JPH08149410A - Image recording and reproducing device - Google Patents

Abstract

PURPOSE: To provide an image recording-reproducing device which can record many images in real time and with high picture quality. CONSTITUTION: In the first recording mode, an encoder 2a encodes the signals in real time or almost in real time and a recording circuit 3a records these encoded signals on a fast access recording medium 4a. At the same time, the signals which are once recorded are decoded by a decoder 6a and encoded by an encoder 2b which is not of fast operating speed but of high picture quality and of low rate. These encoded signals are recorded on a slow access recording medium 4b by a recording circuit 3b. Then an erasing circuit 9 erases the signals of the medium 4a corresponding to the same image as that recorded on the medium 4b. The picture quality is never virtually deteriorated and the recordable image capacity of the medium 4b is increased as the time elapses. Furthermore, the unimportant signals are erased by an erasing means when the recordable area of the medium 4b is small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording / reproducing apparatus for recording an image signal mainly on a randomly accessible recording medium such as a disk or a memory.

[0002]

2. Description of the Related Art Most of the conventional image recording / reproducing apparatuses are encoded by a predetermined one encoding method and recorded on the same recording medium. However, in order to additionally record as many images as possible on a recording medium having a maximum recording capacity, it is necessary to effectively utilize the area of the recording medium on which the image signal has already been recorded.

Therefore, as a method of effectively utilizing the recorded area of the image signal, for example, Japanese Patent Laid-Open No. 62-98467.
Japanese Patent Laid-Open Publication "Image Database Management Method" has been proposed. In this prior art, when recording an image database, the image signal is first recorded as it is on the recording medium. The image signal which has passed a certain time after recording is subjected to pixel thinning in sub-samples, a reduced image of the original image is recorded, and the original image is erased.

[0004]

However, in the above-mentioned prior art, since the amount of data at the time of recording is large because the data is not compressed at the time of recording, it is impossible to record a moving image signal for a long time. Further, after a certain period of time, the number of recorded images is increased by re-recording a reduced image with sub-samples, but there is a problem that the image quality is significantly deteriorated. On the other hand, if an encoding method capable of achieving high image quality with a high compression rate during recording is used, real-time recording is impossible because the encoding requires a lot of time.

Further, in the conventional image recording / reproducing apparatus, only one kind of medium is used as a recording medium. However, when a high-speed access recording medium is used as the recording medium, the access speed is high, but the cost per recording capacity is high, and when a low-speed access recording medium is used, the access speed is low, but the cost per recording capacity is low. Low.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image recording / reproducing apparatus capable of recording in real time or at a speed close thereto and capable of recording more images with high image quality at a constant recording capacity. Another object of the present invention is
An object of the present invention is to provide an image recording / reproducing apparatus capable of reducing the recording medium cost by selectively using a high-speed access recording medium and a low-speed access recording medium at the time of recording / reproducing.

[0007]

According to another aspect of the present invention, there is provided an image recording / reproducing apparatus which comprises a first encoding means for encoding an input image signal at high speed and a signal encoded by the first encoding means. First recording means for recording on the recording medium, first reproducing means for reproducing the signal recorded by the first recording means from the recording medium, and first recording means for the signal reproduced by the first reproducing means. If it is encoded by the encoding means, the first decoding means for performing the decoding corresponding to the first encoding means and the image signal decoded by the first decoding means have a high compression rate. Second encoding means for encoding by the above, a second recording means for recording the signal encoded by the second encoding means on a recording medium, and a signal recorded by the second recording means on a recording medium From the second reproducing means for reproducing from the second reproducing means and the signal reproduced by the second reproducing means by the second encoding means. If it is encoded, it corresponds to the second decoding means for performing the decoding corresponding to the second encoding means, and the same image as the image encoded and recorded by the second encoding means. Erasing means for erasing a recording signal encoded and recorded by the first encoding means from the recording medium,
The reproduced signals of the first decoding means and the second decoding means are output as reproduced image signals.

According to another aspect of the present invention, there is provided an image recording / reproducing apparatus in which a first encoding means for encoding an image signal at a high speed and a signal encoded by the first encoding means are recorded on a high speed access recording medium. First recording means, first reproducing means for reproducing the signal recorded by the first recording means from a high-speed access recording medium, and first encoding means for the signal reproduced by the first reproducing means. And a second encoding means for encoding the image signal decoded by the first decoding means at a high compression rate, and a second encoding means. A high-speed recording signal recorded by the first recording means corresponding to the same image as the image recorded by the second recording means Erase means for erasing from the access recording medium and recording by the second recording means Second reproducing means for reproducing the reproduced signal from the low-speed access recording medium, and second decoding means for performing decoding corresponding to the second encoding means on the signal reproduced by the second reproducing means. And the reproduced signals of the first decoding means and the second decoding means are output as reproduced image signals.

An image recording / reproducing apparatus according to a third aspect is the image recording / reproducing apparatus according to the first or second aspect,
The first coding means performs intra-picture coding, and the second coding means performs inter-screen coding. An image recording / reproducing apparatus according to claim 4 is the image recording / reproducing apparatus according to claim 1 or 2, wherein the first encoding means performs encoding without using motion compensation, and the second encoding means Encoding is performed using motion compensation.

The image recording / reproducing apparatus according to claim 5 is the image recording / reproducing apparatus according to claim 1 or 2.
The first encoding means performs the unidirectional predictive encoding using only the screen at the previous time, and the second encoding means performs the bidirectional predictive encoding using the screens at the previous time and the later time. .
An image recording / reproducing apparatus according to claim 6 is such that an encoding means for encoding an image signal, a separation means for separating the signal encoded by the encoding means into an important component and an insignificant component, and a separation means. First recording means for recording the important component on the high-speed access recording medium, and first reproducing means for reproducing the signal recorded by the first recording means from the high-speed access recording medium,
Second recording means for recording the insignificant component of the separating means on the low-speed access recording medium, second reproducing means for reproducing the signal recorded by the second recording means from the low-speed access recording medium, and high-speed reproduced image If only the reproduction signal of the first reproduction means is output, and in other cases, the reproduction signal of the first reproduction means and the reproduction signal of the second reproduction means are combined and output, Decoding means for decoding the output signal of the means corresponding to the encoding means is provided, and the decoded signal of the decoding means is output as a reproduced image signal.

According to a seventh aspect of the present invention, there is provided an image recording / reproducing apparatus in which a first encoding means for encoding an image signal at a high speed and a first encoding means for recording the signal encoded by the first encoding means on a recording medium.
Recording means, first reproducing means for reproducing the signal recorded by the first recording means from the recording medium, and decoding corresponding to the first encoding means for the signal reproduced by the first reproducing means. A first decoding means for performing coding, a second coding means for coding the image signal decoded by the first decoding means at a high compression rate, and a second coding means for coding. Separation means for separating the signal into an important component and a non-important component, a second recording means for recording the important component and the non-important component separated by the separating means on a recording medium, and a second recording means. First erasing means for erasing from the recording medium the recording signal recorded by the first recording means corresponding to the same image as the image, and second reproducing means for reproducing the signal recorded by the second recording means. ,
A synthesizing means for synthesizing and outputting an important component and an insignificant component of the signal reproduced by the second reproducing means; and a decoding corresponding to the second encoding means for the signal synthesized by the synthesizing means. A second erasing means for erasing the insignificant component recorded by the second recording means to secure a recordable area when the recordable capacity of the recording medium is small; The reproduced signals of the decoding unit and the second decoding unit are output as reproduced image signals.

An image recording / reproducing apparatus according to claim 8 is the image recording / reproducing apparatus according to claim 6 or 7.
The intra-coded signal is the important component, and the inter-coded signal is the non-important component. An image recording / reproducing apparatus according to claim 9 is the image recording / reproducing apparatus according to claim 6 or 7, wherein a component corresponding to a low frequency of the encoded signal is an important component and other signals are non-important components. There is.

An image recording / reproducing apparatus according to a tenth aspect is the image recording / reproducing apparatus according to the sixth or seventh aspect, wherein only the coded signal corresponding to the reproduced image signal viewed by the viewer is used as the non-important component. .

[0014]

According to the structure of the first aspect, at the time of the first recording, the high-speed first encoding means performs the encoding so that the first recording means can perform the recording in real time or in a time close thereto. Is. In addition, the signal once recorded is decoded by the first decoding means, then coded by the second coding means which can realize high image quality and low rate although not at high speed, and then is coded by the second recording means. Will be recorded. Therefore, the recording capacity of the recording medium decreases with almost no deterioration in image quality over time. As a result, recording can be performed in real time or in a time close to that, and more images can be recorded with high image quality.

According to the structure of claim 2, the high-speed first
Since the signal encoded by the encoding means has a low compression rate, the encoded signal has a high rate and cannot be recorded unless it is a high-speed access recording medium, but it is encoded by the second encoding means having a high compression rate. The generated signal has a low rate and can be recorded even on a low-speed access recording medium. Therefore, a low-speed access recording medium, which is cheaper than a high-speed access recording medium, can be used, and the recording medium cost can be reduced.

According to the structure of claim 6, the important component of the encoded signal is recorded on the high-speed access recording medium, and the non-important component is recorded on the low-speed access recording medium. This low-speed access recording medium can obtain a sufficient recording / reproducing rate in the normal-speed image reproduction, and the normal-speed reproduction uses the reproduction signals of the high-speed access recording medium and the low-speed access recording medium to reproduce a high-quality reproduction image. Is obtained. On the other hand, when performing high-speed reproduction, only the reproduction signal of the high-speed access recording medium can be used, and thus the reproduction image quality deteriorates. Moreover, since a low-speed access recording medium that is cheaper than a high-speed access recording medium can be used, the recording medium cost can be reduced.

According to the seventh aspect of the invention, including the configuration of the first aspect of the invention, it is possible to record in real time or in a time close to it, and it is possible to record more images with high image quality. Further, when the recordable area of the recording medium is small, by deleting the unimportant signal by the second erasing means, more images can be recorded although the image quality is deteriorated.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment: Corresponding to Claim 1) FIG. 1 is a block diagram of an image recording / reproducing apparatus according to a first embodiment of the present invention. In the figure, 1 is an image signal which is an input signal to the image recording / reproducing apparatus. A recording medium 4 records an image signal. Reference numeral 2a is an encoder for encoding the image signal at high speed, and corresponds to the first encoding means in claim 1 of the claims. 3a is a recording circuit for recording the signal encoded by the encoder 2a on the recording medium 4,
It corresponds to the first recording means in claim 1 of the claims. Reference numeral 5a is a reproducing circuit for reproducing the signal recorded by the recording circuit 3a from the recording medium 4, and corresponds to the first reproducing means in claim 1 of the claims. Reference numeral 6a is a decoder for performing decoding corresponding to the encoder 2a if the signal reproduced by the reproducing circuit 5a is encoded by the encoder 2a. Corresponds to the first decoding means in.

Reference numeral 2b is an encoder for encoding the image signal decoded by the decoder 6a with a high compression rate, and corresponds to the second encoding means in claim 1 of the claims.
Reference numeral 3b is a recording circuit for recording the signal encoded by the encoder 2b on the recording medium 4, and corresponds to the second recording means in claim 1 of the claims. 5b is a recording circuit 3b
It is a reproducing circuit for reproducing the signal recorded in 1. from the recording medium 4, and corresponds to the second reproducing means in claim 1 of the claims. Reference numeral 6b is a decoder for performing decoding corresponding to the encoder 2b if the signal reproduced by the reproduction circuit 5b is encoded by the encoder 2b. Corresponds to the second decoding means in.

A selector 7 selects one of the reproduced signals of the decoders 6a and 6b and outputs it as a reproduced image signal.
Reference numeral 8 is a reproduced image signal which is an output signal from the image recording / reproducing apparatus. Reference numeral 9 erases from the recording medium 4 the recording signal encoded by the encoder 2b and corresponding to the same image as that recorded by the recording circuit 3b, which is encoded by the encoder 2a and recorded by the recording circuit 3a. It is an erasing circuit.

The operation of the first embodiment of the image recording / reproducing apparatus configured as described above will be described below. The image signal 1, which is an input signal, is recorded in the recording circuit 3 in a state where the encoder 2a performs high-speed encoding to reduce the data amount.
It is recorded on the recording medium 4 by a. The signal recorded on the recording medium 4 by the recording circuit 3a is reproduced from the recording medium 4 by the reproducing circuit 5a and decoded by the decoder 6a to become a reproduced image signal.

The reproduced image signal decoded by the decoder 6a is encoded by the encoder 2b. This encoder 2
Although the time required for encoding b is longer than the time required for encoding by the encoder 2a, encoding with a higher compression rate is performed. The signal encoded by the encoder 2b is recorded on the recording medium 4 by the recording circuit 3b, and at the same time, it is notified to the erasing circuit 9 that the erasing circuit 9 is recorded on the recording medium 4 by the recording circuit 3a. Among the signals, the signal corresponding to the signal recorded by the recording circuit 3b is erased from the recording medium 4 so that the area of the recording medium 4 can be used for recording another signal.

FIG. 2 shows a recording state. In FIG.
Each area represents the amount of data required to record the three types of images of image 1, image 2 and image 3 by its area. FIG. 2A shows an example in which the input image signal is recorded without being compressed, and FIG. 2B shows a state in which the signal is first encoded by the encoder 2a and then recorded by the recording circuit 3a. As time passes, the image 1 is encoded by the encoder 2b with a higher compression rate, and the recording capacity can be reduced as shown in FIG. 2C. 2D, the recording capacity can be reduced as shown in FIG.

Here, the elapsed time of encoding will be described. Large-scale hardware is required to perform real-time encoding with a high compression rate encoding method, but in order to simplify the hardware, several times (non-real time) is required in the above embodiment. Sequential compression is performed. For example, if it takes 5 minutes to compress a 1-minute image input, the compression processing of the image corresponding to the 10th minute of the input signal ends at about 45 minutes to about 50 minutes.

The signal recorded on the recording medium 4 by the recording circuit 3b is reproduced from the recording medium 4 by the reproducing circuit 5b and decoded by the decoder 6b to become a reproduced image signal. When the viewer reproduces the image, the reproduction circuit 5 is controlled by the control signal 20.
By controlling the reproduction positions of a and 5b, the data is reproduced from the position where the desired image is recorded, and the selector 7 is switched according to the encoding method of the image, and the desired reproduction image signal 8
Is obtained.

As described above, the capacity required for recording can be reduced with the lapse of time, the cost of the recording medium 4 per image signal can be reduced, and any encoder or encoder 2a or encoding can be performed at any time. Since the image signal encoded by the device 2b is recorded, a desired reproduced image can be immediately obtained. (Second Embodiment: Corresponding to Claim 1) FIG. 3 is a block diagram of an image recording / reproducing apparatus according to a second embodiment of the present invention. In the figure, the same devices as those in FIG.
Description is omitted. 3 is a recording circuit, 5 is a reproducing circuit, 30,
Reference numeral 31 is a selector. That is, one recording circuit 3 is shared instead of the recording circuits 3a and 3b of the first embodiment, and one reproducing circuit 5 is shared instead of the reproducing circuits 5a and 5b.
It is provided with selectors 30 and 31 for switching signals,
Others are the same as the embodiment of FIG.

The operation of the second embodiment of the image recording / reproducing apparatus configured as described above will be described below. In this embodiment, as described above, one recording circuit 3 is shared instead of the recording circuits 3a and 3b of the first embodiment, and one reproducing circuit 5 is shared instead of the reproducing circuits 5a and 5b. Therefore, the operation is almost the same as that of the first embodiment, and only the difference will be described.

When the operation corresponding to the recording circuit 3a of the first embodiment is required, the selector 30 selects the encoder 2a,
The recording circuit 3 records on the recording medium 4. On the contrary, when the operation corresponding to the recording circuit 3b of the first embodiment is required, the selector 30 selects the encoder 2b and the recording circuit 3 selects the recording medium 4.
At the same time, the erasure circuit 9 is notified and the encoder 2a
The signal corresponding to the signal currently recorded by the recording circuit 3 among the signals encoded by the recording medium 4 and recorded on the recording medium 4 is erased by the erasing circuit 9.
Erase with.

When the operation corresponding to the reproducing circuit 5a of the first embodiment is required, the selector 31 selects the decoder 6a,
On the contrary, when the operation corresponding to the reproducing circuit 5b is required, the selector 31 selects the decoder 6b. However, recording circuit 3
Is shared by the encoder 2a and the encoder 2b, the image signal 1 is encoded by the encoder 2a at a time when the encoder 2b performs encoding with a higher compression rate. ,
The used capacity of the recording medium cannot be reduced.

As described above, by using the selectors 30 and 31, the two recording circuits or the two reproducing circuits of the first embodiment can be shared by one each, and the hardware can be simplified. Can be converted. Other effects are similar to those of the first embodiment. (Third Embodiment: Corresponding to Claim 2) FIG. 4 is a block diagram of an image recording / reproducing apparatus according to a third embodiment of the present invention. In the figure, the same devices as those in FIG.
Description is omitted. Reference numeral 4a is a high-speed access recording medium capable of high-speed access, and 4b is a low-speed access recording medium which cannot be accessed at high speed. That is, this embodiment uses two types of recording media having different access speeds, that is, a high-speed access recording medium 4a and a low-speed access recording medium 4b, instead of the recording medium 4 of the embodiment of FIG. Is the same as the embodiment of FIG.

The operation of the third embodiment of the image recording / reproducing apparatus configured as described above will be described below. This embodiment uses two types of recording media 4a and 4b having different access speeds instead of the recording medium 4 of the embodiment of FIG. 1, and is the same as the embodiment of FIG. 1 except for the recording medium. A description of the same points will be omitted, and only the differences will be described.

The coded signal which is coded at high speed by the encoder 2a is recorded on the high speed access recording medium 4a which can be accessed at high speed by the recording circuit 3a. On the other hand, the encoded signal encoded by the encoder 2b can be recorded at a low rate because of the high compression rate, and thus is recorded on the low-speed access recording medium 4b that cannot be accessed at high speed by the recording circuit 3b. Therefore, the image signal 1 which is the input signal can be recorded at high speed (real time recording) by using the high speed access recording medium 4a, and the content recorded on the high speed access recording medium 4a is further increased as time passes. It is compressed and recorded on the low-speed access recording medium 4b.

The timing at which the contents recorded on the high speed access recording medium 4a are recorded on the low speed access recording medium 4b will now be described. If it takes N times the time length of the input signal to compress the input signal,
The mth minute input signal compression result is obtained at the m × Nth minute. Therefore, recording on the low-speed access medium is started at m × N minutes after the start of recording.

In general, the low-speed access recording medium 4b that cannot be accessed at high speed is cheaper than the high-speed access recording medium 4a that can be accessed at high speed, and as a result, the recording cost can be reduced. In the case of reproducing the image signal, if the reproducing circuits 5a and 5b can reproduce at a speed corresponding to the respective rates of the recording circuits 3a and 3b, the recorded signal can be correctly decoded.

As described above, according to this embodiment, the code signal is transferred from the high-speed access recording medium 4a which can be accessed at high speed to the inexpensive low-speed access recording medium 4b which cannot be accessed at high speed as time passes. The recording cost can be further reduced as compared with the first invention. (Fourth Embodiment: Corresponding to Claims 3 and 4) FIGS. 5 and 6
FIG. 9 is a block diagram of a fourth embodiment of an image recording / reproducing apparatus showing an example of a concrete configuration of encoders 2a, 2b in the image recording / reproducing apparatus of the image recording / reproducing apparatus of FIGS. 1, 3 and 4. In FIG. 5, reference numeral 40a is an intra-frame encoder, and the encoder 2a performs an intra-frame encoding process. In FIG. 6, 40b is an intra-frame encoder, 41 is a motion detection / compensation device, 42 is a frame memory, 43 is a subtractor, 44 is a selector, 45 is an intra-frame decoder, 46 is a selector, 47. Is an adder, and the encoder 2b performs inter-picture encoding as a whole.

The operation of the fourth embodiment of the image recording / reproducing apparatus configured as described above will be described below. The encoder 2a is composed of only the intra-frame encoder 40a and can perform encoding at a relatively high speed, but since the encoding using the correlation between the images cannot be performed, the compression rate is not so high. On the other hand, the input signal of the encoder 2b is compared with the content of the frame memory 42 storing the decoded reproduced image by the motion detector / motion compensator 41, and the motion detector / motion compensator 41
An image signal having a similar pattern is read from the frame memory 42 and output. The subtractor 43 calculates and outputs the difference between the input signal of the encoder 2b and the output signal of the motion detector / motion compensator 41. The selector 44 compares the input signal of the encoder 2b and the output signal of the subtractor 43, selects the signal with the higher compression rate and outputs it.

Whether the compression rate is high or low is determined by, for example, comparing the data rates or entropies or energies of the compressed image signals and determining the smaller one as the higher compression rate. Further, in the above, the operation of finding an image having a similar pattern is called “motion detection”, and the operation of reading the similar pattern is called “motion compensation”.

The intra-frame encoder 40b intra-codes the output signal of the selector 44 into the output signal of the encoder 2b,
Further, the on-screen decoder 45 performs decoding. The selector 46 operates in conjunction with the selector 44. When the selector 44 selects the output signal of the subtractor 43, it outputs it to the adder 47, and the adder 47 adds it to the output signal of the motion detector / motion compensator 41. And writes it in the frame memory 42. On the other hand, when the selector 44 selects the input signal of the encoder 2b, the input signal of the selector 46 is written in the frame memory 42 as it is.

At this time, the frame memory 42 stores at least all the pixel values of one frame before, and normally also stores the pixel values of several frames before. Its value varies depending on the operating mode and conditions. A similar pattern may be read from the pixel corresponding to the previous frame, or may be read from the pixel value of the screen several frames before, and the read pixel changes depending on the content of the image and the mode of the encoder. .

As described above, in the encoder 2b, the motion detector / motion compensator 41 requires complicated processing, and the intra-frame decoder 45 for the intra-frame encoder 40b is also required. A very complicated process is required as compared with the chemical converter 2a. Therefore, in order to realize an equivalent function with a simple hardware configuration, it is necessary to perform long-time processing using time division multiplexing processing. Therefore, the encoder 2b needs more encoding time than the encoder 2a.
Since the inter-picture coding using the correlation between the pictures can be performed, the compression rate becomes high.

As described above, according to the fourth embodiment, the encoder 2 required for the image recording / reproducing apparatus shown in FIGS. 1, 3 and 4.
a and 2b can be configured. (Fifth Embodiment: Corresponding to Claim 5) FIGS. 7 and 8 show other specific configurations of the encoders 2a and 2b in the image recording / reproducing apparatus of the image recording / reproducing apparatus of FIGS. 1, 3 and 4. It is a block diagram of the 4th Example of the image recording / reproducing apparatus which shows the example of FIG. In the same figure, devices that operate in the same manner as in FIG. Reference numeral 41a is a motion detector / motion compensator referring to the front screen, 41b is a motion detector / motion compensator referring to the rear screen, and 50 is a selector.

The operation of the fifth embodiment of the image recording / reproducing apparatus configured as described above will be described below. 7 and 8, the motion detector / motion compensator 41a performs motion compensation using unidirectional prediction using the screen at the previous time. On the other hand, in FIG.
For b, motion compensation is performed using unidirectional prediction using a screen at a later time.

An operation of reading out and outputting an image signal having a similar pattern is called "motion compensation". Image coding is not necessarily performed in the order of input signals.
According to the EG standard, signals input as A, B, C, D, E, ... Are encoded in the order of A, D, B, C ,. At this time, the encoding of B can be performed using the pixels of the screen A at the previous time and the pixels of the screen D actually corresponding to the later time. 7 is the same as FIG. 6 in the circuit diagram, but is rewritten according to the reference numerals of the motion detector / motion compensators 41a and 41b of FIG. The distinction between 41a and 41b is only for the division of the stored data of the prediction from the front and the prediction from the back.

The operation of the encoder 2b shown in FIG. 7 is the same as the operation of the encoder 2a shown in FIG. 6, and a description thereof will be omitted. 8, the selector 50 of FIG. 8 is a motion detector / motion compensator 41.
a and the motion compensation error due to the motion of the front screen and the rear screen detected by the motion detector / motion compensator 41b are compared, and the prediction motion compensation signal with the smaller motion compensation error is output. The subtracter 43 selects the selector 5 from the input signal of the encoder 2b.
The output signal of 0 is subtracted. The other operations are the same as the operations of the encoder 2a in FIG. 6, and the description thereof will be omitted. Since the encoder 2b of FIG. 8 also performs motion compensation using the rear screen, the encoder of FIG.
Although the compression rate can be made higher than that of the encoder 2a, the calculation amount of motion detection / compensation is doubled. Therefore, in order to reduce the hardware, one motion detection /
When the motion compensator is shared by the motion detectors / motion compensators 41a and 41b, the calculation time required for encoding is doubled. As a result, the encoder 2b of FIG. 8 is encoded by the encoder 2a of FIG. Twice the time is required.

As described above, according to the fifth embodiment, the encoder 2 required for the image recording / reproducing apparatus shown in FIGS. 1, 3 and 4 is used.
a and 2b can be configured. (Sixth Embodiment: Corresponding to Claim 6) FIG. 9 is a block diagram of an image recording / reproducing apparatus according to a sixth embodiment of the present invention. In the figure, 1 is an image signal which is an input signal to the image recording / reproducing apparatus. Reference numeral 4a is a high speed access recording medium capable of high speed access for recording an image signal.
Reference numeral 4b is a low-speed access recording medium for recording an image signal, which cannot be accessed at high speed.

Reference numeral 2 is an encoder for encoding an image signal, which corresponds to the encoding means in claim 6 of the claims. Reference numeral 50 denotes a separator for separating the signal encoded by the encoder 2 into an important component and an insignificant component, which corresponds to the separating means in claim 6 of the claims. 3a is a high-speed access recording medium 4 for the important components separated by the separator 50.
The recording circuit for recording in a corresponds to the first recording means in claim 6 of the claims. 5a is a recording circuit 3a
A reproducing circuit for reproducing the signal recorded in (1) from the high-speed access recording medium 4a, which corresponds to the first reproducing means in claim 6.

Reference numeral 3b is a recording circuit for recording the non-important component separated by the separator 50 on the low-speed access recording medium 4b, and corresponds to the second recording means in claim 6 of the claims. A reproducing circuit 5b reproduces the signal recorded by the recording circuit 3b from the low-speed access recording medium 4b, and corresponds to the second reproducing means in claim 6. 5
Reference numeral 1 is a synthesizer that outputs only the reproduction signal of the reproduction circuit 5a when a high-speed reproduction image is required, and otherwise outputs the reproduction signal of the reproduction circuit 5a and the reproduction signal of the reproduction circuit 5b. It corresponds to the combining means in claim 6 of the claims. Denoted at 6 is a decoder for performing decoding corresponding to the encoder 2 on the output signal of the combiner 51, and the decoded signal is output as a reproduced image signal, and the decoding according to claim 6 of the claims is carried out. It corresponds to the means. Reference numeral 8 is a reproduced image signal which is an output signal from the image recording / reproducing apparatus.

The operation of the sixth embodiment of the image recording / reproducing apparatus configured as described above will be described below. The image signal 1, which is an input signal, is encoded by the encoder 2 and separated by the separator 50 into an important component and other non-important components, and an important encoded component (important component). Is recorded on the high-speed access recording medium 4a by the recording circuit 3a, and the less important encoded component (insignificant component) is recorded on the low-speed access recording medium 4b by the recording circuit 3b.
In the reproducing circuits 5a and 5b, the high speed access recording medium 4a is used.
The encoded signal is reproduced from the low-speed access recording medium 4b, the important component and the non-important component are combined by the combiner 51, and then the decoded signal is decoded by the decoder 6 to become the reproduced image signal 8.

Therefore, at the normal reproduction speed, all the encoded signals separated by the separator 50 and recorded by the recording circuits 3a, 3b can be reproduced by the reproducing circuits 5a, 5b, so that the reproduced image signal 8 of high quality can be obtained. Can be output. On the other hand, when it is necessary to reproduce an image at an extremely high speed such as image retrieval or high-speed image reproduction, the encoded signal recorded on the high-speed access recording medium 4a capable of high-speed access can be reproduced, but the high-speed access Impossible low-speed access recording medium 4b
It is impossible to reproduce the coded signal recorded in 1. Therefore, the synthesizer 51 uses the reproduction circuit 5 including an important component.
The output of a is used to output the reproduced image signal 8 whose image quality is worse than the normal reproduction speed. For image retrieval and high-speed image reproduction, high image quality as high as a normal reproduction speed is not required, so that the purpose can be sufficiently achieved.

As described above, according to this embodiment, by recording the important component and the other non-important components on the recording media 4a and 4b having different access speeds, high image quality can be realized in the normal reproduction. By using the low-speed access recording medium 4b that cannot be accessed at high speed, the recording cost can be reduced. (Seventh Embodiment) FIG. 10 is a block diagram of an image recording / reproducing apparatus according to a seventh embodiment of the present invention. In the figure, 1 is an image signal which is an input signal to the image recording / reproducing apparatus. Reference numeral 4a is a high-speed access recording medium capable of high-speed access for recording an image signal. Reference numeral 4b is a low-speed access recording medium for recording an image signal, which cannot be accessed at high speed.

Reference numeral 2a is an encoder for encoding an image signal at high speed, which corresponds to the first encoding means in claim 7 of the claims. Reference numeral 3a is a recording circuit for recording the signal encoded by the encoder 2a on the high-speed access recording medium 4a.
It corresponds to the first recording means in claim 7 of the claims. A reproducing circuit 5a reproduces the signal recorded by the recording circuit 3a from the high-speed access recording medium 4a, and corresponds to the first reproducing means in claim 7.
6a is an encoder 2 for the signal reproduced by the reproducing circuit 5a.
A decoder that performs decoding corresponding to a, and corresponds to the first decoding means in claim 7 of the claims.

Reference numeral 2b is an encoder which encodes the image signal decoded by the decoder 6a at a high compression rate, and corresponds to the second encoding means in claim 7 of the claims. Fifty
Is a separator for separating the signal encoded by the encoder 2b into an important component and an insignificant component, and corresponds to the separating means in claim 7 of the claims. Reference numeral 3b is a recording circuit for recording the important component and the non-important component separated by the separator 50 on the low-speed access recording medium 4b.
Corresponds to the second recording means.

Reference numeral 9 denotes an erasing circuit for erasing the recording signal recorded by the recording circuit 3a corresponding to the same image as the image recorded by the recording circuit 3b from the high speed access recording medium 4a. It corresponds to the first erasing means. Reference numeral 5b is a reproducing circuit for reproducing the signal recorded by the recording circuit 3b, and corresponds to the second reproducing means in claim 7 of the claims.

Reference numeral 51 denotes a combiner for combining and outputting the important component and the non-important component of the signal reproduced by the reproducing circuit 5b, which corresponds to the combining means in claim 7 of the claims. 6
Reference numeral b is a decoder that performs decoding corresponding to the encoder 2b on the signal combined by the combiner 51, and corresponds to the second decoding means in claim 7 of the claims. Reference numeral 60 denotes an erasing circuit for erasing an insignificant component recorded by the recording circuit 3b to secure a recordable area when the low-speed access recording medium 4b has a small recordable capacity. Corresponds to the erasing means.

A selector 7 selects one of the reproduced signals of the decoders 6a and 6b and outputs it as a reproduced image signal.
Reference numeral 8 is a reproduced image signal which is an output signal from the image recording / reproducing apparatus. The operation of the seventh embodiment of the image recording / reproducing apparatus configured as described above will be described below. The description of the device having the same configuration and the same operation as in the third embodiment of FIG. 4 will be omitted. Encoding is performed by the encoder 2b,
The encoded signal is separated by the separator 50 into an important component and other non-important components, and an important encoded component (important component)
The non-important encoded component (non-important component) is recorded on the low-speed access recording medium 4b by the recording circuit 3b. The reproduction circuit 5b reproduces the encoded signal from the low-speed access recording medium 4b, the synthesizer 51 synthesizes the important component and the non-important component, and the decoder 6b decodes the synthesized signal to obtain a reproduced image signal 8.

As in the case of the third embodiment shown in FIG. 4, if the image signal is recorded in the high-speed access recording medium 4a by the selector 7, the output of the decoder 6a, the image signal is transmitted at low speed. If it is recorded on the access recording medium 4b, the output of the decoder 6b is switched to the reproduced image signal 8.
The recording circuit 3b notifies the erasing circuit 9 when recording a signal encoded by the encoder 2b having a higher compression rate than the encoder 2a, and the erasing circuit 9 records the signal on the high-speed access recording medium 4a. Delete the signal corresponding to the relevant image. Further, the recording circuit 3b calculates the data amount of the signal recorded on the low-speed access recording medium 4b by the recording circuit 3b, and notifies the erasing circuit 60 when the free space (recordable area) of the low-speed access recording medium 4b becomes small. Then, the erasing circuit 60 erases the non-important component recorded on the low-speed access recording medium 4b. As a result, when the free space of the low-speed access recording medium 4b is large, the image is recorded with high image quality, and when the free space of the recording medium 4b is small, the image quality is not so good but more images can be recorded.

As described above, according to this embodiment, more images can be recorded by deleting the non-important component when the free space of the low speed access recording medium 4b is small. The effects other than the above are similar to those of the third embodiment. In addition, in the seventh embodiment, two kinds of the high speed access recording medium 4a and the low speed access recording medium 4b are provided, but only one kind of the recording medium may be used.

(Eighth Embodiment) FIG. 11 shows an eighth embodiment of the present invention.
FIG. 3 is a block diagram of an image recording / reproducing apparatus that is an embodiment of the present invention.
In the figure, almost the same as in the seventh embodiment of FIG. 10, the devices that operate in the same manner are assigned the same reference numerals. Reference numeral 70 is an importance degree changer. The operation of the eighth embodiment of the image recording / reproducing apparatus configured as described above will be described below. The description of the device having the same configuration and the same operation as the seventh embodiment is omitted. In the image recording / reproducing apparatus used for the purpose of time shift (time delay), the image signal once reproduced is less likely to be reproduced than the unreproduced image signal. Therefore, in this embodiment, the degree of importance of the image signal once reproduced is reduced so that the image signal can be erased more easily than the unreproduced image signal. That is, when the image signal is reproduced, the synthesizer 51 notifies the importance changing unit 70, and the importance changing unit 70 selects the image currently being reproduced among the signals recorded in the low-speed access recording medium 4b. Make the corresponding signal less important. As a result, when the free space of the low-speed access recording medium 4b becomes small, the reproduced image signal is preferentially erased.

As described above, according to this embodiment, when the low-speed access recording medium 4b has a small free space, the image can be recorded efficiently by deleting it from the reproduced image. In this case, the image may be erased preferentially with respect to the image signal that has already been reproduced only with respect to the non-important component, or may be erased with respect to the important component as well.

In the first, second, third, fourth, fifth, seventh and eighth embodiments, all coded signals coded by the encoder 2a are processed by the encoder 2b. There is no need to re-encode, and some signals (for example, intra-frame encoding for screen refresh) may be left unencoded by the encoder 2a without being re-encoded. Also, the third, sixth, and seventh
In the eighth embodiment, as an example of the recording medium, for example,
High-speed accessible recording medium (high-speed access recording medium)
Is a memory, a high-speed magnetic disk, or the like, and a recording medium that cannot be accessed at high speed (low-speed access recording medium) is a low-speed magnetic disk or an optical disk.

Furthermore, in the seventh and eighth embodiments, the component corresponding to the low frequency (for example, the DC corresponding to the discrete cosine transform or the coefficient corresponding to the low frequency) may be the important component,
Moreover, the signal coded in the screen may be used as the important component. Also, as shown in FIG. 12, each screen is coded by a combination of intra-screen coding (I frame) / unidirectional prediction inter-screen coding (P frame) / bidirectional prediction inter-screen coding (B frame). If the I frame and the P frame are important components and the B frame is a non-important component, most of the image signals can be reproduced with only the important component even if the non-important component cannot be decoded. is there.

Further, in the eighth embodiment, a function for lowering the importance of the image signal which is not reproduced for a long time or changing the importance by combining some parameters may be constructed.

[0063]

According to the image recording / reproducing apparatus of the first aspect, since the image signal is encoded at a high speed by the first encoding means and recorded on the recording medium, real-time recording is possible and the first decoding is possible. Since the image signal decoded by the encoding means is encoded at a high compression rate and recorded on the recording medium and the original image is erased, more images can be recorded with high image quality.

According to the image recording / reproducing apparatus of the second aspect, in addition to the effect of the first aspect, by using the high-speed access recording medium and the low-speed access recording medium, the low-speed and low-speed recording is cheaper than the high-speed access recording medium An access recording medium can be used, and the recording medium cost can be reduced. The effects of the image recording / reproducing apparatus according to claims 3 to 5 are the same as the effects of the image recording / reproducing apparatus according to claim 1 or 2.

According to the image recording / reproducing apparatus of the sixth aspect, the high-speed access recording medium and the low-speed access recording medium are used, the important component is recorded on the high-speed access recording medium, and the non-important component is recorded on the low-speed access recording medium. By doing
An inexpensive low-speed access recording medium can be used as compared with the high-speed access recording medium, and the recording medium cost can be reduced. Also, if only the reproduction signal of the high-speed access medium is used, the reproduction image quality is deteriorated, but high-speed reproduction can be performed, and the reproduction image quality at the normal speed can be made high by using the reproduction signals of both recording media. You can

According to the image recording / reproducing apparatus of the seventh aspect, in addition to the effect of the first aspect, when the recordable area of the recording medium is small, the image quality is deteriorated by deleting the unimportant signal. More images can be recorded. The effects of the image recording / reproducing apparatus of the eighth to tenth aspects are the same as the effects of the image recording / reproducing apparatus of the sixth or seventh aspect.

[Brief description of drawings]

FIG. 1 is a block diagram of an image recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a recording capacity.

FIG. 3 is a block diagram of an image recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 4 is a block diagram of an image recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 5 is a block diagram of an encoder in an image recording / reproducing apparatus of a fourth embodiment of the present invention.

FIG. 6 is a block diagram of an encoder in an image recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram of an encoder in an image recording / reproducing apparatus of a fifth embodiment of the present invention.

FIG. 8 is a block diagram of an encoder in an image recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 9 is a block diagram of an image recording / reproducing apparatus according to a sixth embodiment of the present invention.

FIG. 10 is a block diagram of an image recording / reproducing apparatus according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram of an image recording / reproducing apparatus according to an eighth embodiment of the present invention.

FIG. 12 is a schematic diagram showing states of I, B, and P frames.

[Explanation of symbols]

 2, 2a, 2b Encoder 3, 3a, 3b Recording circuit 4 Recording medium 4a High-speed access recording medium 4b Low-speed access recording medium 5, 5a, 5b Reproducing circuit 6, 6a, 6b Decoder 9, 60 Erase circuit 50 Separation Vessel 51 synthesizer

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G06T 9/00 H04N 5/781 Z 9365-5H G06F 15/62 340 15/66 330 A

Claims (10)

[Claims] 1. A first encoding means for encoding an input image signal at high speed, a first recording means for recording the signal encoded by the first encoding means on a recording medium, and the first recording means. A first reproducing means for reproducing the signal recorded by the first recording means from the recording medium; and a signal encoded by the first encoding means for the signal reproduced by the first reproducing means. If there is, first decoding for the first encoding means is performed.
And a second coding means for coding the image signal decoded by the first decoding means at a high compression rate.
Second recording means for recording the signal encoded by the second encoding means on a recording medium; and second reproducing means for reproducing the signal recorded by the second recording means from the recording medium. If the signal reproduced by the second reproducing means is encoded by the second encoding means, second decoding means for performing decoding corresponding to the second encoding means And an erasing means for erasing from the recording medium the recording signal encoded and recorded by the first encoding means corresponding to the same image as the image encoded and recorded by the second encoding means. And an image recording / reproducing apparatus, wherein the reproduction signals of the first decoding means and the second decoding means are output as reproduction image signals. 2. A first encoding means for encoding an image signal at a high speed, a first recording means for recording the signal encoded by the first encoding means on a high-speed access recording medium, and First reproducing means for reproducing the signal recorded by the first recording means from the high-speed access recording medium, and decoding corresponding to the first encoding means for the signal reproduced by the first reproducing means. Decoding means for performing coding, second coding means for coding the image signal decoded by the first decoding means at a high compression rate, and coding by the second coding means Second recording means for recording the converted signal on the low-speed access recording medium, and the recording signal recorded by the first recording means corresponding to the same image as the image recorded by the second recording means. Erasing means for erasing from a high-speed access recording medium, and the second recording Second reproducing means for reproducing the signal recorded by the means from the low-speed access recording medium, and performing decoding corresponding to the second encoding means on the signal reproduced by the second reproducing means. 2. An image recording / reproducing apparatus comprising: two decoding means, wherein the reproduced signals of the first decoding means and the second decoding means are output as reproduced image signals. 3. The image according to claim 1 or 2, wherein the first encoding means performs intra-picture encoding and the second encoding means performs inter-picture encoding. Recording / playback device. 4. The first coding means performs coding without using motion compensation, and the second coding means performs coding using motion compensation. The image recording / reproducing apparatus according to claim 2. 5. The first coding means performs unidirectional predictive coding using only the screen at the previous time, and the second coding means performs bidirectional predictive coding using screens at the previous time and the later time. The image recording / reproducing apparatus according to claim 1, wherein the image recording / reproducing apparatus is performed. 6. An encoding means for encoding an image signal, a separating means for separating the signal encoded by the encoding means into an important component and an insignificant component, and an important component separated by the separating means. First recording means for recording on a high-speed access recording medium, first reproducing means for reproducing a signal recorded by the first recording means from the high-speed access recording medium, and non-important components of the separating means at low speed. Second recording means for recording on the access recording medium, second reproducing means for reproducing the signal recorded by the second recording means from the low-speed access recording medium, and if high-speed reproduced image is required, the above-mentioned A synthesizing unit for synthesizing only the reproduction signal of the first reproducing unit and outputting the reproduction signal of the first reproducing unit and the reproduction signal of the second reproducing unit, and outputting the reproduction signal of the second reproducing unit. The above code for the output signal An image recording / reproducing apparatus comprising: a decoding unit that performs decoding corresponding to the decoding unit, and outputs the decoded signal of the decoding unit as a reproduced image signal. 7. A first encoding means for encoding an image signal at high speed, a first recording means for recording the signal encoded by the first encoding means on a recording medium, and the first recording means. Reproducing the signal recorded by the recording means from the recording medium,
And a decoding unit corresponding to the first encoding unit for decoding the signal reproduced by the first reproducing unit.
And a second coding means for coding the image signal decoded by the first decoding means at a high compression rate.
Separation means for separating the signal encoded by the second encoding means into an important component and a non-important component, and a second means for recording the important component and the non-important component separated by the separation means on the recording medium. Recording means, first erasing means for erasing a recording signal recorded by the first recording means corresponding to the same image as the image recorded by the second recording means from the recording medium; Second reproducing means for reproducing the signal recorded by the recording means, combining means for combining and outputting the important component and the non-important component of the signal reproduced by the second reproducing means, and the combining means. Second decoding means for performing decoding corresponding to the second coding means on the combined signal, and non-recorded by the second recording means when the recordable capacity of the recording medium is small. Secure the recordable area by erasing important components. And a erasing unit, an image recording and reproducing apparatus is characterized in that so as to output a reproduction signal of the first decoding means and the second decoding means as a reproduced image signal. 8. The image recording / reproducing apparatus according to claim 6, wherein the intra-coded signal is a significant component and the inter-coded signal is a non-critical component. 9. The image recording / reproducing apparatus according to claim 6 or 7, wherein a component corresponding to a low frequency of the encoded signal is an important component and other signals are non-important components. 10. The image recording / reproducing apparatus according to claim 6, wherein only the encoded signal corresponding to the reproduced image signal viewed by the viewer is used as the non-important component.