JP2001218065A - Device and method for processing digital image signal, device and method for recording digital image and data recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to perform image processing procedures that respectively fits a natural image and an image such as a character original. SOLUTION: A CCG 1 photographs a color image. The photographed image is compressed as a digital image signal by an image processing block 7 and recorded on recording media 9. Processing by the block 7 can be switched. When the photographed image is a natural image, the photographed image is compressed by an irreversible coding JPEG, and when the photographed image is the character original, etc., binarization of a photographed colored image and conversion processing to a GIF format including data compression by an LZW are carried out. By this switching, the recorded image of the character original is made clearly distinguishable from the background and is easily read, and compressed data size can be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Recently, a digital image is recorded on a digital still camera or the like using a nonvolatile semiconductor memory device such as a flash memory or a recording medium such as a hard disk or a floppy disk, and recording an object image as image data on the recording medium. Recording devices are rapidly becoming widespread. The digital image recording apparatus 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. In a digital image recording apparatus, a natural image is captured as a color image, and J
What compresses with PEG is known.

[0003]

When photographing a character document, a whiteboard, or the like, it is preferable to record the photographed color image in a binary form rather than recording it as a color image. That is, FIG. 10A shows a color image obtained by photographing a character document, and FIG. 10B shows an image obtained by converting the color image into a binary image. As is clear from FIG. 10, in the binary image, the characters and the background of the subject are clearly distinguished from each other as compared with the color image, and the characters are easy to read.

A conventional digital image recording apparatus has been proposed in which characters are superimposed on a photographed color image. However, when a character original is photographed, it is not binarized. Also, when shooting natural images other than text originals,
It is desired that a color image can be recorded.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a digital camera capable of switching between a process suitable for a captured image of a natural image and a process suitable for a captured image of a text document when processing a captured color image. An object of the present invention is to provide an image signal processing apparatus and method, a digital image recording apparatus and method, and a data recording medium.

[0006]

According to a first aspect of the present invention, there is provided an image processing unit for compressing a digital image signal taken in, and an image processing operation in the image processing unit. A mode designating means for generating a signal designating one of the first mode and the second mode, wherein when the first mode is designated, the image processing means compresses the digital image signal by a lossy encoding method. The first compressed image data is generated, and when the second mode is designated, the image processing means binarizes the digital image signal and compresses the binary image signal by a lossless encoding method. Which is a digital image signal processing device.

According to a second aspect of the present invention, in a digital image recording apparatus for recording an image as a digital signal on a recording medium, an image capturing means for capturing an image and generating a digital image signal, and performing compression processing of the captured digital image signal. Image processing means for performing, a mode designating means for generating a signal for designating an image processing operation in the image processing means to one of a first mode and a second mode, and a recording means for recording an output of the image processing means on a recording medium When the first mode is designated, the image processing means generates first compressed image data obtained by compressing the digital image signal by the irreversible encoding method, and when the second mode is designated, A second compressed image obtained by binarizing the digital image signal by the processing means and compressing the binary image signal by a lossless encoding method; A digital image recording apparatus and generates an over data.

According to a twelfth aspect of the present invention, there is provided a digital image signal in which an image processing operation in an image processing means for compressing a captured digital image signal is designated to one of a first mode and a second mode. A processing method, wherein when a first mode is designated, image processing means generates first compressed image data obtained by compressing a digital image signal by an irreversible encoding method, and when a second mode is designated, A digital image signal, wherein the image processing means binarizes the digital image signal to generate second compressed image data obtained by compressing the binary image signal by a reversible encoding method.

According to a thirteenth aspect of the present invention, there is provided a digital image recording method for recording an image as a digital signal on a recording medium, wherein an image processing operation in an image processing means for compressing a captured digital image signal is performed in a first mode. In the digital image recording method in which one of the first mode and the second mode is designated, when the first mode is designated, the image processing means compresses the digital image signal by the irreversible encoding method. When the compressed image data is generated and the second mode is designated, the image processing means binarizes the digital image signal and generates second compressed image data obtained by compressing the binary image signal by a lossless encoding method. , The generated first compressed image data and the second
And recording one of the compressed image data on a recording medium.

According to a fourteenth aspect of the present invention, the first image file compressed by the lossy encoding method and the second image file compressed by the lossless encoding method are mixedly recorded so as to be identifiable. This is a data recording medium.

According to the present invention, when the photographed image is a natural image, the photographed image is compressed by the irreversible encoding method, and a character document,
In the case of characters and graphics such as white pods, the captured image is binarized and the binary image is compressed by a lossless encoding method to obtain an image in which the background is clear and characters and the like are easy to read. Can be.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 shows a system configuration of the present embodiment, and 1 indicates a CCD (Charge Coupled Device). CC
The number of pixels of D1 (the number of horizontal pixels × the number of vertical pixels) is, for example, V
XGA (1600 × 1200) pixels. The number of pixels of the recorded image is VX with respect to the number of pixels of the captured image (color image).
In addition to GA, SXGA (1280 x 960) pixels, XGA (102
4 × 768 pixels and VGA (640 × 480) pixels can be selected. The CCD 1 outputs a subject image passed through a lens unit (not shown) as an imaging signal. In the lens unit, an automatic aperture control operation and an automatic focus control operation are performed.
An imaging signal is supplied to the camera block 2. Note that CC
D1 may be capable of performing an operation of reading a document similarly to the image scanner. The present invention is also applicable to processing digital color images received from other devices or communication media other than the CCD.

The camera block 2 includes a clamp circuit, a luminance 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. For example, RG from the camera block 2
A digital imaging signal is generated in the form of a component signal composed of a luminance signal and a color difference signal converted from the B signal. The digital imaging signal is supplied to the memory control block 3.

The memory control block 3 has a signal switching section, a display buffer memory, a D / A converter, and the like. The display device 4 and the data transmission path 5 are connected to the memory control block 3. In the memory control block 3, the generated RGB signals are supplied to the display device 4 via the D / A converter. The display device 4 is a liquid crystal display (LCD) provided integrally with the camera.
ay) and other display devices. When the image signal from the camera block 2 is supplied to the display device 4, the image being captured is displayed, and the read image of the recording medium 9 supplied via the data transmission path 5 is displayed. The display device 4 displays a VGA (640 × 480) image.

For the data transmission line 5, a DRAM (Dyn
amic Random Access Memory) 6 and an image processing block 7 composed of a microcomputer. The DRAM 6 is controlled by the memory control block 3 or the image processing block 7, and the captured image (original image) passed through the memory control block 3.
And an area for storing image data after image processing by the image processing block 7.

An operation input unit 8 and a recording medium 9 are connected to the image processing block 7 via interfaces. When control information is supplied from the image processing block 7 to each unit, image data is processed, data is written to and read from the DRAM 6, and writing and reading to and from the recording medium 9 are executed.

The operation input unit 8 has a shutter button, a mode designation switch, and other various switches operated by the photographer. For example, a first mode designated mainly when photographing a natural image and a second mode designated mainly when photographing an image mainly composed of characters such as a text document and a white board can be selected. An operation input from the operation input unit 8 is supplied to the image processing block 7. The recording medium 9 is a memory card (IC card), a floppy disk, a rewritable optical disk, or the like, and is detachable from the still camera body. In addition to the recording medium 9, a communication medium such as the Internet may be used.

In the image processing block 7, an image processing method is different between a first mode mainly used for photographing a natural image and a second mode mainly used for photographing a character image. In the first mode, for example, JPEG (Jo
int Photographic Experts Group) is used. Second
In the mode, the binarization processing of the captured image is performed, and the LZW
(Lempel Ziv Welch) The data is compressed by the method, and necessary components are added to the compressed data to generate a binary image by G.
A process for making an IF file is performed.

JPEG is a standard encoding method for compressing a color still image, and includes a lossless encoding method and an irreversible encoding method. As a lossless coding method, an intra-spatial prediction coding method is adopted, and as a lossy coding method, DCT
(Discrete Cosine Transformer
m). Normally, it is considered that a slight deterioration in image quality due to the irreversible coding method does not cause any practical problem, and the coding method using DCT is used as JPEG. Also in this specification, the term of JPEG quantizes DCT and coefficient data generated by DCT,
It means lossy encoding in which the quantized output is encoded by entropy encoding.

The image processing block 7 controls writing and reading of data to and from the recording medium 9.
The image data stored in the DRAM 6, that is, the JPEG file obtained in the first mode or the GIF file obtained in the second mode is output to the recording medium 9. These image files read from the recording medium 9 are stored in the DRAM 6 by the image processing block 7.

In the above-described embodiment, when a photographer presses a shutter button (operation input unit 8), a color image signal picked up by the CCD 1 is supplied to the camera block 2, and the image after the camera signal processing is performed. Data is stored in the DRAM 104 under the control of the memory control block 3.

When the photographed original image data is stored in the DRAM 6, the original image data is processed by the image processing block 7, and the compressed image data (JPEG file or GIF file) is stored in another area of the DRAM 6. . Then, the compressed image data read from the DRAM 6 by the image processing block 7 is written to the recording medium 9.

When recording compressed image data, a file name is given in the image processing block 7. When the recording medium 9 is a memory card, a still image directory (DCIM) is defined, and the still image directory (D
CIM) defines subdirectories such as MSDCF. A subdirectory is equivalent to an album. If it is one image compressed by JPEG,
DS for subdirectory eg 100MSDCF
C00001. jpg file name and extension are added. Next, the image data recorded on the memory card is GI
F file, the directory and subdirectory are the same, and TXT00002. The file name and extension of the gif are added. Numbers from (0001) to (9999) are added after each of DSC0 and TXT0.

When an image stored in the recording medium 9 is reproduced, desired compressed image data is read from the recording medium 9 by designating a file name, and decompressed by the image processing block 7. The decompressed image data is written to the DRAM 6. Then, the image data stored in the DRAM 6 is displayed on the display device 4 via the memory control block 3.

In the above-described embodiment, the image processing in the second mode mainly used for photographing a character document or the like will be described in more detail. In the second mode, the image processing block 7 performs binarization processing of the captured image. That is, an optimum threshold value is calculated based on the color image data taken into the DRAM 6, and the color image data is converted into binary (white and black) using this threshold value. The luminance data in the color image data is binarized. Although the binarization process can be performed in the CCD 1, the binarization process in the image processing block 7 allows the image processing block 7 to perform a process such as setting a threshold value.

The optimum threshold value is obtained by examining the distribution of the luminance data of the image to be processed, and calculating a threshold value at which the character and the background can be discriminated based on the distribution. For example, a value obtained by adjusting the average value of the maximum value and the minimum value of the luminance data with the adjustment value is calculated as the threshold value. When the data of the original image is used for calculating the threshold value, the number of pixels is large. Therefore, it is preferable to use only the image data obtained by thinning out the original image or only the image data near the center, for example, in the original image. .

Next, in order to create a GIF file, the LZW
Data compression is performed according to the method. In the LZW method, a pattern of an arbitrary length appearing in a data stream is registered in a dictionary (code table), and when the same pattern appears next, a registration number (variable length code) is used as an encoded output. is there. There is no need to edit a dictionary for registering a pattern prior to encoding, and a dictionary is created while reading data.

A GIF file is created from the compressed data. The structure of the GIF file will be specifically described.
FIG. 2 shows an example of a file structure of a general GIF file. GIF files are roughly divided into header block 1
1, a logical screen description block 12, an application extension block 13, a graphic control extension block 14, an image data block 15, and a trailer block 16. By creating these blocks, a GIF file is created.

The header block 11 is composed of, for example, 6 bytes and is arranged at the head. This header block 11
Indicates that the data stream is in GIF format. The header block 11 includes a signature field indicating the start of the data stream, and a version field necessary for performing decoding completely. In addition,
One header block is required for the data stream.

The logical screen description block 12 is arranged next to the header block 11. The logical screen description block 12 defines parameters (size, aspect ratio, color depth) necessary to define an area of an image plane (display device) for rendering an image.
The logical screen description block 12 defines the presence / absence of a global color table and various parameters thereof. This logical screen description block is also mandatory, and there must be exactly one in the data stream.

The global color table block 12a is arranged next to the logical screen description block 12. The color table is a palette that represents RGB values for all colors used in the image as a set of 3 bytes (24 bits). Since the GIF supports up to 256 colors, the global color table can be up to 2 colors.
Includes 56 x 3 bytes. This is the default palette and is used when subsequent images do not have a dedicated local palette. Although this block is optional, the maximum number of global color tables that can be specified for one data stream is one.

Global color table block 12a
The application extension block 13 is placed next to the application. The application extension block 13 includes unique information for only a specific application to perform special processing on image data.

The graphic control extension block 14 is provided next to the application extension block 13. The graphic control extension block 14 includes parameters for controlling a method of displaying an image. The adaptation range is only the first image immediately following. Note that a GIF file can be configured without disposing the block 13, and one graphic control extension block 14 can be disposed before the image data.

An image data block 15 is arranged next to the graphic extension block 14. Each image of the data stream is composed of an image descriptor block 15a and compressed data 15c.

The image descriptor block 15a contains the parameters needed to process a table-based image. The coordinates specified in this block indicate the coordinates of the logical screen, and are in pixel units. The image descriptor block 15a is a graphic rendering block, which may be preceded by one or more control blocks such as a graphic restriction extension, or may be followed by a local color table. Note that, after the image descriptor block 15a, the compressed data 15
c follows. That is, the image descriptor block 15a
Image descriptors that are mandatory for the image and can be specified for the image present in each data stream are:
There is only one. Note that there is no limit on the number of images present in the data stream.

The table-based compressed data 15c is composed of an array of sub-blocks. Compressed data 15
Each sub-block making up c is 255 bytes at maximum and contains an index to the color table.

Then, the graphic control extension block 14 and the image data block 15 described above are repeated by the number of images to be displayed as continuous images, and a trailer block 16 is arranged at the end of the file. The trailer block 16 is a block composed of a single field indicating the end of the GIF data stream. In the case of a GIF file, be sure to use trailer block 1
6 and the trailer block 1
No. 6 cannot be changed.

To create the image data block 15, the original image is converted to a binary image, and the binary image is converted to a GIF.
Is converted to an index value indicating the color palette number. As described later, the binarization process and the conversion to the index value may be performed at once. In that case, the memory used for the binarization processing can be effectively used.

As described above, in one embodiment, LZW
Data compression is performed according to the method. In the LZW method, the smaller the number of patterns appearing in a data stream,
The possibility of matching with the registered contents of the dictionary is increased, and the compression ratio can be increased. A binary image is a data stream consisting of only two values (0 and 1), and the number of patterns that appear is significantly smaller than that of a color image, so that the compression ratio can be increased. In other words, the data size of the compressed image data is reduced.

FIG. 3A shows an example of the captured original color image data. In the case of (640 × 480) pixels, about 370
The data size is kB (kilobytes). If this color image is compressed by JPEG, the image (640 × 480) shown in FIG. 3B has a data size of about 70 kB. As shown in FIG. 3C, an image (640 × 480) shown in FIG.
Thus, the data size becomes about 10 kB. Thus, J
In PEG compression, the compression ratio of about 1/4 to 1/5 is L
In ZW, it is compressed to about 1/30.

The LZW method is a reversible compression method in which a data stream before compression can be completely restored from a sequence of dictionary registration numbers, that is, the same data as original data can be restored from compressed data. . Meanwhile, JPE
G is lossy compression. A binary image is an image having an extremely small number of colors and many sharp edges.
When compressed and decompressed using PEG, there is a disadvantage that the decompressed image contains much image noise.

FIG. 4A shows a 2D image compressed and recorded by JPEG.
The expanded image of the value image is shown enlarged. FIG. 4B shows the LZ
An image obtained by expanding a binary image recorded by GIF and compressed by W is shown in an enlarged manner. In the image recorded by JPEG (FIG. 4A), a noise such as a slight haze occurs around the edge of the character, whereas the image recorded by GIF (FIG. 4B)
Thus, a clearer image can be obtained without noise around the character.

Next, the binary image obtained by binarizing the photographed image is represented by G
An example of the process of converting to the IF format will be described. GI
The F file is to generate blocks as shown in FIG. An example of the processing will be described with reference to FIG.

FIG. 5A shows a captured color image data stream. One pixel is represented by RGB 3-byte data. Next, the color image is binarized to obtain a stream of binarized image data as shown in FIG. 5B. In the binarization processing, pixel data representing black is converted into (R = G = B = 0), and pixel data representing white is converted into (R = G = B = 255). And FIG. 5C
As shown in (2), the index value is converted to 0 (black) or 1 (white) of the index value indicating the color palette.

The processing shown in FIG.
A conversion process to a value image and a conversion process from a binary image to an index value are required. By two conversion processes,
Processing time becomes longer, and a problem arises in terms of effective use of the memory (DRAM 6). Thus, in one embodiment,
By the method described below, binarization and GIF file creation processing are performed.

Since the color table in the global color table block 12a in FIG. 2 is a binary image, the colors used for the image can be determined in advance to include only white and black colors. . That is, in the configuration of the color table, as shown in FIG. 6, an index value 0 corresponds to black (R, G, B = 0) and an index value 1 corresponds to white (R, G, B = 255). Can be predetermined. The present invention is also applicable to a case where each component of a color image is represented by Y (luminance signal), Cb (blue color difference signal), and Cr (red color difference signal). In that case, the information representing black is (Y = 0, Cb = Cr = 12
8), and the information representing white is (Y = 255, Cb = Cr)
= 128).

Next, in the data block 15, the stream actually compressed by the LZW is not the original image data stream itself but a stream of index values indicating the color of each pixel of the original image. It is. In the case of a black and white binary image having the color table shown in FIG. 6, as shown in FIG. 7, a stream composed of binary values of index values "0" and "1" is compressed.

As described above, in the case of a binary image, the white and black pixels can be previously determined to have the index values "1" and "0", so that the original color image data as shown in FIG. By performing a process of binarizing a stream and a process of converting the stream into index values at a time, FIG.
A stream having an index value as shown in FIG. Therefore, as compared with the processing shown in FIG. 5, the processing can be simplified and the processing time can be shortened. Further, as shown in FIG. 5A, the original image information is represented by 3 bytes per pixel, so that the data after the first conversion is 3 bytes per pixel as shown in FIG. 5B.
Requires a byte memory area. In contrast, FIG.
According to the processing shown in (1), since the data after the first conversion is a stream of index values, one data per pixel
It requires only a byte memory area, and has no memory (DRAM
6) can be effectively used.

As described above, when a character image or the like is binarized and photographed by the digital image recording device, and when the recorded image is reproduced to check the contents, the size of the screen of the display device provided in the digital camera is increased. There is a limit, and it is difficult to confirm fine characters and the like. Even if it is possible to record a very large number of pixels, it is not preferable that the contents of the recorded character document or the like cannot be confirmed due to the limitation of the display performance of the display device.

In one embodiment of the present invention, in order to solve such a problem, a function of arbitrarily enlarging and scrolling a reproduced image obtained by reproducing a recorded image from the recording medium 9 is provided. Further, the enlarged image can be recorded on the recording medium 9 as another image file.

FIG. 9 illustrates a function of enlarging / scrolling a reproduced image according to one embodiment. Reference numeral 21 denotes a display system. The display system 21 includes a screen 22 of the display device 4,
It comprises a zoom (enlarge) key 24, a scroll key 25, and a recording key 26. These keys are used by the operation input unit 8
It is provided in. The zoom key 24 is operated when magnifying an image from the same size to 10 times. For example, each time the button is pressed once, the magnification changes from 1 time to 2 times, 3 times,..., 10 times. The zoom key 24 or another key (not shown) has a function of sequentially reducing the enlarged image. The enlarged image is displayed on the entire screen 22.

On the screen 22, a region to be enlarged is shown, and a frame 23 of a size corresponding to the enlargement ratio is displayed in a superimposed manner.
The scroll keys 25 are keys for moving the frame 23 in the screen 22 in the vertical and horizontal directions. The recording key 26 is pressed when recording an enlarged image on the recording medium 9.

As shown in FIG. 9A, in the state where the reproduced image from the recording medium 9 is displayed on the screen 22, the frame 23 is displayed.
Is moved to select an enlarged area, and as shown in FIG. 9B, the image of the enlarged area is displayed at the specified magnification. Therefore, even in the case of a text document, it is possible to display an image whose size is easily legible. As another operation method, the enlarged area is fixed near the center of the screen 22,
Next, a method of displaying an enlarged image at a specified magnification and then scrolling the enlarged image with the scroll key 25 may be adopted.

As shown in FIG. 9C, an enlarged image 27b is obtained from the reproduced image 27a from the recording medium 9 by the above operation. To store the enlarged image 27b, the recording key 26 is pressed. Thereby, the enlarged image 27b is converted into the GIF format and recorded on the recording medium 9. The image 27a and the image 27b are recorded as different files. As described above, it is possible to enlarge a particularly necessary portion in a wide range of a character document or the like, and to record an enlarged image as a separate file.

The present invention can be applied not only to digital cameras but also to other digital image recording devices. For example, when a still image recording function is provided as one function of a digital image recording device for recording moving images, CC
The present invention can be applied to a case where a photographed image is processed by a portable personal computer provided with D.

[0056]

According to the present invention, image processing suitable for an image to be captured can be performed. That is, in the case of a natural image, an image compressed by a lossy encoding method, for example, JPEG, is recorded.
An image obtained by compressing a value image by a reversible encoding method, for example, LZW, can be recorded. Thereby, even if the image pickup means is common, the data size of the character document after compression can be made smaller, and an image in which the background is clear and characters are easy to read is recorded and reproduced. It becomes possible.

[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 schematic diagram illustrating the structure of a GIF file according to an embodiment of the present invention.

FIG. 3 is a schematic diagram used for describing a data size after compression according to an embodiment of the present invention.

FIG. 4 is a schematic diagram used to explain a difference in image quality due to a difference in a compression encoding method according to an embodiment of the present invention.

FIG. 5 is a schematic diagram used to describe an example of a binarization process of a captured image of a character document or the like and a conversion process to a GIF file.

FIG. 6 is a schematic diagram used to explain a process of converting a captured image such as a text document into a GIF file.

FIG. 7 is a schematic diagram used to describe a data stream to be compressed in a GIF data block.

FIG. 8 is a schematic diagram used for explaining a binarization process of a photographed image of a character document or the like and a conversion process to a GIF file according to the embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a process of enlarging a reproduced image according to an embodiment of the present invention.

FIG. 10 is a schematic diagram for explaining a binarization process of a character document;

[Explanation of symbols]

1 ... CCD, 2 ... Camera block, 3 ... Memory control block, 4 ... Display device, 6 ...
・ DRAM, 7 ・ ・ ・ Image processing block, 8 ・ ・ ・ Operation input unit, 9 ・ ・ ・ Recording media

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsuhiko Ueno 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C057 AA01 AA06 AA07 AA13 BA14 EA01 EA02 EA07 EA12 EF01 EL01 EM01 EM09 EM14 GG04 GH05 GM01 GM04 GM08 5C078 AA01 AA04 AA09 BA21 BA57 CA03 DA00 DA01 DA02 DB04 DB06 9A001 EE02 HH22 HH23 HH27 KK42

Claims (14)

[Claims] An image processing means for compressing a captured digital image signal, and a mode designation for generating a signal for designating one of a first mode and a second mode for an image processing operation in the image processing means. When the first mode is designated, the image processing means generates first compressed image data obtained by compressing the digital image signal by an irreversible encoding method, and the second mode is designated. Wherein the digital image signal is binarized by the image processing means to generate second compressed image data obtained by compressing the binary image signal by a lossless encoding method. . 2. A digital image recording apparatus for recording an image as a digital signal on a recording medium, comprising: an image capturing means for capturing an image and generating a digital image signal; and an image processing means for compressing the captured digital image signal. A mode designating means for generating a signal for designating an image processing operation in the image processing means to one of a first mode and a second mode; and a recording means for recording an output of the image processing means on a recording medium. When the first mode is designated, the image processing means generates first compressed image data obtained by compressing the digital image signal by a lossy encoding method, and when the second mode is designated, The image processing means binarizes the digital image signal and compresses the binary image signal by a lossless encoding method. Digital image recording apparatus characterized by generating a second compressed image data. 3. The apparatus according to claim 1, wherein the captured digital image signal is a digital color image signal. 4. The apparatus according to claim 1, wherein the lossy encoding method compresses a digital image signal by orthogonal transformation and entropy encoding. 5. The lossless encoding method according to claim 1, wherein a pattern of an arbitrary length appearing in the data stream is registered in a dictionary, and when the same pattern appears next, the registration number is encoded. An apparatus characterized in that the output is a coded output. 6. The apparatus according to claim 1, wherein the image processing means converts the first and second compressed image data into a file format. 7. The GIF (Graphics Interch) according to claim 6, wherein
ange Format) file format. 8. The apparatus according to claim 7, wherein said image processing means performs a process of binarizing the digital image signal and a conversion to an index value of a GIF color table at a time. 9. The image processing apparatus according to claim 2, further comprising a reproducing unit that reproduces the compressed image data recorded on the recording medium, wherein the image processing unit expands the reproduced compressed image data to reproduce the reproduced image data. A digital image recording apparatus for generating a digital image and displaying the reproduced image on a display means. 10. The digital image recording apparatus according to claim 9, further comprising an enlargement unit that enlarges the reproduced image displayed on the display unit. 11. The digital image recording apparatus according to claim 10, wherein the recording unit records the enlarged image on a recording medium. 12. An image processing operation of an image processing means for compressing a digital image signal taken in is described as a first one.
A digital image signal processing method for designating one of a mode and a second mode, wherein when the first mode is designated, the image processing means encodes the digital image signal by irreversible encoding. Generating first compressed image data compressed by a method, and when the second mode is designated, the image processing means binarizes the digital image signal and compresses the binary image signal by a lossless encoding method A digital image signal processing method, characterized by generating second compressed image data. 13. A digital image recording method for recording an image as a digital signal on a recording medium, wherein the image processing means in the image processing means for compressing the fetched digital image signal comprises a first mode and a second mode.
In the digital image recording method designed to designate one of the modes, when the first mode is designated, the image processing means compresses the digital image signal by a lossy encoding method. When compressed image data is generated and the second mode is designated, the image processing means binarizes the digital image signal and compresses the binary image signal by a reversible encoding method. And recording one of the generated first compressed image data and the second compressed image data on a recording medium. 14. Data recording in which a first image file compressed by a lossy encoding method and a second image file compressed by a lossless encoding method are recorded so as to be identifiably mixed. Medium.