JP2018082409A - Image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing device that restores fading handwriting written with an erasable pen at high speed on an original image without character recognition.SOLUTION: In an image processing device 16, an original image acquisition unit 21 obtains an original image. An image editing unit 22 performs the following in a specific operation mode: (a) detecting density distribution of the original image and identifying background density and pen density on the basis of the density distribution, (b) identifying a detection density range of fading handwriting written with an erasable pen corresponding to the background density and the pen density, and (c) detecting pixels having density belonging to the identified detection density range and changing density of the detected pixels to pen density.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image processing apparatus.

  A certain image processing apparatus extracts characters in a document image using character recognition technology, and repairs the blurring of characters in the document image by connecting the end points of the character lines in the extracted characters (for example, patents). Reference 1).

JP-A-6-52356

  In recent years, “erasable pens” such as so-called “erasable ballpoint pens” that can erase handwriting by frictional heat are becoming popular. The handwriting of “erasable pen” is colorless by heat (ie, high temperature), so when portable devices such as coffee cups, smartphones, notebook PCs, etc., with relatively high temperatures are placed on the original, "May be lighter. Further, when the “erasable pen” handwriting on one side of the document is erased, the “erasable pen” handwriting on the other side may become thin.

  As described above, when the handwriting of the “erasable pen” in the original document becomes thin, it is necessary to perform character recognition if the image processing apparatus described above is to be repaired, which takes time.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain an image processing apparatus that can quickly restore a thinly-erasable pen handwriting in a document image without performing character recognition.

  An image processing apparatus according to the present invention includes: a document image acquiring unit that acquires a document image; and a specific operation mode; (a) detecting a density distribution in the document image, and based on the density distribution, Specify the pen density, (b) specify the detected density range of the erased pen corresponding to the background density and the pen density, and (c) the pixel having the density belonging to the specified detected density range And an image editing unit that changes the detected density of the pixel to the pen density.

  According to the present invention, it is possible to obtain an image processing apparatus that can quickly restore a erasable pen handwriting that has become thin in a document image without performing character recognition.

  These and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus having an image processing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a document described with an erasable pen. FIG. 3 is a view showing the original shown in FIG. 2 in a state where a part of the handwriting of the erasable pen is thinned. FIG. 4 is a flowchart for explaining the operation of the image processing apparatus 16 in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an image forming apparatus having an image processing apparatus according to an embodiment of the present invention. The image forming apparatus 1 shown in FIG. 1 is a multifunction machine, but may be a copying machine, a scanner, or the like.

  The image forming apparatus 1 includes a printing device 11, an image reading device 12, a communication device 13, a peripheral device interface 14, a storage device 15, and an image processing device 16.

  The printing apparatus 11 is an example of an output device, and an original image is electronically generated using toners of CMYK (cyan, magenta, yellow, and black) colors based on image data after various types of image processing by the image processing apparatus 13. An internal device that prints in a photographic process.

  The image reading device 12 is an internal device that optically reads a document image from a document and generates image data of the document image as RGB data.

  Further, the communication device 13 performs data communication with the terminal device 2, a cloud server (not shown), and the like via a network. As the communication device 13, for example, a network interface or the like is used.

  The peripheral device interface 14 is an interface circuit to which a flash drive such as a USB (Universal Serial Bus) memory or a memory card can be connected. For example, a USB interface is used as the peripheral device interface 14.

  The storage device 15 is a rewritable nonvolatile storage device such as a flash memory, and stores various data and programs.

  The image processing device 16 performs image processing on the image data generated by the image reading device 12 or the like. The image processing device 16 is realized by an ASIC (Application Specific Integrated Circuit) or a computer, and operates as a document image acquisition unit 21, an image editing unit 22, and an output processing unit 23.

  For example, the document image acquisition unit 21 controls the image reading device 12 to read a document image from a document and acquire a document image.

  The image editing unit 22 detects (a) the density distribution (that is, the density of each pixel) in the acquired original image in a specific operation mode (herein, the erasable pen correction mode), and uses the density distribution as the density distribution. Based on this, the background density and the pen density are specified, (b) the detected density range of the erased pen corresponding to the specified background density and the pen density is specified, and (c) the original image is specified. A pixel having a density belonging to the detected density range is detected, and the density of the detected pixel is changed to a pen density.

  FIG. 2 is a diagram illustrating an example of a document described with an erasable pen. FIG. 3 is a view showing the original shown in FIG. 2 in a state where a part of the handwriting of the erasable pen is thinned.

  For example, the user confirms a document to be subjected to a job such as copying or scan-to-send, and when the erasable pen handwriting is not thin as shown in FIG. When the image forming apparatus 1 is selected to select the mode in which the processing of the editing unit 22 is not executed, and the handwriting of the erasable pen is partially thin as shown in FIG. An operation for selecting a mode is performed on the image forming apparatus 1. For example, when a hot coffee cup or the like is placed on a document, as shown in FIG. 3, the erasable pen handwriting is partially thinned. When a user operation for selecting the erasable pen correction mode is detected, the image editing unit 22 executes the above-described processing.

  For example, the image editing unit 22 specifies (for example, the average density of a predetermined number of lines) as the background density (that is, the density of the background of the original paper) based on the density of a predetermined number of lines at the beginning of the document image. . For example, the image editing unit 22 specifies the highest density in the document image as the pen density.

  The above-mentioned “detected density range” is, for example, a density range closer to the background density than the pen density.

  Alternatively, the “detection density range” may be a detection density range lower than a threshold value specified based on the difference between the pen density and the background density. For example, a value obtained by adding a density obtained by multiplying a ratio specified by a user operation or user setting to a difference between the pen density and the background density to the background density may be used as the threshold value.

  The image editing unit 22 determines whether or not a plurality of pen colors having at least one of saturation and hue different from each other are detected in the document image, and a plurality of at least one of saturation and hue different from each other in the document image. When the pen color is detected, the above-described processing is executed for each of the plurality of pen colors. That is, the image editing unit 22 specifies the pen density and the background density for each pen color, specifies the above-described detection density range, and sets the density of the pixel having the pen color at the density belonging to the detection density range. Change to concentration. Note that even if the density is changed, the saturation and hue do not change.

  The output processing unit 23 uses the printing device 11 to print the document image edited as described above by the image editing unit 22, or uses the communication device 13, the peripheral device interface 14, etc. 22 transmits image data (such as a PDF file) including the original image edited as described above.

  Next, the operation of the image processing device 16 in this embodiment will be described. FIG. 4 is a flowchart for explaining the operation of the image processing apparatus 16 in FIG.

  When the user performs a predetermined user operation, the operation mode of the image processing device 16 shifts to the erasable pen correction mode (step S1).

  When the user places a document described with an erasable pen on the image reading device 12 and performs a predetermined user operation (operation for starting copy or scan-to-send), the document image acquisition unit 21 reads the image. The reading device 12 is controlled to read the document image of the document, and the document image is acquired from the image reading device 12 (step S2).

  When the original image is acquired, in the pen correction mode that can be erased, the image editing unit 22 specifies the density of each pixel of the original image along the scanning direction, and first detects the background density as described above. In step S3, the pen density is detected (step S4).

  Next, the image editing unit 22 specifies a detection density range that is a correction target of density based on the background density and the pen density, and uses a pixel having a density that belongs to the specified detection density range as a correction portion, so that the original image (Step S5).

  Then, the image editing unit 22 changes the density of the specified correction portion to the pen density (step S6).

  Thereafter, the output processing unit 23 executes output processing (printing, transmission, etc.) of the document image for which the above correction processing has been completed (step S7).

  Prior to the output process, the image editing unit 22 executes a preview display of the document image for which the above correction process has been completed, and whether or not the user permits the output process based on the previewed document image. When the output process is permitted, an instruction indicating that is input, and when the output process is not permitted, an instruction indicating job cancellation or another correction process may be input. In that case, after the output process is permitted, the output processing unit 23 executes the output process. When the output process is not permitted and the correction process is performed again, the above-described ratio is newly input by the user, and the image editing unit 22 specifies the correction part based on the new input ratio. As described above, the density of the corrected portion is changed.

  As described above, according to the above embodiment, the document image acquisition unit 21 acquires a document image. In a specific operation mode, the image editing unit 22 (a) detects the density distribution in the original image, identifies the background density and the pen density based on the density distribution, and (b) determines the background density and the pen density. The detected density range of the handwriting with a thin erasable pen corresponding to the density is specified, (c) a pixel having a density belonging to the specified detected density range is detected, and the density of the detected pixel is changed to the pen density.

  As a result, the erasable pen handwriting that has become thin in the original image is restored at high speed without performing character recognition. Furthermore, not only characters but also graphics written with an erasable pen are repaired in the same manner.

  Various changes and modifications to the above-described embodiment will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the subject matter and without diminishing its intended advantages. That is, such changes and modifications are intended to be included within the scope of the claims.

  The present invention can be applied to an image forming apparatus such as a scanner, a copier, or a multifunction peripheral.

16 Image Processing Device 21 Document Image Acquisition Unit 22 Image Editing Unit

Claims (4)

An original image acquisition unit for acquiring an original image;
In a specific operation mode, (a) a density distribution in the document image is detected, a background density and a pen density are specified based on the density distribution, and (b) a background density and a pen density corresponding to the background density. An image editing unit that identifies a detected density range of a handwriting with a thin erasable pen, (c) detects a pixel having a density belonging to the identified detected density range, and changes the density of the detected pixel to the pen density When,
An image processing apparatus comprising:   The image editing unit detects (a) a density distribution in the document image for each of the plurality of pen colors when a plurality of pen colors having at least one of saturation and hue different from each other are detected in the document image. Then, the background density and the pen density are specified based on the density distribution, and (b) the detection density range of the handwriting with a thin erasable pen corresponding to the background density and the pen density is specified. 2. The image processing apparatus according to claim 1, wherein a pixel having a density belonging to the specified detection density range is detected, and the density of the detected pixel is changed to the pen density.   The image processing apparatus according to claim 1, wherein the detected density range is a density range closer to the background density than the pen density.   The image processing apparatus according to claim 1, wherein the detection density range is a detection density range lower than a threshold specified based on a difference between the pen density and the background density.

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