This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-205297, filed Sep. 19, 2012, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to an image processing of an image formed of an erasable material.
In an image forming apparatus employing an electrophotographic method, an image maybe printed on a medium such as a sheet or the like using, for example, an erasable toner. In such a case, printed contents are made not visible by heating the erasable toner on the medium with an erasing device, for example, to change the characteristics of the erasable toner. Such a medium is often recycled for printing using the image forming apparatus and erasing using the erasing device. As printing and erasing are repeated, a state of the medium gradually deteriorates and a part of the printed image tends to remain even after erasing. For this reason, it may not be easy to read a printed document and the printed document may be misread by a scanner or the like, when a new image is printed on a medium having an old image that is not erased.
A sheet deterioration mark may be printed during each printing in order to determine a deterioration degree of a medium based on an integrated printing ratio. A use of the sheet deterioration mark enables an estimation of a deterioration of a sheet, but it cannot be used to accurately read a new image printed on a sheet on which an old image that is not erased still remains.
In general, embodiments described in the present disclosure are directed to reduce the influence of noise such as a remaining color material after erasing or the like, and to accurately read a new image when the new image is printed on a recycled medium such as a sheet on which printing has been performed using an erasable color material, or the like.
An image processing device according to one embodiment includes an image processing device includes a scanning unit configured to scan an image formed on a medium and create image data corresponding to the image, an analyzing unit configured to analyze the image data, a determination unit configured to determine whether or not a portion of the scanned image meets a predetermined condition based on the analyzed image data, and an image correction unit configured to correct the image data so that a portion of the scanned image based on which the determination unit determines meets the predetermined condition is removed from the scanned image.
Hereinafter, an image processing device according to embodiments will be described with reference to the drawings.
In
The image processing device 1 is able to perform optimal image processing by determining a degree of a medium deterioration which is caused by repeating printing and erasing processes, and by performing an appropriate image processing.
An original document which is read in the image reading unit 10 is assumed to be a questionnaire sheet D as illustrated in
In addition, it is possible to obtain computerized image data by scanning the questionnaire sheet D, on which answers are marked, using the image reading unit 10. Regarding the scanning, it is possible to only perform the scanning of the answers to the questionnaire without erasing the answers, or to perform the scanning of the image using the image reading unit as well as erasing of the image using an erasing device.
Here, when the questionnaire sheet D illustrated in
For this reason, when an image for a questionnaire is printed using an image forming apparatus on a recycled sheet on which an image after erasing, which is illustrated in
In the image processing unit 20, the check mark images are automatically detected using a technology of an image processing such as a technology of Optical Mark Reader (OMR) or the like. For example, spaces for entering an answer (Yes or No) with respect to each question item in the questionnaire sheet D illustrated in
On the other hand, positions of the check boxes 65 and 66 corresponding to answer spaces for question items which are printed on the questionnaire sheet D1 illustrated in
According to the embodiment, when two images are present in two check boxes 65 and 66, which are printed in the answer spaces with respect to each question item, it can be interpreted that one image is an actual check mark 67 made by the respondent and that the other image is a remaining image after the erasing. In this case, it is possible to determine that an image of a thicker density is an image of the actual check mark 67, and an image of a thinner density is the remaining image after the erasing.
Accordingly, gray-scale processing (for example, 256 gray scale) is performed on the image data read by the image reading unit 10, and the image data after the gray-scale processing is performed is subject to binarization. By appropriately changing a threshold value for the binarization, it is possible to perform an optimal image correction in which image data of a lower gray scale corresponding to a remaining image after the erasing, which is one of the images present in the check boxes 65 and 66, is removed, and only the actual check mark 67 is determined to be present. By this process, it is possible to improve precision in recognizing the actual check mark.
It is needed to optimally perform the image correction such that the precision in recognizing the actual check mark is not affected even when a state of the sheet gets worse. A flow of optimization processing of the image correction using a CPU 30 will be described based on a flowchart in
In
In ACT 2, a start of the image processing is instructed to the image processing unit 20, and then the process proceeds to ACT 3. In ACT 2, it is assumed that the start of image processing in which automatic distinguishing of answers in the answer spaces is performed using the OMR technology is instructed with respect to an image of the filled-out questionnaire sheet which is scanned by the image reading unit 10, and on which printing and answer marking are performed using an erasable color material. As a form of the questionnaire sheet, check boxes in which a check mark is supposed to be checked are arranged with respect to each question item, as illustrated in
Accordingly, when it is determined that both the check boxes are checked as a result of the image processing by the image processing unit 20, there is a possibility of recognizing by mistake that a check box which is actually blank is checked since a state of the sheet is deteriorated. Here, it is assumed that a noise is mixed with image data due to the deteriorated sheet state, and a portion at which the noise exists is determined to be a marked portion by mistake in a process of image processing of OMR.
In ACT 3, the medium state determination unit 40 is informed of the image processing result, and is instructed to determine the medium state, and then the process proceeds to ACT 4. In ACT 3, it is assumed that a result of determination regarding a question of asking about “gender” is informed as both “Man” and “Woman”.
The medium state determination unit 40 recognizes that the determination result in which both the check boxes are checked as an answer for the question about “gender” is invalid as a reasonable answer. Here, it is possible to register an invalid answer pattern with respect to an answer for a specific question item like this case, and it is also possible to make a determination by arranging a dummy check box for the determination, leaving the check box blank, and monitoring a state of the check box. In this manner, it is determined that the state of the sheet as a medium is deteriorated since the answer is invalid.
In ACT 4, the image correction unit 50 is informed of the determination result of the medium state, and is instructed to perform an image correction, and then the process proceeds to ACT 5. In ACT 4, it is assumed that a noise is mixed with the image data since the sheet state is deteriorated. For example, there is a case in which a remaining erasable color material or a remaining resin as a base material of toner, which remain on the sheet, are read as noise of image data when scanning. In such a case, the image data includes a noise by which isolated points are scattered in the image, and there is a case in which, when an isolated point overlaps with the check box, the check box is determined to be “checked” by the image processing unit 20 in ACT 2. By performing an image correction of removing such isolated points, it is possible to obtain a correct determination result of image processing. Here, it is possible to remove the isolated points on the base portion which is not a printing and filling out portion of the image data by applying a low pass filter.
In ACT 5, when the correction is applied to the image data in this manner (Yes in ACT 5), the process returns to ACT 2, and the processes of ACTS 2 to 4 are performed. That is, an evaluation of the medium state determination is repeatedly performed with respect to the determination result. With respect to the correction processing, it is possible to set an optimal filtering value, for example, when image corrections are performed so that a cutoff frequency in the low pass filter in each image correction is changed by a certain value in a certain range.
Such a correction processing of removing the isolated points is executed with respect to the question item 1 in
According to the first embodiment, when a presence of an image is recognized in both the check boxes which are two alternatives in the answer space printed in the questionnaire sheet, it is possible to recognize an actual answer, and to reliably perform the determination in the image processing unit 20 by determining that the degree of deterioration of the medium is high, and performing image processing so that an image with low density is removed.
The original document D illustrated in
Assuming that the image of the identification mark 71 illustrated in
Accordingly, it is possible to remove noise caused by an unerased image which remains on a recycled sheet, and to read only a newly printed image formed on the recycled sheet by using the value of A % to determine a cutoff frequency in the above described low pass filter or a threshold value for the binarization processing.
In addition, the identification mark such as the QR code is described as an example in order to determine a state of a medium, and this invention is not limited to this. Thus, it is also possible to use a mark which is printed in the medium, or a given carved seal.
According to the embodiment, a case in which functions for executing the exemplary embodiment is recorded in the device in advance is described, and this invention is not limited to this. The same functions may be downloaded to the device from a network, or a recording medium in which the same functions are stored may be installed in the device. The recording medium may be of any type, if the recording medium can store a program like a CD-ROM and the device can read the recording medium. In addition, the functions which are obtained by installing or downloading in advance in this manner maybe executed by collaborating with an operating system (OS) or the like in the device.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein maybe made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2012-205297 | Sep 2012 | JP | national |