JPH04239281A - Editing method for picture signal - Google Patents

Abstract

PURPOSE:To edit a picture signal by a field unit, even at the time of recording the picture signal by compression-encoding it by an (n) frame unit. CONSTITUTION:Picture signal generators 1, 2, 3, and 4 which input the picture signals to an editing device, generate the picture signals in a raster scanning type time sequence. An editing device 20 is equipped with an input memory 22 for the (n) frame as the unit of a compression-encoding processing, and the picture signals in the raster scanning type time sequence from the picture signal generators are stored in this memory 22 by one field unit. The output of this memory 22 is recorded by a VTR for edition in order to edit and record the picture signals.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to digital VT, for example.
The present invention relates to a method for editing digital image signals from R and television cameras, and particularly to a method that allows editing in units of one field.

0002

[Prior Art] Conventionally, digital VTRs perform error correction processing that is completed on a field-by-field basis without using compression encoding.
With this method, it is possible to easily associate each field of a digital image signal recorded on a tape with a recording track on the tape. Therefore, this kind of digital V
With TR, digital image signals from a plurality of digital VTRs can be easily edited field by field by simply managing time codes.

0003

[Problems to be Solved by the Invention] However, in digital VTRs, such as consumer digital VTRs, which require data compression due to recording rate limitations, generally,
A compression encoding process that is completed in one to multiple frames is performed,
It is divided into multiple tracks and recorded. In this case,
Since image data is not compressed and encoded field by field, it is not possible to easily associate each field with a recording track position on the tape.

[0004] For this reason, in digital VTRs that perform this type of compression encoding processing, it has been difficult to edit on a field-by-field basis.

[0005] In view of the above points, the present invention has been devised so that editing in field units can be easily performed even in digital VTRs that use compression encoding processing that is completed in units of one or more frames during recording processing. This method provides a method for

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, image signals from a plurality of image signal generators are combined, and n frames (n is an integer,
n≧1), the image signal editing method performs compression encoding that is completed when n≧1) and records the image signal on a recording medium, the plurality of image signal generating devices each generating a time series signal in a raster scanning format. selectively supplying digital signals of the image signals from the plurality of image signal generators to a memory means capable of storing image signals for n frames of the unit of compression encoding; , the memory means is capable of storing not only the output image signal from one image signal generation device but also the image signals from at least two image signal generation devices in field units; The output of the memory means is subjected to the compression encoding process and edited and recorded.

[0007]

When the image signal generating device is, for example, a digital VTR, the digital image signal, which is compressed, decoded, and converted back into a time-series signal in raster scanning format, is supplied to memory means for editing. Furthermore, when the digital image signal generating device is, for example, a television camera, the image signal, which is a time-series signal in a raster scanning format, is A/D converted and supplied to the memory means for editing. Ru.

[0008] This editing memory means can store image signals from two or more image signal generators in field units as n frames, which are units of compression encoding processing. be. Then, every n frames of digital image data from this editing memory means is compressed and encoded and edited and recorded.

[0009] Therefore, editing operations such as splicing of image signals can be performed on a field-by-field basis.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the editing method according to the present invention will be described below with reference to the drawings. In the example below, the compression encoding method to be used is, for example, A proposed by the applicant of the present application.
DRC (Adaptive Dynamic Rang)
e Coding; JP-A-61-144989;
JP-A-61-144990, JP-A-62-926
This is the case when the method (see Publication No. 20) is used.

[0011] The ADRC system is an encoding system that utilizes the strong spatio-temporal correlation of television image signals. That is, when an image is divided into blocks, each block often has only a small dynamic range due to local correlation. Therefore, in this ADRC method, the image is divided into blocks, the dynamic range of each block is determined,
By adaptively re-encoding the pixel data, each pixel data can be compressed to a smaller number of bits than the original number of bits.

[0012] Methods for dividing an image into blocks include division only in the horizontal line direction (one-dimensional ADRC), and division into rectangular areas in both horizontal and vertical directions (two-dimensional ADRC).
), and further division (three-dimensional ADRC) considering a spatial region spanning a plurality of frames has been proposed (see the above-mentioned publications).

[0013] In three-dimensional ADRC, motion detection between two frames is performed for each block, and even more efficient encoding can be achieved by performing so-called frame dropping in static blocks, for example, without sending data of subsequent frames. In this case, each block requires a 1-bit motion information code, but data can be compressed to 1/2 in the still area.

In the example described below, three-dimensional AD
RC is performed, and therefore, the unit of compression encoding of the image signal is two frames, and the image signals of the two frames are recorded on the tape as four tracks.

FIG. 1 shows an embodiment of an editing system for carrying out the editing method according to the present invention, and 1 and 2 are digital V for reproduction as an example of an image signal generating device.
TRs, 3 and 4 are video cameras which are also examples of image signal generating devices. 1 and 2 may be digital VTRs for both recording and reproduction.

In the reproduction digital VTR, the three-dimensional A
A digital image signal compressed and encoded by DRC and recorded is reproduced from a magnetic tape to output a digital image signal in the original raster scanning format.

That is, FIG. 2 shows this reproduction digital V
This is a block diagram showing the configuration of an example of a TR, in which a magnetic head 11
The image data picked up from the tape (not shown) is supplied to a reproduction equalizer and data restoration circuit 13 via a reproduction amplifier 12, and is restored to digital data. This restored digital data undergoes error correction in the error correction circuit 14 using the error correction code in the reproduced digital data.

The output data of this error correction circuit 14 is
The data is supplied to the compression/decoding circuit 15, and three-dimensional ADRC decoding processing is performed for each two frames of image data in units of blocks, which are the minimum processing units for encoding. The decoded image data is then supplied to the de-shuffling circuit 16, and the two frames of image data are returned to the original data order. The signal is then supplied to the block decomposition circuit 17 and converted into the original time-series digital image signal in raster scanning format.

The output data of the block decomposition circuit 17 is supplied to the error correction circuit 18, and the image data whose errors could not be corrected by the error correction circuit 14 is corrected by interpolation processing using surrounding image data. Since error correction processing is performed using error-free pixel data around error pixels, it is performed after compression decoding, deshuffling, and block decomposition. The digital image signal from this error correction circuit 18 is sent to an output terminal 19.
is supplied to

As mentioned above, the digital image data immediately after being played back from the tape is a signal in units of two frames, but the two frames of image data are divided into blocks and divided into multiple blocks. It is made up of blocks. Each block is compressed by ADRC block encoding, and each block data is distributed within the two frames according to a predetermined rule. Therefore, when performing editing processing on the image signal at this stage, editing can only be performed in units of two frames.

However, the signal obtained at the output terminal 19 is
The signal is compressed and decoded, deshuffled, and further divided into blocks, resulting in a raster scan format signal that is a time series of the original image signal. If this raster scanning format time-series signal is used, field-by-field editing can be easily performed.

Next, in FIG. 1, 20 is an editing device. This editing device 20 includes an editing controller 21,
It consists of an input selection section 22 and an editing VTR section 23.

The output digital image signals of the digital VTRs 1 and 2 for reproduction are supplied to two input terminals of the plurality of digital input terminals 24 of the editing device 20, and directly supplied to the input selection section 22.

The raster scanning format analog image signals from the video cameras 3 and 4 are respectively supplied to two input terminals of the plurality of analog input terminals 25 of the editing device 20, and are input to A/D converters 26 and 26. After being supplied and converted into a digital image signal, it is supplied to the input selection section 22.

From the video cameras 3 and 4, the reproduction V
When output signals similar to the output digital image signals of TRs 1 and 2 are obtained, the output image signals of the video cameras 3 and 4 are also supplied to the digital input terminal 24 of the editing device 20 and directly input to the input selection section. 22 can be supplied.

Furthermore, the digital VTRs 1 and 2 for reproduction obtain a time code from the reproduction signal from the tape.
This time code is input to the controller 21 of the editing device 20, and is used as a reference signal for an external synchronization signal REF, which will be described later.

The controller 21 controls the playback VTRs 1 and 2.
It also generates an external synchronization signal REF (FIG. 3A) for synchronizing the output image signals from the video cameras 3 and 4, and supplies it to the VTRs 1 and 2 and the cameras 3 and 4, respectively. The controller 21 also generates a selection control signal SE that switches the digital image signal obtained from the input selection section 22 at an editing point set by the operator's key input operation, for example, and sends the selection control signal SE to the input selection section 22. supply to. With this selection control signal SE, the input selection section 22
Switching control is possible in units of one field.

In the reproduction VTRs 1 and 2, during editing operation, servo control is performed based on the external synchronization signal REF from the editing device 20, and the respective output digital image signals V1
, V2 (FIGS. 3B and 3C) are synchronized with this external synchronization signal REF.

Furthermore, the output image signals V3 and V4 (FIGS. 3D and E) from the video cameras 3 and 4 are also synchronized with this external synchronization signal R.
Output in synchronization with EF.

Therefore, each input selection section 22 receives a digital image signal synchronized with the external synchronization signal REF. In this input selection section 22, the selection operation is performed using one field as the minimum selection unit according to the selection control signal SE from the controller 21. Therefore, as shown in FIG. 3F, for example, the digital image signals V1 to V1 to By selecting V4, two frames of digital image signals can be combined.

The editing VTR unit 23 is configured as shown in FIG. 4, for example.

That is, the digital image signal from the input selection section 22 is supplied to an input memory 31 having a capacity of at least the encoding processing unit, and is temporarily stored therein. In this example, the memory 31 has a capacity capable of storing at least two frames of image data, which is a unit of encoding processing. In practice, due to buffering with subsequent processing, 2
Two frame memories are prepared, and the two memories are alternately used.

Field A stored in this memory 31
, B, C, and D, the input selection section 22 can switch and control the selection on a field-by-field basis.As shown in FIG. Image data is stored in each field A, B,
It can be stored as C and D.

In addition, when editing digital image signals from two input sources, for example, reproduction digital VTRs 1 and 2, in such a way as to connect them, field A stores the output VTR of reproduction digital VTR 1 as two frames in the memory 31.
1.Fields B, C, and D are the output V2 of the reproducing digital VTR2, ■Fields A and B are the output of the reproducing digital VTR
1 output V1, fields C and D are reproduction digital VT
There are three storage methods: output V2 of R2, field A, B, and C as output V1 of reproduction digital VTR 1, and field D as output V2 of reproduction digital VTR 2.

Furthermore, in the case of digital image signals from three input sources, the digital image signal from any one input source is stored for two fields, and the digital image data from the other two input sources are stored as follows. Each field stores one field.

The two frames of image data read from the memory 31 are supplied to the blocking circuit 32, and are divided into, for example, 4 pixels in the horizontal direction x 4 pixels in the vertical direction (4 lines).
Image data is divided into blocks consisting of . and,
The data of each divided block is supplied to a shuffling circuit 33, and each block is distributed according to a predetermined rule within two frames.
4, and three-dimensional ADRC compression encoding processing is performed.

The compressed and encoded data from this compression encoding circuit 34 is supplied to a parity addition circuit 35, and
Parity data for error correction is generated and added. Then, the compressed image data to which this parity data has been added is supplied to the recording head 38 via the recording modulation circuit 36 and the recording amplifier 37, and two frames of image data are recorded on the tape in four columns. recorded as a recording track.

The editing VTR 23 has a playback system 4 having exactly the same configuration as the above-mentioned playback digital VTR.
0, data is picked up by the head 41 from the edited and recorded tape T, and the reproduction system 40 reproduces the original time-series digital image signal, which is obtained at the output terminal 42.

Next, the editing operation in this editing device 20 will be explained.

First, the playback VTRs 1 and 2 and the video cameras 3 and 4 receive an external synchronization signal RE from the controller 21.
The output image signals are synchronously controlled by F. As described above, each output image signal is input to the input selection section 22 in the form of a digital signal.

Now, when the editor performs a key input operation to select a digital image signal from the reproduction VTR 1, the selection control signal SE from the controller 21 causes the input selection section 22 to select the digital image signal from the reproduction VTR 1. The signal V1 is supplied to the blocking circuit 32 via the memory 31 and is sequentially recorded.

In this state, if the output image signal V2 of the reproduction VTR 2 is to be recorded following the output image signal V1 of the VTR 1, a key input to that effect is made. Then, the controller 21 selects and controls the selection control signal SE so that the two frames of data at the time of the operation are stored in the memory 31 in a state in which one of the memory patterns from ■ to ■ is described above. Input selection section 22
After that, a selection control signal SE for selecting the output image signal V2 of the VTR 2 is output to the input selection section 22. In this way, you can perform continuous editing on a field-by-field basis.

After that, if it is desired to insert only one field of the signal from the video camera 3, a key input operation to that effect is performed. Then, the controller 21 stores fields A, B, and 2 frames of data in the memory 31.
A selection control signal SE is supplied to the input selection section 22 to select and control the output of the camera 3 to be stored as one field in either C or D, and the output image data of the VTR 2 to be stored in the other fields.

As described above, according to the present invention, n
Even when recording an image signal by performing compression encoding processing that is completed on a frame-by-frame basis, editing can be easily performed on a field-by-field basis.

[0045] In the above example, compression encoding is performed in units of two frames, but the processing unit of compression encoding may be one frame, or even three or more frames. good.

[0046] Furthermore, as a method of compression encoding processing, A
The present invention is not limited to DRC, and various other compression encoding methods such as orthogonal transform encoding methods such as DCT and vector quantization methods can be used.

[0047]

As explained above, according to the present invention, in a method for editing a digital image signal compressed and encoded in units of one or more frames and recorded, the image signal is converted into a time series in the original raster scanning format. By restoring the image to a signal and switching and selecting another image signal in the state of the time-series signal, editing can be easily performed in units of one field as the minimum unit.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of an editing system that implements an editing method according to the present invention.

FIG. 2 is a block diagram of an embodiment of a digital VTR for reproduction.

FIG. 3 is a time chart of output image signals from a plurality of image signal generation devices.

FIG. 4 is a block diagram of an embodiment of an editing VTR section of the editing device.

FIG. 5 is a diagram for explaining an input memory section of an editing VTR section.

[Explanation of symbols]

1, 2 Digital VTR for playback 3,4 Video camera 20 Editing device 21 Controller 22 Input selection section 23 Editing VTR

Claims (1)

[Claims] Claim 1: Combines image signals from a plurality of image signal generators, and generates n frames (n is an integer, n≧1
), the image signal editing method performs compression encoding and records the image signal on a recording medium, wherein the plurality of image signal generation devices each generate an image signal that is converted into a time-series signal in a raster scanning format. to a memory means capable of outputting and storing image signals for n frames of the unit of compression encoding;
Digital signals of the image signals from the plurality of image signal generation devices are selectively supplied, and the memory means stores not only output image signals from one image signal generation device but also at least two image signal generation devices. A method for editing a digital image signal, wherein the image signal from a device can be stored in a state where it is included in each field, and the output of the editing memory means is subjected to the compression encoding process to perform editing recording.