JP2007080138A - Image processing system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing system and an image processing method for automatically correcting the scan image of an object whose solid shape is decided by specifications. <P>SOLUTION: This image processing system includes an image acquiring means for acquiring a scan image; a non-volatile storage medium in which correction information corresponding to an already known object having thickness and plane shape decided by specifications is stored; and a correcting means for, when the object of the scan image is the already known object, correcting the distortion of the scan image, based on the correction information, and for correcting the shadow region of the scan image corresponding to any shadow to be generated from the thickness of the already known object, based on the correction information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing system and an image processing method, and more particularly to modification of a scanned image of an object defined by a standard.

2. Description of the Related Art Conventionally, so-called flatbed type multifunction peripherals having an image reading function and a printing function that can copy a label of a standardized disk type storage medium such as a compact disk (CD) and a DVD are known (for example, (See Patent Documents 1 and 2). However, the conventional multifunction peripheral has a problem that the shadow of the disk placed on the document table and illuminated from below the document table appears on the document mat, and the shadow is printed on a label as a printing medium.
In general, a scanner has a problem that a scanning image is distorted by about 1 to 2% because a sampling pitch at the time of reading is slightly different between a main scanning direction and a sub-scanning direction due to manufacturing tolerance, aging deterioration, temperature change, and the like. . Correcting scan image distortion before reading to compensate for aging deterioration, temperature change, etc. may lead to a decrease in reading speed, or it is necessary to equip the scanner with a reference body that is difficult to change over time and temperature, etc. It is difficult to realize. As a result, the conventional multi-function peripheral has a problem that unintended margins are formed on the label obtained by hard copy, and ink protrudes from an area other than the label.

JP 2004-199489 A JP 2003-1873 A

  The present invention was created in view of the above-described problems, and an object thereof is to provide an image processing system and an image processing method capable of automatically correcting a scan image of an object whose solid shape is defined by a standard. To do.

(1) An image processing system for achieving the above object stores image acquisition means for acquiring a scan image, and modification information corresponding to a known object having a thickness and a planar shape defined by a standard. When a non-volatile storage medium and the object of the scanned image are the known object, after correcting the distortion of the scanned image based on the modification information, it corresponds to a shadow generated from the thickness of the known object Modifying means for erasing the shadow area of the scanned image based on the modification information.
When the scan object has a considerable thickness, the shadow of the object is read as an image when the object is illuminated and read by the flatbed image scanner. If the thickness and planar shape of the scan object and the illumination direction at the time of reading are determined in advance, the shadow area of the scan object appearing in the scan image can be corrected. Further, if the planar shape of the scan object is determined in advance, the scan image can be corrected so that the scan object appears without distortion in the scan image. Therefore, by storing in advance correction information corresponding to a known object whose solid shape is defined by the standard in the image processing system, the distortion of the scanned image is corrected based on the correction information, and appears in the scanned image. The shadow area can be corrected. Further, by correcting the distortion of the scanned image before correcting the shadow area, the shadow area can be corrected accurately without being affected by manufacturing tolerances, aging deterioration, temperature changes, and the like.

(2) The known object may be a disk-type storage medium. The modification means may modify the distortion of the scan image by deforming the scan image so that a rectangle circumscribing the region divided by the region division has an aspect ratio determined by the modification information.
By dividing the image into regions, the disk type storage medium and the region including the shadow can be divided from the entire image. The outer shape of the disk-type storage medium defined by the standard is an extremely accurate circle. The shadow of the disk-type storage medium appears in the image as a crescent. The maximum width of the shadow can be accurately defined according to the thickness of the disk type storage medium defined by the standard. Therefore, the rectangular aspect ratio circumscribing the disk-type storage medium and the area including the shadow thereof can be used as an extremely accurate reference value. Therefore, by deforming the scan image so that the rectangle circumscribing the region divided by the region division has a predetermined aspect ratio, the distortion of the scan image can be corrected with high accuracy.

(3) The image processing system further includes pre-image acquisition means for acquiring a low-resolution pre-scan image, and setting means for setting a rectangular secondary scan area using area division of the pre-scan image. Also good. The image acquisition unit may acquire the scan image read from the secondary scan region. The modifying means may modify the distortion of the scanned image by deforming the scanned image to an aspect ratio determined by the modified information.
The image processing system can divide the known object and the area where the shadow appears from the entire pre-scan image by area division. Therefore, if the form of the object is known, the image processing system can set an appropriate rectangular secondary scan area corresponding to the known object of the pre-scan image and the area where the shadow appears. By deforming the scan image read from the secondary scan area set in this way into an aspect ratio determined by the modification information, it is possible to modify the distortion of the scan image with high accuracy.

(4) The modification unit may modify the shadow area by replacing pixels of the scan image outside the area corresponding to the label of the disk type storage medium with white based on the modification information.
If the object is a disc-type storage medium whose format is strictly defined by the standard, hard copy only the label by replacing the pixels of the scanned image with white outside the area corresponding to the label of the disc-type storage medium The scanned image can be modified to an image that can be processed.

(5) The image processing system reads the scan image from the known object that is placed on a transparent document table, covered by a document mat, and illuminated from a direction that makes a specific angle with a perpendicular to the surface of the document table. Means and printing means for printing the modified scanned image. The modification information may correspond to the specific angle.
If the thickness of the scan object and the illumination direction at the time of reading are determined in advance, the correction information corresponding to the illumination direction is stored in the image processing system so that the shadow of the scan object appearing in the scan image can be detected. The area can be modified.

(6) Image processing for achieving the above-described object includes a scan image obtained from a nonvolatile storage medium in which modification information corresponding to a known object having a thickness and a planar shape determined by a standard is stored. When the correction information is acquired and the object of the scan image is the known object, after correcting the distortion of the scan image based on the correction information, it corresponds to the shadow caused by the thickness of the known object Modifying the shadow area of the scanned image based on the modification information.
When the scan object has a considerable thickness, the shadow of the object is read as an image when the object is illuminated and read by the flatbed image scanner. If the thickness and planar shape of the scan object and the illumination direction at the time of reading are determined in advance, the shadow area of the scan object appearing in the scan image can be corrected. Further, if the planar shape of the scan object is determined in advance, the scan image can be corrected so that the scan object appears without distortion in the scan image. Therefore, by acquiring the correction information from the storage medium in which the correction information corresponding to the known object whose three-dimensional shape is defined in the standard is stored in advance, the distortion of the scan image is corrected based on the correction information. The shadow area appearing on the screen can be corrected.

  Each function of the plurality of means provided in the present invention is realized by hardware resources whose functions are specified by the configuration itself, hardware resources whose functions are specified by a program, or a combination thereof. Further, the functions of the plurality of means are not limited to those realized by hardware resources that are physically independent of each other. In addition, the present invention can be specified not only as an apparatus and method invention, but also as a program invention and a recording medium recording the program.

Embodiments of the present invention will be described below based on examples.
FIG. 2 is a perspective view showing an external appearance of the multifunction machine 1 as an embodiment of the image processing system according to the present invention. FIG. 3 is a block diagram showing the multifunction device 1. FIG. 4 is a schematic diagram showing the structure of the scan unit 50 of the multifunction machine 1. The multifunction device 1 has a function of outputting a scan image read from an object to a personal computer (PC) (not shown), a function of printing image data input from the removable memory 24 or the PC, and a scan image read from the object. And a function for printing.

  A scanning unit 50 as a reading unit is housed in the upper case 18 and includes a light source 52, an image sensor 54, an AFE (Analog Front End) unit 56, a sensor driving unit 74, a sensor carriage driving unit 76, and the like. The light source 52 is composed of a fluorescent tube lamp or the like that is long in the main scanning direction. The image sensor 54 driven by the sensor driving unit 74 is a linear image sensor such as a color CCD linear image sensor having RGB light receiving elements of three channels. The image sensor 54 is mounted on a sensor carriage 96 that moves in parallel with the transparent document table 16. The image sensor 54 outputs an electrical signal correlated with the density of the optical image of the object 92 formed on the light receiving surface by the lens 98 and the mirror 100. The sensor carriage drive unit 76 includes a motor, a drive belt, a drive circuit, etc. (not shown). The sensor carriage drive unit 76 reciprocates the sensor carriage 96 along a guide rod (not shown) installed perpendicularly to the longitudinal direction of the main scanning region. The two-dimensional image can be read by the image sensor 54 moving in a direction perpendicular to the scanning line. The AFE unit 56 includes an analog signal processing unit such as amplification and noise removal, an A / D converter, and the like. The scan unit 50 may have the above-described lens reduction type configuration or a close-contact type configuration.

  A printing unit 86 as a printing unit is housed in the lower case 20 and includes a recording head 84, a head driving unit 82, a head carriage driving unit 78, a paper feeding unit 80, and the like for forming an image on a printing medium by an inkjet method. The print unit 86 may be configured to support other printing methods such as a laser method. The recording head 84 is provided on a head carriage (not shown) on which an ink cartridge is mounted, and includes a nozzle, a piezo element, an ink passage, and the like. The head carriage drive unit 78 includes a motor, a drive belt, a drive circuit, and the like (not shown). The head carriage drive unit 78 reciprocates the recording head 84 in the direction perpendicular to the print medium conveyance direction. The paper feeding unit 80 includes a paper transport roller, a motor, a drive circuit, and the like (not shown). The paper feeding unit 80 conveys the paper and the CD tray 28 (see FIG. 2) in a direction perpendicular to the moving direction of the recording head 84 by rotating the paper carrying roller. The print unit 86 is configured to convey the CD tray 28 and form an image on the label surface of the CD positioned on the positioning unit 30 of the CD tray 28.

The external memory controller 70 is connected to the removable memory 24 inserted into the card slot 22 (see FIG. 2). Data stored in the removable memory 24 is read by the external memory controller 70 and transferred to the RAM 60.
The operation unit 68 includes an LCD 34 for displaying a menu and various push buttons 36, 38, and 40 such as a selection key, a determination key, and a cancel key for operating the menu.

  The control unit 58 includes a RAM 60, a ROM 62, a CPU 64, and a digital image processing unit 66. The CPU 64 executes a control program stored in the RAM 60 to function as an image acquisition unit, a modification unit, a pre-image acquisition unit, and a setting unit, and controls each unit of the multifunction machine 1. A ROM 62 as a non-volatile storage medium is a non-volatile memory storing a control program. The RAM 60 is a volatile memory that temporarily stores various data such as control programs and scanned images. The control program may be stored in the ROM 62 via a network from a remote server, or may be stored in the ROM 62 via a computer-readable storage medium such as the removable memory 24. The digital image processing unit 66 constitutes part of a reading unit and a printing unit, and cooperates with the CPU 64 for image processing such as gamma correction, resolution conversion, color balance correction, halftoning, and color space conversion for a scanned image. A dedicated circuit such as a DSP to be executed.

The hardware configuration of the multifunction machine 1 has been described above. Next, a shadow appearing in the scanned image will be described.
As shown in FIG. 4, the light source 52 is provided at a position off the optical path from the surface of the document table 16 to the image sensor 54. The light source 52 illuminates the object 92 from a direction that makes a specific angle with the perpendicular to the surface of the platen 16. For this reason, when the object 92 is thick, a shadow of the object 92 illuminated by the light source 52 is formed on the original mat 90 fixed to the original cover 10, and this shadow appears in the scanned image.

FIG. 5 is a block diagram illustrating a control program of the multifunction machine 1.
The scan control module 102 is a program component that causes the scan unit 50 to function as a reading unit. The scan control module 102 controls the scan unit 50 in response to the reading start request and stores the scanned image in the RAM 60.

  The CD label processing module 104 is a program component that causes the control unit 58 to function as an image acquisition unit, a modification unit, a pre-image acquisition unit, and a setting unit. The CD label processing module 104 specifies the second scan area by using the area division of the low-resolution scan image (pre-scan image) acquired by the first reading. For the region division, a threshold value (for example, 200/255) obtained by subtracting a predetermined margin from the gray level of the pixel corresponding to the original mat 90 is used. As a result of the region division, the region where the CD and its shadow appear is divided from the entire pre-scan image. The CD label processing module 104 recognizes that the object is a CD through feature analysis of the prescan image. In the feature analysis, for example, it is analyzed whether or not the dimension of the second scan region is a dimension having an allowable range corresponding to the standard dimension of the CD.

  The CD label processing module 104 enlarges / reduces the high-resolution scan image (second scan image) acquired by the second reading at different magnifications. At this time, the CD label processing module 104 enlarges / reduces the second scan image at different magnifications based on the correction information, and deforms the second scan image into a rectangle corresponding to the standard size of the CD. The modification information stored in the ROM 62 includes the number of horizontal pixels and the number of vertical pixels of the rectangle after the deformation, and is set according to the CD diameter standard (12 cm) and the shadow width of the CD. The width of the shadow of the CD is determined by the incident angle of the light emitted from the light source 52 to the document table 16 and the CD thickness standard. Specifically, for example, in a model in which the second reading is executed at a resolution of 720 dpi and the shadow width of the CD in the vertical direction is 1 mm, the horizontal direction of the rectangle circumscribing the deformed CD and the area including the shadow The number of pixels is 3402, and the number of vertical pixels is 3430.

  The CD label processing module 104 deletes the end area of the second scan image based on the modification information. The modification information includes information indicating how much width the shadow of the CD appears in contact with which side of the second scan image. The width of the shadow is set by the ratio of the number of pixels or the length of one side of the second scan image.

  The CD label processing module 104 generates a print target image by replacing the pixel value of the second scan image with white within a range defined by the modification information. Specifically, for example, the CPU 64 replaces pixel values outside the area where the label appears with white while counting the pixels in raster order based on the modification information. Note that the print target image may be generated based on the mask and the second scan image shown in FIG. This mask can be stored in the ROM 60 as modification information. In the area corresponding to the square white image and the CD label, the pixel value of the second scan image has priority, and the outside of the area corresponding to the CD label. In this case, the channel information is composed of α channel which is two-dimensional array information indicating that the pixel value of the white image is given priority and frame information for aligning the white image, the α channel and the second scan image.

  The print control module 106 is a program component that causes the print unit 86 to function as printing means. The print control module 106 performs processing for converting the color space of the image to be printed, which is a modified scan image, to a color space such as CMYK, which is the color space of ink, resolution conversion, halftoning, interlace processing, and the like. Data is generated and the print unit 86 is controlled based on the print data.

FIG. 7 is a flowchart showing an image processing method by the multifunction machine 1 that executes the above-described control program by the control unit 58. The process shown in FIG. 7 is started when the multifunction device 1 transitions to the CD copy mode by a predetermined menu operation.
In step S <b> 100, the control unit 58 causes the scan unit 50 to read the entire readable range on the document table 16 at a low resolution, and stores the pre-scan image in the RAM 60. FIG. 1A shows a pre-scan image read with a CD placed on the document table 16. A CD and a shadow of the CD appear in the pre-scan image. The shadow of the CD appears in a crescent shape on the outer periphery of the CD and the inner periphery of the CD. In FIGS. 1 and 6, the area corresponding to the shadow is shown in black and the area corresponding to the label is hatched.

  In step S102, the control unit 58 identifies a region where a CD and a shadow appear by region division of the pre-scan image. When the object is a CD, the shading level of the area where the CD and its shadow appear is considerably lower than the shading level of the area where the original mat 90 appears. For this reason, when the threshold value of the area division is set with reference to the density level of the area where the original mat 90 appears, the area where the CD and its shadow appear is shown in FIG. Can be divided from Further, the control unit 58 sets a rectangular second scan area based on the area. The second scan area may be a rectangular area circumscribing the area where the CD and its shadow appear. For example, an area excluding the area of 3 mm width from the outer periphery of the rectangular area circumscribing the area where the CD and its shadow appear. Is set as the second scan area. As a result, it is possible to exclude from the three sides of the second scan area the area where the transparent portion existing on the outer periphery of the CD appears. It should be noted that the transparent portion present on the outer periphery of the CD may be replaced with a white pixel by a process described later that replaces the area other than the label area of the second scan image with a white pixel. Alternatively, a second scan area may be set in which the maximum width of the shadow of the CD is removed from one side of a rectangle circumscribing the CD and the area where the shadow appears. Further, as a method for setting the second scan area, edge detection may be used in addition to area division using a gray level threshold.

  In step S104, the control unit 58 determines whether the object is a CD or other than a CD based on the dimensions of the second scan region. Specifically, for example, the control unit 58 determines whether the object is a CD depending on whether the size of the second scan region corresponds to 11.7 cm (± 3%) × 11.8 cm (± 3%). It is determined whether it is other than. If the control unit 58 determines that the object is a CD, the process proceeds to step S106. If the control unit 58 determines that the object is not a CD, the control unit 58 proceeds to step S118 and executes error processing.

  In step S106, the control unit 58 causes the scan unit 50 to read the second scan area set in step S102 with high resolution, and stores the second scan image in the RAM 60. FIG. 1B shows a second scan image read with a CD placed on the document table 16. In the second scan image, the CD label and a part of the shadow of the CD appear.

  In step S108, the control unit 58 enlarges / reduces the second scan image based on the modification information, and transforms the second scan image into a preset rectangle (see FIG. 1C). The tolerance allowed in the standard CD dimensions is extremely small, and the irradiation direction of the light source 52 is substantially free from changes with time and temperature. For this reason, the CD label appears by enlarging and reducing the second scan image 113 at different magnifications in the vertical and horizontal directions based on the modification information set at the time of product shipment according to the standard dimension of the CD and the irradiation direction of the light source 52. The area can be corrected to an exact circle. In addition, since it is not necessary to generate the distortion correction information by reading the reference body at the time of reading, a scan image without distortion can be obtained in a short time. In addition, by correcting the distortion of the scanned image before correcting the shadow area, the shadow area can be corrected accurately regardless of manufacturing tolerances, aging deterioration, temperature changes, etc. It is possible to accurately replace the pixels outside the region where is appearing with white.

In step S110, the control unit 58 clips a region having a predetermined width along one side of the second scan image based on the modification information. As a result, a part of the area where the shadow appears from the second scan image and a part of the area where the transparent part of the outer periphery of the CD appears are deleted, as shown in FIG. The image is deformed.
In step S112, the control unit 58 generates a print target image by replacing the pixel values outside the region where the label of the second scan image appears with white.

In step S114, the control unit 58 generates print data by performing color space conversion, resolution conversion, halftoning, interlace processing, and the like on the print target image.
In step S 116, the control unit 58 controls the print unit 86 based on the print data, and prints an image on the CDR label placed on the CD tray 28. As a result, the CD label placed on the document table 16 is hard-copied to the CDR label. The controller 58 may generate print data and control the print unit 86 so that the label image is printed in a range slightly larger than the blank label to be printed. As a printing medium for copying the CD label placed on the document table 16, a plain seal having a peeling area corresponding to the CDR label can be used.

  The embodiment in which the present invention is applied to the multifunction machine 1 has been described above. However, the present invention can also be applied to a system including a PC and a printer and a scanner connected to the PC. The present invention can also be applied to a system including a scanner capable of outputting a scan image to a removable memory and a printer capable of inputting an image from the removable memory. In this case, the external memory controller provided in the printer constitutes a part of the image acquisition means according to the present invention. The present invention is also applicable to a system in which a complete scan image is stored in a memory in a scanner system, a print target image is generated from the scan image, and the print target image is output to a printer that is an external system. can do. The present invention can also be applied to a printer that acquires a scan image from a scanner, generates print data from the acquired scan image, and prints based on the print data.

  In the above-described embodiments, the CD is exemplified as the known object. However, the object may be any known object whose shape and characteristics can be specified by a standard, for example, other optical disks such as PD and DVD. Also good.

The schematic diagram which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. The block diagram which concerns on the Example of this invention. The schematic diagram which concerns on the Example of this invention. The block diagram which concerns on the Example of this invention. The schematic diagram which concerns on the Example of this invention. The flowchart which concerns on the Example of this invention.

Explanation of symbols

1: MFP (image processing system), 16: document table, 50: scan unit (reading unit), 58: control unit (image acquisition unit, modification unit, pre-image acquisition unit, setting unit), 66: digital image processing Part (reading means, printing means), 86: print unit (printing means), 90: original mat, 92: object

Claims (6)

Image acquisition means for acquiring a scanned image;
A non-volatile storage medium storing modification information corresponding to a known object having a thickness and a planar shape defined by a standard;
When the object of the scan image is the known object, a shadow region of the scan image corresponding to a shadow generated from the thickness of the known object after correcting the distortion of the scan image based on the correction information Modifying means based on the modification information;
An image processing system comprising: The known object is a disk-type storage medium,
The retouching unit corrects distortion of the scan image by deforming the scan image so that a rectangle circumscribing a region divided by region division has an aspect ratio determined by the retouching information.
The image processing system according to claim 1. Pre-image acquisition means for acquiring a low-resolution pre-scan image;
Setting means for setting a rectangular secondary scan region using region division of the pre-scan image,
The image acquisition means acquires the scanned image read from the secondary scan area,
The modifying means modifies the distortion of the scanned image by deforming the scanned image to an aspect ratio determined by the modified information.
The image processing system according to claim 2. The retouching unit retouches the shadow region by replacing the pixels of the scan image outside the region corresponding to the label of the disk-type storage medium with white based on the retouching information.
The image processing system according to claim 2. Reading means for reading the scanned image from the known object that is placed on a transparent document table and covered with a document mat and illuminated from a direction that makes a specific angle with a perpendicular to the surface of the document table;
Printing means for printing the modified scanned image,
The modification information corresponds to the specific angle,
The image processing system according to claim 1. Get a scanned image,
Obtaining the modification information from a non-volatile storage medium storing modification information corresponding to a known object having a thickness and a planar shape defined by a standard;
When the object of the scan image is the known object, a shadow region of the scan image corresponding to a shadow generated from the thickness of the known object after correcting the distortion of the scan image based on the correction information Based on the correction information,
An image processing method.

Images