KR20060027965A - Method of outputting image by determining existence of backside image of scanned document - Google Patents

Abstract

The present invention determines whether there is an image on the back side of the scanned original, and if there is no image on the back side, the image is deleted from memory and the back side of the scanned original is not scanned without scanning the back side of the original. And a method for outputting an image by judging. A method of doing this is a method of outputting an image by determining the presence or absence of a backside image of a scanned original in an image scanning apparatus, and scanning the original to store scanned image data, and using the stored image data to Determining whether an image exists on the back side, and if it is determined that the image does not exist on the back side of the scanned original, deleting the backside data of the stored original. Thus, according to the present invention, while maintaining the scanning method of the prior art, it is determined whether the image exists on the back of the original, and if there is no image on the back of the original, it is deleted from the memory so that the memory can be used efficiently, and the image on the back of the original Is a white image, it is possible to increase the print output speed or the fax transmission speed since the image is not transmitted by the selected functions such as PC transmission, print output, and fax transmission, thereby improving the use efficiency of the device.

Description

Method of outputting image by determining existence of backside image of scanned document}

1 is a block diagram of a general image scanning apparatus.

2 is a flowchart of an image output method according to the prior art.

3 is a flowchart illustrating a method of outputting an image by determining the presence or absence of a backside image of a scanned document according to the present invention.

4 is a flow chart illustrating in more detail the method according to the invention.

<Explanation of symbols for the main parts of the drawings>

1 ... scan control, 2 ... ROM,

3 ... RAM, 110 ... shading memory,

120 ... shading correction control unit, 130 ... shading correction unit.

The present invention relates to a method of outputting an image by determining the presence of a backside image of a scanned original, and in particular, by determining whether there is an image on the backside of the scanned original, and deleting the image from memory when there is no image on the backside. In addition, the present invention relates to a method of outputting an image by determining the presence or absence of a backside image of a scanned original that is not scanned and not scanned.

As is well known to those skilled in the art, an image scanning device such as a scanner is a general means for scanning color or black and white prints, photographs, human-written notes or letters. , Facsimile, character recognizer, digital copier and other essential components.

In recent years, as the demand for office automation equipment such as digital copiers, printers, scanners, and facsimile has increased so as to ride on the evolving office automation, each office automation equipment has a high performance to expand its own functions. In addition, each of the office automation equipment that was used independently is developed in one piece to reduce the economic burden and installation space for the user and at the same time produce and provide a product that performs a complex document output function. Such a device is called 'Multi-Function Peripheral' (MFP). Today, a multifunction device is a typical example of a device employing an image scanning device such as a scanner.

In other words, the multifunction device not only functions as a printer for printing data input from a host computer, but also as a scanner for reading image originals, a copy function for printing and copying scanned and scanned image originals, and an image original through a communication line. It is a device having a compound document output function that performs a function as a facsimile to be transmitted to a remote site. In other words, the multifunction device is a multifunction terminal made by integrating existing terminal devices such as facsimile machines, scanners, printers, and copiers into one, and is generally equipped with a host computer-interface function that is interoperable with a host computer. .

As an example through the all-in-one, a number of products have been released that expand the function through the combination and interworking with the related office automation devices with the scanner as a basic component, the "image" referred to herein Scanning device "will be assumed to be a generic term for such image scanning device based devices, which is generally acceptable to one of ordinary skill in the art, due to the nature of the application of the present invention. would.

The present invention is directly related to a technique for performing shading correction in such an image scanning apparatus, and the shading correction of the image scanning apparatus will be described with reference to the accompanying drawings for the understanding of the present invention. .

In normal image processing, the shading phenomenon is a phenomenon occurring in an image pickup tube such as a videoconductor or a CRT, and refers to a phenomenon in which the brightness varies depending on the screen portion of a television. This is caused by non-uniformity of the target or secondary redistribution from the target to the target, which improves the distorted image quality by providing the adjusting electron lens. On the other hand, recently, the concept limited to the display device has been applied to an image input device such as an image scanning device as an extended concept having the same meaning. Shading correction is performed for image processing that removes such a shading phenomenon and improves distorted picture quality. It is called treatment.

In other words, shading correction corrects that the left and right edges of the screen are darkened or deformed due to the characteristics of the optical system when digitizing general documents, aerial photographs, etc., to generate digital image data for computers. There is a method of correcting the density so that the entire screen has the same brightness by determining the conversion function of the concentration for each divided area, and shading correction is obtained by obtaining the shading data during the dummy scan. And how to do it.

1 is a block diagram illustrating an embodiment of a shading correction apparatus of a general image scanning apparatus.

Referring to FIG. 1, the image sensor unit 20 configured as image sensors for each of the three primary colors firstly reflects the reflected light input through the optical module unit 10 in proportion to the amount of light of each color component of B, G, and R. The analog image signal is acquired by electrically imaging the image sensor of the image sensor. The analog image signal is driven at a predetermined timing according to the sensor driving clock provided from the scanning controller 1, and outputs a constant number of pixels according to the resolution of each image sensor. Occurs. The scanning control unit 1 collects and radiates the light emitted from the lamp 12 controlled by the lamp driver 13 to the original and passes through a constant path in the amount of light reflected in proportion to the original density of the image sensor unit ( 20) to control the input. Accordingly, the input reflected light is converted into a voltage signal proportional to the intensity of the light and output according to the characteristics of the color image sensor which is a semiconductor device.

Thereafter, the analog / digital converter 100 converts the analog image signal of each color component output from the image sensor unit 20 into digital image data of each color component of a predetermined number of bits (m).

The shading memory 110 stores shading data obtained by analog-to-digital conversion of analog image signals of each color component obtained by scanning a shading reference pattern when performing pseudo scanning, at the address of each color component and each pixel position. The shading factor matrix stored in the shading correction controller 120 corresponds to each color component and each pixel position.

The shading memory 110 receives an output (i.e., shading data) from an image sensor of each color component formed by photoelectric conversion of the output of the spectrometer filter for each color component during pseudo scanning, and receives an address corresponding to each color component and each pixel position. Will be saved.

The shading correction control unit 120 reads each shading data stored in the shading memory 110 for each address during the pseudo scan, and calculates a predetermined maximum brightness value M in units of pixels, thereby calculating each color component and each pixel position. The shading factor matrix corresponding to the shading factor matrix is calculated and provided to the shading memory 110, and the shading factor matrix stored in the shading memory 110 when the real scanning is performed is performed by the analog / digital converter. Corresponding to the digital image data output from 100 for each color component and each pixel position, it is output.

Finally, the shading correction unit 130 may determine the digital image data of each color component output from the analog / digital conversion unit 100 and the shading factor matrix output under the control of the shading correction control unit 120 during the actual scan. By multiplying the color components and the respective pixel positions and outputting the shading-corrected digital image data, it is possible to obtain digital image data in which the output deviation between the color components is corrected.

In general, the image scanning apparatus may have a large deviation from system to system due to optical response characteristic differences and optical system assembly tolerances. It is desirable to be able to adjust these deviations mechanically in the assembled state, but in many cases it is technically difficult or impossible to solve this by image processing technique, which is the shading correction process as described above.

Here, the shading factor matrix is the most important factor for determining the characteristics of shading correction, and the white plate and white paper or white roller in which the image sensor unit 20 is installed on its opposite surface. Acquisition is performed through dummy scanning scanning a shading reference pattern. It is apparent that the shading reference pattern used should have the same optical density as the white portion of the original.

The process of acquiring and outputting an original image through shading correction in the image scanning apparatus shown in FIG. 1 is simply and clearly illustrated in FIG. 2.

Referring to FIG. 2, the method for outputting an original image according to the related art includes: starting a function in an image scanning apparatus, for example, starting a scanning function by pressing a fax transmission key or a copy start key (S10); Reading and storing white shading data as a shading data storing step (S20); An original image storing step (S30) of reading and storing the original image; A shading correction step (S40) of correcting pixels of the original image based on the pixel values of the stored shading data; A gamma correction step S50 of correcting each pixel value based on a look up table; Storing the corrected image (S60); And outputting an image to the host computer (PC), sending a fax, printing, or outputting the image (S70).

That is, the conventional image acquisition and output method according to the prior art, through the process of the above steps, to store the image using shading data correction, gamma correction to obtain a clear scanning image by scanning the original, and stored the image Send it to a PC, fax it, or print it out.

However, according to the original image acquisition and output method according to the prior art, it is not determined whether an image exists on the back side of the original. In other words, even if the image on the back side of the document is a white image, the image scanning device performs a function of scanning an image, for example, transferring it to a PC, sending it by fax, or printing it and outputting it, thereby shortening the life of the image scanning device and providing a resource, for example, paper. There was a disadvantage that unnecessary waste of power, time, and the like.

In order to solve the above disadvantages, the present invention is to determine whether there is an image on the back side of the scanned original, and if there is no image on the back side, delete the image from memory and separately remove the back side of the original. The present invention provides a method of outputting an image by determining whether or not an image of the back side of a scanned document is not scanned and output.

According to an aspect of the present invention, there is provided a method of outputting an image by determining whether or not a backside image of a scanned original is scanned by an image scanning device, the method comprising: scanning the original and storing the scanned image data; Determining whether an image exists on the back side of the scanned document by using the stored image data; And if it is determined that there is no image on the back side of the scanned original, deleting the backside data of the stored original, and determining whether there is a backside image of the scanned original, and outputting the image. to provide.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that detailed descriptions of related well-known technologies or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

In the following description, when the member according to the prior art and the member according to the present invention are the same, the same reference numerals used in the prior art are used as they are, and detailed description thereof will be omitted.

3 is a flowchart illustrating a method of outputting an image by determining the presence or absence of a backside image of a scanned document according to the present invention.

Referring to FIG. 3, first, an original is scanned to store scanned image data (step S100), and it is determined whether an image exists on the back side of the scanned original by using the stored image data (step S110). . If it is determined that no image exists on the back side of the scanned original, the stored back side data of the stored original is deleted (step S120).

The method according to the invention may further comprise the step of not separately scanning the back side of the original, if it is determined that no image exists on the back side of the scanned original.

The step S110 may include: (b1) shading correcting and storing image data of the stored original by applying weights to shading data for shading correction; (b2) gamma correcting and storing the shading corrected image data; (b3) removing the gamma-corrected image data from the shading-corrected image data, and determining whether the image data from which the gamma-corrected image data has been removed is a white image. Determining that the image does not exist.

In the step (b1), the weight is set so that the stored image data becomes blacker so that the back image of the stored image data is more visible, wherein the weight is within 10-30% of the saturation value. Can be set.

In the step (b3), the removal of the gamma corrected image data maintains the pixels of the shading corrected image data only when the gamma corrected image data is a white pixel, and the pixels of the remaining shading corrected image data are You can change them all to white pixels so that they are removed.

Now, referring to FIG. 4, a method of outputting an image by determining the presence or absence of a back image of a scanned document according to the present invention will be described in more detail.

It will be apparent to those skilled in the art that the flowchart algorithm of the present invention shown in FIG. 4 is programmed and stored in the control unit 1 (120) and the ROM (2), RAM (3) and the like shown in FIG. That is, the method of the present invention can be preferably implemented by hardware of the image scanning apparatus as shown in FIG.

Referring to Fig. 4, first, the function of the image scanning apparatus is started (step S210). That is, the function is started by pressing a predetermined start key, for example, a key for starting the PC transfer, fax transfer, or copy function. Then, white shading data is generated and read as in the prior art in order to know whether an image exists on the back of the original, and their pixel values are stored in the memory 3 or 110 (Fig. 1) (step S220). ). Then, the scanning control unit 1 stores the image data in the memory while scanning the original (step S230).

After scanning the original in step S230 and storing the image data in the memory, the controller (1) 120 and the shading correction unit 130 apply the weight to the shading data stored in step S220 to scan the image data in step S230 Shading correction (step S240).                     

In step S240, in weighted shading correction, the weight is set within 10-30% of a saturation value, and the weighted shading correction data is preferably the following formula, i.e.

According to "weighted shading correction data = weight * (ADC data-black shading data) / (white shading data-black shading data)".

The shading-corrected image data by applying the weights in step S240 is stored in the memory of the image scanning apparatus under the control of the control unit (1) 120 (step S250), and on the other hand, gamma-corrected and also stored in the memory. (Step S260) (Step S270). The gamma correction may be performed by correcting each pixel based on the lookup table as in the prior art.

It is determined whether the image data gamma corrected and stored in steps S260 and S270 is a white image under the control of the controllers 1 and 120. That is, if the gamma corrected image data is a white image, the controller (1) 120 determines that there is no image on the original surface, that is, the front surface of the original.

Meanwhile, the controller (1) 120 removes and stores the gamma corrected image data from the shading corrected image data stored in the memory through step S250 (step S280) (step S290). Referring to the process of removing the gamma corrected image data from the shading corrected image data, when the gamma corrected image data is a white pixel, the pixel of the corresponding shading corrected image data is maintained, and the gamma corrected If the image data is not a white pixel, the pixel of the corresponding shading-corrected image data is changed to a white pixel and removed.

The image data stored in step S290 becomes image data on the back of the original. It is determined whether the image data on the back of the original stored in step S290 is a white image under the control of the control unit 1 (120) (step S300). That is, if the image data on the back of the document is a white image, the controller (1) 120 determines that there is no image on the back of the document.

If the image data on the back of the original is a white image, the image data on the back of the original stored in the memory is deleted (step S310). In addition, the back surface of the document determined to be no image is not separately scanned. Therefore, the image on the back side of the document is not output (step S320). That is, it does not output images with selected functions such as PC transfer, fax transfer, and copying.

In step S280, the control unit 1 120 and the shading correction unit 130 use the single thresholding image segmentation to perform the background pixel according to the weighted shading in the case where the weight is smaller than the threshold. In this case, the threshold image is obtained by dividing the object pixels behind the original larger than the threshold value, and when the total number of pixels of the threshold image is less than the reference value, it is determined as a white image. The reference value may be set to, for example, 1% compared to a 5% IDC chart.

As described above, it is possible to determine whether there is an image on the back side of the scanned original, and if there is no image on the back side, the image may be deleted from memory and not output without scanning the back side of the original separately.

In addition, it is possible to determine whether an image exists on the back side of the document while maintaining the scanning method of the prior art, and if the image does not exist on the back side of the original, it is deleted from the memory so that the memory can be efficiently used.

On the other hand, if the image on the back of the document is a white image, the image is not sent by the selected functions such as PC transfer, print output, and fax transmission, so that the print output speed or fax transmission speed can be increased, thereby improving the use efficiency of the device. Can be.

In addition, when the image on the back side of the original is a white image, since the back side of the original is not separately scanned, the scanning speed can be increased.

On the other hand, when the image on the back side of the document is a white image, since the image is not scanned and printed out, the life of the image scanning apparatus can be extended, and paper and time can be saved.

Although the preferred embodiments of the present invention have been described in detail above, those of ordinary skill in the art to which the present invention pertains may make various changes without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

Claims (5)

A method of outputting an image by determining the presence or absence of a backside image of an original scanned by an image scanning device, (a) scanning the original to store the scanned image data; (b) determining whether an image exists on the back side of the scanned document using the stored image data; And (c) if it is determined that no image exists on the back side of the scanned original, deleting the back side data of the stored original, and determining whether there is an image on the back side of the scanned original, and outputting the image. Way. The method of claim 1, And if it is determined that no image exists on the back side of the scanned original, further comprising the step of not separately scanning the back side of the original. The method of claim 1, wherein step (b) (b1) shading correcting and storing image data of the stored original by applying weights to shading data for shading correction; (b2) gamma correcting and storing the shading corrected image data; And (b3) removing the gamma-corrected image data from the shading-corrected image data, and determining whether the image data from which the gamma-corrected image data has been removed is a white image. Determining whether an image does not exist, and outputting the image by determining the presence or absence of a back image of the scanned document. The method of claim 3, wherein in step (b1), The weight is set so that the stored image data becomes more black so that the back image of the stored image data is more visible, and the weight is set within 10-30% of the saturation value. A method for outputting an image by judging the presence or absence of an image of the reversed original of the original. The method of claim 1, wherein in step (b3), The removal of the gamma corrected image data maintains the pixels of the shading corrected image data only when the gamma corrected image data is a white pixel, and changes the pixels of the remaining shading corrected image data to white pixels. A method for outputting an image by determining the presence or absence of a backside image of a scanned document, characterized in that to make.

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