JPS6150474A - Scanning converter - Google Patents

Abstract

PURPOSE:To obtain a picture of a sequential scanning system where the number of scanning lines is doubled by synthesizing signals of two adjacent fields in the interface scanning system and outputting repetitively the same field signals to the seqential scanning system. CONSTITUTION:A storage device 2 has an address for N-line's share, where N is the minimum integer larger than the ratio of the vertical scanning period of an input video signal (g) to the horizontal scanning period. A discriminator 8 discriminates whether the video signal (g) is based on the interlace scanning system or the sequential scanning system on the basis of a vertical synchronizing signal (k) or a horizontal synchronizing signal (l), and an address generator is set to the 1st or 2nd mode accordingly. In the 1st mode, the storage device 2 reads one line's share of the preceding field at the 1/2H period of the first half of the said line during the write of one line of the present field and reads one line's share of the present field at the latter 1/2H period. In the 2nd mode, the storage device 2 reads one line's share just before at the first 1/2H period of the said line during the write of one line's share of the present field and reads one line's share of the present field at the latter 1/2H period.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention is an FC system that reproduces high-resolution images by doubling the number of scanning lines of one field of television signals by interpolating between scanning lines. The present invention relates to a scan conversion device.

(b) Conventional technology As a conventional example of this type of scan converter, for example,
There are devices described in Japanese Patent Application Laid-open No. 16380 and Japanese Patent Application Laid-Open No. 101583/1983, etc., but all of the devices described in these publications are capable of inputting a 2:1 interlaced scanning television signal and scanning the adjacent system. A device that combines signals of matching fields and converts them to sequential scanning to double the number of scanning lines,
For example, no consideration is given to compatibility with the case where a progressive scanning video signal, such as a graphic image signal created by a computer device, is input.

Therefore, in the video signal of the progressive scanning system, one picture is completed in one field, and there are six images. When a video signal of the progressive scanning method is inputted, especially if there is any movement in the image content of the input video signal, this will cause deterioration of the converted and synthesized image.

e'9 Problems to be Solved by the Invention The present invention provides an apparatus for converting a video signal for two fields into a progressive scanning video signal in which the field frequency is the same and the number of lines is doubled. This system is designed to be applicable to both interlaced scanning and sequential scanning signals.

B.) Means for Solving the Problems The present invention is an apparatus for converting a video signal for two fields of an interlaced scanning system into a televised video signal of a progressive scanning system in which the field frequency is the same and the number of lines is doubled. A storage device having an address capable of storing N747 worth of video signal information, where N is the smallest integer that is larger than the ratio of the vertical scanning period to the horizontal scanning period, and a control means for controlling writing and reading of this storage device. and a determining means for determining whether the input video signal information is an interlaced scanning method or a progressive scanning method, and the control means cycles through the N747 addresses of the storage device to determine whether the input video signal information is of the interlaced scanning method or the progressive scanning method. The video signal information for each line in each field is sequentially written, and the video signal information for the previous field written to the address for one line in the previous storage device is written, and then the video signal information for that one line is written. The video signal information of the current field written to the address of is successively written at twice the writing speed,
If the determining means determines that the input image signal is of the sequential scanning type, the control means reads the same video signal information of the current field written to the address of one line in the storage device. Reading is repeated twice at a speed twice the writing speed, and a progressive scanning television signal is obtained from each line of video signal information obtained one after another by each successive readout.

(E) Effect With the above configuration, when the discriminating means determines that the input isthographic image signal is of the interlaced scanning method, the storage device writes the information for one line of the current field. During the TR period in the first half of the line (n is one horizontal period in interlaced scanning), information for one line of the previous field is read out, and during the TR period in the second half, information for one line of the current field being written is read out. Repeat. If it is determined (by the above-mentioned determining means) that the input Eirin signal is of the sequential scanning type, the storage device, while writing information for one line of the current field, uses this line during the TR period of the first half of the line. 1#p returns the operation of reading out one line's worth of information immediately before and reading out one line's worth of information of the current field that is being written in the second half TR period.

(f) Example The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the scan conversion device of the present invention, and shows a demodulated television signal that performs fc2:1 interlaced scanning or a progressive scanning television image signal that is created in a computer device or the like. The image signal (image signal) @) is converted into a digital signal by the A/D converter (1), and this storage device (2) is a device consisting of a semiconductor memory, etc. 1) If the minimum integer greater than the ratio of the vertical scanning period and horizontal scanning period of the video signal (self) input to 1) is N, then fc is configured to have addresses for N747, and is given from the counter (6). Signals for controlling write/read operations (hereinafter referred to as “
R/W signal) (n) and address generator (7)
It is controlled to perform write/read operations as described later by address information (0) given from . A signal (h
), the time-axis compressed and read information is converted into an analog video signal (j) by a D/A converter (3),
It is supplied to a display group W1 (not shown) such as a CRT.

On the other hand, the input video signal @) is given to the synchronization separation circuit (4), where horizontal and vertical synchronization signals are separated, and the horizontal synchronization signal (1) is sent to a phase-locked loop including a phase comparator and a voltage-controlled oscillator. The internal horizontal synchronizing signal (8), which is given as one input of the circuit (PLL) (5) and output from the address generator (7), is connected to the horizontal synchronizing signal (1) so that its phase matches that of the horizontal synchronizing signal (1). It is controlled by the PLL circuit (5), and the PLL circuit (5) generates a signal which becomes the basic clock of this system. This clock signal (
2) is given to the counter (6), and the counter (6) with
The fcR/W signal (1m) is generated as described above.

The output signal (P) of the counter (6) is given to an address generator (7), and the generator (7) generates the address information (0) and an internal horizontal synchronization signal (g) based on this signal ψ). ) and is used to horizontally deflect the output video signal. A horizontal deflection synchronizing signal g (%) is supplied to a horizontal deflection device (not shown). Note that this synchronization signal G) is set to twice the frequency of the internal synchronization signal (8).

The vertical synchronization signal (k
) is supplied to a vertical deflection circuit (not shown) and also as one input of the discriminator (8). This discriminator (
8) is based on the input vertical synchronizing signal (k) and horizontal synchronizing signal (1), two periods (two vertical scanning periods) of the vertical synchronizing signal (k) are equal to one period (one horizontal scanning period) of the horizontal synchronizing signal (1). If the input video signal (g) is an odd number multiple of the scanning period), it is determined that the input video signal (g) is of the interlaced scanning method, and if it is an even number of times, it is determined that the input video signal is of the progressive scanning method, and the scanning method of the input video signal is determined. A signal representing (r) is supplied to an address generator (7). The address generator (7) updates the address information 1 as described later depending on the state of the signal (r).

Next, referring to FIGS. 2 and 3, the storage device (2)
The operation will be explained.

Figure 2 (b) shows that the input video signal (see Figure 2 (a)) is of the interlaced scanning method, and the discriminator (8) determines that it is interlaced scanning, and the signal (r) Figure 6 (1) is a timing diagram showing the operation of the storage device (2) when the address generator (7) is set to the first mode in relation to the input signal waveform shown in Figure 2 (a). signal(
! l) (Refer to Figure 3 (6))] is a progressive scanning method, and the discriminator (8) determines that it is a progressive scanning method, and the address generator (7) is set to the second mode by the signal (r). 6 is a timing diagram showing the operation of the storage device (2) in the case of setting in relation to the input signal waveform shown in FIG. 6 (6), in which the horizontal axis in FIG. indicates time, the vertical axis indicates the address of the storage device, the solid line indicates the write timing, and the broken line indicates the read timing. Furthermore, in Figure 2 (P) and Figure 6 (A), for convenience of explanation, the ratio of the vertical and horizontal scanning periods of the input video signal is set to be significantly smaller than that of the current N Too system. A) is shown as 7.5:1, and FIG. Lines are labeled with symbols as shown. As shown in Fig. 1, this device processes A/D converted digital signals, so the video signal information has waveforms as shown in Fig. 2 (a) and Fig. 6 (a). Although it cannot be displayed, it is expressed as an analog video signal for convenience of explanation.

Now, as can be seen from FIGS. 2 and 6, in the write operation of the storage device, the address generator (7) is in the first mode and
The same operation is performed regardless of the mode. In other words, the write operation of the storage device (2) is performed by setting the minimum integer larger than the ratio of the vertical scanning period to the horizontal scanning period of the input video signal to be N (in this case, "8"), and writing to the storage device for these 8 lines. By cycling through the addresses, video signal information for each line of each field of the input video signal is sequentially written.

By the way, the read operation of the storage device (2) is shown in FIGS. 2 and 6.
As can be seen from the figure, different operations are performed in the first mode and the second mode.

First, the address generator (7) is set to the first mode f
To explain the operation of the storage device (2) in the case of cS, taking the TO period in FIG. While writing the video signal information for one line to the address for one line, the previous field (second field) b', 1H, which has already been written to the address for one line.
The video signal information of C" is read in the first half TR, and then the video signal information of C" written in the corresponding period TO is read out in the second half TR.
Read with H. At this time, reading is performed at twice the writing speed. Since the memory device is controlled so that such an operation is repeated, the signals read out during the T1 period are bb-c-o-dd, p,
Similarly, in period T2, b'-(/'-6/-/
-d' -e cr) It can be seen that the signals of each line of the two fields are read out alternately and time-base compressed every +H period.

Next, the address generator (7) is set to the second mode.
Wow,. i! c! [1 If (21°Kaya 2ka 3-2
To explain using an example, when the video signal information b of the 6th field existing in this period T3 is being written to the address of one line, the address of one line immediately before the address of one line is written. The current field written to (
6th field) is read out in the first half T11 period at twice the writing speed, and then the video signal information b'' written in the period T3 is read out at twice the writing speed. It is read in the second half, H period.

Since the storage device is controlled so that such an operation is repeated, for example, the signals read out during the T4 period are a-b-b-c-c-d, p, and similarly, T.
In period 5, a″-V′-V′-C″-C″-d′
An interpolated signal is formed by adjacent lines 1 of the same field, such as α. Of course, in this case as well, each signal is read out after being compressed on the time axis.

At twice the horizontal interval, the vertical deflection frequency w1. By deflecting the input video signal at the same frequency as the vertical OL [1st period], a progressive scanning image with twice the scanning lines is formed on the display device.

To set the above read operation to the first and second (need),
The read address (
It will be appreciated that this can be done by delaying tJ (indicated by dashed lines in FIGS. 2 and 6) by the +R period period, and that this change is quite simple.

As described above, the present invention can suitably handle both interlaced scanning and progressive scanning video signals, and can obtain high-definition images. Also, although not detailed, JP-A-5
As described in Publication No. 8-77373, in order to cope with deterioration in image quality when the image content of an interlaced scanning video signal has a large motion component, a motion detector is provided, and the output of this detector is It is possible to improve the image quality by setting the second mode for parts with a lot of movement.

In this embodiment, the case where one signal series is processed will be explained. However, when there are multiple signal series such as a luminance signal, a color difference signal, etc. as in a color television, each series is processed separately. What is necessary is just to configure it so that it can perform the above-mentioned operation.

(F) Effects of the Invention According to the present invention, if the input video signal is an interlaced scanning method, it is automatically detected and the video signals of two adjacent fields are combined. If an image is obtained by progressive scanning with twice the number of scanning lines, and if the input video signal is based on the progressive scanning method, this will be automatically detected and the video signal of the same field will be repeatedly scanned. By outputting p, the number of scanning lines in one field is 2.
A multiplied progressive scanning image can be obtained.

Therefore, even when the input video signal of the progressive scanning method includes many moving images, such as computer images with a high contrast ratio of the image content or computer games, high-resolution images can be obtained without deteriorating the image quality. You can get it. Another advantage is that it is possible to easily change the operation mode of the storage device in order to sequentially apply it to both the interlacing methods.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a scan converter according to the present invention, and FIGS. 2 and 6 are diagrams for explaining its operation. (2)...Storage device, +61...Counter, (7)...Address generator, (8)...
...Discriminator.

Claims (1)

[Claims] (1) A device that converts two interlaced scanning field video signals into a progressive scanning television video signal with the same field frequency and twice the number of lines, comprising a vertical scanning period and a horizontal scanning period. a storage device having an address capable of storing video signal information for N lines, where N is the smallest integer larger than the ratio of a determining means for determining whether the scanning method or the sequential scanning method is used, and the control means cycles through the addresses of the N lines of the storage device, and the video signal of each one line in each field of the input video signal is In addition to sequentially writing information, if the input video signal is determined by the discrimination means to be of the interlaced scanning method, the control means writes the video of the previous field written to the address of one line in the storage device. The signal information and the video signal information of the current field that is subsequently written to the address for one line are read at a speed twice the writing speed, and the determining means determines that the input video signal is of the sequential scanning type. If the same video signal information of the current field written to the address of one line of the storage device is read out twice by the control means at twice the writing speed, and by each readout, A scan conversion device characterized in that a progressive scanning television signal is obtained from each line of video signal information obtained.