JP2001134026A - Device and method for image processing and storing medium that can be read by computer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reproduced image signal at a desired resolution without deteriorating the precision of character recognition. SOLUTION: This device is provided with an image reading part 1002 where an image of an original 1001 is read and an image recognizing part 4000 where a character in the read image is recognized at a 1st resolution and the recognized character is replaced by a 2nd font with resolution that is lower than the 1st resolution to generate the reproduced image. Furthermore, the reproduced image is generated by replacing the recognized characters with a font that is processed to be modified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called so-called video signal which recognizes a character from an image signal obtained by optically scanning a document, replaces the character with font data to form a reproduced image, and records / reproduces or transmits the reproduced image to an external system. The present invention relates to an image processing apparatus such as a digital copying machine or a facsimile.

[0002]

2. Description of the Related Art The character recognition technology is capable of performing almost real-time processing at a copying speed of a low-speed copying machine due to the recent increase in the speed of CPUs and semiconductors. In recent years, since most of the copied originals are created by a word processor or the like, the recognition accuracy has been improved, and has reached a practical level.

[0003] The applicant of the present invention has also disclosed, for example, Japanese Unexamined Patent Publication No.
If the image is reproduced by converting the character image information of the original into recognized font image information using the technology already disclosed in 876 or the like, image deterioration due to repeated copying in principle is eliminated.

[0004]

However, in recent years, this type of apparatus has a function of converting image information into a predetermined resolution and transmitting the image information to an external system in addition to a simple copying function, and reads an image. A problem occurs if the processing is performed uniformly at the resolution. An object of the present invention is to solve the above problems.

[0005]

An image processing apparatus according to the present invention comprises: reading means for reading an image of a document; recognition means for recognizing characters in an image read by the reading means at a first resolution; Generating means for generating a reproduced image by replacing the character recognized by the means with a font having a second resolution lower than the first resolution.

Further, the image processing apparatus of the present invention has a reading means for reading an image of a document, a recognizing means for recognizing a character in the image read by the reading means, and a modification processing for the character recognized by the recognizing means. And a generating means for generating a reproduced image by replacing the font.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a block diagram showing an embodiment, and each component will be described below together with its operation.

An original 1001 image is read by an image reading unit 1002.
An image is formed on the CCD 102 from the lens 101 of the camera, and A / D converted by the A / D converter 103. The signal after the A / D conversion is input to the image processing unit 103. Image processing unit 100
In 3, the shading correction 104 is performed, and the process proceeds to the mode switching circuit 105.

Here, the output destination is switched based on the recognition copy mode or the normal copy mode in accordance with the setting of the operator by the operation unit 116. In the normal copy mode, the luminance data is converted into recording density data by the light density conversion circuit 106 and output to the image editing unit 107.
In the image editing unit 107, the RAM 1 in the CPU circuit 113
The editing process is performed based on the data processed according to the image processing settings stored in the image processing unit 15. When recording and reproducing, the edited image data is stored in the image recording unit 100.
4 is output. On the other hand, when image information is transmitted to another system via a so-called FAX or LAN network or various types of personal computer IFs, the image transmission unit 119 performs a predetermined process such as compression, coding, and modulation, and outputs it to the outside. I do.

An image recording unit 1004 includes a control circuit such as a motor for transporting transfer paper and the like, a laser control circuit unit for writing a video signal input from the image processing unit 1003 to a photosensitive drum, and a development control circuit for developing. And an image is recorded on a recording medium such as recording paper.

On the other hand, when the recognition copy mode is set,
The output of the mode switching circuit 105 is the image recognition unit 400
It is switched to zero. The image recognizing unit 4000 uses the image buffer memory 118 to recognize characters in the document, and passes the recognized result to the image data converting unit 110, where the character code of the recognition output is converted into an output font image signal. Convert.

The operation unit 112 is connected to the image processing unit 100.
It has various key groups and various LED groups for instructing an image copy operation such as image editing contents, the number of copies, and a magnification ratio for 3 and a display unit for displaying the contents at the time of operation.

FIG. 2 is a sectional view showing the structure of the image copying apparatus in the embodiment.

In FIG. 2, reference numeral 1 denotes a document feeder serving as a document feeder, which feeds the placed documents one by one or two at a predetermined position on the platen glass surface 2 continuously. Reference numeral 3 denotes a scanner constituted by a lamp, a scanning mirror 5, and the like. The scanner 3 is placed on the platen glass surface 2 by the document feeder 1 and gives, for example, a copy instruction or a character recognition instruction from the operation unit 116.
The scanner scans in a predetermined direction (horizontal direction in the drawing), passes the original reflected light through the lens 8 via the scanning mirrors 5 to 7, and forms an image on the image sensor unit 9.

Reference numeral 100 denotes a control unit on which the various circuits shown in FIG. 1 are mounted. An exposure unit 10 receives an image signal from an image signal control unit (not shown) that generates an image signal based on image data from an image editing unit 107 in the control unit 100 and sends a light beam to the photoconductor 11. Irradiate. 12,13
Denotes a developing device for visualizing the electrostatic latent image formed on the photoconductor 11 with a developer (toner) of a predetermined color. Reference numerals 14 and 15 denote transfer paper stacking portions, on which recording media of a fixed size are stacked and stored, and which are fed to a position where a registration roller is provided by driving a feeding roller and are aligned with the image formed on the photoreceptor 11. The sheet is fed again in a timed manner.

Reference numeral 16 denotes a transfer / separation charger, which transfers the toner image developed on the photoconductor 11 to a transfer sheet, and separates the photoconductor 11 from the photoconductor 11 to be fixed by a fixing unit 17 via a transport belt. Reference numeral 18 denotes a paper discharge roller which stacks and discharges the transfer-receiving paper on which image formation has been completed on the tray 20. Reference numeral 19 denotes a directional flapper, which switches the transport direction of the transfer-receiving sheet on which the image formation has been completed between the paper discharge port and the internal transport direction, and prepares for the multiplex / double-side image forming process.

FIG. 3 shows an operation unit 116 used in this embodiment.
FIG.

A power switch 5001 controls power supply to the apparatus main body. A reset key 5002 operates as a key for returning to the standard mode during standby.
Reference numeral 5003 denotes a copy start key. A clear key 5004 is used to clear a numerical value such as the number of copies.

Reference numeral 5005 denotes an ID key.
05 enables copying operation for a specific operator,
For other operators, the copying operation can be prohibited unless an ID is input with the ID key. 5
Reference numeral 006 denotes a stop key, which is used to interrupt or stop copying. Reference numeral 5007 denotes a guide key, which is used when the user wants to know each function. Reference numeral 5008 denotes an up cursor key, which is a key for moving a pointer upward on each function setting screen. 50
Reference numeral 09 denotes a down cursor key, which is used to move a pointer downward on each function setting screen. A right cursor key 5010 is a key for moving the pointer to the right on each function setting screen. A left cursor key 5011 is a key for moving the pointer to the left on each function setting screen. Reference numeral 5012 denotes an OK key, which is depressed on each function setting screen when this is sufficient.

Reference numeral 5013 denotes 50 in each function setting screen.
Press this key to execute what is output to the lower right of the screen 52. A standard size reduction key 5014 is used to reduce the standard size to another standard size. 501
Reference numeral 5 is used to select the same-size copy. A standard enlargement key 5016 is used to enlarge the standard size to another standard size. A cassette selection key 5017 selects a cassette stage to be copied. A copy density adjustment key 5018 reduces the density. An AE key 5019 automatically adjusts the copy density with respect to the density of the original. A copy density adjustment key 5020 increases the density. 5021 is a key for specifying the operation of the sorter. Reference numeral 5022 denotes a preheating key for turning on a preheating mode.
Used for / OFF. 5023 is an interrupt key,
Press this button to interrupt and copy during copying.
Reference numeral 5024 denotes a numeric keypad, which is used to input numerical values.

Reference numeral 5025 denotes a marker processing key for setting trimming, masking, and partial processing (oblique contour processing, halftone processing, shadowing processing, negative / positive processing). 5026
A pattern processing key is used to represent a color in a pattern or to express a color by a density difference.
A color erasing key 5027 is used to erase a specific color. Reference numeral 5028 denotes an image quality key, which is used to set a copy mode related to image quality such as recognition copying according to the present invention. Reference numeral 5029 denotes a halftone processing key, which is used when performing halftone processing. Reference numeral 5030 denotes an image create key, which is used when performing contour processing, shadowing processing, negative / positive inversion, italic, mirror processing, and repeat processing.
Reference numeral 5031 denotes a trimming key used to designate an area and perform trimming. A masking key 5032 is used to designate an area and perform masking. Reference numeral 5033 denotes a partial processing key, which designates an area, and thereafter designates partial processing (oblique contour processing, halftone processing, shadowing processing, negative / positive processing). Reference numeral 5034 denotes a frame erasing key, which is used when erasing a frame in accordance with a mode. The modes are sheet frame erasing (creating a frame for the sheet size), document frame erasing (creating a frame according to the document size. With original size specified), and book frame erasing (frames matching the spread size of the book). Create a blank in the center. Book spread size specified). A binding margin key 5035 is used to create a binding margin at one end of a sheet.

Reference numeral 5036 denotes a movement key for moving an image in a desired area, which is used when moving is desired.
The movement includes parallel movement (up, down, left and right), center movement, corner movement, and designated movement (point designation). 5037
Is a zoom key, which can set a copy magnification from 25% to 400% in increments of 1%. Further, the main scanning and the sub-scanning can be set independently. The magnification of the image is controlled by controlling the moving speed of the scanner 3 in the sub-scanning direction of the document, and the image data read out from the scanner 3 is thinned out or interpolated in the main scanning direction of the document. Do with.

Reference numeral 5038 denotes an automatic scaling key, which automatically enlarges or reduces the size according to the size of the copy sheet. In addition, the main scanning and the sub-scanning can be automatically scaled independently. Reference numeral 5039 denotes an enlargement continuous shooting key, which is used when one original is enlarged to a plurality of copies and copied. Reference numeral 5040 denotes a reduced layout key, which is used when copying a plurality of originals by enlarging / reducing them. Reference numeral 5043 denotes a continuous shooting key which is used to divide a copy area on the glass surface of the original platen into two right and left sides and to perform continuous copying in which two copies are automatically made (page continuous shooting, double-side continuous shooting). Reference numeral 5044 denotes a double-sided key, which is used when two-sided output is desired (single-sided double-sided, page continuous double-sided, double-sided double-sided). Reference numeral 5045 denotes a multiplex key, which is used when multiplexing is desired (multiplexing, page continuous copying multiplexing). 50
Reference numeral 46 denotes a memory key, which is used when a mode using a memory is desired (memory synthesis, area synthesis, watermark synthesis). A projector key 5047 is used when using the projector. Reference numeral 5048 denotes a printer key, which is used when setting for a printer.
Reference numeral 5050 denotes an original mixed key which is used when originals are mixed when copying using the feeder. Reference numeral 5051 denotes a mode memory key, which is used when registering a copy mode set for copy, when calling the registered copy mode. Reference numeral 5052 denotes a liquid crystal display with a touch panel, which displays the state of the apparatus, the number of copies, the copy magnification, and the copy paper size, and displays the mode settings of the recognition copy mode or the normal copy mode and the contents of the set copy mode. .

In the FAX function, by pressing a key 5055, a destination can be set or various transmission modes can be set by a display on the liquid crystal display 5052 with a touch panel and input of a touch panel key. For example, the resolution of the transmission image in G3 is 8 ^* 3.85 lines / mm in the standard mode, 8 ^* 7.7 lines / mm in the fine mode, 16 ^* 15.4 lines / mm in the super fine mode. The image signals binarized at the respective resolutions are compression-encoded and transmitted.

Next, a character recognition unit which is a feature of this embodiment will be described in detail with reference to FIG. For recognition processing, the image signal read at 600 DPI, which is the highest resolution of the present system, and stored in the image buffer memory 118 converts the image into two values by binarizing the image by the character cutout unit 108 in one direction.
Divide into average character meshes containing the characters. FIG.
Is a diagram showing a state projected in one direction. From this histogram, an average line spacing G and an average character height H are obtained, and from this, an average character mesh including one character is set. Good. The size of the character recognized according to the present invention can be specified from the size of each mesh to be divided. On the other hand, the characters in each mesh are normalized, and their characteristic amounts are obtained by the vector analysis unit 109 as unknown character vectors. When an unknown character, for example, a feature amount is input to the recognition control unit 111, a plurality of standard patterns before and after similar are grouped along the tree structure of the dictionary of the control unit to form a next stage. Find the minimum distance between the standard pattern of each group and the unknown character in each stage, perform a downward search while forming a path connecting the groups giving the minimum distance, and obtain the shortest distance character recognition result obtained in the final stage Is output as a recognition character.

FIG. 5 shows the above recognition method using a tree-structured dictionary in the case of an unknown character [king].

Here, one level of i in the tree structure dictionary
The standard pattern vector (feature amount) of the group
v ^i, as if the * u the input vector of the unknown character, vector * v ⁱ and the distance between the vector * u is, the number of dimensions of the vector r,

[0028]

[Outside 1] It is represented by This is the distance that has been determined as described above. In each row, the group with the smallest distance is selected to form a path to the last character [king] shown in FIG.

By the way, when the image included in each mesh is recognized using the dictionary as described above, when the image in the mesh is not a character, for example, a part of a line segment forming a table graphic is used. In this case, the specific character or symbol stored in the dictionary is determined to be the shortest one regardless of the absolute value of the distance. Therefore, for example, when a part of the ruled line is a straight line with the number [1] ruled line, it is converted into the number [ten]. Therefore, the following judgment is made, assuming that the distance to the character obtained in the last stage is V.

When V <K: a character is not in the mesh; otherwise, a character is not in the mesh (K is a constant)

That is, if the distance V is equal to or less than the predetermined value K, the character is determined to be a character. If not, the character is determined to be image information. Therefore, if V <K in the case of FIG.
The image data conversion unit 110 converts the stored font ROM into dot data using a 2-byte code indicating the character [king]. Therefore, V> ==
In the case of K, the image data stored in the image buffer memory is selected, while in the case of V <K, the corresponding font data is selected and sent to the image editing unit.

By performing the above processing on all meshes, the character portion is a recognized character font, and the area other than the character is recorded and displayed as a reproduced image in which both are mixed as image information similar to the conventional copier. Becomes possible.

When an image is reproduced by mixing image information and font data as described above, a higher-quality reproduced image can be obtained by using font data that matches the font of the characters on the document. As a feature of the present invention, recognition of a font will be described with reference to a flowchart shown in FIG.

In FIG. 6, as described above, a feature amount is obtained from the image signal in each mesh divided into meshes S10, and character recognition S11 is performed from the dictionary. As a result, if the shortest distance V is less than a predetermined value K, the recognized character Two bytes of information are stored in the mesh address as a code S13.

Further, in this case, since the recognized image clearly has a high probability of a character, the character feature amount Sj is calculated. This feature amount is a physical amount represented by, for example, the thickness distribution of line segments. The feature amount is to recognize whether it is Mincho, Gothic, or italic, and the like. The process is repeated for the images in all the meshes. When the process is completed in step S16, the font recognition is performed by using the average font feature amount integrated in step S15 and using the font dictionary prepared in advance.
Step 17 is performed.

The font expansion S18 is performed with the determined font. If the distance V is equal to or greater than K, the process branches from S12 to S16, so that the feature amounts of the figures and the like are not added in S15, and therefore, in the font recognition S17, highly accurate recognition can be performed. In the font development S18, it is possible to substitute the font data faithfully to the original document based on the character size obtained at the time of mesh division and the recognized font, but the font is developed in a predetermined font regardless of the font recognition result. Things are also possible. The italic conversion will be described as an example.

When the image creation function is selected by the operation key 5030 described above, the liquid crystal display 505 is displayed.
The screen 2 changes to a screen 420 shown in FIG. 7, and an italic character key 424 is selected from the screen. If italic is selected,
The screen shifts to 430, where the italic angle is set.
Recognized characters are developed with an italic font having an italic angle set by adjusting the increase / decrease keys 431 and 433, and the replacement is completed.

By disposing the developed italic font data so that the center thereof is the center of each mesh, it is possible to convert it to italic without deviating from the original character position in the document.

Conventionally, this italic function has been realized by reading a character as an image and sequentially shifting the image signal by a minute pixel for each line in the arrangement direction of the CCD sensor. At the top and bottom of the image, the top of the character line was not aligned and its use was limited. However, according to the present embodiment, italic processing can be performed only on a complete character portion.

It is also possible to use the trimming key 5031 to perform italic conversion only on characters in a predetermined area.

Next, a description will be given of font development at a specific resolution that is set when a reproduced image signal is transmitted to another system such as a facsimile. In the present invention, in order to recognize characters in a document, even if the resolution required for the final image is low, the recognition process must be performed at a high resolution that allows stable recognition regardless of the resolution. .
Therefore, the conversion to the designated resolution is performed at the time of font development of the recognized character.

If the number of recognized characters in the original is 14 points, when recording and reproducing at a recording density of 600 DPI, each recognized character is developed into a recording dot of about 117 ^* 117 pixels. If the image transmission by is selected, since the recording density is 8 ^* 3.85 lines / mm, in order to record and display with the size equal to 14 points at the destination, each recognition character must be 40 ^* 19 pixel dots. Expand to
Similarly, when transmitting and inputting to another personal computer or the like at a resolution of 300 ^* 300 DIPI, for example, the data is expanded to dots of 58 ^* 58 pixels.

Normal resolution conversion from 600 DPI to a designated resolution is performed so that the so-called image data portions that are not recognized as characters can be recorded and displayed as images of the same size at the transmission destination.

(Another embodiment) The resolution at the time of transmission is low.
If the size of the recognized character is small, the font must be expanded from a normal font to a small number of dots. In that case, the size matches, but the thinning processing makes the character unclear. Therefore, dot development is performed using an abbreviation font according to the recognized character size and resolution. That is, for example,

[0045]

[Table 1] And

The above settings can be changed by the user.

(Alternative Embodiment) The image creation function for italic characters during font development has been described.
Various character modification processes such as shading, negative / positive reversal, contouring, and shadowing can be performed only on recognized characters. In any case, processing is performed for each font when the font is expanded for each character.

Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine, a facsimile, etc.) Device).

Another object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU or MPU) of the system or apparatus. Can also be achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May, of course, include a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU provided in the function expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

[0054]

According to the present invention, a reproduced image signal at a desired resolution can be obtained without lowering the recognition accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a hardware configuration according to an embodiment.

FIG. 2 is a cross-sectional view of the copying apparatus according to the embodiment.

FIG. 3 is an external view of an operation unit in the embodiment.

FIG. 4 is a projection view of a character in the embodiment.

FIG. 5 is a tree diagram illustrating a character recognition process according to the embodiment.

FIG. 6 is a flowchart in the embodiment.

FIG. 7 is a diagram showing an operation screen of an image create function in the embodiment.

[Explanation of symbols]

 1001 Original document 1002 Image reading unit 1003 Image processing unit 1004 Image recording unit 4000 Image recognition unit 113 CPU

Claims (16)

[Claims] A reading unit for reading an image of a document; a recognition unit for recognizing a character in the image read by the reading unit at a first resolution; and a first unit for recognizing the character recognized by the recognition unit. An image processing apparatus, comprising: generating means for generating a reproduced image by replacing a font with a second resolution lower than the resolution. 2. The image processing apparatus according to claim 1, wherein a size of the font generated by the generation unit is substantially equal to a size of a character in the image of the document. 3. The image processing apparatus according to claim 1, wherein an image area other than the character recognized by the recognition unit is converted from the first resolution to the second resolution. 4. The image processing apparatus according to claim 1, further comprising an output unit that outputs the reproduced image generated by the generation unit to an external device. 5. The image processing apparatus according to claim 1, wherein the generation unit selects a different font according to the value of the second resolution. 6. The image processing apparatus according to claim 1, wherein the font replaced by the generation unit includes an abbreviation font. 7. The image processing apparatus according to claim 1, wherein the generation unit selects a different font according to a size of a character in the image recognized by the recognition unit. 8. A reading means for reading an image of a document, a recognizing means for recognizing a character in the image read by the reading means, and a reproduced image obtained by replacing the character recognized by the recognizing means with a font subjected to a modification process. An image processing apparatus, comprising: a generation unit configured to generate an image. 9. The image processing apparatus according to claim 8, further comprising instruction means for instructing replacement with the font subjected to the modification processing. 10. The image processing apparatus according to claim 8, wherein the modification processing is an italic processing. 11. An image processing apparatus according to claim 10, further comprising setting means for setting an oblique angle of said oblique processing. 12. The image processing apparatus according to claim 8, wherein the decoration processing is any one of shading processing, negative / positive inversion processing, contour processing, and shadowing processing. 13. A reproduced image is generated by recognizing a character in an image of a document at a first resolution and replacing the recognized character with a font having a second resolution lower than the first resolution. Image processing method. 14. An image processing method comprising recognizing a character in an image of a document, replacing the recognized character with a font subjected to a modification process, and generating a reproduced image. 15. A computer which performs processing for recognizing a character in an image of a document at a first resolution and replacing the recognized character with a font having a second resolution lower than the first resolution to generate a reproduced image. A computer-readable storage medium storing a program to be executed by a computer. 16. A computer storing a program for causing a computer to execute a process of recognizing a character in an image of a document and generating a reproduced image by replacing the recognized character with a font subjected to a modification process. A readable storage medium.