JPH0832811A - Method and device for coding image - Google Patents

Abstract

PURPOSE:To attain high speed reading by storing coded data with a minimum resolution coded by a hierarchical coding means and other coded data separately. CONSTITUTION:Encoding is started by allowing the user to use an operation section 8 to designate a file name of coded data. Then a CODEC section of an image code conversion section 4 applies hierarchical coding of all layers to the data and the code conversion section 4 applies buffering only to coded data with a minimum resolution as coded data for icon. Then the coded data are stored in a coded data area 21 according to a format represented by a header 26-1 and coded data 26-2 by an entered file name. The header 26-1 is information required to decode data of all layers. Then the coded data with a minimum resolution are stored continuously to a coded data area 20 for icon. Thus, the icon image is displayed at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image coding method and apparatus for separately storing coded data of the lowest resolution and other coded data.

[0002]

2. Description of the Related Art As a binary image encoding method for electronic files, facsimiles, etc., there is a binary image hierarchical encoding method. For the hierarchical encoding of this binary image, see ISO / C.
International standardization is being considered by JBIG, the organization of CITT. Also, color images are being studied by JPEG.

For example, in the case of JBIG, for example, 5
Hierarchy, from highest resolution to lowest resolution (HITOL
If it is encoded in O), encoded data as shown in FIG. 7 can be created. In the figure, reference numeral 70 denotes a header portion, which stores information necessary for decoding such as image size, the number of layers, and option information at the time of encoding.
71-1 to 71-5 are coded data in each layer, 7
2 is the coded data of the lowest resolution.

In the case of managing a large amount of these coded data, in a normal computer system, each coded data is given a file name and managed by this file name. FIG. 8 is a diagram showing the concept of such a management method. In this case, the computer system is configured to read the portion storing the directory, obtain the storage location of the corresponding file from the portion, read the contents of the file, and process the file.

[0005]

However, in the above-mentioned conventional example, when a user manages a large amount of encoded data by file names, the characteristics of the actual encoded data are expressed when each file name is given. It had the drawback of being difficult to name. Further, when the image data of the lowest resolution (hereinafter referred to as an icon image) is continuously displayed on the display device, the storage position of the encoded data to be displayed from the directory area is calculated for each encoded data, and each code is calculated. It is necessary to read out the coded data of the lowest resolution of the coded data, decompress and display the coded data, and there is also a drawback that the seek time (overhead) of the disk necessary for reading the coded data of each lowest resolution is long.

Further, the encoded data is HITLO (see FIG. 8).
As shown in, the data is stored in order from the high resolution encoded data), after determining the storage position of the corresponding encoded data, the storage position of the lowest resolution encoded data in the encoded data Must be calculated, in which case the overhead becomes even larger.

When storing encoded data in a tape type device represented by CMT, an icon image is displayed when confirming what image data of encoded data is saved in the tape. Considering what to do, there is also a drawback that it takes a lot of time.

The present invention has been made to solve the above-mentioned problems, and is an image code capable of storing the coded data of the lowest resolution hierarchically coded and other coded data separately and reading them at high speed. It is an object of the present invention to provide a method and an apparatus for converting the same.

[0009]

In order to achieve the above object, the image coding apparatus of the present invention has the following configuration.

That is, an image coding apparatus for separately storing the coded data of the lowest resolution and the other coded data, which is a hierarchical coding means for hierarchically coding the image data, and the hierarchical coding means. And a storage unit for separately storing the coded data of the lowest resolution coded in 1. and other coded data.

In order to achieve the above object, the image coding method according to the present invention has the following steps.

That is, an image coding method for separately storing the coded data of the lowest resolution and other coded data, which is a hierarchical coding step of hierarchically coding the image data, and the hierarchical coding step. And a storage step of separately storing the coded data of the lowest resolution coded in 1. and other coded data.

[0013]

In such a structure, the image data is hierarchically encoded, and the encoded lowest resolution encoded data and other encoded data are stored separately.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic block diagram showing the structure of an image coding apparatus according to the embodiment. In the figure, 1 is a system bus for connecting various devices attached to the system. A CPU unit 2 controls the entire system. A scanner / printer unit 3 includes a scanner that reads image data and a printer that forms a permanent visible image. An image code conversion unit (CODEC) 4 is a code conversion unit that encodes / decodes binary image data, and a code conversion unit that divides the encoded data into encoded data of the lowest resolution and encoded data of other layers. It consists of and. 5 is a hard disk (HD),
Reference numeral 6 is a removable disk type storage device such as OMD, and 7 is a tape type storage device such as CMT. 8 is an operation unit such as a keyboard.

In the following embodiment, the document is read by the scanner of A4 size (4752 × 3360 pixels), 400 dpi provided in the scanner / printer unit 3, encoded by the code conversion unit 4, and hard disk 5, A case where encoded data is stored in the storage device 6 or 7 will be described as an example. The codec unit of the image code conversion unit 4 uses the binary image hierarchical coding method proposed by JBIG and performs coding in five layers. In addition, the encoded data output from the codec section has the highest resolution [4
00 dpi] to lowest resolution [25 dpi] (H
It shall be output in ITOLO). Further, the device of the storage or output destination is specified by the user with a pointing device such as a mouse provided on the operation unit 8.

<First Embodiment> Next, detailed operation of the first embodiment will be described with reference to FIGS. In the first embodiment, a case where encoded data is stored in the hard disk 5 will be described.

FIG. 2 is a conceptual diagram showing the storage format of the encoded data output by the image code conversion unit 4. In the figure, reference numeral 20 denotes an area for storing coded data for icon image dedicated to displaying an icon image, and only coded data for icon image is stored. On the other hand, 21 is an area for storing all encoded data output by the image code conversion unit 4.
In the first embodiment, all encoded data is stored in 21 areas. Further, in the example shown in FIG. 2, encoded data of four images is stored. 22-1 to 22
-4 is the coded data for the icon images of the four types of images, which is the coded data of the lowest resolution of the JBIG method. 23-1 to 23-4 are coded data of four types of images corresponding to the coded data for the icons 22-1 to 22-4 and include all coded data from the lowest resolution to the highest resolution. I'm out. The format of this encoded data is 2
6-1 and 26-2. Reference numeral 26-1 is header information of encoded data, which is image data size (4752 × 336).
Information such as 0 pixel) and the number of layers 5 is stored. Two
6-2 is coded data from layer 5 to layer 0. Numerals 24 and 25 indicate the storage format of the encoded data for the icon, 24 is the encoded data of the lowest resolution, and as shown in 24-1 and 24-2, it is called the JBIG header and the encoded data. Store in the format. In the header information of 24-1, header information such as an image size (149 × 105 pixels) and the number of layers 0 (only the lowest resolution) is stored so that the code is completed in this layer. Reference numeral 25 is a pointer that points to all the encoded data 21, and in this embodiment, as shown in 25-1 and 25-2, JBIG CO
The file name of all encoded data is stored together with the MMENT marker code.

The operation of the image coding apparatus according to the first embodiment will be described below with reference to the flow chart shown in FIG.

FIG. 3 shows the operation of encoding image data read by a scanner or the like and outputting it to an output medium. First, in step S1, the user specifies the file name of the encoded data from the operation unit 8 to start encoding. Next, step S2
At, the codec unit of the image code conversion unit 4 performs hierarchical coding of all layers, and the code conversion unit buffers only the coded data of the lowest resolution as the coded data for the icon. Then, in step S3, the encoded data is stored in the encoded data area 21 shown in FIG.
The file name input in 1 is stored according to the format shown in 26-1 and 26-2. Here, the header information of 26-1 is header information necessary for full-layer decoding, as indicated by 41 in FIG.

Next, in step S4, the coded data of the lowest resolution buffered in step S2 is output to the coded data area 20 for the icon. Here, the header information 24-1 shown in FIG. 2 is the one shown at 42 in FIG. When the BS2_1 of 22-2 is stored, it is continuously stored immediately after the BS1_1 of 22-1. Then, in step S5, step S1
The file name input in step 1 is added to the end of the encoded data together with the COMMEMT marker code and written, and the process ends.

A case of displaying encoded data stored in the above format will be described. First, when displaying the icon image of the encoded data stored in the storage medium, the seek point is moved to the beginning of the encoding area 20 for the icon shown in FIG. 2 and the code for the icon stored therein is displayed. The decoded data is decoded and displayed. 2 here
Since the first piece of encoded data is stored immediately after the first piece of encoded data, it is not necessary to seek the head. Then, this process may be repeated for the number of stored images.

Further, in the case of displaying a high resolution image, the corresponding encoded data in 21 shown in FIG. 2 may be read from the file name following the COMMENT marker code, and decoded and displayed in order from the lowest resolution. .

By thus storing the coded data for icons in a continuous area in the dedicated area in a concentrated manner, the coded data is read from the hard disk and the icons are continuously displayed on the image display device. In doing so, the head of the hard disk is sought at the beginning of the first encoded data, and after that, continuous reading is performed and decoding / decoding is performed.
Only by displaying, it becomes possible to display the icon images of all the stored images.

According to the first embodiment, in the image data hierarchical coding apparatus, when the coded data is stored in the disk type storage device, the coded data for the icon and all the coded data are separated from each other. It is possible to display the icon image at high speed by continuously writing the area of, particularly, the encoded data for the icon continuously.

In the above-described embodiment, the file name is used as a pointer from the coded data for icons to all the coded data, and the user specifies the file name. However, the present invention is not limited to this. Instead, it may be created in the system. Further, it can be easily inferred that the physical storage position of the hard disk for all encoded data may be directly used.

<Second Embodiment> In the first embodiment, the coded data stored in the coded data area is the coded data of all layers, but in the second embodiment, the code of the lowest resolution is used. The case of storing hierarchically encoded data other than the encoded data will be described. The encoded data for the icon in this case is the same as that in the first embodiment.

The detailed operation principle of the second embodiment will be described below with reference to the drawings. The operation flow chart, the coded data for icons, and the concept of the coded data are the same as those in the first embodiment. Therefore, the explanation is omitted, and FIGS.
Only parts different from the first embodiment will be described with reference to FIG.

Steps S1 and S2 shown in FIG. 3 perform the same operations as in the first embodiment. In step S3, the header information shown in FIG. 5 is output, and then layer 5 to layer 1 are output.
The encoded data up to the encoded data area 21 shown in FIG.
Output to. This header information indicates that this encoded data starts from layer 1. The codec section is H
Since the encoded data is output by ITOLO, the code conversion unit may simply output the encoded data up to layer 1 as it is. Next, in step S4, the encoded data for the icon is output. Here, the coded data after the coded data stored in step S3, that is, the coded data of the lowest resolution is stored in the coded data area for the icon. Here, the storage format is the same as in the first embodiment.

In this embodiment, the coded data stored in the coded data area 21 can be made smaller than in the first embodiment. Further, the code conversion unit also eliminates the processing of buffering the coded data for icons, which has been performed in the first embodiment.

<Third Embodiment> Next, as a third embodiment, a case where encoded data is stored in a tape device represented by CMT will be described. In this case, it is assumed that the encoded data stored in the hard disk described in the first and second embodiments is stored in the CMT as a backup.

Details of the third embodiment will be described below with reference to FIG.

First, as shown by 61-1 to 61-4 in FIG. 6, four pieces of coded data for icons 1 to 4 are continuously saved in the CMT. Then, the EOD code 63 is output to indicate the end of the encoded data for the icon. After that, as shown by 62-1 to 62-4 in FIG. 6, four pieces of BS1 to BS4 are output in the same order as all the encoded data in the order in which the encoded data for icons is saved. Finally, 64 EOTs indicating the end of data on the tape
And output.

In the third embodiment, the case where the encoded data stored in the HD is backed up in the CMT has been described, but the present invention is not limited to this.

When appending the encoded data to the tape which has already been backed up, the encoded data backed up on the tape is once sucked up to the hard disk, and all encoded data is transferred by the method described in the third embodiment. Back up again. Alternatively, it may be newly added after the EOT code by this method.

According to the third embodiment, even when stored in a tape-type medium, the encoded data for the icon is collected and saved in the head portion of the tape, and the encoded data group for the icon is stored. By storing the encoded data groups of other layers later, when displaying all the encoded data stored in the tape, simply read the head part of the tape,
The icon images of all the encoded data stored on the tape can be instantly displayed on the display device.

In the embodiment described above, the binary image JBIG has been described as an encoding method, but the same applies to the JPEG hierarchical encoding method corresponding to a color image.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device.

It goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0040]

As described above, according to the present invention,
It is possible to perform high-speed reading by separately storing the lowest-resolution coded data that has been hierarchically coded and other coded data.

[0041]

[Brief description of drawings]

FIG. 1 is a schematic block diagram illustrating a configuration of an image encoding device according to an embodiment.

FIG. 2 is a conceptual diagram showing a storage format of hierarchically encoded data in the embodiment.

FIG. 3 is a flowchart showing the operating principle of the embodiment.

FIG. 4 is a diagram showing a storage format of hierarchically encoded data in the first embodiment.

FIG. 5 is a diagram showing a storage format of hierarchically encoded data in the second embodiment.

FIG. 6 is a diagram showing a storage format of hierarchically encoded data in the third embodiment.

FIG. 7 is a diagram showing an encoded data format of HITOLO.

FIG. 8 is a conceptual diagram showing a file management method in a computer system.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H04N 7/30 H04N 7/133 Z

Claims (4)

[Claims] 1. An image coding apparatus for separately storing coded data of the lowest resolution and other coded data, wherein a hierarchical coding unit for hierarchically coding the image data, and the hierarchical coding unit. An image coding apparatus comprising: a storage unit that separately stores the coded data of the lowest resolution coded in 1. and other coded data. 2. The image coding apparatus according to claim 1, wherein the storage unit writes the coded data of the lowest resolution in a continuous area. 3. The image coding apparatus according to claim 1, wherein the storage unit writes the coded data of the lowest resolution together with a comment. 4. An image coding method for storing coded data of the lowest resolution and other coded data separately, comprising a hierarchical coding step of hierarchically coding image data, and the hierarchical coding step. And a storage step of separately storing the coded data of the lowest resolution coded in 1. and other coded data.