JP2537240B2 - Digital image storage device and playback device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic still camera system, and more particularly to reading an image signal from a storage device in which an image signal representing a still image is stored in the form of digital data and storing it in another storage device. The present invention relates to a digital image storage device for reproduction on a video monitor device and the reproduction device.

BACKGROUND ART For example, in an electronic still camera described in JP-A-59-183592, a memory is detachably connected to a camera body having an image pickup optical system and a solid-state image pickup device, and a video signal representing a still image picked up by the image pickup device is transmitted. It is stored in this memory in the form of digital signals. The memory storing this video signal is removed from the electronic still camera and loaded into the digital image reproducing apparatus. The reproducing apparatus reads out image signal data from the memory and reproduces it as a visible image on the screen of the video monitor.

The digital electronic still camera is also described in Japanese Patent Laid-Open Nos. 54-140510 and 57-92981. The former discloses one in which a video signal once stored in an internal memory is stored in a magnetic tape or a magnetic disk or is output to a printer. The latter is for connecting a semiconductor memory in which a video signal captured by a digital electronic still camera is stored, reading the video signal and recording it on a magnetic tape.

In these conventional devices, a memory cartridge in which images of a plurality of frames taken by a digital electronic still camera are stored in the form of digital video signals is connected to an image reproducing device, and the video signals are reproduced from the memory cartridge one screen at a time. It is configured to be read into the device and perform image processing. The digital image reproducing device performs image processing by a built-in micro processing system.

As a memory cartridge connected to a digital electronic still camera, generally, a semiconductor memory such as SRAM, which is capable of storing data with low power consumption, is suitable. SR
AM has a high optimum read / write speed, but its memory retention time is limited to, for example, a few years or less due to the support of a battery. In addition, the SRAM memory cartridge realized by the current technology, for example, when an image of one frame is represented by 1 M to 1.5 M bit data, the storage capacity of one chip 4 M bit is about 8 to 5 frames respectively. A storage device will be realized. Therefore, to save a large number of frame images for a long
SRAM is not enough.

Therefore, it is preferable if various types of memories such as EPROMs and EEPROMs whose memory retention is semi-fixed can be used. It is also desirable to be able to store images of many frames in those memories including SRAM.

In view of the above demands, the present invention is directed to a digital image storage device capable of storing in a memory image data of a large number of frames obtained by a video signal source such as a digital electronic still camera, and a reproducing device thereof. The purpose is to provide.

DISCLOSURE OF THE INVENTION In a digital image storage device according to the present invention, a first connector means to which a first memory module in which an image signal is stored in the form of digital data is detachably connected, and an image signal in the form of digital data are connected. A second connector means to which a second memory module for storing is detachably connected, and image signal data is read from the first memory module connected to the first connector means, and is also connected to the second connector means. And a band compression unit that band-compresses the image signal data. The control unit stores the image signal data read from the first memory module. Band compression is performed by the band compression means, and the band-compressed image signal data is stored in the second memory module.

Further, the digital image reproducing apparatus according to the present invention comprises a connector means to which a memory module storing image signals in the form of digital data is detachably connected, and a band expanding means for band expanding the band compressed image signal data. ,
A storage device that temporarily stores image signal data, a signal conversion device that is connected to the storage device and that reads out the image signal data stored in the storage device and converts the image signal data into a corresponding analog video signal, and a utilization device are connectable, An output terminal for outputting an analog video signal to the utilization device, a control means for controlling the band expansion means and the storage means, reading image signal data from the memory module connected to the connector means, and outputting the analog video signal to the output terminal. When the image signal data read from the memory module is band-compressed, the control unit band-expands the image signal data by the band expansion unit and stores the band-expanded image signal data in the storage unit. .

Description of Embodiments Embodiments of a digital image storage device and a reproducing device according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, an embodiment of the present invention is shown in which memory cartridges 10 and 12 mountable in a digital electronic still camera are removably connected to connectors 14 and 16, respectively. The memory cartridge 10 is a cartridge in which a rewritable digital storage device such as an SRAM semiconductor memory is mounted. It may take other forms, such as an integrated circuit (IC) card. In the present specification, the term "module" is used to include those mounting forms. Memory cartridge 10
Is a SRAM with a storage capacity of 16 Mbits per chip, for example, when an image of one frame is represented by 1 M to 1.5 Mbits of data.
Then, two chips will realize a memory device that captures 32 to 21 frames, respectively.

The data input / output line of the memory cartridge 10 is a connector
A control line connected to the image data bus 18 through 14 and including its address, read / write enable, chip select, strobe, clock, etc.
Is connected to the address / control line 20 via Similarly, the data input / output line of the memory cartridge 12 is connected to the image data bus 18 through the connector 16, and its control line is connected to the address / control line 22 through the connector 16.

In this embodiment, one connector, that is, the read side connector
A memory cartridge 10 in which image signal data is stored in a digital electronic still camera, for example, is connected to 14 for reading the data. The other side, that is, the writing side connector 16 is connected to the memory cartridge 12 for storing the image signal data read from the memory cartridge 10, for example, in the present apparatus. This memory cartridge 12 may also take the form of another module such as an IC card. In this embodiment, for example, SRAM is used, but ROM such as EPROM or EEPROM may be used.

The image data bus 18, and address and control lines 20 and 22 are connected to the control circuit 24 as shown. A keyboard 26 is connected to the control circuit 24, and various instructions and input data of the operator for this apparatus are input from the keyboard 26. In this embodiment, the control circuit 24 is a control function unit that is constituted by a micro processing system and controls the entire apparatus in response to an instruction from the keyboard 26.

By the way, the memory cartridges 10 and 12 have a function of generating a memory identification code for specifying a memory characteristic or a type of a memory element included in the memory cartridge 10 such as a type and a storage capacity. This is, for example, a connector
It is realized by connecting the pins of the cartridge 10 or 12 engaged with 14 or 16 so as to output a specific logic state. For example, to identify whether it is ROM or RAM, one or two terminals are sufficient. Alternatively, the identification code may be semi-fixedly written in a specific storage area of a memory element included in each of the memory cartridges 10 and 12. The output line of this identification code is connected to the signal line 50 via the connector 14 for the memory cartridge 10 and to the signal line 52 via the connector 16 for the memory cartridge 12. Both signal lines 50 and 52 are connected to the control circuit 24.

Power lines 72 and 74 for memory cartridges 10 and 12
Are connected to the power supply unit 60 of the present apparatus via connectors 14 and 16, respectively. The power supply unit 60 includes a connector 14 and
A power supply of a type capable of supplying various kinds of memory cartridges connectable to 16 is provided, and these are selectively supplied to the power supply lines 72 and 74 under the control of the control line 70 of the control circuit 24.

The image data bus 18 is also connected to the image memory 28. It may also be connected to a file storage device such as an optical disk device or a floppy disk device. In the present embodiment, the image memory 28 is a RAM having a storage capacity for temporarily storing image signal data of at least one frame, that is, one field or one frame,
The video signal data read from the memory cartridge 10 is stored therein. Control signals including its address, read / write enable, strobe, clock, etc. are received from control circuit 24 through address / control line 36.

The image signal data output 42 of the image memory 28 is connected to a digital-analog conversion circuit (DAC) 44. The conversion circuit 44 is a signal conversion circuit that converts image signal data read from the memory 28 into a corresponding analog signal and outputs the analog signal to an output terminal 46 thereof. The output terminal 46 is a device output of this device, and a utilization device such as a video monitor device 48 for visualizing a video signal of the output 46 or an image printer is connected to the output terminal 46.

The image data bus 18 is further connected to a band companding circuit 100. The band companding circuit 100 is connected to the image data bus 18.
The uncompressed image data provided by the same is band-compressed by a predetermined method and output to the bus 18, and the compressed image data provided by the same bus 18 is band-expanded by a predetermined method. This is a signal conversion circuit for outputting to the bus 18. The band compression and band expansion method and compression ratio may be fixed to the apparatus, but in this embodiment, they are variably set from the control circuit 24 through the control line 102. Band companding circuit
100 may be included in the processing system that constitutes the control circuit 24. As the band companding method, a compression encoding method suitable for companding the image signal data, for example, a DPCM or Hadamard transform method is advantageously applied.

With respect to this encoding companding, the control circuit 24 determines, if image data is already stored in the memory cartridges 10 and 12 connected to the connectors 14 and 16, respectively, its band compression mode, that is, whether band compression is performed or not. , And has a function of reading and identifying data indicating a band compression method and a compression ratio. Further, when the image data compressed by the band companding circuit 100 is written in the writing side memory cartridge 12, it also has a function of writing the data showing the band compression form in a specific storage area of the memory of the memory cartridge 12.

The operation of this apparatus will be described with reference to the operation flow of the control circuit 24 shown in FIG. For example, a memory cartridge in which video signal data is stored in a digital electronic still camera
Connect 10 to connector 14. If it is only desired to reproduce the image stored in the memory cartridge 10 on the video monitor device 48, nothing need be connected to the connector 16. When it is desired to store this video signal data also in another memory cartridge 12, it is connected to the connector 16. The keyboard 26 is operated to instruct reading from the memory cartridge 10. At this time, the number of the frame to be read may be specified.

In response to the key operation, the control circuit 24 first confirms the connection of the memory cartridge 10 on the reading side (81) and then the signal line 50.
Read that memory identification code from. When the memory cartridge 12 on the writing side is connected, the signal line
The memory identification code is also read from 52.

The control circuit 24 uses the read memory identification code to read and write memory cartridges.
The types of 10 and 12, that is, the type and storage capacity are determined (82). The control circuit 24 determines the operating voltage and the reading speed of the memory cartridges 10 and 12 according to the determined memory type, and determines the addressing method according to the storage capacity. The control circuit 24 determines the operating conditions of the device according to the memory characteristics such as the operating voltage, the reading speed and the addressing method thus determined (83).

More specifically, the control circuit 24 controls the power supply unit 60 by the control line 70 and determines the type of power supply supplied from the power supply unit 60 to the memory cartridges 10 and 12. For example, if the memory cartridge 10 is SRAM, a 5V power supply would be selected.

In this apparatus, the video signal data read from the memory cartridge 10 is temporarily stored in the image memory 28. In that case, the control circuit 24 first sends the read address and the timing signal of the image signal data of a specific frame from the address / control line 20 to the memory cartridge 10. An address method such as a specifiable address space is determined based on a storage capacity defined by a memory identification code. In addition, these control signals are generated according to the above-described determined writing speed and addressing method.

Therefore, the control circuit 24 accesses a specific storage area of the memory cartridge 10 and reads the data indicating the band compression form stored in the specific storage area. If nothing is stored in this area, or if the band compression form data indicates no compression, the control circuit 24 determines that the image signal data stored in the cartridge 10 is not band-compressed. Then (84), the operation mode for reading the uncompressed image signal data, that is, the process proceeds to steps 85 to 87.

Then, the image signal data of the frame is read out from the addressed storage position of the memory cartridge 10 to the image data bus 18. The image data on the bus 18 is temporarily stored in the image memory 28 (85).

The image signal data stored in the image memory 28 is repeatedly read from the read data line 42 to the digital-analog conversion circuit 44 at the television signal rate, converted into a corresponding analog signal, and output from the device output 46. This is visualized, for example, on a video monitor device 48, which is connected to the device output 46.

Then, when the keyboard 26 instructs the memory cartridge 12 on the writing side to store the data, the control circuit 24 performs the writing operation 86 on the cartridge 12 according to the conditions on the writing side in the same manner as the reading side. More specifically, the control circuit 24
Determines the type and storage capacity from the memory identification code of the memory cartridge 12 on the writing side, determines the operating voltage and writing speed of the memory cartridge 12 according to the determined memory type, and determines the addressing method according to the storage capacity. According to the memory characteristics determined in this way, the control circuit 24
Sets the operating conditions of this device.

The control circuit 24 controls the power supply unit 60 by the control line 70,
The type of power supply 62 supplied from the power supply unit 60 to the memory cartridge 12 is set. For example, memory cartridge 12 is EP
If it is a ROM, the 20V power supply will be selected.

The control circuit 100 also includes a band companding circuit through the control line 102.
Control 100 and specify its band compression type. As a result, the band companding circuit 100 has a band compressing operation,
The band compression method and compression ratio are set. Note that these compression methods and compression ratios may be fixed to the device, that is, may be of a single type.

Therefore, the control circuit 24 reads out the temporarily stored image signal data from the image memory 28 by the address / control line 36, and this is transmitted through the image data bus 18 to the band companding circuit 100.
Transfer to. At that time, the control circuit 24 may perform image processing such as gradation correction or editing on the image signal data. The band companding circuit 100 band-compresses and encodes the image signal data from the bus 18 according to the set band compression form, and sends the image signal data to the bus 18 again. The compressed image signal data is transferred to the writing side memory cartridge 12 through the bus 18. The control circuit 24 uses the address / control line 22.
A control signal including the write address and timing signal is sent to the write side memory cartridge 12 via. An address method such as a specifiable address space is determined based on a storage capacity defined by a memory identification code. These control signals are generated according to the above-described determined writing speed and addressing method. As a result, the video signal data is written in the designated writing position, that is, the address in the writing side memory cartridge 12 (86).

The control circuit 24 writes a code indicating the band compression mode at that time in a specific storage area of the memory cartridge 12 on the writing side together with the writing of the compressed image signal data. It is written to its storage area of the memory cartridge 12 by the normal route through the image data bus 18 (87).

Similarly, the image signal data of the other frames stored in the memory cartridge 10 on the reading side is stored in the image memory.
While reading out to 28 and outputting to the video monitor device 48,
The band is expanded in the band companding circuit 100 and stored in the next storage area of the writing side memory cartridge 12. In this way, the image data stored in the memory cartridge 10 on the reading side can be transferred to the memory cartridge 12 on the writing side in a band-compressed form for storage. As a matter of course, the band-compressed data can represent the amount of information before compression with a small amount of data, so that the image signal data of more frames than the number of frames stored in one memory cartridge 10 can be represented by the other. Can be stored in the memory cartridge 12. If an EPROM or an EEPROM is used for the other memory cartridge 12, the memory can be held more fixedly.

In step 84, the data indicating the band compression form stored in the specific storage area of the memory cartridge 10 is read out, and if the data indicates the specific band compression form or the presence of the band compression, the control circuit 24 causes the cartridge 10 to read the data. It is determined that the stored image signal data has been band-compressed. Therefore, for example, when the reproduction output mode for reproducing an image on the video monitor device 48 is designated by the keyboard 26 (90), the operation of reading the compressed image signal data from this, that is, steps 91 to 92 is performed. In addition,
The form of band compression thus does not take the form of data stored in a particular storage area of the memory cartridge 10, such that the pins of the cartridge 10 engaged with the connector 14 output a particular logic state. It may be connected.

The control circuit 24 sets the band compression method, compression ratio, etc. in the band companding circuit 100 by the control line 102 according to the data indicating the band compression form obtained from the memory cartridge 10, and specifies the band expanding operation in the circuit 100. Yes (91). Therefore, the control circuit 24 is the same as the above-mentioned memory cartridge.
Image signal data is sequentially read from 10. The read image signal data is transferred from the image data bus 18 to the band companding circuit 10
Entered in 0. The band companding circuit 100 band expands the image signal data according to the set band compression method and compression ratio, and outputs the image signal data to the image data bus 18. This is transferred to and accumulated in the image memory 28. The decompressed image signal data stored in the image memory 28 is read and output to the device.
The operation output to 46 is as described above.

In the present embodiment, the control circuit 24 to the band companding circuit 10
Although the band compression method and the compression ratio can be selectively set to 0, it is not always necessary to selectively set the band compression method and the compression ratio to a predetermined band compression method and compression ratio. It may be fixedly set to 100.

Effect According to the present invention, the image signal data stored in the memory is read by the video signal source such as a digital electronic still camera, band-compressed, and stored in another memory. Also, the image signal data that has been band-compressed and stored in the memory is read out, band-expanded and reproduced. Therefore, images of many frames can be stored in the memory, which is convenient for storage.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a digital image recording / reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is an operation flow chart showing an example of image data reading / writing operation of a control circuit in the embodiment shown in FIG. Is. Explanation of symbols of main parts 10,12 …… Memory cartridge 20,22 …… Address / control line 24 …… Control circuit 28 …… Image memory 60 …… Power supply section 100 …… Band companding circuit

Continuation of front page (56) Reference JP-A-57-92981 (JP, A) JP-A-59-54015 (JP, A) JP-A-60-200679 (JP, A) JP-A-61-284186 (JP , A) Television Society Journal Vol. 39, No. 10 (1985) P. 934-940 Tanimoto et al. "Band compression of high-definition television by TAT (Time-Axis Trams form)"

Claims (9)

(57) [Claims] 1. An image signal data representing a frame of image is transferred from a first memory module in which an image signal is stored in the form of digital data to a second memory module which stores the image signal in the form of digital data. Then, in the digital image storage device for storing the image signal data in the second memory module, the device includes first connector means to which the first memory module is detachably connected, and the second memory device. A second connector means to which the memory module is detachably connected, and the image signal data is read from the first memory module connected to the first connector means, and a second connector means is connected to the second connector means. A control means for storing the image signal data in a memory module and a first connector means for reading from the first memory module. The control means includes: storage means for temporarily storing the output image signal data; and band compression means for band-compressing the image signal data stored in the storage means in a predetermined band compression mode. Generating means for generating band compression form data representing a form of band compression for the entire image signal data representing the image of one frame in the compression means, and a form of band compression corresponding to the image signal data accumulated in the storage means. Determining means based on the band compression form data stored in the first memory module, wherein the determining means determines that the image signal data stored in the first memory module is band-compressed. It is determined whether or not the image signal data is stored in the first memory module based on the band compression form data stored in the first memory module. When the determination means determines that the image signal is not compressed, the image signal data is read from the first memory module and stored in the storage means, and the image signal data stored in the storage means is read out and the band A digital image storage device, wherein band compression is performed by a compression unit, and the band compression form data generated by the generation unit is stored in the second memory module together with the band-compressed image signal data. 2. The storage device according to claim 1, wherein the judging means stores band compression form data corresponding to the image signal data stored in the first memory module in the first memory module. A digital image storage device characterized by determining that the image signal data is not band-compressed when it is not stored. 3. The storage device according to claim 1, wherein the control means stores the image signal data indicating that the image signal data stored in the second memory module has been band-compressed. An image storage device, characterized in that it generates band compression form data representing a form of band compression. 4. The storage device according to claim 1, wherein the control means stores the image signal data indicating a band compression method and a compression ratio of the image signal data stored in the second memory module. An image storage device, characterized in that it generates band compression form data representing a form of band compression. 5. A storage device according to claim 1, wherein said storage device has first and second memory modules according to operating conditions of the first and second memory modules connected to the first and second connector means. Operating circuit means for operating the second memory module, wherein the first and second memory modules each include a first
And memory identification information that defines memory characteristics of the second memory module, and the control means includes the memory identification information from the first and second memory modules respectively connected to the first and second connector means. And deriving operating conditions of the first and second memory modules according to the obtained memory identification information, controlling the operating circuit means according to the derived operating conditions, 2. An image storage device characterized by performing the image signal data read operation and the compressed image signal data write operation to the second memory module. 6. The storage device according to claim 1, wherein the storage device is connected to the storage means, reads image signal data accumulated in the storage means, and converts the image signal data into a corresponding analog video signal. An image storage device, comprising: a signal conversion unit for performing the conversion, and an output unit that is connectable to the utilization device and outputs the analog video signal to the utilization device. 7. A memory module in which image signals are stored in the form of digital data, and band compression showing a form of band compression for the entire image signal data representing an image of one frame stored in the memory module. Connector means to which a memory module carrying morphological data is detachably connected, band expansion means for expanding the band-compressed image signal data, and temporary expansion of the image signal data expanded by the band expansion means. A storage unit for storing, a signal conversion unit connected to the storage unit for reading out the image signal data stored in the storage unit and converting the image signal data into a corresponding analog video signal, and a utilization device are connectable, and the analog video Output means for outputting a signal to the utilization device, and controlling the band expanding means and the storage means, connected to the connector means. Control means for reading image signal data from the memory module and outputting an analog video signal to the output means, wherein the control means stores the band compression form data in the memory when reading the image signal data from the memory module. The control unit is provided with a determination unit that obtains from the module and determines whether the image signal data stored in the memory module is band-compressed by the band compression form data, and the control unit is stored in the memory module. When the determining unit determines that the image signal data is band-compressed, the image signal data is read from the memory module, the band is expanded by the band expanding unit, and the band-expanded image signal data is output. A digital image reproducing apparatus characterized in that the digital image reproducing apparatus stores the image in the storage means. 8. The reproducing apparatus according to claim 7, wherein the band compression form data includes data indicating at least one of a band compression method and a compression ratio of image signal data stored in the memory module, The band expansion unit can selectively set a band compression method and a compression ratio, expands image signal data according to the selectively set band compression method and compression ratio, and the control unit sets the band compression method. An image reproducing apparatus, characterized in that at least one of a band compression method and a compression ratio according to the form data is set in the band expanding means. 9. A reproducing apparatus according to claim 7, wherein the reproducing apparatus includes operation circuit means for operating the memory module according to an operation condition, the operation circuit means being connected to the connector means. Holds the memory identification information that defines the memory characteristics of the memory module, the control means obtains the memory identification information from the memory module connected to the connector means, and responds to the obtained memory identification information according to the obtained memory identification information. The image reproducing apparatus is characterized in that the operating condition of the memory module is derived, the operating circuit means is controlled in accordance with the derived operating condition, and the image signal data is read out from the memory module.