Patent Application
20130016408
This application claims priority from Korean Patent Application No. 10-2011-0069208, filed on Jul. 13, 2011, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a host apparatus, an image scanning apparatus, image scanning methods thereof, and a computer-readable recording medium, and more particularly, to a host apparatus, an image scanning apparatus, image scanning methods thereof, and a computer-readable recording medium which are configured to remove Moire of a low-resolution scanned image.
2. Description of the Related Art
Image scanning apparatuses are apparatuses which scan original images of texts, pictures, films, or the like and convert scanned images into digital data. At this time, the digital data may be displayed on a monitor of a computer or printed by a printer as an output image. As an example of the image scanning apparatuses, there are scanners, copiers, facsimiles, or multiple function peripherals (MFPs) which multiply implement functions thereof through one apparatus.
When the image scanning apparatuses scan printed texts such as newspapers or magazines with halftoning, a phenomenon on which periodic patterns which are not present in the printed texts are generated in scanned images occurs and is called Moire.
Since the image scanning apparatuses represent images with a binary level of two states according to output presence/absence of a dot differently from imaging apparatuses which represent images with multi levels. The image scanning apparatuses have to convert the images represented with the multi-levels into the image represented with the binary levels. The process of converting the multi-level image into the binary-level image is called the halftoning.
There are various methods of performing the halftoning and one of the methods of performing the halftoning is a screening halftoning. The screening halftoning method is a method of performing binarization by comparing gray values (0 to 255) of each pixel to be binarized with a preset screen.
The Moire pattern is represented by interferences between halftoning screen patterns of the text and sampling pixels of the image scanning apparatus. The Moire pattern occurs when a halftoning screen frequency of the text is larger than ½ of a scanning resolution of the image scanning apparatus. That is, when the halftoning screen frequency of the text is larger than ½ of the scanning resolution of the image scanning apparatus, a periodic pattern which is not present in the text is represented in the scanned image.
In general, halftoning screen frequencies of a newspaper, a magazine, and a commercial print are about 85 lpi, about 133 lpi, and 175 lpi, respectively, but the halftoning screen frequencies thereof are not limited thereto. In recent years, with the development of print technology, a high-resolution halftoning screen tends to be used gradually.
To prevent Moire from occurring when scanning the text printed with halftoning, the text has to be scanned with a resolution two times or more the halftoning screen frequency of the text. To obtain Moire-free image, the text has to be scanned with a high resolution, for example, with 300 dpi or more in a newspaper or a magazine or 600 dpi in a commercial print. When a user selects a low scanning resolution in a scan application, the image scanning apparatus performs a scanning operation with a designated scanning resolution, performs a down-sampling operation with a scanning resolution input by the user, and outputs a low-resolution image to the scan application. When a text with halftoning is scanned, Moire occurs. To prevent Moire from occurring when the text printed with halftoning is scanned, the text printed with halftoning has to be scanned with a resolution two times or more the halftoning screen frequency of the text. However, when the text is scanned with a high scanning resolution of 300 dpi or more or with a scanning resolution of 600 dpi or more, an image size as well as a file size is increased. Therefore, the scanning resolution with about 150 to 200 dpi is generally used.
Thus, when a text having a halftoning screen frequency of 85 to 200 lpi is scanned with a resolution of 300 dpi or less, Moire frequently occurs. A video processing algorithm called Descreen is used to remove Moire from the final scanned image in the related art.
When removing Moire using a Descreen filter, a large capacity of a memory is used to process an image and a scanning time is increased.
In addition, the above-described method is used to remove Moire which has already occurred and thus it is difficult to restore the text in an original state.
One or more exemplary embodiments may overcome the above disadvantages and other disadvantages not described above. However, it is understood that one or more exemplary embodiment are not required to overcome the disadvantages described above, and may not overcome any of the problems described above.
One or more exemplary embodiments are to effectively prevent or remove Moire which can be generated when an image scanning apparatus scans a text with halftoning with a low resolution.
According to an aspect, there is provided a host apparatus. The host apparatus may include: a display unit configured to display a user interface (UI) window for an image scanning apparatus; a control unit configured to elevate and determine an optical scanning resolution of the image scanning apparatus according to Moire-related information when a scanning resolution is input and a Moire removing function is selected, in the UI window, and control the image scanning apparatus to perform a scanning operation according to the determined optical scanning resolution; a communication interface unit configured to receive a scanned image scanned with the optical scanning resolution in the image scanning apparatus; a filtering unit configured to remove a halftoning screen pattern from the received scanned image; and a sampling unit configured to down-sample the filtered scanned image with the input scanning resolution.
The Moire-related information may include the scanning resolution input through the UI window and the control unit may elevate the input scanning resolution and determine the elevated scanning resolution to the optical scanning resolution.
The control unit may elevate the input scanning resolution two times or more and determine the elevated scanning resolution to the optical scanning resolution.
The Moire-related information may include a halftoning frequency of a text input through the UI window and the control unit may elevate a text resolution corresponding to the input halftoning frequency and determine the elevated text resolution to the optical scanning resolution.
The Moire-related information may include a kind of text input through the UI window and the control unit may read information for an optical scanning resolution corresponding to the input kind of text from a data base in which pieces of information for optical scanning resolutions set to be different from each other according to kinds of texts are stored and determine the optical scanning resolution according to the read optical scanning resolution information.
The Moire-related information may include a Moire removal level input through the UI window and the control unit may determine the optical scanning resolution corresponding to the input Moire removal level.
According to another aspect, there is provided an image scanning apparatus. The image scanning apparatus may include: a UI unit configured to allow a Moire removing function for the image scanning apparatus to be selected; a control unit configured to elevate and determine an optical scanning resolution thereof according to Moire-related information when the Moire removing function is selected; a scanning unit configured to perform a scanning operation according to the determined optical scanning resolution; a filtering unit configured to a halftoning screen pattern from a scanned image scanned at the scanning unit; and a sampling unit configured to down-sample the filtered scanned image with a pre-input scanning resolution.
The Moire-related information may include the pre-input scanning resolution and the control unit may elevate the pre-input scanning resolution and determine the elevated scanning resolution to the optical scanning resolution.
The control unit may elevate the pre-input scanning resolution two times or more and determine the elevated scanning resolution to the optical scanning resolution.
The Moire-related information may include a halftoning frequency of a text input through the UI unit and the control unit may elevate a text resolution corresponding to the input halftoning frequency and determine the elevated text resolution to the optical scanning resolution.
The Moire-related information may include a kind of text input through the UI unit and the control unit may read information for an optical scanning resolution corresponding to the input kind of text from a data base in which pieces of information for optical scanning resolutions set to be different from each other according to kinds of texts are stored and determine the optical scanning resolution according to the read optical scanning resolution information.
The Moire-related information may include a Moire removal level input through the UI unit and the control unit may determine the optical scanning resolution corresponding to the input Moire removal level.
According to another aspect, there is provided an image scanning method of a host apparatus. The method may include: displaying a UI window for an image scanning apparatus; when a scanning resolution is input and a Moire removing function is selected, in the UI window, elevating and determining an optical scanning resolution of the image scanning apparatus according to Moire-related information; controlling the image scanning apparatus to perform a scanning operation according to the determined optical scanning resolution; receiving a scanned image scanned with the optical scanning resolution through the scanning operation; performing filtering to remove a halftoning screen pattern from the received scanned image; and down-sampling the filtered scanned image with the input scanning resolution.
The Moire-related information may include the scanning resolution input through the UI window and the elevating and determining may include elevating the input scanning resolution and determining the elevated scanning resolution to the optical scanning resolution.
The elevating and determining may include elevating the input scanning resolution two times or more and determining the elevated scanning resolution to the optical scanning resolution.
The Moire-related information may include a halftoning frequency of a text input through the UI window and the elevating and determining may include elevating a text resolution corresponding to the input halftoning frequency and determining the elevated text resolution to the optical scanning resolution.
The Moire-related information may include a kind of text input through the UI window and the elevating and determining may include reading information for an optical scanning resolution corresponding to the input kind of text from a data base in which pieces of information for optical scanning resolutions set to be different from each other according to kinds of texts are stored and determining the optical scanning resolution corresponding to the read optical scanning resolution information.
The Moire-related information may include a Moire removal level input through the UI window and the elevating and determining may include determining the optical scanning resolution corresponding to the input Moire removal level.
According to another aspect, there is provided an image scanning method of an image scanning apparatus. The method may include: receiving selection of a Moire removing function for the image scanning apparatus; when the Moire removing function is selected, elevating and determining an optical scanning resolution thereof according to Moire-related information; performing a scanning operation according to the determined optical scanning resolution; performing filtering to remove a halftoning screen pattern from a scanned image scanned through the scanning operation; and down-sampling the filtered scanned image with a pre-input scanning resolution.
The Moire-related information may include the pre-input scanning resolution and the elevating and determining may include elevating the pre-input scanning resolution and determining the elevated scanning resolution to the optical scanning resolution.
The elevating and determining may include elevating the pre-input scanning resolution two times or more and determining the elevated scanning resolution to the optical scanning resolution.
The Moire-related information may include a halftoning frequency of a text input to the image scanning apparatus and the elevating and determining may include elevating a text resolution corresponding to the input halftoning frequency and determining the elevated text resolution to the optical scanning resolution.
The Moire-related information may include a kind of text input to the image scanning apparatus and the elevating and determining may include reading information for an optical scanning resolution corresponding to the input kind of text from a data base in which pieces of information for optical scanning resolutions set to be different from each other according to kinds of texts are stored and determining the optical scanning resolution corresponding to the read optical scanning resolution information.
The Moire-related information may include a Moire removal level input to image scanning apparatus and the elevating and determining may include determining the optical scanning resolution corresponding to the input Moire removal level.
According to another aspect, there is provided an image scanning method in a computer-readable recording medium in which a program code for executing an image scanning method of a host apparatus is stored. The method include: displaying a UI window for an image scanning apparatus; when a scanning resolution is input and a Moire removing function is selected, in the UI window, elevating and determining an optical scanning resolution of the image scanning apparatus according to Moire-related information; controlling the image scanning apparatus to perform a scanning operation according to the determined optical scanning resolution; receiving a scanned image scanned with the optical scanning resolution in the image scanning apparatus; performing filtering to remove a halftoning screen pattern from the received scanned image; and down-sampling the filtered scanned image with the input scanning resolution.
As described above, according to the various exemplary embodiments, it is possible to effectively remove scan Moire which can occur when a text printed with halftoning is scanned with a low resolution, using Moire-related information received from the user.
Additional aspects and advantages will be set forth in the detailed description, will be obvious from the detailed description, or may be learned by practicing the exemplary embodiments.
The above and/or other aspects will be more apparent by describing in detail exemplary embodiments, with reference to the accompanying drawings, in which:
Hereinafter, exemplary embodiments will be described in more detail with reference to the accompanying drawings.
In the following description, the same reference numerals are used for the same elements when they are depicted in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the exemplary embodiments. Thus, it is apparent that the exemplary embodiments can be carried out without those specifically defined matters. Also, functions or elements known in the related art are not described in detail since they would obscure the exemplary embodiments with unnecessary detail.
The display unit 201 functions to displaying several operations of the host apparatus 200.
Specifically, the display unit 201 may display a UI window for the image scanning apparatus. The user may use various kinds of functions of the UI window displayed in the display unit 201 using a UI unit which will be described later. Moire-related information may be displayed in the UI window and include a scanning resolution, setting/non-setting of a Moire removing function, a halftoning frequency of a text, a kind of text, and a Moire removal level.
In addition, the display unit 201 may receive an image scanned in the image scanning apparatus and display the scanned image.
Here, the display unit 201 may be implemented with at least one of liquid crystal displays (LCDs), thin film transistor-liquid crystal displays (TFT-LCDs), flexible displays, organic light emitting diodes (OLEDs), and three-dimensional (3D) displays.
The communication interface unit 202 functions to connect the host apparatus 200 with the image scanning apparatus.
Specifically, the communication interface unit 202 may transmit a control signal according to the Moire-related information generated in the control unit 205, which will be described later, to the image scanning apparatus.
In addition, the communication interface unit 202 may receive a scanned image scanned with an optical scanning resolution in the image scanning apparatus from the image scanning apparatus.
The communication interface unit 202 may be formed to connect the host apparatus 200 to the image scanning apparatus. The communication interface unit 202 may connect the host apparatus to the image scanning apparatus in a wireless manner through an Internet network or in a wired manner. Alternatively, the communication interface unit 202 may connect the host apparatus to the image scanning apparatus using a universal serial bus (USB) port.
The filtering unit 203 performs low-pass filtering to remove a halftoning screen pattern from the scanned image received from the image scanning apparatus. Parameters such as a filter size, a filter coefficient, and a sigma of the filtering unit 203 may be applied with different values according to conditions such as the scanning resolution input by the user, a Moire removal level, or a real optical scanning resolution of the image scanning apparatus. The conditions may be stored with optimal values previously defined by experiments.
The filtering unit 203 may be a Gaussian filter. However, the filtering unit 203 is not limited thereto and any low-pass filter may be applied as the filtering unit.
The sampling unit 204 functions to down-sample the filtered scanned image by the filtering unit 203 with the scanning resolution input by the user. The down-sampling method of the sampling unit 204 may be determined by considering an image processing time and a degree of reduction in Moire.
The sampling unit 204 may use bilinear interpolation. However, the down-sampling method of the sampling unit is not limited thereto and any algorithm for down-sampling may be applied as the sampling method.
The control unit 205 controls an overall function of the host apparatus 200. That is, the control unit 205 controls the display unit 201, the communication unit 202, the filtering unit 203, and the sampling unit 204.
Specifically, the control unit 205 controls the display unit 201 to display the UI window for the image scanning apparatus when the user uses the image scanning apparatus.
The control unit 205 may control the overall function of the host apparatus 200 according to the user input input through a UI unit (not shown).
When Moire-related information is input or selected in the UI window, the control unit 205 may elevate and determine the optical scanning resolution of the image scanning resolution according to the Moire-related information. The Moire-related information may include a scanning resolution, setting/non-setting of Moire removing function, a halftoning frequency of a text, a kind of text, and a Moire removal level.
That is, when a scanning resolution (for example, 75 dpi, 100 dpi, 150 dpi, 200 dpi, and the like) is received from the user in the UI window displayed in the display unit 201 and the Moire removing function is selected, the control unit 205 may elevate and determine the optical scanning resolution of the image scanning apparatus.
When the Moire-related information input from the user is the scanning resolution and the Moire removing function selection, the control unit 205 may elevate the input scanning resolution and determine the elevated scanning resolution as the optical scanning resolution of the image scanning resolution.
Specifically, the control unit 205 may elevate the input scanning resolution two times or more and determine the elevated scanning resolution as the optical scanning resolution. The halftoning frequency of a print is typically about 85 lpi in a newspaper, about 133 lpi in a magazine, and about 175 lpi in a commercial print. To prevent Moire from occurring, the magazine or newspaper has to be scanned with a high optical scanning resolution of 300 dpi or more and the commercial print has to be scanned with a high optical scanning resolution of 600 dpi or more. When the user selects a scanning resolution of 150 dpi, Moire occurs in all scanned images for the newspaper, magazine, and commercial print. Therefore, the control unit 205 may determine the optical scanning resolution of the image scanning apparatus to 300 dpi or more, that is, two times or more the input scanning resolution of 150 dpi. At this time, Moire does not occur in the scanned images for the newspaper or the magazine. When the control unit 205 determines the optical scanning resolution to 360 dpi or more, Moire does not also occur in the scanned image for the commercial print.
When the Moire-related information received from the user is the scanning resolution, the Moire removing function selection, and the halftoning frequency of a text, the control unit 205 may elevate a text resolution corresponding to the input halftoning frequency and determine the elevated text resolution to the optical scanning resolution of the image scanning apparatus. The control unit 205 may elevate the text resolution two times or more and determine the elevated text resolution to the optical scanning resolution of the image scanning apparatus.
A user may know general halftoning frequencies of prints, that is, 85 lpi of the newspaper, 133 lpi of the magazine, and 175 lpi of the commercial print. In this case, the user may input the halftoning frequency of a text using the UI window displayed in the display unit 201. In this case, to prevent Moire from occurring, the control unit 205 may determine the optical scanning resolution to 170 dpi in the newspaper, 266 dpi in the magazine, and 360 dpi in the commercial print.
When the halftoning frequency of a text is received from the user, it is possible to calculate more accurate optical scanning resolution to remove Moire as compared with when the optical scanning resolution is determined using the scanning resolution as described above.
When the Moire-related information received from the user is the scanning resolution, the Moire removing function selection, and a kind of text, the control unit 205 may read an optical scanning resolution corresponding to the input kind of text from a data base in which optical scanning resolutions set to be different from each other according to kinds of texts are stored and determine the optical scanning resolution of the image scanning apparatus corresponding to the read optical scanning resolution.
The user inputs whether the kind of text is the magazine, the newspaper, or the commercial print using the UI window displayed in the display unit 201. In this case, a storage unit (not shown) may store the optical scanning resolutions set to be different from each other according to the kinds of texts. That is, the storage unit may store optical scanning resolutions, for example, 170 dpi or more for the newspaper, 266 dpi or more for the magazine, and 360 dpi or more for the commercial print to prevent Moire from occurring and the control unit 205 may read an optical scanning resolution corresponding to the kind of text from the storage unit and determine the optical scanning resolution of the image scanning apparatus corresponding to the read optical scanning resolution.
When the kind of text is received from the user, it is possible to calculate the more accurate optical scanning resolution to remove Moire as compared with when the optical scanning resolution is determined using the scanning resolution as described above.
When the Moire-related information received from the user is the scanning resolution, the Moire removing function selection, and the Moire removal level, the control unit 205 may determine the optical scan resolution corresponding to the input Moire removal level.
Specifically, the user may input the Moire removal level using the UI window displayed in the display unit 201. In this case, optical scanning resolutions corresponding to Moire removal levels are stored in the storage unit (not shown). The control unit 205 may determine the optical scanning resolution of the image scanning apparatus using the optical scanning resolution corresponding to the Moire removal level.
Alternatively, the control unit 205 may determine the lowest optical scanning resolution scannable in the image scanning apparatus among the optical scanning resolutions determined to minimize a scanning time and remove Moire using minimum resources.
Specifically, an example in which the optical scanning resolutions of the image scanning apparatus are 300 dpi and 600 dpi will be described. In this case, when the halftoning frequency is 130 lpi, the control unit 205 may determine the optical scanning resolution not to 600 dpi but to 300 dpi.
When the scanning resolution input from the user is not low, the control unit 205 may determine the optical scanning resolution of the image scanning apparatus to the input scanning resolution according to the scanning resolution. In this case, since the input scanning resolution is high sufficient to remove Moire, Moire does not occur even when the optical scanning resolution of the image scanning apparatus is set to the scanning resolution input from the user. Here, the reference for the low resolution may be set by the user or determined by the pre-stored value. For example, the control unit 205 may determine the scanning resolution of 150 dpi or less to the low resolution.
The control unit 205 may determine the scanning resolution received from the user to the optical scanning resolution of the image scanning apparatus when the Moire removing function is not selected using the UI window displayed in the display unit 201.
In addition, the control unit 205 may control the image scanning apparatus to perform a scanning operation according to the determined optical scanning resolution.
Specifically, the control unit 205 may transmit a control signal, which allows the scanning operation to be performed according to the determined optical scanning resolution, to the image scanning apparatus through the communication interface unit 202.
When a scanned image is received from the image scanning apparatus, the control unit 205 may control the filtering unit 203 to perform low-pass filtering for removing a halftoning screen pattern from the received scanned image.
The control unit 205 may control the sampling unit 204 to down-sample the scanned imaged filtered in the filtering unit 203 with the scanning resolution input from the user.
As described above, according to the various exemplary embodiments, it is possible to effectively remove Moire, which can occur when a text with halftoning is scanned with a low resolution, using the Moire-related information received from the user.
The storage unit 306 stores various programs and data necessary to drive the host apparatus 300 and the image scanning apparatus (400 of
Specifically, the storage unit 306 may store optical scanning resolutions corresponding to kinds of text input from the user.
In addition, the storage unit 306 may store optical scanning resolutions corresponding to Moire removal levels input from the user.
The storage unit 306 may be implemented with an embedded type storage device or an attachable/detachable type storage device.
The UI unit 307 may allow the user to set or select functions supported in the host apparatus 300.
The user may select the Moire-related information in the UI window displayed in the display unit 301 using the UI unit 307.
The UI unit 307 may be implemented with an apparatus in which an input and an output are simultaneously realized such as a touch pad. Alternatively, the UI unit may be implemented by combining an input apparatus such as a mouse or a keyboard and a display apparatus such as a cathode-ray tube (CRT) monitor, a liquid crystal display (LCD) monitor, a light-emitting diode (LED) monitor.
The UI unit 401 allows the user to set or select various functions supported in the image scanning apparatus 400.
The user may select the Moire-related information in the UI window displayed in the display unit (not shown) using the UI unit 401 of the image scanning apparatus. Moire-related information may include an input scanning resolution, selection/non-election (setting/non-setting??) of a Moire removing function, a halftoning frequency of a text, a kind of text, and a Moire removal level.
The UI unit 401 may be implemented with an apparatus in which an input and an output are simultaneously realized such as a touch pad. Alternatively, the UI unit may be implemented by combining an input apparatus such as a mouse or a keyboard and a display apparatus such as a CRT monitor, a LCD monitor, and an LED monitor.
The scanning unit 402 reads out a text. Specifically, the scanning unit 402 includes a lens unit (not shown) which forms light reflected from the text on an image sensor and read out image information of the text from the light formed on an image sensor.
Here, the image sensor of the scanning unit 402 may be implemented with a complementary metal oxide semiconductor (CMOS) image sensor (CIS) or a charge-coupled device (CCD).
The filtering unit 403 performs low-pass filtering to remove a halftoning screen pattern from the scanned image scanned in the scanning unit 402. Parameters such as a filter size, a filter coefficient, and a sigma of the filtering unit 403 may be applied to be different from each other according to conditions such as the scanning resolution and Moire removal level input by the user and a real optical scanning resolution of the image scanning apparatus. Alternatively, the parameters may be stored with optimal values previously defined by experiments.
The filtering unit 403 may include a Gaussian filter. However, the filtering unit 403 is not limited thereto and any low-pass filter may be applied as the filtering unit 403.
The sampling unit 404 down-samples the scanned image filtered in the filtering unit 403 with the scanning resolution input from the user. A down-sampling method of the sampling unit 404 may be determined by considering an image processing time and a degree of reduction in Moire.
The sampling unit 404 may use bilinear interpolation. However, the down-sampling method of the sampling unit 404 is not limited thereto and any algorithm for down-sampling may be applied to the down-sampling method of the sampling unit 404.
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The control unit 405 controls an overall function of the image scanning apparatus 400. That is, the control unit 405 controls the UI unit 401, the scanning unit 402, the filtering unit 403, and the sampling unit 404.
Specifically, the control unit 405 controls the overall function of the image scanning apparatus 400 according to the user input input through the UI unit 401.
That is, the control unit 405 may elevate and determine the optical scanning resolution of the image scanning apparatus according to Moire-related information when the Moire-related information is input or selected in the UI window through the UI unit 401. Here, the Moire-related information may include an input scanning resolution, setting/non-setting of a Moire removing function, a halftoning frequency of a text, a kind of a text, and a Moire removal level.
When the scanning resolution (for example, 75 dpi, 100 dpi, 150 dpi, 200 dpi, and the like) is received through the UI unit 401 and the Moire removing function is selected through the UI unit 401, the control unit 405 may elevate and determine the optical scanning resolution of the image scanning apparatus.
When the Moire-related information received from the user is the Moire remove function selection, the control unit 405 may elevate the input scanning resolution and determine the elevated scanning resolution to the optical scanning resolution of the image scanning apparatus 400.
In addition, the control unit 405 may elevate the input scanning resolution two times or more and determine the elevated scanning resolution to the optical scanning resolution.
When the Moire-related information received from the user is the Moire removing function selection and the halftoning frequency of a text, the control unit 405 may elevate a text resolution corresponding to the input halftoning frequency and determine the elevated text resolution to the optical scanning resolution of the image scanning apparatus. In addition, the control unit 405 may elevate the text resolution two times or more and determine the elevated text resolution to the optical scanning resolution.
When determining the optical scanning resolution using the halftoning frequency received from the user, it is possible to calculate the more accurate optical scanning resolution for removing Moire as compared with when the optical scanning resolution is determined using the scanning resolution as described above.
When the Moire-related information received from the user is the Moire removing function selection and the kind of text, the control unit 405 may read an optical scanning resolution corresponding to the input kind of text from a database in which optical scanning resolutions set to be different from each other according to kinds of texts are stored and determine the optical scanning resolution of the image scanning apparatus corresponding to the read optical scanning resolution.
When determining the optical scanning resolution using the kind of text received from the user, it is possible to calculate the more accurate optical scanning resolution for removing Moire as compared with when the optical scanning resolution is determined using the scanning resolution as described above.
When the Moire-related information received from the user is the Moire removing function selection and the Moire removal level, the control unit 405 may determine the optical scanning resolution corresponding to the input Moire removal level.
The user may input the Moire removal level through the UI unit 401 of the image scanning apparatus 400. In this case, the storage unit (not shown) may store optical scanning resolutions corresponding to Moire removal levels. The control unit 405 may determine the optical scanning resolution of the image scanning apparatus using the optical scanning resolutions corresponding to the Moire removal levels.
In addition, to minimize a scanning time and remove Moire with a minimum resource, the control unit 405 may determine the lowest optical scanning resolution scannable in the image scanning apparatus among the determined optical scanning resolutions.
When the input scanning resolution is not low, the control unit 405 may determine the input scanning resolution to the optical scanning resolution of the image scanning apparatus. In this case, since the input scanning resolution is high sufficient to remove Moire, Moire may not occur even when the scanning resolution input from the user is determined as the optical scanning resolution of the image scanning apparatus 400. Here, the reference for the low resolution may be determined by setting of the user or by the pre-stored value. For example, the control unit 405 may determine the scanning resolution of 150 dpi or less to a low resolution.
The control unit 405 may determine the input scanning resolution to the optical scanning resolution of the image scanning apparatus when the Moire removing function is not selected through the UI unit 401.
The control unit 405 may control the scanning unit 402 to perform a scanning operation based on the determined optical canning resolution.
In addition, the control unit 405 may control the filtering unit 403 to perform low-pass filtering for removing a halftoning screen pattern from the scanned image scanned in the scanning unit 402.
The control unit 405 may control the sampling unit 404 to down-sample the scanned image filtered in the filtering unit 403 with the scanning resolution input through the UI unit 401.
The control unit 405 may control the communication interface unit (not shown) to transmit the down-sampled scanned image to the host apparatus.
As described above, according to the various exemplary embodiments, it is possible to effectively remove Moire which can occur when a text with halftoning is scanned with a low resolution.
The storage unit 506 stores various programs and data necessary to drive the image scanning apparatus 500.
Specifically, the storage unit 506 may store optical scanning resolutions corresponding to kinds of texts input from the user.
In addition, the storage unit 506 may store optical scanning resolutions corresponding to Moire removal levels input from the user.
Here, the storage unit 506 may implemented with a storage device embedded therein such as a hard disc drive (HDD) or an attachable/detachable storage device such as a USB memory.
The display unit 507 may display a UI window for the image scanning apparatus 500. The user may use various functions of the UI window displayed in the display unit 507 using the UI unit 501.
In addition, the display unit 507 may display an image scanned in the image scanning apparatus 500.
Here, the display unit 507 may be implemented with any one of liquid crystal displays (LCDs), thin film transistor-liquid crystal displays (TFT-LCDs), organic light-emitting diodes (OLEDs), flexible displays, and three-dimensional (3D) displays.
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The image scanning methods of a host apparatus according to the above-described various exemplary embodiments may be implemented by a program code which is stored in various kinds of recording media and executed by a central processing unit (CPU) or the like.
Specifically, the code for executing the above-described methods may be stored in various kinds of terminal-readable recording media such as random access memories (ROMs), flash memories, read only memories (ROMs), erasable programmable ROMs (EPROMs), electronically erasable and programmable ROMs (EEPROMs), registers, hard discs, removable discs, memory cards, universal serial bus (USB) memories, and compact disc-ROMs (CD-ROMs).
The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present inventive concept. The exemplary embodiments can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2011-0069208 | Jul 2011 | KR | national |
