JP2000149001A - Digital image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the picture quality by recording the noncompressed image data and also to decrease the frequency of cases, where the image data cannot be recorded on a recording medium due to a large quantity of the image. SOLUTION: A quantity Da of noncompressed data which are produced in a step S1 is compared with an idle capacity Cm of an external storage medium (S2). If Cm>=D, the noncompressed data are recorded (S5). If Cm<Da, the file that is produced in a step S3 is compressed by means of a reversible and self-thawing file compression technologs. A data quantity Db of a compressed file is compared with a capacity Cm (S4). If Cm>=Db, the compressed file is recorded (S5). Otherwise, the compressed file is not recorded, and a warning is issued (S6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image recording apparatus applicable to, for example, a digital camera.

[0002]

2. Description of the Related Art In recent years, digital cameras for recording an image of a subject as image data on a nonvolatile semiconductor memory device such as a flash memory or a recording medium such as a hard disk or a floppy disk instead of a silver halide film have been rapidly spreading. . Therefore, the digital camera device is configured to convert a photographed subject image into a digital image signal, compress the digital image signal, and record the compressed image information on a recording medium. Further, a digital camera device using a 3.5-inch floppy disk as a recording medium has a feature that image input to a personal computer is simple and easy to use. Further, there is known an image recording apparatus having a recording mode in which an image is not compressed when recording.

[0003]

When recording uncompressed image data, if the recording medium is a fixed storage capacity, such as a floppy disk, and if the recording file cannot be recorded because the recording file is too large, the recording itself is not performed. Can not be done. For this reason, a situation has arisen in which it is not possible to record an image taken at an angle. In particular, recently, the resolution of the image sensor has been increased, and the amount of generated image data has been increased. In order to record uncompressed data, JPEG (Joint Photographic
(Experts Group) to compress the image and record it. However, even if recording is possible, since JPEG is irreversible encoding, there is a problem in that the advantage of recording in an uncompressed format (that is, image resolution can be increased and color reproducibility is good) is lost. Occurs. Also, the file format differs from the uncompressed format due to image compression.

Accordingly, it is an object of the present invention to provide a digital image recording apparatus which does not cause these problems.

[0005]

In order to solve the above problems, a first aspect of the present invention is to provide a digital image recording apparatus for recording image data on a storage medium, in which a non-compressed image data is reversibly and self-decompressed. A digital image recording apparatus comprising: a data compression unit for compressing data by a compression method of a type; and a unit for recording compressed data from the data compression unit on a recording medium.

According to a second aspect of the present invention, in a digital image recording apparatus for recording image data on a storage medium, the free space of the storage medium is compared with the data amount of uncompressed image data, and the free space is determined by the size of the image data. When more than quantity,
When the image data is recorded on the storage medium and the free space is smaller than the data amount of the image data, the image data is compressed by a reversible compression method, the compressed data is compared with the free space,
A digital image recording apparatus characterized in that when the free space is larger than the data amount of the compressed data, the compressed data is recorded on the storage medium, and when the free space is smaller than the data amount of the compressed data, the storage in the storage medium is not performed. It is.

According to the present invention, the image data is compressed and recorded only when the data amount of the uncompressed image data is larger than the free space of the storage medium. As a compression method, a reversible self-decompression type compression method is used. Lossless encoding is a compression method that can completely restore original data when decoded. The self-decompression type is a compression method that allows decompression without software for decompression. Therefore, it is possible to avoid a situation in which image data cannot be recorded, and
Image quality deterioration due to compression can be prevented.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall configuration of an embodiment of the present invention. As shown in FIG. 1, a digital camera device includes a lens unit 1, a CCD (Charge Coupled D).
evice) 2, sample and hold and A / D converter 3, camera signal processor 4, memory controller 5, buffer memory 6, D / A converter 7, LCD (Liquid Crystal Dis
play) 8, DRAM (Dynamic Random Access Memory)
9, interface unit 10, external storage medium 11, CP
U12, operation input unit 13, and encoder / decoder 1
5.

The lens unit 1 and the CCD 2 constitute an imaging unit. A control signal from the CPU 12 is supplied to the lens unit 1, and an automatic aperture control operation and an automatic focus control operation are performed. The CCD 2 switches between an operation mode for reading all pixels (photographing mode) and a line thinning operation mode for outputting a signal in which the number of lines is reduced to, for example, ３ (EtoE mode) by a control signal from the CPU 12. It is possible. The number of pixels of the CCD 2 is, for example, XGA (eX
tended Graphics Array, 1024 x 768 pixels).

[0010] In the EtoE mode, a display unit (LCD) is used without taking data of a photographed image into a recording medium (DRAM).
This is the mode displayed in 8). In EtoE mode,
The angle of view is determined during shooting, and the focus, exposure, and white balance are adjusted appropriately. That is, the EtoE mode is a state in which the subject is checked before the shutter is pressed in the photographing mode. In the EtoE mode, an image pickup signal of 1024 × 256 pixels is obtained. As an example, in the shooting mode, an imaging signal of 10 frames per second is output, and in the EtoE mode, an imaging signal of 30 frames per second is output.

The output signal of the CCD 2 is supplied to a sample hold and A / D converter 3, and the sample hold and A / D converter 3 generates a digital image signal of 10 bits per sample. Sample hold and A / D
The conversion unit 3 has a configuration of a correlated double sampling circuit,
Noise removal, waveform shaping, and compensation for defective pixels are performed.

The digital image signal is supplied to the camera signal processing unit 4
Supplied to The camera signal processing unit 4 includes a digital clamp circuit, a luminance signal processing circuit, a color signal processing circuit, a contour correction circuit, a defect compensation circuit, an automatic aperture control circuit, an automatic focus control circuit, an automatic white balance correction circuit, and the like.
The camera signal processing unit 4 generates a digital image signal in the form of a component signal composed of a luminance signal and a color difference signal converted from the RGB signals.

Each component of the digital image signal from the camera signal processing unit 4 is supplied to a memory controller 5. The display buffer memory 6 and the bus 14 of the CPU 12 are connected to the memory controller 5. The buffer memory 6 generates RGB signals by processing the component signals, and outputs the RGB signals to the D / A converter 7. An analog signal from the D / A converter 7 is supplied to the LCD 8. Further, the buffer memory 6 outputs the RGB signals at a timing corresponding to the display timing of the LCD 8.

A DRAM 9 and a CPU 1
2, encoder / decoder 15, interface unit 1
0 is connected. The DRAM 9 is controlled by addresses and control information supplied from the memory controller 5 or the CPU 12. Further, the memory controller 5 has a pixel number conversion function, converts the number of pixels according to the setting of the photographer, and forms a screen of a predetermined size.

The encoder / decoder 15 compresses (encodes) or decompresses (decodes) image data by a predetermined method. For example, when processing a still image during normal shooting, JPEG is used. In this embodiment, an operation of recording uncompressed image data on a storage medium without compressing the image data is also possible. The JPEG encoding / decoding process is also performed by the CPU 1
2 may be performed by software processing.

The interface unit 10 is an interface between the external storage medium 11 and the CPU 12. For example, the interface unit 10 outputs a JPEG file (normal shooting mode), uncompressed image data (for example, bitmap data) or compressed image data obtained by compressing uncompressed image data to the external storage medium 11 in the MS-DOS format. I do. As the external storage medium 11,
A disk-shaped recording medium such as a floppy disk or a semiconductor memory such as a memory card can be used.

In FIG. 1, reference numeral 13 denotes an operation input unit. The operation input unit 13 is provided with a shutter button, various setting switches operated by a photographer, and the like. I have. In the operation input unit 13, the operation states of the buttons and switches are detected, and this detection signal is supplied to the CPU 12 as operation information.

In one embodiment configured as described above, for example, a normal photographing operation and a non-compressed recording operation can be set for a subject taking operation in a photographing mode.

For example, when the shutter button is pressed in a state where normal shooting is set, the subject image at that timing is A / D converted and converted into a digital image signal, and the obtained one still image is obtained. Image data is temporarily DRA
Written to M9. Then, the still image data once written in the DRAM 9 is read out, the data is compressed by JPEG, and the JPEG file data is stored in the external storage medium 1.
The data is supplied to a floppy (registered trademark) disk 1 and written in a predetermined area.

In the non-compression recording mode, one still image data is stored in the DRAM as in the normal photographing operation.
9 is stored. Then, as described later, the capacity (free space) available for recording on the external storage medium 11 is checked. If the free space is larger than the data amount of the image data, the still image data is read, and the read data is supplied to the floppy disk as the external storage medium 11 via the interface unit 10 and written into a predetermined area.

If the free space is smaller than the data amount of the image data, the image data is subjected to a reversible and self-decompressing compression method. The compressed data is stored in the DRAM 9 or another memory. Then, the compressed data and the free space of the external storage medium 11 are compared. If the free space is larger than the data amount of the compressed data, the compressed data is read, and the compressed data is written to the external storage medium 11 via the interface unit 10.

The operation for recording the above-described uncompressed image data will be further described with reference to FIG. The processing shown in FIG. 2 is performed by the CPU 12 including the compression processing. First, in step S1, uncompressed recording file data is generated. At this point, in order to determine the amount of file data to be actually recorded, the file data is created in a format for actually recording, for example, a bitmap format.

In step S2, the data amount Da of the generated file is compared with the free space Cm of the external storage medium 11. As a result of the comparison, when Cm ≧ Da, that is, when the data amount of the uncompressed file is equal to or less than the free space of the external storage medium 11, the data can be recorded in the same file format. Writing is performed (step S5). As a result of the comparison in step S2, if Cm <Da, the free space of the external storage medium 11 is insufficient, and the uncompressed file cannot be recorded as it is, so the process proceeds to step S3.

In step S3, the generated file is compressed using a reversible and self-extracting file compression technique. Reversible means that the original file data can be restored when decompressed. By using a reversible compression method, image quality deterioration due to compression is prevented. Also, the self-extracting type means that decompression is possible without software for compression and decompression. Actually, a decompression program is added to the file, and the specified OS
Can only be thawed on top. The reason why the self-decompression type compression method is used is that an image can be restored without providing a decompression tool, and the image can be restored even by a digital camera, for example. Specifically, L for MS-DOS
Software such as HA can be used.

In step S4, the data amount Db of the compressed file generated in step S3 and the external storage medium 1
One free capacity Cm is compared. As a result of the comparison, Cm ≧
Db, that is, when the data amount of the compressed file is equal to or less than the free space of the external storage medium 11, the data can be recorded in the compressed file format. Therefore, writing is performed to record the compressed file on the external storage medium 11 (step S5). ).

As a result of the comparison in step S4, if Cm <Db, the free space of the external storage medium 11 is insufficient, so that even a compressed file cannot be recorded, and the process proceeds to step S6. . That is, step S
6 stops writing to the external storage medium 11, and in step S7, issues a warning to inform the user that recording could not be performed. As the warning, a method of using a warning such as a beep, or a method of displaying a message on the LCD 8 can be used.

According to the present invention, image data is transmitted.
The present invention is also applicable to a system in which image data is recorded on the receiving side.

[0028]

According to the present invention, since the amount of data to be recorded can be reduced, it is possible to reduce the frequency of occurrence of a situation where it is not possible to record an image captured at an odd photo opportunity. In addition, since uncompressed image data is recorded and the data is compressed by a reversible compression method only when necessary,
Image quality deterioration due to compression can be prevented. Furthermore, by using a common self-extracting compression method, the compressed file can be decompressed simply by opening the file with a personal computer, without requiring the user to install decompression software. Further, according to the present invention, since compression is performed only when the free space is small, it is possible to reduce a case where a delay required for reproducing a compressed file on a personal computer occurs.

[Brief description of the drawings]

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

FIG. 2 is a flowchart used to explain the operation of the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lens part, 2 ... CCD, 4 ... Camera signal processing part, 5 ... Memory controller, 9 ... DR
AM, 10 interface unit, 11 external storage medium, 12 CPU, 13 operation input unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/24 H04N 5/92 H 5C059 7/13 Z 5C078 F-term (Reference) 5B047 AA05 AB02 AB04 BA02 BB04 BC14 CA21 CB25 EB15 5B050 AA09 BA10 EA10 FA03 5B057 AA11 BA17 BA19 CB12 CC01 CG07 5B082 AA13 GA01 5C053 FA08 FA23 FA27 GB21 KA03 KA24 KA25 LA01 5C059 KK00 MA45 PP01 SS15 TA16 TB04 TC15 TD11 UA02 DA18 UA02

Claims (5)

[Claims] 1. A digital image recording apparatus for recording image data on a storage medium, comprising: a data compression means for compressing uncompressed image data by a reversible and self-decompression type compression method; Means for recording data on a recording medium. 2. A digital image recording apparatus for recording image data on a storage medium, wherein a free space of the storage medium is compared with a data amount of uncompressed image data, and the free space is larger than a data amount of the image data. Sometimes, the image data is recorded on the storage medium, and when the free space is smaller than the data amount of the image data, the image data is compressed by a reversible compression method, and the compressed data is compared with the free space. When the free space is larger than the data amount of the compressed data, the compressed data is recorded in the storage medium, and when the free space is smaller than the data amount of the compressed data, the storage in the storage medium is not performed. A digital image recording apparatus characterized by the above-mentioned. 3. The digital image recording apparatus according to claim 1, wherein the image data is still image data which is photographed by an imaging means and converted into a digital signal. 4. The digital image recording apparatus according to claim 2, wherein the compression method is a self-decompression type compression method. 5. The digital image recording apparatus according to claim 2, wherein a warning that recording is not possible is issued when the storage in the storage medium is not performed.