JP2000261756A - Image data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a picture in a shortest time in response to the size of main picture data and to reduce the file size. SOLUTION: When a card control section 10 of a digital camera records respectively main picture data, non-compressed sub picture data and compressed sub picture data to a memory card 13, a discrimination section 10-1 of the card control section 10 discriminates the size of the main picture data. When the result of discrimination indicates that the size of the main picture data is a prescribed size or below, a recording control section 10-2 does not record the non-compressed sub picture data to the memory card 13, but records the main picture data and the compressed sub picture data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, image processing of image data obtained by photographing a subject, recording the image data on a recording medium such as a memory card, and transferring the image data recorded on the recording medium to an external device. The present invention relates to an image data recording apparatus most suitable for application to a digital camera for transferring data to a personal computer.

[0002]

2. Description of the Related Art For example, a digital camera converts a captured image of a subject into digital image data and stores the image data in a recording medium such as a memory card. This digital camera can transfer image data recorded on a recording medium of the digital camera to a personal computer by connecting to a personal computer, for example, and can process, print, or save the image data on the personal computer side. It is assumed that.

[0003] By the way, recording on a recording medium by such a digital camera is performed in a data format in consideration of exchange of information with a personal computer.
It is performed according to the standard of xif. This Exif 2.0
Is a graphics data format for digital cameras and the image part is JPEG (joint photogra
This is a phic coding experts group) format, with shooting conditions and conditions added. The recording on the recording medium is performed by searching for a desired image from main image data of a full image obtained by imaging a subject and a plurality of images recorded on a digital camera in accordance with the Exif standard. And sub-image (thumbnail) data used for this purpose are recorded on a recording medium. The sub-image data is created by thinning out the pixels of the main image data.

When such main image data and sub-image data are created and the image data is transferred, the size of the sub-image data is generally fixed to, for example, 120 × 80 pixels (about 10,000 pixels). . Therefore, if the size of the main image data is 1 million pixels, the size of the sub-image data is 10,000 pixels. Even if the size of the main image data is 100,000 pixels, the size of the sub-image data is 10,000 pixels. Even if the size of the image data is 10,000 pixels, the size of the sub-image data is 10,000 pixels.

[0005]

However, when the personal computer retrieves desired image data from a plurality of image data recorded on the digital camera and transfers the image data, the image data is transferred with the above image size. When transferred, if the size of the main image data is 1 million pixels, the size of the sub-image data is 10,000 pixels, and the transfer time of the image data is much shorter than the transfer time of the main image data. Although the transfer time of the short sub-image data is added, when the size of the main image data is 10,000 pixels, the size of the sub-image data is also 10,000 pixels, which is the same as the main image data size. The transfer time is the sum of the transfer time of the main image data and the transfer time of the sub-image data that is the same as the transfer time of the main image data. Made shall require the doubling of the transfer time of delivery time. Further, the size of the image file is twice as large as the main image data and the sub image data having the same size as the main image data size.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image data recording apparatus capable of transferring an image in a shortest transfer time according to the size of main image data and keeping the file size small.

[0007]

According to a first aspect of the present invention, there is provided an image data recording apparatus comprising: an uncompressed main image data; an image obtained by reducing all or a part of the main image data; Uncompressed sub-image data for the image of the region;
First recording control means for recording the compressed sub-image data obtained by compressing the uncompressed sub-image data on a recording medium; discriminating means for discriminating the size of the main image data; A second recording control unit that records the main image data and the compressed sub-image data without recording the non-compressed sub-image data on the recording medium if the data size is equal to or smaller than a predetermined size. I have.

According to a second aspect of the present invention, there is provided an image data recording apparatus comprising:
2. The image data recording apparatus according to claim 1, wherein the second recording control means determines that only the main image data and the compressed sub-image data are provided when determining that the size of the main image data is substantially the same as the size of the uncompressed sub-image data. Is recorded on a recording medium.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an image data recording apparatus applied to a digital camera.

The imaging lens system 1 has a CCD (solid-state imaging device) 2 incorporated therein. The output terminal of the CDD 2 is connected to the imaging unit 3 and outputs an analog image signal from the imaging unit 3.

An output terminal of the imaging unit 3 has an A / D converter for converting an image signal from the imaging unit 3 into digital image data.
A conversion unit 4, a Y / C unit 5 for processing image luminance and color difference, a buffer memory 6, and an image size conversion unit 7 for reducing main image data by thinning are connected. An irreversible data compression unit 9 and a card control unit 10 are connected.

When the main image data is reduced by thinning out, the image size conversion unit 7 sends out the main image data as it is, for example, at a reduction ratio of 1: 1, and transmits the main image data at a reduction ratio of 1:10. Is reduced to obtain sub-image data. The image size conversion unit 7 is connected to a mode changeover switch 12 via a photographing mode unit 11. In particular, when the size of the main image data is small, the mode changeover switch 12 is controlled to switch the sub image data to the data size. The data is sent to the compression unit 9. The mode change switch 12 allows the image data size to be transmitted in a normal size, or reduces the size to a size smaller than the normal size, for example, 120 × 80 pixels (approximately 10,000 pixels) substantially the same size as the sub-image data size. It is something to switch.

The data compression section 9 receives the digital sub-image data from the image size conversion section 7, performs DCT (discrete cosine transform) for each block unit of the sub-image data, and subsequently performs each of the quantization of the luminance and the color difference. It has a function of obtaining code data (hereinafter, referred to as compressed sub-image data) by quantizing using a conversion table.

The card control unit 10 includes an image size conversion unit 7
Receiving the uncompressed main image data, the uncompressed sub-image data and the compressed sub-image data from the data compression unit 9,
These uncompressed main image data, uncompressed sub-image data, and compressed sub-image data are each converted into a file in a separate area in the memory card 13 as a recording medium in accordance with the TIFF (tag image file format) standard of the image data format. It has a recording function.

Here, FIG. 2 shows one example according to the TIFF standard.
FIG. 2 shows a schematic diagram of an image file format for image data.

First, there is an image file header.
th IFD (0th image file directory) is formed. The 0th IFD includes the number of directory entries, the width of an image, a pointer to main image data, and a sub-IFD.
Each area includes a pointer to the next IFD and a pointer to the next IFD.

Next, an area for the 0th IFD data is formed, and then a sub-IFD is formed.
Each area includes the number of entries, a maker note N1, and a pointer (0) to the next IFD.

Next, a sub-IFD data area is formed, and in this area, a maker's data as an auxiliary data area is provided.
A region for the note N2 is formed. In the maker note N2, a maker note directory is formed as shown in the enlarged view on the right side of FIG. 2, where the maker note header, the number of directory entries, a pointer to the compressed sub-image data, and the next IFD Each area such as a pointer is formed. And then, the manufacturer note data,
Each area of the compressed sub-image data Qs is formed.

Next, a 1st IFD (a directory of a 1st uncompressed sub-image) is formed. In the first IFD, areas such as the number of directory entries, the width of an image, a pointer to uncompressed image data, a maker note N3, and a pointer (0) to the next IFD are formed.

Next, an area for 1st IFD data, an area for uncompressed sub-image data Qf, and an area for main image data Qm are formed.

In the image file format conforming to the TIFF standard as described above, it is determined that uncompressed main image data, which is a full image, is recorded in the 0th IFD and uncompressed sub-image data is recorded in the 1st IFD. ing.

The card control unit 10 stores the main image data in the main image data area Q of the 0th IFD in accordance with the TIFF standard.
m, the uncompressed sub-image data is recorded in the uncompressed sub-image data area Qf of the 1st IFD, and the compressed sub-image data is stored in an auxiliary area, for example, the auxiliary area of the main image data, that is, the data in the sub-IFD. It has a function of recording in the compressed sub-image data area Qs in the maker note N2.

The card control unit 10 has the following functions as a control operation for recording the main image data, the uncompressed sub-image data, and the compressed sub-image data on the memory card 13. Note that each of the control operations for recording on the memory card 13 may be set to any one of the control operations, and a desired control operation is set by the user.

That is, the card controller 10 records the main image data in the main image data area Qm of the 0th IFD in accordance with the TIFF standard as described above, and
The first control function of recording in the non-compressed sub-image data area Qf of the st IFD, and when the compressed sub-image data is selectively recorded in the memory card 13, the compressed sub-image data is stored in the non-compressed A second control function of recording the compressed sub-image data in the area Qf.

The card control unit 10 also includes main image data, non-compressed sub-image data, and auxiliary data relating to the main image data or non-compressed sub-image data, that is, the 0th image file directory and the 1st non-compressed sub-image. A first control function for recording each directory and a file on the memory card 11, and when selectively recording compressed sub-image data on the memory card 13, the compressed sub-image data is stored as auxiliary data in the memory card 13. And a second control function for recording in the area, that is, the maker note N3 of the 1st IFD.

Further, the card control unit 10 determines a size of the main image data to be recorded on the memory card 13 and, as a result of the determination by the determination unit 10-1, determines that the size of the main image data is predetermined. When it is determined that the size of the main image data is equal to or smaller than the size of the non-compressed sub-image data, for example, the main image data and the compressed sub-image data are recorded on the memory card 13 without recording the non-compressed sub-image data. It has the functions of a recording control unit 10-2 for recording.

The functions of the discriminating unit 10-1 and the recording control unit 10-2 operate during each control operation of recording the image data on the memory card 13 as described above to reduce the size of the main image data. Accordingly, it is determined whether or not to record the uncompressed sub-image data.

On the other hand, a communication control unit 14 is connected to the card control unit 10, and the communication line 1 is connected to the communication control unit 14.
5, a personal computer 16 is connected via, for example, RS-232C. Therefore, the card control unit 10 transmits the T recorded on the memory card 13 to the personal computer 16 through the communication control unit 14.
It has a function of reading and transferring an image file conforming to the IFF standard.

The main controller 17 comprises a CCD 2, an image pickup unit 3, an A / D converter 4, a Y / C unit 5, a buffer memory 6, and an image size converter 7 in accordance with a series of image pickup operation algorithms for photographing the subject A. , The data compression unit 9 and the card control unit 10 and the personal computer 1
6 has a function of controlling the operation of the communication control unit 14 according to a transfer operation algorithm when transferring an image file.

Next, the operation of the device configured as described above will be described.

The image of the subject A is changed to C through the imaging lens system 1.
When an image is formed on the CD2, the CDD2 photoelectrically converts the image of the subject A, and the next imaging unit 3 processes the output signal of the CCD2 and outputs it as an analog image signal. The next A / D converter 4 converts an analog image signal output from the imaging unit 3 into digital image data.
The digital image data image from the / D conversion unit 4 is processed for luminance and color difference and sent to the buffer memory 6.

Next, the image size converter 7 reads the digital image data recorded in the buffer memory 6 and reduces the digital image data by a reduction ratio of 1:
In step 1, the digital image data is transmitted as main image data without reduction, and the digital image data is reduced by thinning out at a reduction ratio of 1:10 and transmitted as sub-image data. The main image data and the sub image data are sent to the card control unit 10 through the shooting mode changeover switch 8, and the sub image data is also sent to the data compression unit 9 by changing the shooting mode changeover switch 8. You.

The image size conversion unit 7 switches the size of the main image data to a size smaller than the normal size, for example, 120 × 80 pixels (approximately the same size as the size of the sub-image data) by switching the photographing mode changeover switch 8. (10,000 pixels). The reduced main image data is also sent to the card control unit 10.

The data compression section 9 receives the sub-image data from the image size conversion section 7, performs DCT for each block unit of the sub-image data, and subsequently quantizes using the quantization tables for luminance and chrominance. Find compressed sub-image data.

The card controller 10 receives the non-compressed main image data, the non-compressed sub-image data from the image size converter 7 and the compressed sub-image data from the data compressor 9 and The main image data, the uncompressed sub-image data and the compressed sub-image data are respectively stored in the memory card 1
3 is recorded as a file according to the TIFF standard image file shown in FIG. 2, and at this time, the determination unit 10-1 of the card control unit 10 determines the size of the main image data to be recorded on the memory card 13. .

As a result of this determination, if the size of the main image data is equal to or larger than the predetermined size, the card control unit 10 transmits the uncompressed main image data and the uncompressed sub image data from the image size conversion unit 7 as described above. The image data and the compressed sub-image data from the data compression unit 9 are received, and the uncompressed main image data, the uncompressed sub-image data and the compressed sub-image data are respectively transmitted to the memory card 13 according to the TIFF standard shown in FIG. File and record according to the image file.

However, when it is determined that the size of the main image data is equal to or smaller than a predetermined size, for example, the size of the main image data is substantially equal to or smaller than the size of the uncompressed sub-image data (about 10,000 pixels), the recording controller 10-2 is the memory card 13
The main image data and the compressed sub-image data are recorded without recording the uncompressed sub-image data.

Therefore, when the size of the main image data is equal to or smaller than the predetermined size, the card control unit 10 sets the main image data to 0
th The main image data area Qm of the IFD is recorded, and the compressed sub-image data is stored in the sub-IFD data of the main image data.
Record in s.

The card control unit 10 sets the desired control operation according to the following control operations according to the user's setting.
The main image data and the compressed sub-image data are filed and recorded in the memory card 13, respectively.

That is, when recording the main image data in the main image data area Qm of the 0th IFD and selectively recording the compressed sub-image data in the memory card 13, the card control unit 10 It is recorded in the area Qf of the uncompressed sub-image data of the 1st IFD in the memory card 13.

Further, the card control unit 10 files the main image data and the 0th image file directory relating to the main image data, and records them on the memory card 11.
When the compressed sub-image data is selectively recorded on the memory card 13, the compressed sub-image data is stored in the memory card 13.
In the auxiliary data area, that is, the maker note N3 of the 1st IFD.

After the photographing of the subject A has been completed as described above and the main image data and the compressed sub-image data have been recorded on the memory card 13, the personal computer 16 is connected to the digital camera, and the image data is transferred. Is performed, the card control unit 10 sets the communication control unit 1
The image file according to the TIFF standard recorded on the memory card 13 is read out and transferred to the personal computer 16 through 4.

At this time, if a plurality of image data are recorded on the memory card 13 of the digital camera, the personal computer 16 searches the plurality of image data recorded on the memory card 13 and retrieves the desired image data. However, compressed sub-image data is used for the search of the image data.

Here, the personal computer 16
The compressed sub-image data can be received and searched.

Then, the personal computer 16
An image file transferred from the digital camera is received, and the image data is processed, printed, or stored, for example.

As described above, in one embodiment,
When the main image data, the uncompressed sub-image data, and the compressed sub-image data are respectively recorded on the memory card 13 by the card control unit 10, the discrimination unit 10-
1, the size of the main image data is determined, and as a result of the determination, if the size of the main image data is determined to be equal to or smaller than the predetermined size, the recording control unit 10-2 controls the memory card 1
Since the main image data and the compressed sub-image data are recorded in the digital camera 3 without recording the uncompressed sub-image data, the personal computer retrieves desired image data from a plurality of image data recorded in the digital camera. When transferring image data, if the size of the main image data is large and 1,000,000 pixels, the size of the sub image data is 10,000 pixels,
The transfer time of the image data is the transfer time of the main image data plus the transfer time of the sub-image data, which is very short compared to the transfer time, and the size of the main image data is 1
Even with 10,000 pixels, since the compressed sub-image data obtained by compressing the uncompressed sub-image data is used, the transfer time of the image data is a short time obtained by adding the transfer time of the compressed sub-image data having a small data amount to the transfer time of the main image data. Can be in the transfer time. In addition, the size of the image file can be reduced because the compressed sub-image data is used.

Therefore, the image can be transferred in the shortest transfer time according to the size of the main image data, and the file size can be reduced.
Can be increased.

The present invention is not limited to the above-described embodiment, but may be modified as follows.

For example, the compressed sub-image data may be recorded not only in the maker note in the Exif standard image file but also in another area.

The present invention can be applied not only to a digital camera but also to other devices for recording image data on a recording medium.

[0052]

As described above in detail, according to the present invention, it is possible to provide an image data recording apparatus capable of transferring an image in the shortest transfer time according to the size of the main image data and keeping the file size small. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment in which an image data recording device according to the present invention is applied to a digital camera.

FIG. 2 is a schematic diagram of an image file format according to the TIFF standard applied to the apparatus.

[Explanation of symbols]

 1: imaging lens system, 2: CCD (solid-state imaging device), 3: imaging unit, 4: A / D conversion unit, 5: Y / C unit, 6: buffer memory, 7: image size conversion unit, 9: data Compression unit, 10: card control unit, 10-1: discrimination unit, 10-2: recording control unit, 13: memory card, 14: communication control unit, 16: personal computer, 17: main control unit.

Claims (2)

[Claims] 1. An uncompressed main image data, an uncompressed sub-image data corresponding to an image obtained by reducing all or a part of the main image data or an image of a partial area of the main image data, and First recording control means for recording, on a recording medium, compressed sub-image data obtained by compressing compressed sub-image data; discriminating means for discriminating the size of the main image data; A second recording control unit that records the main image data and the compressed sub-image data without recording the uncompressed sub-image data on the recording medium if the data size is equal to or smaller than a predetermined size. An image data recording device, characterized in that: 2. When the second recording control unit determines that the size of the main image data is substantially the same as the size of the uncompressed sub-image data, the second recording control unit deletes only the main image data and the compressed sub-image data. 2. The image data recording apparatus according to claim 1, further comprising a function of recording on the recording medium.