JPH07244715A - Image processor - Google Patents

Abstract

PURPOSE:To read and file image documents at a high speed without using a mass-storage memory. CONSTITUTION:A color image document is read by a color document input part 101, and compressed and stored. Nearly simultaneously with the compressing and storing process, color multi-valued image data are converted into black-and-white and binarized. The binary data are stored in a binary page memory 106 and the image is thinned out almost at the same time to generate a reduced image. In this reduced image, areas where black pixels succeed are defined as rectangular areas, and data regarding the rectangular areas are generated. As for only the areas defined as the rectangular areas, the binary data are read out of the binary page memory 106 and compressed, and the compressed data are stored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus for filing a document in which characters and images are mixed.

[0002]

BACKGROUND OF THE INVENTION Conventionally, an image filing apparatus for reading and filing a document in which a photographic image and characters are mixed on one page has been constructed as shown in FIG.

In FIG. 12, 101 is a color original input section such as a scanner which reads an original every 8 bits of R, G and B in the main scanning direction, and 202 is an area determination for separating an image area and a character area in one page. Reference numeral 203 denotes a region determination result storage unit that stores the region determination result, and 102 performs compression coding processing on the read color original document over one page, for example, J
A color multi-value compression coding unit according to the PEG system, 103 is a color code storage unit configured by a hard disk or a magneto-optical disk that stores the color code data after compression coding, and 104 is a color that calculates black and white data from the color data. A black-and-white conversion unit, 105 is a binarization processing unit that binarizes the black-and-white data output from the color black-and-white conversion unit, 107 is a binary compression encoding unit that compresses and encodes the binary data of the designated area, and 108. Is a black and white code storage unit that stores binary compressed data configured on the same medium as the color code storage unit.

For the binarization processing, many methods such as a simple binarization method in which a threshold value is fixed, an error diffusion method in which the reproducibility of a halftone portion is improved, and an average density preservation method are proposed. , Here, since the character and the front part are the target, the binarization method most suitable for it is used. Further, as a compression method for monochromatic binary data, a method using MH, MR, MMR, arithmetic code, or the like is used.

Next, the process of reading an original in which a photographic image and characters are mixed and filing the original by the apparatus having the above-described structure will be described with reference to the flowchart shown in FIG. 13 and the time chart shown in FIG. To do.

That is, in step S301, a first page of the document is read by prescanning a document of a certain page (141 in FIG. 14), and at the same time, the area determination unit 202 makes 1
Extract the photo image area in the page (142 in FIG. 14),
In step S302, the position information is stored in the area determination result storage unit 203. Then, in step S303, the second reading of the original on the same page is started (see FIG. 1).
4 of 143).

Then, in step S304, whether or not the read image is a photographic area is checked based on the position information of the photographic image stored in the area determination result storage section 203. Here, if the read image is in the photograph area, the process proceeds to step S305 and multi-value compression is performed by the color multi-value compression encoding unit 102 (144 in FIG. 14), but the read image is not in the photograph area. If so, step S30 is performed.
6, the binary compression encoding unit 107 performs binary compression (145 in FIG. 14). Finally, in step S307, the result is stored in the color code storage unit 103 or the monochrome code storage unit 108.
Accumulate with.

[0008]

However, in the above-mentioned conventional example, an operation (prescan) of reading the document in advance is required to determine the photographic area in the document, and as a result, the document is read twice for one page of the document. However, there is a disadvantage that the processing time becomes long because the reading operation of is required.

Further, since the original reading, multi-value compression, and binary compression must be operated in synchronization, the processing of the other parts of the apparatus must be matched with the processing with the slowest speed, which results in high speed processing. Not only is it an obstacle, but there is also the problem that the system becomes complicated. Therefore, it is not suitable for the purpose of processing a large number of originals at high speed.

In order to solve such a drawback, when an original is input from the color original input section 101, the original is simultaneously stored in the multivalued page memory and read again from the multivalued page memory without rereading the original. A device that makes one reading operation has also been proposed. However, an apparatus having such a configuration requires a large-capacity multi-valued page memory. For example, a color data of A4 size and a recording density of 400 dpi requires a memory of 48 MB, which is advantageous from the viewpoint of suppressing the production cost of the apparatus. After all it is not preferable.

The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide an image processing apparatus capable of reading and processing an image original at a high speed and making a file while suppressing the production cost of the apparatus.

[0012]

In order to achieve the above object, the image processing apparatus of the present invention has the following configuration. That is, reading means for reading an image original, first compression means for compressing multivalued image data representing the image original read by the reading means, and multivalued image data compressed by the first compressing means are stored. The first storing means, the binarizing means for binarizing the multi-valued image data, and the binary data of a predetermined amount are input from the binarizing means almost at the same time as the compression by the first compressing means. And the binary data is thinned out at a predetermined thinning rate to form a reduced binary image, and information on the area is defined for each area defined by the presence or continuity of black pixels in the reduced binary image. And a region defined by the region discrimination means,
Second compression means for compressing the binary data binarized by the binarization means based on the information of the generated area, and binary image data compressed by the second compression means are stored. An image processing apparatus having a second storage means is provided.

[0013]

With the above-described structure, the present invention binarizes the multivalued image data representing the image original at almost the same time as compressing the data, and when the binary data is obtained in a predetermined amount, the binary data is set to the predetermined value. A reduced binary image is formed by thinning out at a thinning rate, region information is generated for each region defined by the presence or continuity of black pixels in the reduced binary image, and the region information is generated. It operates to compress the binary data based on the information.

[0014]

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

[First Embodiment] <Outline Configuration of Apparatus (FIG. 1)> FIG. 1 is a block diagram showing the configuration of an image processing apparatus which is a typical embodiment of the present invention. In the configuration of FIG. 1, the same components as those of the conventional example shown in FIG. 12 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 1, reference numeral 106 denotes a binary page memory having a capacity of about 2 MB for storing one page (A4 size recording density 400 dpi) of the binarization processing result, and 107 denotes binary data of a designated area. A binary compression encoding unit that reads out from the value page memory 106 and performs compression encoding, 109 reduces the binary data obtained from the binarization processing unit 105 and collects adjacent black pixels in the reduced image together. The same labeling, and different labels are attached to the clusters of black pixels that are not adjacent to each other, 110 is a label memory for storing the rectangular data obtained by the reduction / labeling unit 109, and 111 is the original 1
After the page has been read, the combining unit that reads the rectangular information from the label memory 110 and combines the rectangular regions, 112 is a text rectangular region storage unit that stores information indicating the position of the text region after being processed by the combining unit 111, and 113 is An operating unit for operating the apparatus from the outside, 114 a CPU for controlling the entire apparatus, 115 a ROM storing a control program executed by the CPU 114, and 116 a RAM used as a work area for executing the control program.

Note that the synthesis performed by the synthesis unit 111 is RO
It is executed according to a control program which is a predetermined procedure stored in M115.

In the conversion from color data to monochrome data executed by the color monochrome conversion unit 104, the luminance component (Y) is calculated from R, G and B according to the following equations (1) and (2), The obtained luminance component (Y) is converted into a density value (D) according to the Log curve.

Y = 0.3R + 0.6G + 0.1B (1) D = -LogY (2) <Outline of operation of device> Next, an outline of operation of this device will be described.
This will be described with reference to the time chart shown in FIG. 2 and the flow charts shown in FIGS.

First, in step S101, the operation unit 11
In accordance with a document input start instruction from the user from 3, the document reading for one page, the compression of the color image (multi-value compression) and the storage thereof, the storage of the binarized data and the storage of the rectangular data (described later) are performed. The details are as follows.

The color original input section 101 separates the image data into R, G and B and reads them (121 in FIG. 2). When the JPEG method is used, the color multi-level compression encoding unit 102 performs processing in block units of 8 pixels × 8 pixels, and thus requires an image buffer of at least 8 lines. JP
Details of the EG method are ISO / IEC / JTC1 CD10
Since it is defined by 918-1 and the like, description thereof will be omitted here. The multi-valued color code data after compression is stored in the color code storage unit 103 (122 in FIG. 2). Therefore, when the input of the color original is completed, the color multi-value compression encoding unit 10
Although there is a delay of 8 lines in 2, the accumulation of the multi-valued color code data is completed almost at the same time.

On the other hand, R, G, B from the color original input section
The data is converted into monochrome data by the color monochrome conversion unit 104. As shown in Expressions (1) and (2), the color / black-and-white conversion processing is processing in pixel units, and the calculation can be performed with a delay of about one pixel. The obtained black-and-white data is converted into binary data by the binarization processing unit 105 and stored in the binary page memory 106, and at the same time, the reduction / labeling unit 10
Labeling processing is performed by 9 (123 in FIG. 2).

The rectangular data storage processing (processing until the character area and the table area in the image are extracted) will be described in detail below with reference to the flowchart shown in FIG.

First, in step S1001, the image is thinned out and reduced. A logical sum of vertical m dots and horizontal n dots is taken from the original image to newly thin out m × n pixels to one pixel. Here, if even one dot has a black pixel in the original image (m × n dots), the thinned image is black. Figure 5
It is a figure shown about the example of m (vertical) = 4 and n (horizontal) = 8.

In step S1002, a label is added to the black pixels in the image after thinning, one pixel at a time, and
Pixels that are continuous on the left and right and diagonally are given the same label,
At the same time, the rectangular area surrounding the black pixel of the same label is defined, and the data (rectangular data) of the rectangular area is generated. Rectangle data is information representing an area adjacent to a black pixel surrounded by a rectangular area. In Figure 6, "●"
Indicates a black pixel in the thinned image, and “◯” represents a white pixel in the thinned image. Labels (here, capital letters A to E) are attached to the respective black pixels. The rectangular area 61 is an area in which black pixels are continuous in the vertical, horizontal, and diagonal directions, and the same value is set in the label letters A to E.

Here, an area in which only one black pixel is isolated is also defined as one rectangular area, and rectangular data is generated.

Such processing is performed for each row (Y-axis direction in FIG. 6), and when one page has been read, a plurality of rectangular data as shown in FIG. 7 are created in the label memory 110. . As shown in FIG. 7, in each piece of rectangle data, a rectangle label, the start point coordinate value (the XY coordinate value of the upper left end of the rectangle), the end point coordinate value (the XY coordinate value of the lower right end of the rectangle) of the rectangle area, and the rectangle thereof. The number of pixels surrounded by the area is included.

Next, at the same time when the image reading operation is completed and the rectangular data is created and stored, the processing is performed in step S1.
Moving to 02, the rectangular data is read from the label memory 110 (125 in FIG. 2), and what kind of data the rectangular area is (for example, whether it is a sentence or a table or a separator). Is determined. Details of this processing are steps S1003 to S1 in the flowchart of FIG.
Corresponding to 007.

That is, in steps S1003 to S1005, the synthesizing unit 111 uses the width, height, area, and the number of pixels per area, that is, the pixel density of the rectangle obtained based on the read rectangle data, and the combining unit 111 separates the separator. (Step S1003), the set direction (step S1004), and the finding type (step S1005) are detected, and in step S1006, a plurality of rectangular areas are merged into one rectangular area based on the detection result if necessary. As a result, the rectangles corresponding to the text, figure, photograph, table, and separator are distinguished (124 in FIG. 2). The information distinguished in this way is set in the pixel label of FIG. And
In step S1008, the result is temporarily stored in the text rectangular area storage unit 112.

Next, in step S103, the process reads binary image data from the binary page memory 106 only for the area indicated by the text rectangular area storage section,
Binary compression 107 is performed (126 in FIG. 2). The result is stored in the binary compressed data storage unit 108 in step S104. Therefore, an area defined by only white pixels in which a rectangular area is not defined is not compressed and stored.

Therefore, according to the present embodiment, the image is compressed by reading the image original once, and only the binarized portion of the image input to the original is stored once in the binary page memory. An image binarized using the stored data distinguishes a rectangular area containing black pixels from an area containing only white pixels, and for a rectangular area containing black pixels, what kind of image (text , Table, separator, etc.). Then, since the binarized image data is compressed and stored based on the information, an area constituted by useless white pixels is not compressed, and further, a large capacity for storing all color images. It is possible to obtain various information necessary for filing of the image by one-time image reading without using the page memory of No. 1 and perform image compression to store and manage the read image data.

This makes it possible to read and filing image data at higher speed. In addition, by dividing the processes having different speeds such as multi-value compression and binary compression, there is also an advantage that each process can be operated at the most suitable speed.

[Second Embodiment] In this embodiment, the case where the processing described in the first embodiment is applied to an image processing apparatus having a double buffer structure for a binary page memory and a label memory will be considered.

FIG. 8 is a block diagram showing the arrangement of the image processing apparatus according to this embodiment. In FIG. 8, the same components as those described in the first embodiment and the conventional example are designated by the same reference numerals and the description thereof will be omitted. Here, only the characteristic parts of this embodiment will be described.

In this embodiment, the binary page memory 106 and the label memory 112 described in the first embodiment have a double buffer structure, and the page memory 106 is a binary page memory 701 and a binary page memory 702, and a label memory 11 is used.
0 is used as the label memory 703 and the label memory 704.

FIG. 9 is a time chart showing the operation timing of the internal processing unit according to this embodiment. Since the double buffer itself is a general technique, description thereof will be omitted. However, by adopting the double buffer configuration, as shown in FIG. 9, during the processing of the first page, that is, the rectangular data is read from the label memory, The image original of the second page can be read and color image compression processing and writing to another binary page memory or label memory can be executed while determining what kind of the rectangular area is. .

Therefore, according to the present embodiment, since the binary page memory and the label memory have the double buffer structure, the processes relating to two different image originals can be overlapped and executed. High-speed reading and filing of high-speed image data can be performed as compared with the embodiment.

In the first and second embodiments, the input image data is divided into the multi-valued color image and the binarized black-and-white data for image processing, but the present invention is not limited to this. Absent. For example, regarding the binarized black and white data,
Further, a character recognition process may be added, and the character information obtained by the character recognition process may be stored as text data represented by code data in a storage area different from the black and white storage unit 108.

FIG. 10 is a block diagram showing the arrangement of the image processing apparatus of the first embodiment to which a character recognition processing function is added. In FIG. 10, reference numeral 801 is a character recognition unit that reads binary data in a designated area, performs character recognition processing, and converts the data into code data, and 802 is a text data storage unit that stores character code data.
The text data storage unit 802 is a color code storage unit 103.
It may be configured on the same medium as the black and white code storage unit 109.

Further, in the above-mentioned embodiment, the multivalued color image data of the input image data was not treated specially, but in consideration of the fact that the entire input page can be a binarized image, As shown in the flowchart of FIG. 11, in addition to the processing shown in the flowchart of FIG. 3, the processing of steps S120 to S121 is added, and when it is determined that the entire input page is a binarized image, the compressed multi-valued The apparatus may be configured to delete the color image from the color code storage unit 103. As a result, useless data is prevented from being stored in the color code storage unit 103, and the color code storage unit 103 can be used more efficiently.

Furthermore, the color document input section described in the above embodiment is similar to the conventional example in that the document is read in the main scanning direction by R,
A scanner or the like that reads every 8 bits of G and B was considered, but it goes without saying that the scanning method and the number of effective bits of pixels are not limited to this, and other specifications can be applied.

Furthermore, in the above embodiment, the case of inputting a color image original from a color original input unit such as a scanner was considered, but the present invention is not limited to this. For example, the color original input unit is a monochrome scanner, the color black-and-white conversion unit is omitted, and the color multi-value compression encoding unit and the color code storage unit are configured as units for handling monochrome halftone (multi-valued) images. Is also good. As a result, the apparatus can handle a monochrome halftone (multi-valued) image and a monochrome binary image such as a character or a table exclusively, and can read the image at a high speed and perform filing.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0044]

As described above, according to the present invention, when the multi-valued image data representing the image original is compressed almost at the same time, the data is binarized and a predetermined amount of the binary data is obtained. Value data is thinned out at a predetermined thinning rate to form a reduced binary image, and area information is generated for each area defined by the presence or continuity of black pixels in the reduced binary image. Since the binary data is compressed based on the information of the generated area, for example, when reading and filing an image original in which characters and photographs are mixed, the image is appropriately compressed by reading the original once. Can be filed.

As a result, it is possible to perform high-speed processing from image reading to filing without using a large-capacity storage means for storing the image information of the entire read image original. Furthermore, since it is not necessary to use a large-capacity storage means, it contributes to the reduction of the production cost of the device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a time chart showing image reading and filing processing according to the first embodiment.

FIG. 3 is a flowchart showing image reading and filing processing.

FIG. 4 is a flow chart showing details of rectangular data generation and area discrimination processing relating to image reading and filing processing.

FIG. 5 is a diagram showing an outline of thinning-out reduction processing.

FIG. 6 is a diagram for explaining labeling of black pixels and definition of a rectangular area.

FIG. 7 is a diagram showing a structure of rectangular data.

FIG. 8 is a block diagram showing a configuration of an image processing device according to a second embodiment.

FIG. 9 is a time chart showing image reading and filing processing according to the second embodiment.

FIG. 10 is a block diagram showing a configuration of a device in which a character recognition function is added to the image processing device according to the first embodiment.

FIG. 11 is a flowchart showing another embodiment of image reading and filing processing.

FIG. 12 is a block diagram showing a configuration of an image processing apparatus according to a conventional example.

FIG. 13 is a flowchart showing image reading and filing processing according to a conventional example.

FIG. 14 is a time chart showing image reading and filing processing according to a conventional example.

[Explanation of symbols]

 101 Color Original Input Unit 102 Color Multi-Valued Compression Encoding Unit 103 Color Code Accumulation Unit 104 Color Monochrome Conversion Unit 105 Binarization Processing Unit 106 Binary Page Memory 107 Binary Compression Encoding Unit 108 Monochrome Code Accumulation Unit 109 Reduction / Labeling Part 110 Label memory 111 Compositing part 112 Text rectangular area storage part 113 Operation part 114 CPU 115 ROM 116 RAM

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 1/411

Claims (8)

[Claims] 1. A reading unit for reading an image original, a first compressing unit for compressing multivalued image data representing the image original read by the reading unit, and a multivalued image compressed by the first compressing unit. First storage means for storing data, binarization means for binarizing the multi-valued image data almost simultaneously with compression by the first compression means, and a predetermined amount of binary data from the binarization means. When input, the binary data is decimated at a predetermined decimation rate to form a reduced binary image, and the reduced binary image is formed for each region defined by the presence or continuity of black pixels. With respect to the area discriminating means for generating information of the area and the area defined by the area discriminating means, the binary data binarized by the binarizing means is compressed based on the information of the generated area. Second compression means The image processing apparatus characterized by having a second memory means for storing the binary image data compressed by the second compression means. 2. The area defined by the area discriminating means is a rectangular area surrounding black pixels continuous in a vertical direction, a horizontal direction or an oblique direction, or an isolated black pixel is a black pixel. The image processing apparatus according to claim 1, wherein the image processing apparatus is an enclosing rectangular area. 3. The image processing apparatus according to claim 1, wherein the compression by the first and second compression means is performed in units of one page of the image original. 4. A binary digitized by the binarizing means
It further comprises buffer means for storing the value data for one page of the image original, and area information storage means for storing the information of the area generated by the area determining means for the one page of the image original. The reading of the image original by the means, the compression by the first compression means, the storage of the binary data in the buffer means, and the storage of the information of the area in the area information storage means are performed substantially at the same time. 4. The method according to claim 3,
The image processing device according to item 1. 5. The image processing apparatus according to claim 4, wherein each of the buffer means and the area information storage means has a double buffer configuration composed of two storage media. 6. A character recognizing unit for recognizing a character from binary data binarized by the binarizing unit based on the information of the generated region with respect to the region defined by the region discriminating unit. The image processing apparatus according to claim 1, further comprising: a third storage unit that stores the character information obtained by the character recognition unit. 7. If all the image originals read by the reading means are binarized and defined as the area based on the information of the area generated by the area determining means, The image processing apparatus according to claim 1, further comprising a deleting unit that deletes the compressed multi-valued image data stored in the first storage unit. 8. The image original is a color image original, and the binarizing unit converts multi-valued color image data representing the color image original into black-and-white multi-valued image data and converts the black-and-white multi-valued image data into two. The image processing apparatus according to claim 1, wherein the image processing apparatus performs binarization.