JPH0290876A - Field/frame discriminating device - Google Patents

Abstract

PURPOSE:To always correctly perform the discrimination of field recording/ frame recording by comparing a video signal and a neighboring video signal recorded in a recording area whose writing order is adjacent to the recording area where the video signal is recorded. CONSTITUTION:The video signal demodulated by an FM demodulator 6 is stored in a memory 12a or the memory 12b selected by a memory switch 11. Here, the memory switch 11 is interlocked with a head switch 4, and therefore, for instance, the video signal read by an outer circumference head 3a is stored in the memory 12a, and the video signal read by an inner circumference head 3b is stored in the memory 12b. These stored video signals are compared by a correlator 13 as a comparing means, and this compared result is supplied to a system controller 14. Then, the discrimination of field/frame is performed by using the video signal recorded clearly at a high level. Thus, the discrimination of field recording/frame recording can be performed always correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a field/frame discrimination device for discriminating whether a video signal recorded on a recording medium such as a floppy disk is a field picture or a frame picture. Regarding
For example, it is particularly effective when applied to electronic still cameras.

[Conventional technology]

In recent years, advances have been made in the development of systems such as electronic still cameras or still video floppy disk players that record still image video signals on floppy disks (so-called disk backs) and then reproduce the recorded images on a television screen. When recording video signals on a floppy disk, there is field recording, in which one field of information is recorded on one track, and one image (field picture) is recorded on that track alone, and field recording, in which one field of information is recorded on one track, and the other is recording video signals on adjacent floppy disks. The first field information is recorded on one of the two trunks (for example, the outer track) and the second field information is recorded on the other (for example, the inner trunk), and the There is a frame recording in which information of a field and a second field are combined into one image (frame picture).

Regarding electronic still cameras, unified standards have already been established regarding recording methods and various other items. According to this, when recording video signals on a magnetic recording medium (floppy disk), both field recording and frame recording are allowed, and field recording and frame recording can be performed on the same floppy disk. Records are often made in mixed forms. Therefore, in order to be able to identify whether an image is a field recording or a frame recording when reproducing an image, it is prescribed that data for identification should be recorded in advance. The recorded signal for this identification is called an ID signal, and is multiplex recorded on the recording medium together with the video IR code. That is, in a frame image recorder, it is specified that field/frame ID signals are frequency-multiplexed recorded on video tracks. The carrier frequency for this recording is 13 times the horizontal scanning frequency f (i.e.
The NTSC system uses 204,54 KHz), the modulation method is DPSK, and the bit rate is determined so that 4H section (H is one horizontal scanning period, hereinafter the same) corresponds to one bit. (Nikkei Electronics 1984.7
．． (See 2nd prize).

Furthermore, bit allocation on the recording track is done as shown in FIG. In other words, the vertical synchronization signal (V
, 5YNC) from the start point (leading edge of the signal) to 28H or 2
The 4H interval (i.e., 1 bit interval) after 8.5H is set as the initial bit, and the following <8H interval (i.e.,
A 2-bit section) is allocated for an ID signal for field/frame recording. ID in the above 2-bit interval
When the identification data indicated by the signal is ``00'', it corresponds to a field record (when it is ``01J'' or ``10'', it corresponds to a frame record. Of the above frame records, ``01j'' indicates that the trunk concerned is It also indicates that it is the outer side of a pair of frame recording tracks.
” indicates that the tracks are on the same inside track.

[Invention or problem to be solved]

As mentioned above, in the conventional field/frame discrimination device,
Field recording L3/frame recording is determined based on the identification information.

However, for example, in electronic still cameras, the ID signal indicating the above-mentioned identification information is recorded at a low frequency of 13fh, and in consideration of the influence on adjacent video signals (chroma), it is recorded at 'C-14' compared to the standard chroma signal. Since the ID signal is recorded at a low level of ±2 dB, it is difficult to always read this ID signal accurately. Therefore, the field/
Frame discrimination cannot be performed with high accuracy.

Therefore, it is conceivable to read the ID signal many times and take a majority vote, but this method increases the circuit scale and takes extra time, but no particular effect can be obtained.

The present invention has been made in consideration of these circumstances, and its purpose is to improve field recording/frame recording.
An object of the present invention is to provide a field/frame discriminating device that can always accurately discriminate records.

[Means to solve the problem]

In order to solve the above problems and achieve the objects, the present invention has taken the following measures. That is, a video signal is compared with an adjacent video signal recorded in a recording area that is adjacent to the recording area in which this video signal is recorded, and as a result of this comparison, if there is no correlation between the two video signals, The video signal is determined to be a field picture, and if there is a correlation between the two video signals, it is determined that the video signal is a frame picture.

[Effects] By taking such measures, the following effects are achieved. That is, since field/frame discrimination is performed using a video signal that is generally recorded clearly at a high level, it is possible to prevent misjudgment due to reading errors when reading signals from a recording medium, and highly accurate discrimination can be performed.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A still video floppy disc player constructed by applying a field/frame discrimination device according to an embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows the still video floppy disk player (
FIG. 2 is a block diagram showing 14 configurations. 1 in the figure is a Sunal video floppy disk (hereinafter referred to as a floppy disk)
It is. A plurality of annular recording tracks 2 are concentrically formed on this floppy disk, and the video signals recorded on each of the recording tracks 2 are read by a two-channel multihead (hereinafter referred to as a head) 3. It will be done. The head 3 has an outer circumferential head 3a located on the outer circumferential side of the floppy disk 1 and an inner circumferential head 3b located on the inner circumferential side with respect to the radial position of the floppy disk 1, so that their head gaps are aligned in the radial direction. It is an in-line head that is arranged. The outer circumferential head 3a and the inner circumferential head 3b are each connected to a head switch 4,
The head switch 4 selects a video signal read by either the outer head 3a or the inner head 3b and inputs it to the reproduction amplifier 5. The video signal input to the reproduction amplifier 5 is amplified by the reproduction amplifier 5, demodulated by the FM demodulator 6, and input to the process circuit 7. Then, the video signal is processed by the process circuit 7, which sets the length of the first scanning line of each field, performs color difference signal synchronization processing, performs dropout compensation, and performs brightness! After performing well-known processing such as adjusting the delay time of the text signal and color difference signal, the encoder 8 converts the signal into a signal that drives the decoded video output and the TV monitor 9 for Y/C minutes. and is given to the TV monitor 9 and displayed as an image on the screen of the TV monitor 9.

On the other hand, the FM demodulator 6 (U modulated) video signal is also input to the A/D converter 10 and converted into a digital signal, which is then stored in the memory 12a or 12b1 selected by the memory switch 11. Here, the memory switch 11 is linked to the head switch 4, and therefore, for example, a video signal read by the outer head 3a is stored in the memory 12a, and a video signal read by the inner head 3b is stored in the memory 12b. The video signals stored in the memories 12a and 12b are compared by a correlator 13 as comparison means, and the comparison result is input to the system controller 14.This system controller Controls the entire still video disc player (for example, switching the head switch 4 and memory switch 11, driving the process circuit 7 and other devices; till control, etc.); /It has a frame discrimination means 14a, which discriminates whether the recording track 2 on which the outer peripheral head 3a is located is field recording or frame recording based on the comparison result given from the correlator 13. 15 is a disk drive, and 16 is a head access section.

Next, the operation of the still video floppy disc player constructed as described above will be explained.

First, Lv (not shown): When playback is instructed from the part,
The head access section 16 performs head access to the head 3 so that the outer circumferential head 3a is located on the first track (the outermost recording track of the disk 1). Then, the head switch 4 is switched to the outer head 3a side, and the video signal recorded on the first trunk is read out by the outer head 3a. At this time, memory switch 1
1 selects the memory 12a as described above, and the read video signal is demodulated and converted into a digital signal as described above, and then stored in the memory 12a.

Here, in order to save memory capacity and shorten the time required for comparison in the correlator 13, which will be described later, only the image No. 43 of the 0th scanning line is stored in the memory 12a.

When the reading of the video signal recorded on the first track and the storage of the read video signal in the memory 12a are completed, the hentos isochi 4 is switched and the inner circumferential head 3b
Select. Here, since the outer peripheral head 3a is located on the first track, the inner 1,'J head 3b is located on the second track.
(track one track inner than the first track). Then, the video signal recorded on the second track is read out by the inner circumferential head 3b. Here, the memory switch 11 selects the memory 12b as described above, and the read video signal is demodulated and converted into a digital signal as described above, and then stored in the memory 12b. Note that here, only the video signal of the (m+1)th scanning line is stored in the memory 12b.

When the reading of the video information recorded on the second track and the storage of the video signal into the memory 12b are completed, the video signal of the mth scanning line stored in the memory 12a and the mth+1st scanning line stored in the memory 12b are At the same time, the correlator 13 manually inputs the video signal and the video signal from the video signal to the correlator 13, and the correlator 13 compares the two video signals. Here, only the video signals for one horizontal scanning line are compared in order to shorten the comparison time, but the accuracy of discrimination can be improved by comparing the video signals for the same number of horizontal scanning lines. Furthermore, if it is desired to further shorten the comparison time, only a portion of the video signals of one horizontal scanning line may be compared. Then, the system controller 14 receives the result of the video signal comparison by the correlator 13 and determines whether the first track is a field recording or a frame image recording as follows. That is, if there is no correlation between the video signal stored in the memory 12a and the video signal stored in the memory 12b, the first track is considered to be field recording,
In addition, the video signal stored in the memory 12H and the memory 12b
If there is a correlation with the video signal stored in the first track, the first track is considered to be frame recording. This is because in a frame image, the image in the first field and the image in the second field are almost the same image, and therefore, in a frame image, there is no correlation between the video signal in the first field and the video signal in the second field. This is because there is.

Based on this determination result, the system controller 14 performs the reproduction operation as follows. That is, when it is determined that the first track is field recording, the video signal recorded on the first track is a field image, so
Perform the filter image playback operation using a well-known procedure. Also, the first
If it is determined that the track is frame recording, the video signal recorded on the first track is a video signal that forms a set of frame images with the video signal recorded on the second trunk. A frame image reproduction operation is performed using a well-known procedure using the video signal recorded on the first track as first field information and the video signal recorded on the second track as second field information.

In this way, it is automatically determined whether the first track is field recording or frame recording, and the playback operation is performed in a format corresponding to the type of video signal recorded on the first trunk.

Next, when the reproduction of the next image is instructed from an operation unit (not shown), if the first track is field recording, the head 3a is moved so that the outer peripheral head 3a is located on the second track.
If the first track is frame recording, the head 3 is accessed so that the outer head 3a is positioned on the third track, and then the field/frame discrimination processing and reproduction operation described above are performed. and,
These processes are performed on all tracks of the disc 2.

As described above, according to this embodiment, it is possible to determine whether field recording or frame recording is being performed from the video signal without depending on the ID signal. Since the video signal is recorded at a high level, there are almost no errors when reading it, and therefore fields/frames can be accurately discriminated.

Further, in the case of this embodiment, since the comparison of video signals is performed for only one scanning line, the capacity of the memories 12a and 12b can be kept small, and the determination can be made in a short time.

Note that the present invention is not limited to the above embodiments.

For example, in the above embodiment, the field/frame discrimination device according to the present invention may be applied to a still video floppy disk player, a still video floppy disk erasing device, or a device that does not use a still video floppy disk. It's good. Further, the recording medium is not limited to a floppy disk, and various recording media such as memory, magnetic tape, optical disk, etc. can be applied. Furthermore, although the above embodiment shows an example of a two-channel inline head, the same effect can be obtained by moving a single head to adjacent tracks sequentially and reading the video signal of each track. Can be done.

〔Effect of the invention〕

According to the present invention, a video signal is compared with an adjacent video signal recorded in an adjacent recording area based on the writing order in the recording area where the video signal is recorded, and as a result of this comparison, it is found that there is a correlation between both video signals. If there is no , the above video signal is a field image, and if there is a correlation between the two video signals, it is determined that the above video signal is a frame image. It is possible to determine whether it is a picture or a frame picture, and it is possible to determine whether it is a picture or a frame picture.
l-Always accurately distinguish recording/frame recording.
field/frame discriminator, etc.).

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a still video floppy disk player configured by applying a field/frame separate device according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating the prior art. . 1.Still video floppy disk, 2-.3 Self-recording track, 3..2-channel multihead, 10-
A/D converter, 12 a, ], 2 b-memory,
13...Correlator, 14...System controller, 14a...Field/frame discrimination means. Applicant's agent Patent attorney Atsushi Tsuboi

Claims (1)

[Claims:] A field/frame discrimination device that discriminates whether a video signal recorded on a recording medium in which a plurality of recording areas for recording video signals for one field are set is a field picture or a frame picture. a comparison means for comparing a video signal and an adjacent video signal recorded in a recording area adjacent in writing order to the recording area in which the video signal is recorded; and as a result of the comparison by the comparison means, both video signals If there is no correlation between the two video signals, the video signal is a field picture, and if there is a correlation between the two video signals, the video signal is a frame picture. /Frame discrimination device.