JP5223985B2 - Encoding system and encoding program - Google Patents

Description

  The present invention relates to an encoding system and an encoding program.

  For example, when an image is generated by a computer from document data used in an office, vector data is converted into raster data, text data is converted into image data for printing out, etc. Processing such as converting raster data into pseudo-gradation raster data is performed. Here, these are collectively referred to as drawing. In some cases, it is desired to convert the resolution of the drawn raster data. At this time, inadvertently converting the resolution causes various image quality problems. For example, when raster data of a character image is subjected to resolution conversion, that is, enlarged / reduced, fine lines constituting the character may be blurred, smooth curves may be uneven, or line widths and line intervals may be uneven. If so, the character quality is significantly reduced. A similar phenomenon occurs when the raster data of a graphic image is enlarged / reduced. Furthermore, even when the pseudo-gradation raster data, that is, halftone dot image data is enlarged / reduced, moire occurs and the edges formed by the halftone dots are blurred.

As a technique related to these, for example, in Patent Document 1, a line position corresponding to a character size is set by changing a generation position of a contour pattern in accordance with instructions of thickness information and skeletal line position displacement information. However, a technique that enables high-quality character generation is described.
Further, Patent Document 2 aims to provide a character display device in which a display position is not shifted due to a rounding error, and a rounded display position on a display coordinate space of a display unit such as a CRT or a printer, and a designated display position. A position error calculating means for calculating a position error between the origin data, an origin moving means for moving the origin in the coordinate space of the contour data by an amount corresponding to the error, and a dot pattern based on the contour data after the movement A technique characterized by comprising dot pattern generation means for generation is described.

Japanese Patent Laid-Open No. 01-035483 Japanese Patent Laid-Open No. 05-181451

The present invention has been made in the background of such a background art, and an encoding system and an encoding program capable of performing encoding capable of generating a high-resolution and high-resolution image at the time of decoding. The purpose is to provide.
Here, the high resolution and the low resolution are used when comparing the resolutions of two image data (for example, the finally generated image and the original image). Therefore, depending on the resolution of the images to be compared, for example, even 100 dpi (dot / inch) may be a high resolution, and even 600 dpi may be referred to as a low resolution.

The gist of the present invention for achieving the object lies in the inventions of the following items.
[1] Image extraction means for extracting specific image data from the input image data and extracting the position data;
Image data dictionary registration means for registering the image data cut out by the image cutting means in a dictionary;
Similar image data detection means for detecting an index in the dictionary of image data similar to the image data cut out by the image cutout means from the image data registered in the dictionary;
Encoding means for encoding the image data cut out by the image cutout means with the index detected by the similar image data detection means and the position data extracted by the image cutout means ;
Image data centroid calculating means for calculating the centroid of the image data registered in the dictionary and the image data cut out by the image cutting out means
With
The image data dictionary registration means registers the image data in the dictionary when there is no image data similar to the dictionary by the similar image data detection means,
An encoding system characterized by using similar phases estimated from the centroid calculated by the image data centroid calculating means when detecting similar image data by the similar image data detecting means .

[ 2 ] Image extraction means for extracting specific image data from the input image data and extracting the position data;
Image data dictionary registration means for registering the image data cut out by the image cutting means in a dictionary;
Similar image data detection means for detecting an index in the dictionary of image data similar to the image data cut out by the image cutout means from the image data registered in the dictionary;
Image data centroid calculating means for calculating the centroid of a plurality of image data to be encoded with the same index and estimating the phase when similar image data is generated from the relative position of the centroid;
High-resolution image data generating means for generating image data having a higher resolution than the original resolution from the phase and image data estimated by the image data centroid calculating means,
Low-resolution image data generating means for generating reduced images at different phases from the image data generated by the high-resolution image data generating means;
Dictionary data correction means for correcting the dictionary by registering the reduced image generated by the low resolution image data generation means in the dictionary;
Index replacement means for replacing a plurality of image data to be encoded with the same index with an index of image data reduced by the low-resolution image data generation means;
An encoding system comprising: encoding means for encoding the image data cut out by the image cutout means with an index and position data extracted by the image cutout means.

[ 3 ] The encoding system according to [1] or [2] , wherein the specific image data is character image data.

[ 4 ] To the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An encoding function for encoding the image data cut out by the image cut-out function with the index detected by the similar image data detection function and the position data extracted by the image cut-out function ;
Image data centroid calculation function for calculating the centroid of the image data registered in the dictionary and the image data cut out by the image cut-out function
Realized,
The image data dictionary registration function registers the image data in the dictionary when there is no image data similar to the dictionary by the similar image data detection function,
An encoding program characterized by using similar phases estimated from centroids calculated by the image data centroid calculation function when detecting similar image data by the similar image data detection function .

[ 5 ] To the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An image data centroid calculating function for calculating a centroid of a plurality of image data to be encoded with the same index and estimating a phase when similar image data is generated from a relative position of the centroid;
A high-resolution image data generation function for generating image data having a higher resolution than the original resolution from the phase and image data estimated by the image data centroid calculation function;
A low-resolution image data generation function for generating reduced images at different phases from the image data generated by the high-resolution image data generation function;
A dictionary data correction function for correcting the dictionary by registering the reduced image generated by the low-resolution image data generation function in the dictionary;
An index replacement function for replacing a plurality of image data to be encoded with the same index with an index of image data reduced by the low-resolution image data generation function;
An encoding program that realizes an encoding function that encodes image data cut out by the image cut-out function with an index and position data extracted by the image cut-out function.

  According to the encoding system and the encoding program of the present invention, encoding capable of generating a high-quality and high-resolution image at the time of decoding can be performed as compared with the case where the present configuration is not provided.

It is a figure explaining the method of producing | generating a high resolution image from a low resolution image. It is a figure explaining the outline of the image processing by an image processing system. It is a block diagram which shows the structural example of an image processing system. It is a figure explaining the example of drawing by an image processing system. It is a figure explaining the hardware structural example of an image processing system. It is a flowchart explaining the image processing performed by an image processing system. It is a block diagram which shows the structural example of the image processing system which is 2nd Embodiment. It is a figure explaining the conversion example of the resolution by the image processing system which is 2nd Embodiment. It is a flowchart explaining the image processing performed by the image processing system which is 2nd Embodiment. It is a block diagram which shows the structural example of the image processing system which is 3rd Embodiment. It is a flowchart explaining the image processing performed by the image processing system which is 3rd Embodiment. It is a block diagram which shows the structural example of the image processing system which is 4th Embodiment. It is a flowchart explaining the image processing performed by the image processing system which is 4th Embodiment.

In order to understand the present embodiment, a super resolution technique and an outline of the embodiment will be described.
The super resolution technique is a technique for composing a single image having a resolution larger than the imaging resolution from a plurality of images obtained by slightly shifting the imaging position of a camera or the like.
A method for generating a high-resolution and high-quality image from a low-resolution image will be described with reference to FIG. In general, there are nearest neighbor and linear interpolation methods to generate a high-resolution image from a low-resolution image (also referred to as enlargement). However, when applied to character images, jaggies, blurs, etc. occur. End up.
Image data 101, image data 102, image data 103, and image data 104 in FIG. 1 are image data of image shift phases 1 to 4 acquired from document image data that is an original image. Each is created by shifting the original image in units of 1/2 pixel. For example, the image data 101 is obtained by shifting the original image by 1/2 pixel in the lower left direction, and the image data 102 is shifted by 1/2 pixel in the lower right direction. Using these four pieces of image data, image data 111 having a resolution of four times is generated. The image data 111 having a resolution four times is an image having a resolution four times that of the original image. As a method for generating a high-resolution image from a plurality of low-resolution images, there are various methods such as interpolating with other low-resolution corresponding pixels and arranging in a high-resolution image. In this manner, a high-resolution and high-quality image can be generated from a low-resolution image.

However, when such a technique is used, it is necessary to slightly shift the imaging position by using a plurality of cameras with different imaging directions or by shifting the imaging optical system. For example, when scanning a document with a scanner, it is necessary to slightly change the carriage position of the line sensor and execute a plurality of scans. For this reason, an increase in apparatus cost and a decrease in reading speed due to the execution of a plurality of scans occur.
Further, since the raster data of the document image generated based on the vector data is drawn with a uniform phase, the above technique cannot be used.

This embodiment dares to draw a low-resolution sampling grid when drawing an equivalent image with a different phase, or when generating a low-resolution image from a high-resolution image (also referred to as reduction). Shift every specific image.
The outline of the image processing by the image processing system will be described with reference to FIG.
Raster data is drawn by the graphic / character / halftone drawing module 201 and the image reduction module 202. If an equivalent partial image exists, the phase of the image data to be drawn is shifted. The images whose phases are shifted are arranged in low-resolution images (low-resolution image 206A and low-resolution image 206B).
The low resolution image 206A and the low resolution image 206B are transferred to, for example, another image processing system and received by the image processing system. Encoding may be performed when transferring. Equivalent partial images (similar partial image 208, similar partial image 209, similar partial image 210) are extracted from the received low resolution image 207A and low resolution image 207B, and a high resolution image (high resolution image) is extracted from the plurality of partial images. 211) can be generated.

When there are a plurality of equivalent partial images when drawing a graphic / character / halftone dot, the phase when drawing each is shifted. The target for shifting the phase is the same for each character, word, or page in the case of a character image, the equivalent for each graphic or page, for a graphic image, and the same for halftone dots. For each photo image or page. In the following embodiments, description will be made assuming that each character of the character image is shifted.
Alternatively, when the raster data of the image is reduced, the character / graphic / halftone image data is cut out, and when there are a plurality of similar image data, the phase is shifted when reducing each.
Since the phases of the plurality of graphics / characters / halftone dots included in the image data generated in this way are shifted from each other, it is possible to construct image data with higher resolution using these plurality of image data. Become.
Here, the equivalent image includes at least the same image and includes similar cases, and the range depends on how high the image quality is to be obtained when generating a high-resolution image.

Hereinafter, various preferred embodiments will be described with reference to the drawings.
FIG. 3 is a conceptual module configuration diagram of the image processing system according to the first embodiment.
The module generally refers to a component such as software or hardware that can be logically separated. Therefore, the module in the present embodiment indicates not only a module in a program but also a module in a hardware configuration. Therefore, the present embodiment also serves as an explanation of a program, a system, and a method. In addition, the modules correspond almost one-to-one with the functions. However, in mounting, one module may be composed of one program, or a plurality of modules may be composed of one program. A plurality of programs may be used. The plurality of modules may be executed by one computer, or one module may be executed by a plurality of computers in a distributed or parallel environment. Hereinafter, “connection” includes not only physical connection but also logical connection.
In addition, the system includes a configuration in which a plurality of computers, hardware, devices, and the like are connected via a network or the like, and includes a case where the system is realized by a single device.
Hereinafter, document image data (characters, graphics, images, etc., or a combination thereof) used in the office will be mainly exemplified and described as image data.

The image processing system according to the present embodiment draws raster data from vector data. As shown in FIG. 3, a vector identification module 301, a phase amount calculation module 303, and a vector drawing module 305 are provided.
The vector identification module 301 identifies the input vector data, and gives an instruction to shift the phase to the phase amount calculation module 303 when the same vector data input in the past is input.
The phase amount calculation module 303 calculates a phase amount to be shifted in accordance with an instruction from the vector identification module 301 and outputs the phase amount to the vector drawing module 305.
The vector drawing module 305 draws vector data and generates raster data. Then, at the time of drawing, the origin of the two-dimensional coordinates is moved according to the phase amount from the phase amount calculation module 303. FIG. 4 is used to show an image whose phase is shifted when, for example, a parabolic curve is drawn. FIG. 4A shows vector data drawn without shifting the origin. FIG. 4B shows vector data drawn by shifting the origin to the left by 1/2 pixel. FIG. 4C shows vector data drawn by shifting the origin by 1/2 pixel downward. FIG. 4D shows vector data drawn by shifting the origin to the lower left by 1/2 pixel.
The vector identification module 301 detects that there are a plurality of equivalent vector data from the input vector data, and instructs the phase amount calculation module 303 to perform drawing while shifting the phase when drawing. The phase amount calculation module 303 calculates a phase amount. The vector drawing module 305 draws as shown in FIGS. 4 (A) to 4 (D). An image whose phase is shifted is drawn in the image data.
Thereafter, when a high-resolution image is generated, a high-resolution image can be generated from the four partial images.

  A hardware configuration example of the image processing system according to the embodiment will be described with reference to FIG. Note that this hardware configuration example is common to other embodiments, and thus the description thereof is omitted in the description of the other embodiments. The configuration illustrated in FIG. 5 is an image processing system configured by, for example, a personal computer (PC), and illustrates a hardware configuration example including a data reading unit 417 such as a scanner and a data output unit 418 such as a printer. . This hardware configuration is also applied to other embodiments.

  A CPU (Central Processing Unit) 401 is a computer that describes the execution sequence of each module such as the vector identification module 301, the phase amount calculation module 303, and the vector drawing module 305 described in the above embodiment. It is a control part which performs the process according to a program.

  A ROM (Read Only Memory) 402 stores programs used by the CPU 401, operation parameters, and the like. A RAM (Random Access Memory) 403 stores programs used in the execution of the CPU 401, parameters that change as appropriate during the execution, and the like. These are connected to each other by a host bus 404 including a CPU bus.

  The host bus 404 is connected to an external bus 406 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 405.

  A keyboard 408 and a pointing device 409 such as a mouse are input devices operated by an operator. The display 410 includes a liquid crystal display device or a CRT (Cathode Ray Tube), and displays various types of information as text and image information.

  An HDD (Hard Disk Drive) 411 includes a hard disk, drives the hard disk, and records or reproduces a program executed by the CPU 401 and information. The hard disk stores vector data, raster data, and the like. Further, various computer programs such as various other data processing programs are stored.

  The drive 412 reads data or a program recorded on a mounted removable recording medium 413 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and the data or program is read from the interface 407 and the external bus 406. , And supplied to the RAM 403 connected via the bridge 405 and the host bus 404. The removable recording medium 413 can also be used as a data recording area similar to a hard disk.

  The connection port 414 is a port for connecting the external connection device 415 and has a connection unit such as USB, IEEE1394. The connection port 414 is connected to the CPU 401 and the like via the interface 407, the external bus 406, the bridge 405, the host bus 404, and the like. The communication unit 416 is connected to a network and executes data communication processing with the outside. The data reading unit 417 is a scanner, for example, and executes document reading processing. The data output unit 418 is a printer, for example, and executes document data output processing.

  Note that the hardware configuration of the image processing system shown in FIG. 5 shows one configuration example, and the image processing system of the present embodiment is not limited to the configuration shown in FIG. 5 and will be described in the present embodiment. Any configuration can be used as long as the module can be executed. For example, some modules may be configured by dedicated hardware (for example, ASIC), and some modules may be in an external system and connected via a communication line. A plurality of systems shown in FIG. 5 may be connected to each other via communication lines so as to cooperate with each other. Further, it may be incorporated in a copying machine, a fax machine, a scanner, a printer, a multifunction machine (also called a multi-function copying machine, which has functions of a scanner, a printer, a copying machine, a fax machine, etc.).

Next, the function and operation (operation) will be described.
The operation flow of the image processing system shown in FIG. 3 will be described with reference to FIG.
In step S602, the vector identification module 301 inputs vector data. More specifically, the vector data is input to the image processing system via the HDD 411, the drive 412, the connection port 414, or the communication unit 416.
In step S603, the vector data input in step S602 is compared with the vector data input in the past by the vector identification module 301 to identify whether they are equivalent. If there is (Yes), the process proceeds to step S604, and if not (No), the process proceeds to step S606.
In step S604, the vector identification module 301 instructs the phase amount calculation module 303 to shift the phase.

In step S605, the phase amount calculation module 303 calculates the phase amount to be shifted according to the number of equivalent vector data in the past.
In step S606, the input vector data is drawn according to the phase amount from the phase amount calculation module 303 or when there is no equivalent vector data in step S603.
This process is repeated until there is no more vector data. The generated image data is stored in the HDD 411 or the removable recording medium 413, or output to the external connection device 415 and the communication unit 416.
As a result, the generated image data has a low resolution, but the image data having a high resolution and a high image quality can be generated later.

A second embodiment will be described with reference to FIGS.
First, as a summary, in the second embodiment, a low resolution image is generated from a high resolution image. At that time, the center of gravity of the partial image data is calculated, and a sampling grid for reduction is taken with the center of gravity as the origin. Furthermore, partial images having different phases are generated by moving the origin of the sampling grid in accordance with the phase amount.
When the same partial image data can be obtained due to the high accuracy of the partial image data cut-out, it is not necessary to calculate the center of gravity. In this case, a reduced sampling grid may be taken with reference to the end points of the image data.

FIG. 7 is a conceptual module configuration diagram of the image processing system according to the second embodiment.
The image cutout module 701 cuts out character image data, graphic image data, or halftone dot image data from the input document image data, and extracts the position data. The extracted partial image data is transferred to the similar image data extraction module 703, and the position data is transferred to the arrangement position calculation module 713.
The similar image data extraction module 703 compares the partial image data cut out by the image cut-out module 701 and extracts similar image data.
The shift instruction module 705 gives an instruction to shift the phase to the phase amount calculation module 707 when there is similar image data extracted by the similar image data extraction module 703.
The phase amount calculation module 707 calculates a phase amount to be shifted when rendering the partial image data in accordance with an instruction from the shift instruction module 705. This depends on how many similar images have been used in the past.

The image data centroid calculation module 709 calculates the centroid of the similar image data extracted by the similar image data extraction module 703.
The image data reduction module 711 moves the origin of the reduced sampling grid according to the centroid calculated by the image data centroid calculation module 709 and the phase amount calculated by the phase amount calculation module 707 to extract similar image data. The similar partial image data extracted by the module 703 is reduced.
The arrangement position calculation module 713 calculates the position where the reduced image data is arranged according to the reduction ratio.
The image data arrangement module 715 arranges the image data reduced by the image data reduction module 711 at the position calculated by the arrangement position calculation module 713.

  The image data reduction module 711 in the image processing system without the image data centroid calculation module 709 is a similar partial image extracted by the similar image data extraction module 703 according to the phase amount calculated by the phase amount calculation module 707. Reduce the data. The sampling grid at the time of reduction is based on the end point of similar image data that is a divided image extracted by the similar image data extraction module 703.

Next, the function and operation (operation) will be described.
Processing performed in the second embodiment will be described with reference to FIG. The partial image 801 and the partial image 803 are extracted from the high-resolution document image data to be reduced by the image extraction module 701 and extracted by the similar image data extraction module 703 as similar partial image data. It is.
The centroids of the arrow image 811 and the arrow image 813 are calculated by the image data centroid calculation module 709. The centroid of the arrow image 811 is the intersection of the two centroid lines 821. Similarly, the centroid of the arrow image 813 is the intersection of the two centroid lines 823.

The image data reduction module 711 adjusts the centroids of the arrow image 811 and the arrow image 813 to the sampling grid of the low-resolution image as in the partial image 805 in FIG. That is, the intersection point of the two centroid lines 825 is matched with the sampling grid of the partial image 805.
Then, the partial image 801 (or partial image 803) is reduced, and a partial image 807 (or partial image 809) is generated according to the phase amount shifted from the phase amount calculation module 707. For example, the center of gravity of the arrow image 817 (the intersection of the two center of gravity lines 827) moves according to the phase amount.
Thus, when there are a plurality of similar partial images, by generating reduced images with different phases, when enlarging (generating a high resolution image) from the reduced image (low resolution image), It becomes possible to generate a high-quality image.

The operation flow of the second image processing system shown in FIG. 7 will be described with reference to FIG.
In step S902, the image cutout module 701 inputs document image data. More specifically, the document image data is input to the image processing system via the HDD 411, the drive 412, the connection port 414, or the communication unit 416.
In step S903, the image cutout module 701 classifies character / graphic / halftone dot image data from the input document image data. This uses an existing character / photo separation technique. As a result, the document image data is classified into partial image data of character image data, graphic image data, and halftone dot image data. At that time, the image cutout module 701 calculates the positions of the classified character image data, graphic image data, and halftone dot image data in the original document image data.
In step S904, the arrangement position calculation module 713 calculates the position in the reduced image data of the classified partial image data.

In step S905, the similar image data extraction module 703 extracts similar partial image data. Whether or not they are similar is determined by taking the exclusive OR of the two partial images and judging whether or not they are similar by the number of different pixels, or by performing feature extraction and judging by the distance in the feature space, etc. Is done.
In step S906, it is determined whether a similar image has been extracted in step S905. If there is no similar partial image data, the process proceeds to step S910, and if there is similar partial image data, the process proceeds to step S907.
In step S907, the shift instruction module 705 gives an instruction to shift the phase of the reduced image of the similar partial image data to the phase amount calculation module 707.
In step S908, the phase amount calculation module 707 calculates the phase amount to be shifted according to how many partial image data are similar.
In step S909, the image data center-of-gravity calculation module 709 calculates the center of gravity of each partial image data. The center of gravity may be calculated as the center of the circumscribed rectangle, or the center of gravity may be calculated by weighting black pixels.

In step S910, the image data reduction module 711 reduces the partial image extracted by the similar image data extraction module 703 according to the reduction ratio, and reduces the reduced image according to the calculated center of gravity and the designated phase amount. Moving.
In step S911, the image data arrangement module 715 arranges the reduced partial image data created at the position calculated in step S904, and generates reduced image data.
In step S912, the image data to which the reduced partial image data is pasted is stored in the HDD 411 or the removable recording medium 413, or is output to the external connection device 415 and the communication unit 416.
As a result, the generated image data has a low resolution, but the image data having a high resolution and a high image quality can be generated later.

Hereinafter, the third embodiment and the fourth embodiment relate to an image processing system that performs encoding.
First, the state of the encoding method in the lossy compression method targeted by the third and fourth embodiments will be described.
For example, a character image in a document image, particularly character image data expressed in a binary data format is a compression target. As a method of encoding character image data in binary data format, character image data is cut out and registered in a dictionary, as in JBIG2 Text region, and character image data similar to the character image data is registered as dictionary registered image data. There is a method of encoding with the index and the extracted character position. According to such a method, even if the phase is different for each extracted character image data, it is replaced with a single character image data registered in the dictionary, and as a result, all are changed to the same phase. Therefore, even similar character images having different phases are decoded as uniform partial images having the same phase, and the original image cannot be faithfully restored (reproduced).

A third embodiment will be described with reference to FIGS. 10 and 11.
FIG. 10 is a conceptual module configuration diagram of an image processing system according to the third embodiment.
The image cutout module 1001 cuts out specific image data from the input image data and extracts its position data.
The image data centroid calculation module 1005 calculates the centroid of the image data registered in the image data dictionary and the image data cut out by the image cutout module 1001.
The image data dictionary registration module 1007 registers the image data cut out by the image cut-out module 1001 in the image data dictionary. If there is no image data similar to the dictionary by the similar image data detection module 1003, the image data is registered in the dictionary.

The similar image data detection module 1003 detects an index in the image data dictionary that is similar to the image data cut out by the image cut-out module 1001 from the image data registered in the image data dictionary. Further, when detecting similar image data by the similar image data detection module 1003, it may be used that the phases estimated from the centroid calculated by the image data centroid calculation module 1005 are similar. That is, not only the shape and the like are similar, but also the phase is one of the similar determination elements.
The encoding module 1009 encodes the image data cut out by the image cutout module 1001 with the index detected by the similar image data detection module 1003 and the position data extracted by the image cutout module 1001.

Next, the function and operation (operation) will be described.
The operation flow of the image processing system according to the third embodiment shown in FIG. 10 will be described with reference to FIG.
The processing from step S1102 to step S1104 is the same as step S902 to step S904 in the operation flow (FIG. 9) of the image processing system according to the second embodiment.
The processing in step S1105 is the same as step S909 in the operation flow (FIG. 9) of the image processing system according to the second embodiment.
The processing in step S1106 includes the processing in step S905 in the operation flow (FIG. 9) of the image processing system according to the second embodiment, and whether the phase estimated from the center of gravity calculated in step S1105 is also similar. As an element of judgment.

In step S1107, it is determined whether a similar image is extracted in step S1106. If there is no similar partial image data, the process proceeds to step S1108. If there is similar partial image data, the process proceeds to step S1109.
In step S1108, the image data dictionary registration module 1007 registers the target partial image data in the image data dictionary. At the time of registration, an index is assigned to the new partial image data.
In step S1109, if the image data dictionary registration module 1007 has a similar image (Yes in step S1107), the index of the similar image data in the image data dictionary is output, and there is no similar image. In the case (No in step S1107), an index of new partial image data registered in the image data dictionary is output.

Thereafter, the encoding module 1009 uses the position data from the image cutout module 1001, the index of the similar image from the similar image data detection module 1003, and the image data dictionary, and the portion cut out by the image cutout module 1001. Encode the image data.
In decoding, image data is generated by reproducing and arranging partial image data from the encoded index and position data using the same image data dictionary used in encoding.
By this encoded image processing system, even partial image data having similar shapes and the like are registered in the dictionary as different ones having different centroids. As a result, the code amount increases, but a high-quality image can be generated when decoding.

A fourth embodiment will be described with reference to FIGS.
Unlike the third embodiment, the fourth embodiment differs from the third embodiment in that when the similar image data detection module 1203 determines that the image data is similar once, the similar image data detection module 1203 creates an image data dictionary having a different phase thereafter. By registering with, another index is given.
FIG. 12 is a conceptual module configuration diagram of an image processing system according to the fourth embodiment.

The image cutout module 1201 cuts out specific image data from the input image data and extracts its position data.
The image data dictionary registration module 1205 registers the image data cut out by the image cut-out module 1201 in the dictionary.
The similar image data detection module 1203 detects an index in the image data dictionary that is similar to the image data cut out by the image cut-out module 1201 from the image data registered in the image data dictionary.

The image data center-of-gravity calculation module 1207 calculates the center of gravity of a plurality of image data to be encoded with the same index, and estimates the phase when similar image data is generated from the relative position of the center of gravity. .
The high resolution image data generation module 1209 generates image data having a higher resolution than the original resolution from the phase and partial image data estimated by the image data centroid calculation module 1207, respectively.
The phase designation module 1211 designates a phase amount to be shifted when the similar image data is reduced to the low resolution image data generation module 1213.
The low resolution image data generation module 1213 generates reduced images of the image data generated by the high resolution image data generation module 1209 with different phase amounts.

The dictionary data correction module 1217 corrects the dictionary by registering the reduced image generated by the low resolution image data generation module 1213 in the image data dictionary.
The index replacement module 1215 replaces the plurality of image data to be encoded with the same index with the index of the image data reduced by the low resolution image data generation module 1213.
The encoding module 1219 includes the index detected by the similar image data detection module 1203 and the image cutout module 1201 detected by the similar image data detection module 1203 without being replaced by the index replacement module 1215 or the image data cut out by the image cutout module 1201. Is encoded with the position data extracted by.
Further, the processing by the image data center-of-gravity calculation module 1207, the high-resolution image data generation module 1209, the phase designation module 1211, and the low-resolution image data generation module 1213 is processed intermittently according to, for example, a request for a compression rate or high image quality May be performed.

Next, the function and operation (operation) will be described.
The operation flow of the image processing system according to the fourth embodiment shown in FIG. 12 will be described with reference to FIG.
The processing from step S1302 to step S1304 is the same as step S902 to step S904 in the operation flow (FIG. 9) of the image processing system according to the second embodiment.
In step S1305, the image data dictionary registration module 1205 registers the target partial image data in the image data dictionary. At the time of registration, an index is assigned to the new partial image data.
The processing in step S1306 is the same as step S905 in the operation flow (FIG. 9) of the image processing system according to the second embodiment.

In step S1307, it is determined whether a similar image is extracted in step S1306. If there is no similar partial image data, the process proceeds to step S1313. If similar partial image data exists, the process proceeds to step S1308.
The processing in step S1308 is the same as that in step S909 in the operation flow (FIG. 9) of the image processing system according to the second embodiment.
In step S1309, the image data center-of-gravity calculation module 1207 estimates each phase when similar image data is generated from the relative position of the center of gravity.
In step S1310, the high resolution image data generation module 1209 generates image data having a higher resolution than the original resolution from the phase and partial image data estimated in step S1309.

In step S1311, the low resolution image data generation module 1213 converts the partial image data that has become high resolution in step S1310 to low resolution in accordance with the phase amount specified by the phase specification module 1211.
In step S1312, the dictionary data correction module 1217 registers the reduced image data (low-resolution image data) generated in step S1311 in the image data dictionary. As a result, the partial images once determined to be similar are given different indexes. As a result, similar partial images having different phase amounts are assigned different indexes. As a result, the amount of code increases, but a high-quality image can be generated when decoding.

In step S1313, the encoding module 1219 uses the position data from the image cutout module 1201, the index of the similar image from the index replacement module 1215, and the image data dictionary from the dictionary data correction module 1217 to use the image cutout module. The partial image data cut out at 1201 is encoded.
In decoding, image data is generated by reproducing and arranging partial image data from the encoded index and position data using the same image data dictionary used in encoding.
By this encoded image processing system, even partial image data that is similar, partial image data having a different phase is generated and registered as a different dictionary. As a result, the code amount increases, but a high-quality image can be generated when decoding.

In the above embodiment, document image data is shown as image data, but other image data (for example, drawing data, photo data, etc.) may be used.
Further, it is possible to target only specific partial image data, for example, character image data, as the partial image data.

In addition, about the program demonstrated, it is also possible to store in a recording medium, and it can also be grasped | ascertained as the following invention, for example in that case.
On the computer,
A vector identification function for identifying whether the first vector data and the second vector data are equivalent;
When the vectors are identified to be equivalent by the vector identification function, the phase differs when the second vector data is converted into raster data and the first vector data is converted into raster data. A phase amount calculation function for calculating a phase amount as a phase;
A computer readable recording of an image processing program, which realizes a vector conversion function for converting the second vector data into raster data in accordance with the phase amount calculated by the phase amount calculation function recoding media.

On the computer,
An image cutout function for cutting out character image data, graphic image data, or halftone dot image data from the input image data, and extracting the position data;
A similar image extraction function for comparing the image data cut out by the image cut-out function and extracting similar image data;
A shift instruction function that gives an instruction to shift the phase when there is similar image data extracted by the similar image extraction function;
A phase amount calculation function for calculating a phase amount to be shifted in response to an instruction by the shift instruction function;
An image data reduction function for reducing the similar image data extracted by the similar image extraction function in accordance with the phase amount calculated by the phase amount calculation function;
An arrangement position calculation function for calculating the position where the reduced image data is arranged according to the reduction ratio;
A computer-readable recording medium on which an image processing program is recorded, which realizes an image data arrangement function for arranging the image data reduced by the image data reduction function at a position calculated by the arrangement position calculation function .

On the computer,
An image cutout function for cutting out character image data, graphic image data, or halftone dot image data from the input image data, and extracting the position data;
A similar image extraction function for comparing the image data cut out by the image cut-out function and extracting similar image data;
A shift instruction function that gives an instruction to shift the phase when there is similar image data extracted by the similar image extraction function;
A phase amount calculation function for calculating a phase amount to be shifted in response to an instruction by the shift instruction function;
A centroid calculation function for calculating the centroid of the similar image data extracted by the similar image extraction function;
The origin of the reduced sampling grid is moved according to the centroid calculated by the centroid calculation function and the phase amount calculated by the phase amount calculation function, and the similar image data extracted by the similar image extraction function is Image data reduction function to reduce,
An arrangement position calculation function for calculating the position where the reduced image data is arranged according to the reduction ratio;
A computer-readable recording medium on which an image processing program is recorded, which realizes an image data arrangement function for arranging the image data reduced by the image data reduction function at a position calculated by the arrangement position calculation function .

On the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An encoding function for encoding the image data cut out by the image cut-out function with the index detected by the similar image data detection function and the position data extracted by the image cut-out function is realized. The computer-readable recording medium which recorded the encoding program to perform.

On the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An image data centroid calculating function for calculating a centroid of a plurality of image data to be encoded with the same index and estimating a phase when similar image data is generated from a relative position of the centroid;
A high-resolution image data generation function for generating image data having a higher resolution than the original resolution from the phase and image data estimated by the image data centroid calculation function;
A low-resolution image data generation function for generating reduced images at different phases from the image data generated by the high-resolution image data generation function;
A dictionary data correction function for correcting the dictionary by registering the reduced image generated by the low-resolution image data generation function in the dictionary;
An index replacement function for replacing a plurality of image data to be encoded with the same index with an index of image data reduced by the low-resolution image data generation function;
A computer-readable recording of an encoding program characterized by realizing an encoding function for encoding image data extracted by the image extraction function with an index and position data extracted by the image extraction function Recording medium.

The “computer-readable recording medium on which a program is recorded” refers to a computer-readable recording medium on which a program is recorded, which is used for program installation, execution, program distribution, and the like.
The recording medium is, for example, a digital versatile disc (DVD), which is a standard established by the DVD Forum, such as “DVD-R, DVD-RW, DVD-RAM,” and DVD + RW. Standards such as “DVD + R, DVD + RW, etc.”, compact discs (CDs), read-only memory (CD-ROM), CD recordable (CD-R), CD rewritable (CD-RW), etc. MO), flexible disk (FD), magnetic tape, hard disk, read only memory (ROM), electrically erasable and rewritable read only memory (EEPROM), flash memory, random access memory (RAM), etc. It is.
The program or a part of the program can be recorded on the recording medium and stored or distributed. Also, by communication, for example, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a wired network used for the Internet, an intranet, an extranet, etc., or wireless communication It can be transmitted using a transmission medium such as a network or a combination of these, and can also be carried on a carrier wave.
Furthermore, the above program may be a part of another program, or may be recorded on a recording medium together with a separate program.

The above-described embodiment may be grasped as follows.
[A] vector identifying means for identifying whether or not the first vector data and the second vector data are equivalent;
When the vectors are identified as equivalent by the vector identification means, the phase differs when the second vector data is converted into raster data and the first vector data is converted into raster data. A phase amount calculating means for calculating a phase amount to be a phase;
An image processing system comprising: vector conversion means for converting the second vector data into raster data in accordance with the phase quantity calculated by the phase quantity calculation means.

[B] The vector conversion means converts the vector data into raster data by moving the origin of the two-dimensional coordinates in accordance with the phase amount calculated by the phase amount calculation means [A] The image processing system described in 1.

[C]
A vector identification function for identifying whether the first vector data and the second vector data are equivalent;
When the vectors are identified to be equivalent by the vector identification function, the phase differs when the second vector data is converted into raster data and the first vector data is converted into raster data. A phase amount calculation function for calculating a phase amount as a phase;
An image processing program for realizing a vector conversion function for converting the second vector data into raster data according to the phase amount calculated by the phase amount calculation function.

[D] Image cutout means for cutting out character image data, graphic image data, or halftone dot image data from the input image data, and extracting the position data;
Similar image extraction means for comparing image data cut out by the image cutting means and extracting similar image data;
A shift instruction means for giving an instruction to shift the phase when there is similar image data extracted by the similar image extraction means;
A phase amount calculating means for calculating a phase amount to be shifted in response to an instruction from the shifting instruction means;
Image data reduction means for reducing the similar image data extracted by the similar image extraction means in accordance with the phase quantity calculated by the phase quantity calculation means;
An arrangement position calculating means for calculating a position where the reduced image data is arranged according to a reduction ratio;
An image processing system comprising: image data arrangement means for arranging the image data reduced by the image data reduction means at the position calculated by the arrangement position calculation means.

[E] Image cutout means for cutting out character image data, graphic image data, or halftone dot image data from input image data, and extracting the position data;
Similar image extraction means for comparing image data cut out by the image cutting means and extracting similar image data;
A shift instruction means for giving an instruction to shift the phase when there is similar image data extracted by the similar image extraction means;
A phase amount calculating means for calculating a phase amount to be shifted in response to an instruction from the shifting instruction means;
Centroid calculating means for calculating the centroid of the similar image data extracted by the similar image extracting means;
The origin of the reduced sampling grid is moved according to the center of gravity calculated by the center of gravity calculating means and the phase amount calculated by the phase amount calculating means, and the similar image data extracted by the similar image extracting means is extracted. Image data reducing means for reducing;
An arrangement position calculating means for calculating a position where the reduced image data is arranged according to a reduction ratio;
An image processing system comprising: image data arrangement means for arranging the image data reduced by the image data reduction means at the position calculated by the arrangement position calculation means.

[F]
An image cutout function for cutting out character image data, graphic image data, or halftone dot image data from the input image data, and extracting the position data;
A similar image extraction function for comparing the image data cut out by the image cut-out function and extracting similar image data;
A shift instruction function that gives an instruction to shift the phase when there is similar image data extracted by the similar image extraction function;
A phase amount calculation function for calculating a phase amount to be shifted in response to an instruction by the shift instruction function;
An image data reduction function for reducing the similar image data extracted by the similar image extraction function in accordance with the phase amount calculated by the phase amount calculation function;
An arrangement position calculation function for calculating the position where the reduced image data is arranged according to the reduction ratio;
An image processing program that realizes an image data arrangement function that arranges image data reduced by the image data reduction function at a position calculated by the arrangement position calculation function.

[G]
An image cutout function for cutting out character image data, graphic image data, or halftone dot image data from the input image data, and extracting the position data;
A similar image extraction function for comparing the image data cut out by the image cut-out function and extracting similar image data;
A shift instruction function that gives an instruction to shift the phase when there is similar image data extracted by the similar image extraction function;
A phase amount calculation function for calculating a phase amount to be shifted in response to an instruction by the shift instruction function;
A centroid calculation function for calculating the centroid of the similar image data extracted by the similar image extraction function;
The origin of the reduced sampling grid is moved according to the centroid calculated by the centroid calculation function and the phase amount calculated by the phase amount calculation function, and the similar image data extracted by the similar image extraction function is Image data reduction function to reduce,
An arrangement position calculation function for calculating the position where the reduced image data is arranged according to the reduction ratio;
An image processing program that realizes an image data arrangement function that arranges image data reduced by the image data reduction function at a position calculated by the arrangement position calculation function.

DESCRIPTION OF SYMBOLS 201 ... Graphic / character / halftone drawing module 202 ... Image reduction module 301 ... Vector identification module 303 ... Phase amount calculation module 305 ... Vector drawing module 701 ... Image extraction module 703 ... Similar image data extraction module 705 ... Shift instruction module 707 ... Phase amount calculation module 709 ... Image data centroid calculation module 711 ... Image data reduction module 713 ... Arrangement position calculation module 715 ... Image data arrangement module 1001 ... Image extraction module 1003 ... Similar image data detection module 1005 ... Image data centroid calculation module DESCRIPTION OF SYMBOLS 1007 ... Image data dictionary registration module 1009 ... Coding module 1201 ... Image extraction module 1203 ... Similar image data detection module 1205 ... Image data dictionary Registration module 1207 ... image data centroid calculating module 1209 ... high-resolution image data generation module 1211 ... phase specified module 1213 ... low-resolution image data generation module 1215 ... index substitution module 1217 ... dictionary data modification module 1219 ... encoding module

Claims (5)

Image cutout means for cutting out specific image data from the input image data and extracting the position data;
Image data dictionary registration means for registering the image data cut out by the image cutting means in a dictionary;
Similar image data detection means for detecting an index in the dictionary of image data similar to the image data cut out by the image cutout means from the image data registered in the dictionary;
Encoding means for encoding the image data cut out by the image cutout means with the index detected by the similar image data detection means and the position data extracted by the image cutout means ;
Image data centroid calculating means for calculating the centroid of the image data registered in the dictionary and the image data cut out by the image cutting out means
With
The image data dictionary registration means registers the image data in the dictionary when there is no image data similar to the dictionary by the similar image data detection means,
An encoding system characterized by using similar phases estimated from the centroid calculated by the image data centroid calculating means when detecting similar image data by the similar image data detecting means . Image cutout means for cutting out specific image data from the input image data and extracting the position data;
Image data dictionary registration means for registering the image data cut out by the image cutting means in a dictionary;
Similar image data detection means for detecting an index in the dictionary of image data similar to the image data cut out by the image cutout means from the image data registered in the dictionary;
Image data centroid calculating means for calculating the centroid of a plurality of image data to be encoded with the same index and estimating the phase when similar image data is generated from the relative position of the centroid;
High-resolution image data generating means for generating image data having a higher resolution than the original resolution from the phase and image data estimated by the image data centroid calculating means,
Low-resolution image data generating means for generating reduced images at different phases from the image data generated by the high-resolution image data generating means;
Dictionary data correction means for correcting the dictionary by registering the reduced image generated by the low resolution image data generation means in the dictionary;
Index replacement means for replacing a plurality of image data to be encoded with the same index with an index of image data reduced by the low-resolution image data generation means;
An encoding system comprising: encoding means for encoding the image data cut out by the image cutout means with an index and position data extracted by the image cutout means. Encoding system according to claim 1 or 2, wherein the specific image data is character image data. On the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An encoding function for encoding the image data cut out by the image cut-out function with the index detected by the similar image data detection function and the position data extracted by the image cut-out function ;
Image data centroid calculation function for calculating the centroid of the image data registered in the dictionary and the image data cut out by the image cut-out function
Realized,
The image data dictionary registration function registers the image data in the dictionary when there is no image data similar to the dictionary by the similar image data detection function,
An encoding program characterized by using similar phases estimated from centroids calculated by the image data centroid calculation function when detecting similar image data by the similar image data detection function . On the computer,
An image cutout function for cutting out specific image data from the input image data and extracting the position data;
An image data dictionary registration function for registering the image data cut out by the image cut-out function in a dictionary;
A similar image data detection function for detecting an index in the dictionary of image data similar to the image data cut out by the image cut-out function from the image data registered in the dictionary;
An image data centroid calculating function for calculating a centroid of a plurality of image data to be encoded with the same index and estimating a phase when similar image data is generated from a relative position of the centroid;
A high-resolution image data generation function for generating image data having a higher resolution than the original resolution from the phase and image data estimated by the image data centroid calculation function;
A low-resolution image data generation function for generating reduced images at different phases from the image data generated by the high-resolution image data generation function;
A dictionary data correction function for correcting the dictionary by registering the reduced image generated by the low-resolution image data generation function in the dictionary;
An index replacement function for replacing a plurality of image data to be encoded with the same index with an index of image data reduced by the low-resolution image data generation function;
An encoding program that realizes an encoding function that encodes image data cut out by the image cut-out function with an index and position data extracted by the image cut-out function.

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