects a moving part by using interframe correlation of the image signal; a fourth signal processing circuit that is controlled by the output of the signal processing circuit and operates to mix the respective outputs of the first and second signal processing circuits at a predetermined ratio or select one of them; and a first inter-field interpolation processing circuit which uses the input and output signals of the delay circuit as sample and interpolation signals, respectively, to delay the output of the fourth signal processing circuit by one field period, and the input and output signals of the delay circuit. a second inter-field interpolation processing circuit that produces interpolation and sample signals, respectively; and a fifth signal processing circuit that obtains a first progressive scanning signal from the respective output signals of the first and second inter-field interpolation processing circuits. , a sixth signal processing circuit that obtains a second progressive scanning signal from the output signal of the first inter-field interpolation processing circuit; and fifth and sixth signal processing circuits that use the output of the third signal processing circuit as a control signal. A seventh signal processing circuit that selects one of the output signals of the circuits or mixes them at a predetermined ratio is arranged.

Operation In the receiving device according to the present invention having the above-mentioned configuration, the fourth
The output of the signal processing circuit is supplied to a delay circuit for one field. The first inter-field interpolation processing circuit uses the output of the fourth signal processing circuit as a sample signal, uses the output of the delay circuit as an interpolation signal, and performs inter-field interpolation processing on the still image portion, and the second inter-field interpolation processing circuit performs delay processing. The output of the circuit is used as a sample signal and the fourth
Interfield interpolation processing is performed on the still image portion using the output of the signal processing circuit as an interpolation signal. Fifth
The signal processing circuit converts one of the outputs of the first and second field interpolation processing circuits, whose output signals are relatively different in time by one field, into a sample scanning line signal and the other into an interpolation scanning line signal. A progressive scanning signal is sent out, and the sixth signal processing circuit sends out a second progressive scanning signal only from the output of the first inter-field interpolation processing circuit. A seventh signal processing circuit, to which the first and second progressive scanning signals are supplied, selects one of the two input signals according to the output of the third signal processing circuit, which detects moving parts of the image. or mixed at a predetermined ratio.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings. Components having the same purpose and operation as those in FIG. 2 showing the conventional example are designated by the same reference numerals and the explanation thereof will be omitted.

FIG. 1 is a block diagram showing the configuration of a receiving device according to an embodiment of the present invention.
and the second field interpolation filter 72, respectively. The first field interpolation filter 71 uses the signal on the conductor 43, that is, the output of the mixing circuit 40, as a sample scanning line signal, and uses the signal on the conductor 44, that is, the output of the field memory 60, as an interpolation scanning line signal, and uses it as an interfield interpolation processing circuit. For example, if the field is an odd field, as shown in FIG.
For the pixel signal a sent out by the field memory 60, four pixel signals of adjacent upper and lower scanning lines are given a predetermined weight and synthesized, and for the interpolation pixel part c, the field memory 60 Two adjacent pixel signals among the signals sent out by the memory 60 and two adjacent pixel signals among the signals sent out by the mixing circuit 40 are combined with predetermined weighting. Therefore, this first field interpolation filter 1
sends a signal obtained by performing inter-field interpolation processing on the signal of the current field using the signal of the previous field to the signal output terminal 101 via the conductor 710. The second field interpolation filter 72 is opposite to the first field interpolation filter 71, that is, uses the output of the field memory 60 supplied via the conductor 45 as a sample scanning line signal, and uses the output of the field memory 60 supplied via the conductor 46 as a sample scanning line signal, and inputs the sample scanning line signal to the mixing circuit via the conductor 46. 40 is used as an interpolation scanning line signal to perform interpolation processing between fields. For example, when the field is an odd number field, as shown in FIG. 4, even number field scanning lines 5463, 564, . . . The sample pixel b and the non-sample pixel c are subjected to processing similar to that of the first field interpolation filter, respectively, and a signal is sent to the conducting wire 720. The conductors 710 and 720 are supplied with signals in which the sample scanning line signals are relatively different by one field and subjected to inter-field interpolation processing, respectively, and the first and second time compression circuits 80 and 81 convert the time axes of these signals. Compress to 1/2. Switch 82 is terminal 83
Two input signals are selected for each scan line in the progressive scan mode in response to a switching signal from the first progressive scan line 84 to provide a first progressive signal for the still image portion. 1st
The conversion circuit 85 is the first field interpolation filter 71
The second progressive scanning signal is obtained only from the output signal of the , and is supplied to series-connected delay circuits 851 and 852 for delaying the interlaced scanning signal one scanning line at a time, as shown in FIG. 5, for example. Then, an adding circuit 853 generates a scanning line interpolation signal, a third time compression circuit 854 compresses the time axis to 1/2, and a sample scanning line signal from the connection midpoint of delay circuits 851 and 852 is converted into a fourth time signal. Compression circuit 855
The time axis is compressed to 1/2 by the switch 856, and the signals from the time compression circuits 854 and 855 are alternately selected for each scanning line in the progressive scanning signal. A progressively scanned signal is sent on conductor 857. The switch 86 receives the first and second progressive scanning signals from the conductors 84 and 857 as input signals, and converts the motion control signal supplied through the terminal 53 into a progressive scanning motion control signal by a second conversion circuit 87. The converted signal is used as a control signal, and the signal from the conductor 84 for the still image portion and the signal from the conductor 857 for the moving image portion are selected and sent to the signal output terminal 102. This conversion circuit 87 includes, for example, a one-pixel delay circuit 871, as shown in FIG.
An interpolation filter 870 consisting of an adder circuit 872 and a switch 873 is arranged to process the number of pixels in one scanning line to be the same as the number of pixels of the conductive lines 710 and 720 in FIG. Although it is desirable to convert the motion control signal into a progressive scanning signal, the present invention is not necessarily limited to this configuration. For example, interpolation filter 870
Various modifications and applications are possible in implementing the present invention, such as omitting the switch 86 and using a mixing circuit as the switch 86. Note that a conventional interlaced scanning image signal subjected to inter-field interpolation is extracted from the signal output terminal 101.

Effects of the Invention As described above, the television signal receiving apparatus according to the present invention restores the interlaced scanning signal, which has been subjected to band compression processing by multiplex sub-Nyquist sampling, in the form of interlaced scanning, and from the restored signal. When converting to a sequential scanning signal, the control signal is the output signal of the motion detection circuit used for restoration in the band compression process, and the still image part is converted from the signal of two adjacent fields, and the moving image part is converted from the signal of a single field only. Since it is possible to obtain a progressive scanning signal using the The display device can be of either an interlaced scanning type or a progressive scanning type, which has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a television signal receiving device according to an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional television signal receiving device, and FIGS. 3 and 4 are block diagrams showing a television signal receiving device according to the present invention. The figures used to explain the operation of the present invention, FIGS. 5 and 6, are block diagrams showing partial specific examples of the present invention. 20, 82, 86...Switch, 30...Frame memory, 35...Movie filter, 50...Motion detection circuit, 40...Mixing circuit, 60...Field memory,
71, 72... Interpolation filter, 80, 81... Time compression circuit, 85, 87... Conversion circuit, 10, 42, 5
3, 101, 102...terminal.

Claims (1)

[Claims] 1. A receiving device for interlaced scanning television signals subjected to band compression processing using multiple sub-Nyquist sampling, which includes a first signal processing circuit that performs interframe interpolation processing, and a current field signal that is an incoming input signal. a second signal processing circuit that performs spatial interpolation processing, and a third signal processing circuit that detects moving parts using interframe correlation of image signals.
and a signal processing circuit, which is controlled by the output of the third signal processing circuit and operates to mix the respective outputs of the first and second signal processing circuits at a predetermined ratio or to select either one of them. A fourth signal processing circuit and an output signal of this fourth signal processing circuit.
A delay circuit that delays the fields; a first inter-field interpolation processing circuit that uses the input and output signals of the delay circuit as sample and interpolation signals, respectively; and a first inter-field interpolation processing circuit that uses the input and output signals of the delay circuit as interpolation and sample signals, respectively. a second inter-field interpolation processing circuit; a fifth signal processing circuit for obtaining a first progressive scanning signal from the respective output signals of the first and second inter-field interpolation processing circuits; a sixth signal processing circuit for obtaining a second progressive scanning signal from the output signal of the insertion processing circuit;
and a seventh signal processing circuit for selecting one of the outputs of the sixth signal processing circuit or mixing the outputs at a predetermined ratio.
A television signal receiving apparatus characterized in that the signal processing circuit is controlled by the output of the third signal processing circuit.