JPH03143084A - Electronic camera and picture recording method - Google Patents

Abstract

PURPOSE:To vary the memory capacity necessary for recording one frame by deciding whether or not a recording to a recording medium is possible from the amount of picture data stored in a buffer memory and the recordable space capacity of the recording medium. CONSTITUTION:A recording medium 15, a data compression part 27, 28, 31, a mode selection part 24, a buffer memory 31, and a decision part 24 are provided. And, even when the data amount of the picture to be picked up is varied, this data is once stored in the memory 31, whether or not this can be written into the recording medium 15 is decided, and it is fetched by this recording medium 15 only when it is decided that the data can be written in. Thus, there is no damage to the picked up picture data even when varying the data amount (mode) for each image pickup, and the remaining amount corresponding to this mode is displayed each time the mode is varied, so an electronic camera with a good ease of used for the user can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic camera and an image recording method that use, for example, a semiconductor memory card as a recording medium and record still images on the recording medium.

(Prior Art) In recent years, as an alternative to conventional (still) cameras that capture and record still images using the exposure of silver halide film, that is, photographic film using silver halide photosensitive materials,
CCD (charge coupled device)
2. Description of the Related Art Electronic cameras have been commercialized that capture a still image of a subject using a solid-state image pickup device such as a solid-state image pickup device, and record the still image on a rotating magnetic recording medium, that is, a video floppy. However, since this type of electronic camera uses a rotating magnetic recording medium, it requires a drive device inside the camera to drive the rotating magnetic recording medium relative to the recording head. is not very suitable. Therefore,
As a system that does not require such a drive device and is advantageous for miniaturization, there is an all-solid-state electronic camera system that records image information on a memory card using semiconductor memory (that is, stores image information on the semiconductor memory of the memory card). is proposed. An example of a typical configuration of such an electronic camera cover 11 is shown in FIG.

An image of the subject is formed on a CCDI 26, which is an image sensor, via a lens 121, an aperture 22, and a color filter 120, and photoelectrically converted by the CCD 126. CC0
The output signal of 126 is subjected to predetermined processing in a preprocessing circuit 127, and then converted into a digital signal by an A/D converter 128 and recorded on the memory card 115.

The memory card 115 stores signals from each pixel of the image sensor.
It will be digitized and recorded. A preprocessing circuit 127 performs predetermined processing such as amplification, white balance correction, and γ correction on the signal of each pixel of the image sensor as preprocessing. memory card 115
The pixel data subjected to the above preprocessing is recorded in the order according to the pixel arrangement. During playback, the data recorded on the memory card 115 is set in a playback device, subjected to necessary signal processing, and then D/A converted and input to a TV monitor where it is displayed as an image. Note that FIG. 13 shows a case 110, a release switch 111 for triggering the imaging operation. = battery 123 as g,
A shutter control circuit 124 for controlling the aperture 122 and electronic shutter operation. A CCD drive circuit 125 and monitor section 130 are also shown. The CCD drive JJ+ circuit 125 includes the shutter control circuit 124 and the CCD 12
6. Preprocessing circuit 127. This is a circuit for controlling and driving the A/D conversion circuit 128 and the memory card 115.

The monitor section 130 displays a photographed image based on a signal passed through the preprocessing circuit 127 during photographing, and is used as a finder.

In this way, with the method of recording data corresponding to each pixel of a fixed image sensor as is on a memory card, signal processing is simple and the configuration of the device is also simple. however,
For example, if the recording conditions such as the number of pixels of the fixed image sensor of an electronic camera or the arrangement of color filters differ, the data arrangement in the memory card to be recorded or the amount of data per frame will also change. This makes the memory card incompatible with other devices, that is, with an electronic camera used for recording and an electronic camera whose solid-state image sensor has a different pixel count and one-color filter arrangement.

If one electronic camera can perform recording under a plurality of different recording conditions, compatibility can be achieved to some extent. However, in this case, the memory capacity required to record image data for frames of the captured still image differs depending on the recording conditions (recording mode) at the time of photography.

For this reason, even though one frame of still images was taken, there may not be enough space left on the installed memory card to record that one frame, or the image data of a certain frame may be deleted. This creates an inconvenience in that even if new image data is attempted to be written in the recording area, the capacity may be insufficient and recording may not be possible.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned drawbacks, and allows the memory capacity required for recording one frame to be changed as desired.
The number of images that can be recorded on the recording medium can be efficiently changed depending on the image quality. It is an object of the present invention to provide a new electronic camera and an image recording method thereof that can flexibly deal with discrepancies in recording areas when recording images.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a data compression unit which is provided with a removably attached recording medium for recording photographed image data, such as a memory card, and which compresses the image data to be recorded. , a mode selection section for selecting a recording mode, that is, a compression mode, provided in connection with the data compression section; and a mode selection section for temporarily storing the image data compressed in the compression mode selected by the mode selection section. The electronic camera includes a buffer memory and a determination unit that determines whether image data stored in the buffer memory can be recorded on the recording medium.

In addition, the present invention can efficiently change the number of images that can be recorded on a recording medium, for example, a memory card, depending on the image quality, and can also record a mixture of multiple types of image data in different modes on one recording medium. It will not cause any inconvenience. Furthermore, with the electronic camera, it is also possible to easily erase only the data of the ↓ frame and record new image data.

Furthermore, the electronic camera is an image recording method that allows the captured image contents to be recorded on another recording medium even if it is discovered after the image is taken that the capacity of the attached recording medium is insufficient. Therefore, according to the present invention, it is possible to provide an electronic camera and an image recording method thereof that are easy to use as a system including a recording medium.

(Function) Even if the amount of data of the image to be captured is varied, this data is temporarily stored in memory, and it is determined whether it can be written to a recording medium, and only when it is determined that it can be written, it is imported to this recording medium. Even if the amount of data (mode) is varied for each image capture, the captured image data will not be spoiled.

Furthermore, each time the mode is changed, the remaining amount corresponding to the mode is displayed one by one, so it is possible to provide an electronic camera that is extremely user-friendly for the user.

(Example) Hereinafter, a first example of an electronic camera according to the present invention will be described with reference to the drawings.

An electronic camera system consists of an electronic camera and a playback device. The former, an electronic camera, is a device that uses a semiconductor memory card as a recording medium to image and record a subject, and the latter, a playback device, reads image information recorded on a memory card from the memory card and displays it on a TV.
This is a device for displaying images on a receiver or the like.

FIG. 1 is a perspective view of the electronic camera as seen diagonally from the rear, and descriptions of parts having the same functions as a normal still camera (using photographic film) will be omitted. The electronic camera IO is provided with a release 1, an imaging mode changeover switch 12, and an imaging number display section 13. Further, the electronic camera IO is provided with an inlet 14 for volatilizing the semiconductor memory card 15 from the right side.

Further, the electronic camera 10 is provided with a shutter speed selection dial 8. Each of these parts will be explained in detail later.

FIG. 2 shows a schematic basic configuration of the electronic camera IO. When taking images, do you know what to do? Like the 1t still camera,
Focusing is performed by operating the lens system 21,
The shutter speed is then selected by operating the shutter speed selection dial 18. Adjustment of the aperture is performed by controlling the aperture 22 by the control circuit 24. This electronic camera 10 utilizes shutter speed adjustment using a so-called electronic shutter. With electronic shutter, 1
The shutter speed is adjusted by controlling the charge accumulation time of the CCD array 26, which is a cell. An image of the subject is formed on the CCD array 26 via the lens system 21.

Imaging operation is started, and when the release 11 is first pressed halfway (the release button is pressed halfway) by the operator, that is, the user, the power supply voltage is supplied from the battery-based power source 23 for the imaging operation. (In other words, when a power switch (not shown) is turned on, power is supplied only to the parts required in the preparation stage for imaging.
The power supply voltage is supplied to other parts necessary for imaging only after the release 11 is pressed halfway). The amount of incident light is measured by the exposure sensor 19, and the control circuit 2.1 controls the aperture 22 according to the amount of incident light. The external color temperature is measured by the white balance sensor 17, and the control circuit 2
4 generates a white balance control signal according to the measured color temperature.

When the release 11 is pushed further and the state changes from a half-pressed state to a fully-pressed state (a state in which the release button is fully pressed), the control circuit 24 generates a shutter pulse. v
In response to the shutter pulse, the jA motion circuit 25
A control signal is given to the D array 26, preprocessing circuit 27, A/D conversion circuit 28, and signal processing circuit 31. In response to this control signal, the CCD array 26, the preprocessing circuit 27, the A/
The D conversion circuit 28 and the signal processing circuit 31 operate. C
An image information signal consisting of an analog signal outputted from the CD array 26 is given to an A/D conversion circuit 28 via a preprocessing circuit 27, and is converted into a digital signal by the A/D conversion circuit 28.

The digitized image information signal is further subjected to predetermined signal processing by a signal processing circuit 31. The digital image information signal output from the signal processing circuit 31 is supplied to the semiconductor memory card 15 together with a control signal including an address signal Z. In this way, the image information signal of the captured still image is stored in the semiconductor memory card 15 as a digital signal.

Prior to imaging, the user can selectively set the format of data to be recorded on the semiconductor memory card 15 by operating the mode switch I2.

The mode switch 12 is used to select and set a desired mode from a plurality of modes with different image qualities.

By selecting a mode using the mode switch 12, it is possible to change the amount of digital data required to record one frame of image (therefore, the number of image frames that can be recorded on one memory card 15). For example, when mode (A), which is a high image quality mode, is set, one frame of image is recorded in 640 bytes as digital data with high image quality.

In mode ([1), one frame of image is recorded in 320 bytes with the highest image quality next to mode (A), and in mode (C), one frame of image is recorded in 160 bytes in mode (B). In mode (D), which is the second highest image quality and the lowest image quality mode, one frame of image is recorded at 80 bytes, which is the smallest memory space per frame. For example, 2
．． If 56 MB of memory is installed, depending on the image quality selected, mode (A) will produce 4 frames per memory card 15, mode (B) will produce 8 frames,
In mode (C), 16 frames of images can be recorded, and in mode (D), 32 frames of images can be recorded. The recording mode can be selected for each frame using the mote switch 12. Details of the method for storing data in the memory card 15 will be described later. Note that the amount of data per frame may not only be determined by a plurality of fixedly set modes, but also the compression rate may be arbitrarily set by the user. In other words, mode switch 1
2. In the case described above, the compression rate can be arbitrarily determined by the user, as well as in the case where the configuration is such that a plurality of modes (A) to (D) can be switched by a dial type as shown in FIG. 18(a). If you want to set it as shown in Fig. 18(b), or 1 to N (N
is an integer (N is within the above-mentioned minimum unit), an arbitrary compression ratio, for example 1.15, can be set.

FIG. 3 shows the basic configuration of the memory card 15. The memory card 15 is composed of a printed circuit board on which a plurality of RAM (random access memory) chips 36 are mounted. At one end of the memory card 15, an external terminal 32 including a data terminal, an address terminal, and a control terminal, and a power terminal 33 are provided. The memory card I5 is used by being loaded into the electronic camera 10 or the playback device.

Power supply voltage is supplied to the memory card 15 via the power supply terminal 33, and signals are input and output to and from the memory card 15 via the external terminal 32. The memory card 15 includes a dedicated battery 34 for holding stored data, that is, recorded data. The memory card 15 is provided with a power switching circuit 35.
When the memory card 15 is loaded into the electronic camera 10 or the player, the RAM chip 36 is powered by the built-in battery 34.
while switching to the t source 23 of the electronic camera 1o.

In FIG. 4, as a more specific example of the memory car 1-15, 20 1M byte RAM chips 361 to 3 are shown.
A memory card 15 using 620 is shown.

External terminals 321 to 32 are provided at one end of the memory card 15.
3 and a power supply terminal 33 are provided. External terminal 32
1 to 323 are 8-bit data terminals 321. It is comprised of an address terminal 322 and a control terminal 322 that receive address information AO to A20. The memory card 15 shown in FIG. 4 has a capacity of 20 Mbits (2.56 Mbytes). The control terminals 323 include a terminal C8 for selecting the RAM chip 36, a terminal WP for write pulses, and a terminal CE for selecting cards when there are several playback cards.
Consisting of Decoder 1211 by input from terminal C8
and 1212 is selected. The decoder 1211 corresponds to the RAM chips 361 to 3610,
The decoder 1212 includes RAM chips 3611 to 3620
It corresponds to

For example, a CCD array 26, which is a solid-state image sensor, is used as an image sensor for capturing a frame 21 image of a still image. CCD array 2 used in the electronic camera of the present invention
6 is suitable, for example, a frame interline transfer type CCD array.

FIG. 5 shows a schematic configuration of an example of a frame incline transfer type CCD solid-state imaging device.

In this CCD array, pixel light receiving sections 51 each consisting of a photoelectric conversion element such as a photodiode are two-dimensionally arranged. The vertical transfer section 5 is adjacent to the pixel light receiving section 51 row of each column.
2 is provided. The charge in each pixel light receiving section 51 is transferred to the corresponding vertical transfer section 52 by field shift pulse φvQ.
and is transferred via the transfer gate 53 to the charge storage section 54 which is a frame memory section. The signal charges in the charge storage section 54 are transferred to the output circuit 56 via the horizontal transfer section 55.
output as an electrical signal. A sweeping section 57 is provided at the other end of the vertical transfer section 52 .

In order to obtain a color image signal using only one CCD array, an optical system is installed on each pixel light receiving section 5I to separate R (red), G (green) and B (blue) light components. Color filters are arranged. Various types and arrangements of optical color filters are known, and the electronic camera of the present invention is not limited to any particular one.

The electronic camera IO according to this embodiment will be described in detail with reference to FIG. 6, which shows a more specific configuration.

Before pressing the release 11, the user can select a desired mode by operating the mode switch 12, considering the image quality to be recorded on the memory card and the number of frames to be recorded on the memory card. A mode may be selected individually for each l frame of still images and imaging may be performed. The reason why the mode can be changed for each frame in this manner will be described later.

The selected mode signal is detected by the central processing unit (CPU).
The signal is input to a switch 315 consisting of 241. Note that when the memory card 15 is attached to the camera body, the CPU 2
41 reads information from the memory card 15 (file number, number of used blocks, etc., which will be described later).

If it is a new card, it will be initialized.

When the release 11 is pressed halfway, the white balance sensor 17 and exposure sensor 19 send external color temperature information and exposure amount information to the I/F 242, respectively.
is input to the CPU 241 via the . Based on the read exposure amount information, the CPU 241 drives and controls the calibration 22 via the aperture drive circuit 245. Also, C
The PU241 uses the interface (I/F) based on the information for the white balance σ and the information on the exposure amount.
CC via 243 and signal generator 251
Controls the D drive circuit 252.

The CCD array 26 is driven and controlled by this CCD drive circuit 252. Furthermore, from the CPU 241 to the I/F 24
The flash drive circuit 244 is controlled by the signal a supplied through the flash drive circuit 2 at the time of photographing a.
44 is set to drive or not drive the flash 16, such as an electronic flash. In addition, the amplifier circuit 271 and the color separation/γ correction/white balance circuit 272 are both connected to the I/F from the CPU 241.
243 and the signal given from the CPU 241 to I
/F 243 and a signal given via the signal generator 251.

Next, when the release 11 is pushed further into the fully pressed state, the signal generator 251 causes the CCD array 26. Amplifier 271, color separation/γ correction/white balance circuit 272, A/D conversion circuit v128, signal processing circuit 311. Filter 312, subsample circuit 3
13. Drive signals corresponding to each element are supplied to the data compression circuit 314, switch 315, and memory interface (memory/F) 317, respectively.

In response to the operation of the release 11, one image information signal is sent to the CCD.
Output from array 26. The image information signal is sent to amplifier 2.
71 to a predetermined level, and further includes a color separation circuit, a white balance circuit, and a γ correction circuit.
After passing through the white balance/γ correction circuit 272, R, G
and B signals are input to the A/D converter 28 in parallel. The R, G, and B digital signals output in parallel from the A/D converter 28 are converted into a luminance signal Y1 and color difference signals CRI and CBI by a signal processing circuit 311.
And (the luminance signal Y1 remains unchanged) two types of color difference signals CR
1 and CBI are input into the reduction filter 312 with the number of samples reduced to 1/2. Luminance signal Yl.

The color difference signals CRI and CBI are linearly quantized data with one sample being 8 bits. The relationship between the sample points of the luminance signal Y1 and the sample points of the color difference signals CRI and CBI is as shown in FIG. Low pass filter 31
2 is a pre-reduction filter for the sub-samples. The luminance signal Yl and color difference (i-th CRI and CBI) are provided to a sub-sampling circuit 313 after passing through a reduction filter 312.

In the subsampling circuit 313, the luminance signal is subjected to line offset subsampling to produce a luminance signal Y2 with a sample count of 172, and the color difference signals CRI and CBI are subsampled every other line to produce color difference signals CR2 and Y2 with a sample count of 1/2. It becomes CB2. The relationship between each sample data point at this time is as shown in FIG. The luminance signal Y2 and color difference signals CR2 and CB2 are input to the data compression circuit 314. As already mentioned, the luminance signal Y
2. The color difference signals CR2 and CB2 are each linearly quantized with 8 bits per sample, but the data compression circuit 3
14, the number of data bits for one sample is reduced. In this embodiment, the data compression method is, for example, DPCM.
Data compression is performed using (differential pulse code modulation). Data compression using DPCM is a well-known technique in which the difference between sample data and the previous sample data is nonlinearly compressed and quantized. For example, regarding the luminance signal Y12 in FIG. 8, the difference between the luminance signals Yll and Y12 is nonlinearly quantized, and one sample is made up of 4 bits or 2 bits. Similarly, one color difference signal CR2 and C
B2 is also compressed, with one sample being 4 bits or 2 bits. The luminance signal compressed in this manner is designated as Y3, and the color difference signals are designated as CR3 and CB3.

The switch 315 changes the brightness to 7 depending on the set mode.
It is provided to select No. 2 and color difference signals.

For example, when mode (A) is selected, the signals Yl, CR1 and CBI output from the signal processing circuit 311
is selected by the switch 315 and directly recorded on the memory card 15 via the buffer memory 316. Similarly, in mode (B), the signal Y2. If CR2 and CB2 are in mode (C), they are compressed by the data compression circuit 314, and ↓Sample 4
Signal Y3. expressed in bits. CR3 and CB3 are
If the mode is CD), the signal Y3 is compressed by the data compression circuit 314 and represented by 2 bits per sample.
．． CR3 and CB3 are each selected by switch 315. The signals selected by these switches 315 are sent to the memory card 1 via a buffer memory 316.
Recorded in 5.

In addition to the image data, information on which mode has been selected is also recorded on the memory card 15 at the same time as the image data.

(For example, in the case of mode (A), rooIJ.

In the case of mode (B), it is recorded as a binary code indicating the mode number, such as roloJ. )moreover,
The memory card 15 stores, for example, control data on whether to use a flash and white balance.

Imaging data information such as exposure data (or aperture data) and shutter speed data can also be recorded in binary code, similar to mode information. These pieces of information are displayed on the display unit 13 by the CPU 241, and the user, that is, the operator, can confirm this information on the display unit 13.

The method of recording data on the memory card 15 will be explained in detail with reference to FIG. 9. Here, as shown in Fig. 4, an example will be explained in which a 20 Mbit, that is, 2.56 Mbyte memory card is used, in which 20 pieces of 1 Mbit RAM, such as 5RAlvi (static RAM), are mounted. do.

As shown in FIG. 9(A), the entire memory space is divided into the directory area and F A T (fil, e location).
It is divided into an n table, e) area and a data area.

As shown in Figure 9 (B), the directory area contains information indicating the file number, that is, the image (frame A) number when the file is image data, and information classification, that is, whether it is image data, audio data, or other data. Information indicating classification, 525/60 series or 625 for images
150 series, image mode, that is, information that shows the image compression method (including motes before compression), audio mode, that is, information that shows the compression method for audio data, and information that shows the year of recording (imaging). , information indicating the month of recording,
Information indicating the date of recording, information indicating the time of recording, and information indicating the amount recorded are each written in 1 byte, and the number of the data block (entry block number) where the file (image data file) starts and the number of the data block of the file (image data file) are written. Writes the number of data blocks used for recording. This directory area has 16 bytes per file and 256 bytes.
Allocate files (256 frames for images).

Therefore, the directory area is 4 bytes. FIG. 9(C) shows the structure of the FAT area, and FIG. 9(B) shows the structure of the data area. Prepare 256 bytes for the FAT area, and assign addresses from OOH address to FFI (address).The data area is divided into blocks for each IOK byte, and each block is assigned a block number 00H-FEH.
Assign.

To simplify the explanation, assume that approximately 40 bytes are required to record one frame of data, for example. In this case, the entry block number is written in the directory area as, for example, 11H1, and the number of blocks used is 041 (FAT
12H at address IIH of the area 13H1 at address 112H
2AH at address 13H, F F at address 2AH
Write H. This one frame of image data has block number 11H in the data area.

12IT, 13H, and 2AH are linked to 40 byte area. FAT area 2
FFH written to address A1 (indicates that it is the last block. Figure 9 (E) shows the memory area of 40 bytes to which the block is linked. The first block, 256 bytes of block number 11) records data on imaging conditions including flash use, white balance data, exposure value (or aperture value), and shutter speed value, and the remaining 252 bytes are used as a user area to record titles, etc. Leave it open.2
Image data is continuously recorded from the 57th byte to block number 2AH. In the above mode (A), 6.
1 block, 32 blocks in mode (B), mode (
In mode C), 16 blocks are used, and in mode (D), 8 blocks are used.

With this method, even when variable-length retention is used, in which the required memory capacity after percussion differs for each frame, recording on a memory card can be performed without any problem. That is, after encoding, the data is stored in the buffer memory 316. The capacity of the buffer memory 316 is set to the capacity required to store at least one frame. The memory capacity required to record the data of each E-frame that is actually captured can be determined by the usage status of the buffer memory 316, and based on this, the number of blocks required to record the data of one frame can be determined. It is possible to calculate how many data blocks to use. If the number of unused blocks in the memory card 15 is insufficient, the image data remains stored in the buffer memory 316, and the next imaging cannot be continued unless a new memory card is inserted. Note that in order to cope with a situation where it takes a long time to obtain a new memory card, the buffer memory 316 is backed up by a battery.

For example, it is desirable that the contents of the buffer memory 316 be retained for a long time even when the power switch of the device is turned off. Further, when the image data stored in the buffer memory 316 is no longer needed, the buffer memory 316 is reset by the reset button 9 in FIG.

The processing procedure for performing such recording will be explained in detail with reference to the flowchart of FIG.

The routine of the flowchart in FIG.
It will be launched at i71.

First, when the memory card 15 is inserted into the camera body,
The CPU 241 detects that the memory card 15 is inserted via the memory I/F 317 (step 5T1).
, and reads the directory information of the memory card 15 (for example, information such as the file number already in use and the number of blocks already in use) (step 5T2).
Next, it is determined whether new data can be written to the buffer memory 316 (that is, the buffer memory 316 is in a cleared state) (step 5T3). If new data can be written to the buffer memory 316, the mode information (at that time) set (modes (A) to (D)) is read (step 5T4), and according to this mode information, switch 5w
315 selection states are set. Therefore, the selection state of the switch 5W315 changes every time the mode information is changed by the mode switch.

Then, when the imaging operation is started and an input is given by operating the release 11 (step 5T6) (release 1
1), the captured image data is written to the buffer memory 316, and imaging information to be written to the directory area of the memory card 15, such as information on whether or not to use a flash, white Balance information, exposure value (or aperture value) information, shutter speed information, yearly information, month information, and day information.

Hour information and minute information are captured (step 5T)
7). Note that the mode information and the directory information of the installed memory card 15 have already been stored in step ST4.
and is captured in step ST2. Based on this information, the entry block number of the memory card 15 is set (step 5T8), and the number of data blocks used to record the image of the frame to be imaged based on the above mode information is determined. (Step 5T9). Check the recordable capacity (remaining capacity) of the installed memory card 5, and if the required number of data blocks to record images cannot be secured in the memory card 15 (step 5 TIO), The user is prompted to replace the memory card 15 (by a display at 13 or by two appropriate notifications, for example by sounding a buzzer). Then, if a new memory card I5 is installed (step 5T14), the process returns to step STI. If the required number of data blocks for recording images can be secured in the installed memory cart 15 (step 5 TIO), the FAT address of the memory card 15 is assigned (
Step 5TII): Transfer the image data (already stored in the buffer memory 316) and the above-mentioned imaging information to the memory card 15 via the buffer memory 316.
Write (step 5T12).

After all the data is transferred to the memory card 15, the buffer memory 316 is cleared and the buffer memory 316 is put into a memorizable state (step 5T13). Step 5T
After step ST3, the process returns to step ST3.

On the other hand, when a new memory card 15 is inserted, the process returns to step STI and the directory information of the new memory card 15 is read (step 5T2). If the number of blocks to be written to the memory card 15 is insufficient and a new memory card 15 is inserted, the buffer memory 31
6 has not been cleared (step 5T3), the process advances to step sT8 to process the entry block number setting of the memory cart 15, and then proceeds to step ST9.
Step 5 via 5TIO, 5Tll and 5T12
It reaches T13.

On the other hand, if a new memory card is not installed in step 5T14, the @
The image data is discarded by a reset signal generated by operating the reset button 9 (step 5T15), and the process proceeds to step 5T13.

Next, the image data is read from the memory card 15 and T
A playback device that displays images on a V monitor or the like will be described with reference to FIG. 11.

When the memory card 15 is inserted into the playback device 90 and a file number (image number) is specified by operating the keyboard 104, the CPU (central processing unit) 102 reads the memory card through the card interface (card I/F) 91. Read the directory area information.

The CPU 102 checks whether the information classification of the designated file number is image data, what the image format is, and what the mode of compression is, and also recognizes the encoder block number. Next, the CPU 102 reads information on all block numbers from the FAT area. The CPU 102 gives the block number to the card I/F 91, and the card I/F 91 generates an address according to the block number and reads out the image data one byte at a time. Also,
The CPU 102 controls the signal processing path according to the image format and mode information read out previously. for example,
When the mode is mode (C), the data compressed to 4 bits is restored to 8-bit linear quantized data by the data restoration circuit 92, and when the mode is mode (D), the data is restored from 2 bits to 8 bits. In modes (A) and (B), the read image data is input to the interpolation circuit 94 without passing through the data restoration circuit 92. A luminance signal Y and two color difference signals CR and CB are output from the interpolation circuit 94, and E frame data is written into the frame memory 95. Furthermore, in modes (C) and (D), one image data is written to the frame memory 95 via the data restoration circuit 92 and the interpolation circuit 94.

Note that route control according to the above-mentioned modes is performed as follows.

The number [Motoy] output from the card I/F91 is C
The signal is input to the determination circuit 100 via the PU 102, and the mode is determined by the determination circuit 100. Depending on the determination result in the determination circuit 100, the state of the switch 106 is changed, and the operations of the data restoration circuit 92 and the interpolation circuit 94 are also controlled.

Further, data other than the image data output from the card I/F 91 is sent to the frame memory 9 via the data circuit 93.
5, it is stored in the same way as the image data.

After one frame of data is written to the frame memory 95, the signal generator 103 is stored in this memory 95.
A readout clock is supplied from the source, and the luminance signal Y and color difference signals CR and CB are read out.

Luminance signal Y and color difference signal % CR and CB are respectively D/
The A (digital-to-analog) converter 96 converts the voltage back into an analog doubler, and the input method of the TV monitor 107 is changed to R.
(red), G (green) and B (blue) input method, the analog R, G
and B signals are generated and input to the TV monitor 107. If the input method of the TV monitor 107 is the NTSC composite input method, the analogized luminance signal Y, color difference signals CR and CB are sent to the first encoder 98 and the second encoder 98.
It is converted into a composite signal by the encoder 99 and T
The signal is input to the V monitor 107. If the input method of the TV monitor 107 is a Y-C separate input method, the analogized luminance signal Y, color difference signals CR and CB are converted into a luminance signal Y and a color signal C by the first encoder 98, and then output to the TV
It is input to the monitor 107.

In the manner described above, images captured and stored in the memory card 15 can be displayed. Of course, it is also possible to make a hard copy by connecting output terminals such as the R, G and B output terminals to, for example, a video printer.

Next, in the system of the present invention, recorded images can also be erased frame by frame. This image erasure for each frame is performed in a first-order manner.

When you operate the keyboard 104 of the player to specify the image number and issue an erase command, the CPU 102
/F91, the directory area of the memory card 15 is searched for an image number (file number) that matches the designated image number.

When the specified image number is found, F F H is written in the image number, entry block number, and used block number area of the corresponding directory. Further FA
The recorded contents of the address that was used in the T area are erased (
OOH is written to all applicable addresses).

In addition, when recording an additional frame of image with an electronic camera, (under the control of CPU 24)
The AT area is searched for the address where OOH is written. The smallest address where OOH is written is set as the entry block number, the required number of blocks is calculated from the memory capacity required to record t frames, and an address for linking the blocks is written in the FAT area. Next, open the empty directory (
Data such as the file number and information classification are written in one of the files (file numbers FFH), and the entry block number and the number of used blocks are written in the last two words. Thereafter, imaging condition data and image data, such as those shown right before flash usage, are sequentially written into the linked blocks.

As a result of searching the FAT area, if the number of blocks is insufficient for image recording, a signal is generated indicating that writing is not possible, and this signal causes, for example, a warning to be displayed on the display unit 13 indicating that writing is not possible. Ru.

This warning may be displayed, for example, by lighting an LED (light emitting diode).

In the above example, the ↓ block is 1. Although we have explained the case of OK bytes, if the memory capacity required to record one frame of image data varies minutely,
The size of the block may be reduced, or the minimum memory capacity required to record one frame t1 may be set to one block. The size of the above block should be set to a value that is the greatest common divisor of the capacity for recording one frame in each mode, so that the active part of the memory is zero or the minimum in each selectable mode. desirable.

In this way, when the size of one block is set to a value that is the greatest common divisor of the capacity for recording one frame, there is an advantage that the size of the FAT can be reduced.

For example, as mentioned above, the capacity of one frame of image data is 640 byte mode (A), 320 byte mode (B), 160 byte mode (C), and 80 byte mode (D). ), and if the size of one data block is 80 bytes, the FAT size for memory card 15 with 2.56 MB of memory installed is only 32 bytes. .

Moreover, although the case where the luminance signal Y and the two color difference signals CR and CB are used has been described above, the RY and BY signals may also be used as the color difference signals. These signals Y, R-Y and B-Y are obtained from the R, G and B signals X by Y=-0,3OR+0.59G+0.11BR-Y=-
0,7OR-0,59G-0,11BB-Y=-0,3
It can be easily converted as OR-0.59G+0.89B. It is also possible to use the optical and Q signals as two color difference signals at the same time.

Furthermore, in the above, we have explained the case where data is compressed using DPCM in order to reduce the bit capacity of one sample, but such data compression may involve differences in the method of creating prediction signals or quantization for nonlinear quantization. There are many methods, such as different methods depending on the choice of equipment or methods using transform coding. No matter what method is used, it is possible to cope with the problem by recording information indicating which method has been adopted as mode information on a memory card in the form of binary data.

Furthermore, FIG. 12 shows a configuration according to a second embodiment of the present invention, and in this embodiment, A in FIG.
/D conversion circuit 28, signal processing circuit 31.1, filter 3
12, sub-sample circuit 313, data compression circuit 314
The mixer circuit 41 includes the switch 315 and the switch 315.
A/D conversion circuit 28', YC processing circuit 42, filter 312', data compression circuit 314' and switch 31
Replace with 5'. In this embodiment, R2O and B output from the one color separation/γ correction/white balance circuit 272 are
The signals are synthesized by a mixer circuit 41, digitized by an A/D conversion circuit 28', and applied to a YC processing circuit 42.
The luminance signal and color difference signal output from the YC processing circuit 42 are passed through a filter 312' to a data compression circuit 314'.
give to The input and output of data compression circuit 314' are selected by switch 315'.

In the method adopted in the first embodiment described with reference to FIG. 10, image data corresponding to the mode set by shooting a still image is temporarily stored in a buffer memory, and then this stored image data is stored in a buffer memory. Although it is determined whether or not the captured data can be written to the memory card, a method may also be adopted in which the user is informed whether or not the data can be written in a mode set prior to photographing. Since the directory information on the memory card 15 is managed by the CPU 241, in this method, when the CPU 241 determines that writing is not possible in the set mode, the display section 13
display or issue an alarm (buzzer). In this case, steps ST9.5TIO and 5T14 in the flowchart of FIG. 10 will be provided before the step corresponding to step ST6. Step (corresponding to ST15) is unnecessary.Furthermore, the display unit 13 may display how many images can be taken in the set mode with the remaining capacity of the installed memory card 15.

The configuration of an electronic camera according to a third embodiment of the present invention having these features is shown in FIG. 14, and the procedure of the recording process is shown in the flowchart of FIG. 15.

The electronic camera shown in FIG. 14 has exactly the same configuration as that shown in FIG. 6 except that the reset switch 9 is not provided.

In FIG. 15, each step corresponds to steps 5TIO and 5T14 in the flowchart of FIG. Step 5T10' of requesting whether the necessary number of data blocks to record the 'tj image can be secured in 15, and Step 5T14' of checking whether the new card is loaded R' are performed in step S
Step ST of operation input of release 11 corresponding to T6
It is installed in the front stage of 6'. In the flowchart of FIG. 15, if the required number of data blocks to record one frame of image cannot be secured in the memory card 15, an appropriate alarm will be displayed on the display unit 13 or a suitable alarm will sound, such as a buzzer. Step 5T20 prompting the user to replace the memory card 15 is step 5TIO.
' and step ST]4'. Additionally, if the memory card 15 can secure the required number of data blocks to record one frame of image,
The number of remaining frames that can be recorded in that mode is displayed on the display section 13 (Step 5T21), and whether there is a mode change is checked (Step 5T22). If there is a mode change, the process returns to Step ST4.

Note that in the flowchart of FIG. 15, in step ST9', the CPU 241 calculates the number of data blocks used for recording the image data of the upper frame based on the set mode information.
The number of data blocks may be determined by separately providing a ROM (read only memory) in which the amount of data for each frame for each recording mode is stored in advance, and searching this ROM. This method is particularly effective when there are a large number of recording modes. Furthermore, instead of being managed by the CPU 241, the data regarding the remaining capacity of the attached memory card 15 may be held in a register provided in the memory I/F 317 and may be referenced.

The types of recording modes are not limited to the four types mentioned above, but may also include differences in data compression rates, differences in data compression methods, differences in information to be compressed, differences in the number of imaging pixels, differences in other imaging or recording conditions, or A wide variety of recording modes can be considered by combining these.

In the electronic camera according to the third embodiment, for example, the remaining capacity of the memory card 15 is 8 in mode (D).
Even though the camera's mode setting was set to mode (A) (640K) and a warning was issued when the number of blocks was such that a byte worth of data could be recorded in 0 but no more data could be recorded. When release 11 is pressed, the shooting mode is forcibly set to Mort (
D) may be set and written to the memory card 15.

As a semiconductor memory that can be used in the above-mentioned memory card 15, battery-backed SRAM (sta
tic random-access memory)
, or DRAM (dynamic random
m-access memory), for example, E
P ROM (erasable programa)
BL, e read-only memory), or E”P ROM (electrical
asable programmable, e read-
only memory), etc. can be considered. Data writing methods differ depending on the type of memory, and some memories of the same type have different access times when writing. In this way, an electronic camera that uses many types of memory cards 15 with different semiconductor memories needs to read the type of semiconductor memory of the memory card 15 and use a writing method suitable for the 5 memories.

On the other hand, a function that is often required for still cameras is a continuous shooting function that continuously captures multiple frames.

The upper limit of this continuous shooting speed is determined by the film winding mechanism in the case of a camera using silver halide film, and the movement of the magnetic head in the case of a video floppy camera.
In both cases, there were limitations due to mechanical operating speed.

However, in the case of a memory card type digital electronic camera such as the electronic camera of the present invention, which does not have a moving part for the recording medium, the upper limit of the continuous shooting speed is limited by the time required for the semiconductor memory to be heated. Therefore, when the electronic camera of the present invention is provided with a continuous shooting function, it is necessary to manage the upper limit of the continuous shooting speed.

Therefore, when an electronic camera is equipped with a continuous shooting function, the upper limit of the continuous shooting speed is determined according to the type of semiconductor memory of the memory card 15 and the write access time, and the upper limit of the continuous shooting speed is displayed. Display a warning if the set continuous shooting speed exceeds the upper limit of the continuous shooting speed obtained as a result of the above judgment, or display a warning if the set continuous shooting speed exceeds the upper limit of the continuous shooting speed obtained as a result of the above judgment. It is desirable to prohibit writing if the limit is exceeded. FIG. 16 shows the configuration of an electronic camera according to a fourth embodiment of the present invention having such functions.

The configuration shown in FIG. 16 has the configuration shown in FIG. 6 further provided with a continuous shooting setting switch 50 for setting a continuous shooting mode. The continuous shooting speed is determined by this continuous shooting mode setting. Memory card number 5 used in this electronic camera
As shown in FIG. 17, information on the memory type and access time is written in advance in the directory area. For example, in the example shown in FIG. 17, 1 byte is used as memory type information and 1 byte is used as access time information.

The CPU 241 displays on the display unit 13 the upper limit of the continuous shooting speed based on the memory type and access time information read from the memory cards 15 to 1. Furthermore, when the user operates the continuous shooting setting switch 50 to set the continuous shooting mode, the CPU 241 determines whether or not correct shooting can be performed with the settings. In other words, when the continuous shooting speed determined by the set continuous shooting mode exceeds the upper limit of the continuous shooting speed based on the memory type and access time, the CPU
241 displays a warning on the display unit 13 that correct photographing cannot be performed. As a method of warning, a warning using a buzzer or the like may also be used. In this way, when the continuous shooting speed in the set continuous shooting mode exceeds the upper limit of the above continuous shooting speed, the CPU 241 further controls the memory I/F 3.
1.7, a 4"! writing prohibition command to the memory card I5 is given to prevent erroneous writing.

It is not necessary to take all of the above-mentioned protective measures against the continuous shooting speed, and even if some of them are taken, it is effective to some extent.

〔Effect of the invention〕

According to the present invention, an extremely user-friendly electronic camera and image recording method can be provided.

[Brief explanation of the drawing]

1 is a perspective view showing the external appearance of an electronic camera according to a first embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of the electronic camera according to the embodiment of FIG. 1, and FIG. 1 is a perspective view for explaining the basic configuration of a semiconductor memory card used in the camera of the embodiment shown in FIG. 1; FIG. 4 is a configuration diagram for explaining a more detailed configuration of the memory card in FIG. 3, and FIG. 5 is a diagram showing a schematic configuration of a CCD array used in the example shown in FIG. FIG. 6 is a configuration diagram showing the configuration of the electronic camera shown in FIG. 2 in more detail, and FIGS. Figures 9(A) to 9(E) are diagrams for schematically explaining the first
A diagram for explaining the recording format in the memory card in the embodiment shown in the figure, FIG. 10 is a flowchart showing the detailed procedure of processing when taking an image in the embodiment of FIG. 1, and FIG. 11 is a camera of the present invention. FIG. 12 is a block diagram showing the detailed structure of a second embodiment of the present invention, and FIG. A diagram for explaining an electronic camera, FIG. 14 is a configuration diagram showing a detailed configuration of a third embodiment of the present invention, and FIG. 15 shows a detailed procedure of processing during image capture in the embodiment of FIG. 16 is a block diagram showing the detailed configuration of the fourth embodiment of the present invention; FIG. 17 is a diagram for explaining the format of the directory in the memory card in the embodiment of FIG. 16;
FIG. 18 is a diagram for explaining mode selection.

Claims (8)

[Claims] (1) Imaging processing means for capturing images and obtaining image data; recording mode selection means for varying the amount of image data obtained by this imaging processing means; and data set by this recording mode setting means. a buffer memory that temporarily stores the image data obtained from the image processing means according to the amount; a removably coupled recording medium that appropriately stores the image data stored in the buffer memory; a determining means for determining whether or not the image data can be recorded on the recording medium based on the amount of image data and the available storage capacity of the recording medium; An electronic camera comprising a recording control means for recording image data on the recording medium. (2) means for retaining the storage contents of the buffer memory until the determination means determines that the image data stored in the buffer memory can be recorded when the determination means determines that recording is not possible; The electronic camera according to claim 1, characterized in that: (3) The electronic camera according to claim 1, wherein the imaging processing means includes compression processing means for compressing the image data at a predetermined compression rate. (4) The electronic camera according to claim 1, wherein the recording mode setting means includes compression rate variable means for externally setting the compression rate of the amount of data set by the imaging processing means. (5) an imaging processing means for obtaining image data in a plurality of recording modes with different amounts of data per frame; and a recording mode selection means for selecting a recording mode provided corresponding to the imaging processing means; , a coupling means for removably coupling a recording medium; a remaining capacity detection means for detecting the recordable capacity of the recording medium coupled to the coupling means via the coupling means; and the recording mode selection means. In response to the selection, the amount of image data per frame in the selected recording mode is determined, and the amount of image data per frame and the recordable capacity detected by the remaining amount detecting means are combined with the combining means. calculation means for determining the number of frames that can be recorded in the recording mode of the recording medium selected by the recording medium; display means for displaying the number of frames determined by the calculation means; An electronic camera characterized by comprising: recording means for recording image data obtained from the imaging processing means in accordance with a recording mode on a recording medium coupled to the coupling means. (6) an imaging processing means for imaging a subject and obtaining image data of a still image; a coupling means for removably coupling a memory card equipped with a semiconductor memory; and the above-mentioned memory coupled to this coupling means. memory information reading means for reading information on the type of semiconductor memory of the card and write access time from the memory card via the coupling means; provided in association with the imaging processing means, in the imaging processing means; continuous shooting mode setting means for setting a continuous shooting mode for continuously obtaining image data of a plurality of frames of still images at a plurality of different continuous shooting speeds; upper limit speed determining means for determining the upper limit of continuous shooting speed from information on the type of semiconductor memory and write access time; and recording means for recording image data obtained from the image processing means on a memory card coupled to the coupling means. An electronic camera comprising: (7) Arbitrarily set recording modes with different amounts of data per frame, temporarily record image data that can be obtained according to the set recording mode in a buffer memory, and record the image stored in the buffer memory. An image characterized in that it is determined whether or not data can be recorded on a recording medium set in a camera, and only when it is determined that data can be recorded, the image data stored in the buffer memory is recorded on the recording medium. Recording method. (8) Select a desired recording mode from multiple recording modes with different amounts of data per frame, obtain image data according to the selected recording mode, detect the recordable capacity of the recording medium, and select the selected recording mode. Determine the amount of image data per frame in , calculate the number of frames that can be recorded in the recording mode of the recording medium from the amount of image data per frame and the detected recordable capacity, and determine the number of frames obtained. 1. An image recording method, comprising: displaying the following: and recording image data obtained according to the selected recording mode on the recording medium.