JP3200648B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an image processing apparatus for recording a compression-encoded image signal.

[0002]

2. Description of the Related Art In recent years, in the field of television systems, systems using high-definition television signals have been developed for not only moving image broadcasting but also still image broadcasting. This high-definition television system has more than five times the amount of image information compared to the current television system, and the wide screen allows you to enjoy detailed and realistic images. Therefore, a method of transmitting a signal while compressing and encoding information to save a transmission band (or transmission bit rate) has been studied due to limitations on broadcast radio waves and communication capacity. Therefore, in order to receive and view such a still image broadcast, a still image broadcast receiver and a still image broadcast decoder are required.

Just as there is a VTR as a recording / reproducing means for a moving picture broadcast, some recording / reproducing means is required for a still image.

FIG. 3 is a conceptual block diagram showing a system configuration for receiving, recording, and reproducing still image broadcasting and moving image broadcasting. In video broadcasting, video broadcasting (for example, MU
A radio wave (such as an SE broadcast) is input to the video broadcast receiver 12 and is decoded by the video broadcast decoder 14. The moving picture signal decoded by the moving picture broadcast decoder 14 is transmitted to the VTR 1 if necessary.
6 and output to the monitor device 22 via the switches 18 and 20. By switching the switch 18, the reproduced video signal of the VTR 16 is
0 can be applied to the monitor device 22. The VTR 16 can also record an output video signal of the television camera 24.

On the other hand, with respect to a still picture broadcast, a still picture broadcast radio wave is inputted from an antenna terminal 26 to a still picture broadcast receiver 28, decoded by a still picture broadcast decoder 30, and recorded in a still picture recording / reproducing device 32 as necessary. Are applied to the monitor device 22 via the switches 34 and 20. By switching the switch 34, the reproduction output of the still image recording / reproducing device 32 can be applied to the monitor device 22 via the switches 34 and 20. The recording medium of the still image recording / reproducing device 32 is a magnetic tape, a magnetic disk, an optical disk, a magneto-optical disk, or the like.

[0006]

However, in the above configuration, a receiver, a decoder, and a recording / reproducing device must be separately prepared for moving picture broadcasting and still picture broadcasting, which is very expensive as a whole system. It becomes something. Also,
Since the number of devices increases and a large space is required for installation, it has been difficult to spread them to ordinary households.

It is an object of the present invention to solve these problems and to provide an image processing apparatus capable of easily recording a plurality of compression-encoded image signals having different transmission rates.

[0008]

According to the present invention, there is provided an image processing apparatus comprising: recording means for recording an image signal on a recording medium;
First input means for inputting the first image signal, encoding means for encoding the first image signal inputted by the first input means by a predetermined compression encoding method, and the first image signal And a second image signal for inputting a second image signal encoded by the predetermined compression encoding method.
Input means, conversion means for converting the second image signal input by the second input means into a recording rate of the recording means, and first image signal encoded by the encoding means.
And a supply unit for selectively supplying the image signal and the second image signal converted by the conversion unit to the recording unit.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. First, the recording / reproducing operation of a moving image signal will be described.
The analog moving image signal input to the input terminal 44 is converted by the A / D converter 45 into a digital signal of a predetermined bit rate. The sub-sampling circuit 46 includes, for example, a line
A predetermined pixel is thinned by offset / subsampling or the like, and the DPCM encoding circuit 47
6 is DPCM encoded. As a result, the amount of information is greatly reduced. The output of the DPCM encoding circuit 47 is
The voltage is applied to the ECC adding circuit 50 via the contact b of the switch 48. The ECC addition circuit 50 adds an error correction code, and the modulation circuit 52 performs low band suppression modulation (for example, NRZI conversion) on the output of the ECC addition circuit 50. The output of the modulation circuit 52 is amplified by a recording amplifier (not shown), applied to a magnetic head 56 via a recording / reproduction switch 54, and recorded on a magnetic tape 58.

During reproduction, a signal read from the magnetic tape 58 by the magnetic head 56 is supplied to the demodulation circuit 66 via the switch 54 and a reproduction amplifier (not shown).
The signal demodulated by the demodulation circuit 66 is error-corrected by the ECC decoding circuit 68 and supplied to the DPCM decoding circuit 72 via the switch 70. The DPCM decoding circuit 72 performs the reverse process of the DPCM encoding circuit 47, and the subsample decoder 74 interpolates the pixels thinned out by the subsample circuit 46. That is, the original information amount is restored by the DPCM decoding circuit 72 and the sub-sample decoder 74.
The output of the subsample decoder 74 is a switch 76,
The signal is applied to the D / A converter 82 through the a contact 80 and is converted into an analog signal. An analog output of the D / A converter 82 is supplied from an output terminal 84 to a monitor device or the like as an analog moving image signal.

In the above-described recording / reproducing operation, the system control circuit 86 controls the switches 48, 70, 76, 80 and controls the head drum motor 60 and the capstan motor 62 via the motor drive circuit 88. The rotation of the head drum and the magnetic tape 5
8 is controlled.

Next, the operation of a decoder for a compressed and encoded still picture broadcast signal will be described. The input terminal 40
A still image signal subjected to A / D conversion, subsampling, and DPCM encoding is input on the transmission side. The signal of the input terminal 40 is supplied to the DPCM decoding circuit 72 through the contact b of the switch 70.
Where DPCM decoding is performed. The sub-sample decoder 74 performs interpolation corresponding to sub-sampling at the time of transmission on the output of the DPCM decoding circuit 74, and the output is supplied to the memory device 78 via the switch 76. Here, since the data rate of the reproduction operation signal and the data rate of the signal input to the terminal are different, the DPCM decoding circuit 72 and the sub-sample decoder 7
4 and the writing frequency of the memory device 78 are switched by the operating frequency switching circuit 87. That is, at the time of decoding the input signal from the input terminal 40, each of the above frequencies is set lower than at the time of reproducing a moving image.

The memory device 78 has at least two frame memories, and by alternately writing and reading these, the received and restored still image data can be read from one of the frame memories.
The image data read from the memory device 78 is applied to a D / A converter 82 via a switch 80, where it is converted into an analog signal and output from an output terminal 84 to a monitor device or the like.

Since the memory device 78 has a plurality of frame memories, these can be used to provide screen effects such as wipe, enlargement / reduction, transfer, and multi-display.

Next, the operation for recording the received still image will be described. The still image data input to the input terminal 40 is temporarily stored in the memory device 41, stored for one screen, and then read out at the same transmission rate as in the case of a moving image.
This is because the transmission rate of a still image is lower than the transmission rate of a moving image. For example, in the present embodiment, both the moving image and the still image are compressed to 1/2 by the sub-sample and the DPCM encoding, respectively, and 10 Mbits per screen.
But the transmission rate of still images is 2Mbit
Because it is slow.

At this time, it is preferable that all of the switches 70, 76 and 80 are connected to the contact b. By doing so, the still image data at the input terminal 40 is transferred to the DPCM decoding circuit 72, the sub-sample decoder 74, and the memory device 78.
Thus, the analog video signal of the still image that has been restored as described above and received from the output terminal 84 to the monitor device (not shown) can be supplied, and it is possible to determine whether or not to record while watching the monitor screen. In response to the operation of a recording switch (not shown), the system control circuit 86 starts reading data from the memory device 41, and connects the switch 48 to the contact b.

The data stored in the memory device 41 is read out at the moving image transmission rate and applied to the ECC adding circuit 50 via the switch 48. The same processing as in the case of a moving image is performed by the ECC addition circuit 50 and the modulation circuit 52, applied to the magnetic head 56 via the switch 54, and recorded on the magnetic tape 58. At this time, the magnetic tape 58 is
By the motor 62 and the pinch roller 64, the image is conveyed in the same manner as in the case of a moving image, and a still image is recorded frame by frame following the frame recorded immediately before.

When reproducing the still image recorded on the magnetic tape 58, the output of the magnetic head 56 is
4 and is applied to a demodulation circuit 66, and the demodulation circuit 66 and the ECC decoding circuit 68 perform the same processing as in the case of a moving image. The output of the ECC decoding circuit 68 is applied to the DPCM decoding circuit 72 via the switch 70, and thereafter, is decoded by the DPCM decoding circuit 72 and the sub-sample decoder 74, as described above. The data is supplied to the memory device 78 and written. At this time, the switching circuit 87 controls the operating frequency of the DPCM decoding circuit 72, the sub-sample / decoder 74, and the writing frequency of the memory device 78 so as to be the same as those at the time of reproducing the moving image.

The data read from the memory device 78 is applied to a D / A converter 82 via a switch 80, and is converted into an analog signal. The output of the D / A converter 82 is
An analog video signal is supplied from the output terminal 84 to the monitor device. Thus, the still image recorded on the magnetic tape can be reproduced and observed on the monitor screen.

FIG. 2 is a conceptual diagram of a system configuration when the apparatus of FIG. 1 is incorporated in a moving image / still image receiving system. As can be seen from a comparison with FIG. 3, the configuration is very simple.

When playing back a moving image, the memory device 78 is used to wipe, enlarge, reduce, move,
Multi display and the like can be performed.

FIG. 4 is a block diagram showing the configuration of another embodiment of the present invention. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the same memory device 42 as the memory device 41 in FIG. Still images are read from the memory device 42 at the transmission rate at the time of recording and reproduction of moving images, and recording and reproduction of still image signals are performed in the same manner as in the embodiment of FIG. The difference from the embodiment of FIG. 1 is that the still image signal is supplied to the DPCM decoding circuit 72 at the moving image transmission rate even when the still image signal is recorded.

As a result, the operating frequency of the DPCM decoding circuit 72 and the sub-sample decoder 74 and the writing frequency of the memory device 78 become the same at the time of recording a still image as at the time of reproducing a still image. Need not be provided with an operating frequency switching circuit 87.

Although the case where a magnetic tape is used as a recording medium has been described as an example, it goes without saying that other recording media such as a magnetic disk, a magneto-optical disk, and an optical disk can be used.

[0026]

As can be easily understood from the above description, according to the present invention, a plurality of compression-encoded image signals having different transmission rates can be recorded by a small and inexpensive apparatus.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is a conceptual configuration diagram of a moving image / still image receiving system using the apparatus of FIG. 1;

FIG. 3 is a conceptual configuration diagram of a conventional moving image / still image receiving system.

FIG. 4 is a configuration block diagram of another embodiment of the present invention.

[Explanation of symbols]

 41, 42: Memory device 46: Sub-sampling circuit 47: DPCM encoding circuit 54: Recording / playback changeover switch 56: Magnetic head 58: Magnetic tape 60: Head drum motor 62: Capstan motor 72: DPCM decoding circuit 74 : Sub-sample decoder 78: Memory device 87: Operating frequency switching circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N ^7/ 24-7/68

Claims (2)

(57) [Claims] Recording means for recording an image signal on a recording medium; first input means for inputting a first image signal; and a first image signal input by the first input means. Encoding means for encoding by a compression encoding method; and a second input for inputting a second image signal encoded by the predetermined compression encoding method, the transmission rate being different from the first image signal. Means, conversion means for converting a second image signal input by the second input means to a recording rate of the recording means, first image signal encoded by the encoding means, and the conversion means Supply means for selectively supplying the second image signal converted by the above to the recording means. 2. The image processing apparatus according to claim 1, wherein the first image signal is a moving image signal, and the second image signal is a still image signal.