JP2007201607A - Image input apparatus, image input method, and image input program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image input apparatus, an image input method, and an image input program reading an original under an optimum read condition depending on the original to eliminate the need for a user to setting the read condition again and to execute operations of re-reading, and preventing an excessive data size. <P>SOLUTION: The image input apparatus detects a size and a contrast of smallest characters of the original, determines an optimum resolution in reading the original on the basis of the size and the contrast, reads the original by the resolution, and generates image data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image input device, an image input method, and an image input program, and more particularly to an image input device, an image input method, and an image input program capable of setting a reading condition.

  In an image input device such as a scanner that scans and reads a document and generates image data, the user can set scanning conditions such as resolution in advance and perform scanning under various conditions such as resolution desired by the user. The image data of the performed original document was generated.

  However, due to the small character size and the relationship between density and contrast, the desired image cannot be reproduced even if the document is scanned under preset scanning conditions. I had to scan.

  As a method of ensuring image reproducibility, for example, there is a method of always reading a document at a high resolution. However, since the size of image data increases as the resolution increases, the resolution is low, such as when the character size is large. Even if the reproducibility can be ensured, there is a problem that the size of the image data always increases.

In order to solve such a problem, the image data is subjected to processing such as enlargement / reduction according to the character size or the character size and the ability of the image data reception side, and then transmitted to the reception side. Have been proposed (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 10-075349 Japanese Patent Laid-Open No. 11-187252

  However, when the image data is enlarged / reduced, there is a problem that the image quality is deteriorated as compared with the case where the original is scanned at the resolution from the beginning, and further, the process of enlarging / reducing the image takes time.

  Therefore, according to the present invention, it is possible to read an original under an optimum reading condition according to the original, and eliminate the need for operations such as resetting and re-reading of the reading condition by the user, and suppressing an excessive data size. To provide an image input apparatus, an image input method, and an image input program.

  An image input apparatus according to the present invention includes an image reading unit that scans an original and reads an image, a reading condition setting unit that sets an image reading condition when reading the image, and an image processing unit that processes the image. The image processing means determines the character size and contrast of the document based on the image, determines the resolution based on the determination result, and the reading condition setting means determines the image according to the resolution. The reading condition is changed, and the document reading unit scans the document again based on the changed image reading condition to read an image.

  The image processing means further includes display means for displaying a character determined as the minimum character size of the original.

  Further, the apparatus further comprises automatic document conveying means for sequentially conveying a plurality of documents to the image reading means, scanning the document set on the automatic document conveying means with the document reading means, obtaining an image, The resolution of each original is determined by an image processing means, the image reading condition is changed by the reading condition setting means according to the resolution, and the original set on the automatic document conveying means is changed to the changed image. The image is read by scanning again with the document reading means based on the reading condition.

  Next, according to the present invention, in an image input method in which an original is scanned by an image reading unit to read an image, and the image is processed by the image processing unit, the original is scanned by the image reading unit to perform preliminary reading of the image. And determining the character size and contrast of the document from the image by the image processing unit, determining the resolution by the image processing unit based on the determination result, and determining the resolution by the image reading unit according to the resolution. A scanning condition setting unit changes a reading condition when performing normal reading by scanning a document, and performs normal reading by scanning the document again by the document reading unit based on the changed reading condition. It is characterized by.

  The present invention provides an image input program that scans an original with an image reading unit, reads an image, and causes an image input apparatus to execute processing for processing the image with the image processing unit. Performing preliminary reading of the image, determining the character size and contrast of the document from the image by the image processing unit, and determining the resolution by the image processing unit based on the determination result; Depending on the resolution, the reading condition when the original is scanned by the image reading means to perform normal reading is changed by the reading condition setting means, and the original reading means is changed based on the changed reading condition. Causing the image input device to execute a step of re-scanning the original and performing normal reading And wherein the door.

  According to the present invention, it is possible to digitize a document under optimum reading conditions according to the document, and it is possible to prevent troubles such as re-reading by the user and excessive image data size.

  FIG. 1 is a schematic functional block diagram showing an example of the configuration of an image input apparatus according to the present invention.

  As shown in the figure, the image input apparatus scans and reads a document, acquires an image, processes an image acquired by the image reading unit 10, and uses a PC (Personal Computer), a medium, or the like. An image processing unit 20 that generates image data to be transmitted to another device, a reading condition setting unit 30 that sets various conditions (reading conditions) when the image reading unit 10 reads a document, such as resolution, and image processing A transmission unit 40 is provided that transmits the image data generated by the unit 20 to another device.

  Further, the image processing unit 20 includes a switching unit 21 that switches processing of an image read by scanning an original with the image reading unit 10 and a character region determination unit 22 that determines a character region in which characters or symbols are formed. A minimum character size determination unit 23 that determines the size of the minimum character, a character contrast determination unit 24 that determines the contrast of the character, a resolution determination unit 25 that determines the resolution when performing normal scanning, and the image reading unit 10 An image compression unit 26 that compresses the image read in step S <b> 1 to generate image data and an image memory 27 that temporarily stores the image data are provided.

  Here, the switching unit 21 switches image processing depending on whether it is preliminary reading for determining the resolution of the reading condition or normal reading for generating image data. The first reading performed after an image reading instruction is issued from the operation panel or the like is determined as preliminary reading, and the reading performed subsequent to the preliminary reading is determined as normal reading, and the image processing is switched.

  The character area determination unit 22 performs the same processing as character extraction used in OCR (Optical Character Reader) or the like on the image at the time of preliminary reading, and determines the character area.

  The minimum character size determination unit 23 determines the minimum character size based on the resolution at the time of preliminary reading and the height or width of the character area.

  The character contrast determination unit 24 determines the contrast of the character based on the difference between the intensity of the pixel constituting the minimum character and the intensity of the pixel adjacent to the character area of the minimum character.

  The pixel intensity is the intensity of reflected light when the reflection of light applied to the original is detected by a CCD (Charge Coupled Devices) of the carriage and the original is scanned, and the intensity of the reflected light is represented by 8 bits. In this case, it is represented by a value between the 0 level (the intensity of the irradiated light and the reflected light is equal) to the 256 level (the reflected light is not detected).

  Therefore, for example, if the intensity of the pixel constituting the minimum character is 128 level and the intensity of the pixel adjacent to the character area of the minimum character is 64 level, the contrast is 64 level.

  When there are a plurality of minimum characters, the average contrast value is used as the contrast of the document. However, the minimum contrast value may be used as the contrast value of the document.

  The resolution determination unit 25 sets the resolution to be set in the reading condition setting unit 30 based on the character size and contrast value of the minimum character, as shown in FIG. 2 as an example of the relationship between the character size and contrast value and the resolution. decide.

  Note that the resolution value derived from FIG. 2 based on the character size and contrast is an example, and is not limited to the value, and an appropriate value can be used as necessary.

  When the image processing unit 20 acquires the image read from the original by the image reading unit 10, the switching unit 21 performs switching between processing of the image as preliminary reading or processing as normal reading.

  Here, in the case of processing as normal reading, image data is generated by the image compression unit 26, and the image data is temporarily stored in the image memory 27.

  On the other hand, when processing as preliminary reading, the character area determination unit 22 determines the character area, the minimum character size determination unit 23 determines the minimum character size, and the character contrast determination unit 24 determines the character contrast. To do.

  Also, the resolution determination unit 25 determines the resolution from the minimum character and character contrast values, and transmits the resolution to the reading condition setting unit 30.

  Note that the switching unit 21, the character region determination unit 22, the minimum character size determination unit 23, the character contrast determination unit 24, the resolution determination unit 25, the image compression unit 26, and the reading condition setting unit 30 in FIG. 1 are realized by software or the like. This is the part.

  Using the above configuration, the image input apparatus according to the present invention performs preliminary reading of a document by the image reading unit 10, determines the resolution at the time of normal reading by the image processing unit 20, and the reading condition setting unit 30 as necessary. After changing the setting of the reading conditions, the image reading unit 10 performs normal image reading, the image processing unit 20 generates image data, and the transmission unit 40 transmits the image data to another device.

  FIG. 3 is a flowchart showing an example of a processing flow in the image input apparatus when scanning an original to read an image and generating image data.

  First, when an original reading instruction is received (step 100), preliminary reading of the original is performed (step 101), and the resolution at the time of normal reading is determined (step 102).

  Next, the resolution under the current reading condition is compared with the resolution determined by the preliminary reading, and it is determined whether or not to change the resolution under the reading condition (step 103).

  Here, when the resolution determined by the preliminary reading is less than the resolution of the current reading condition (NO in step 103), normal reading of the original is performed under the current reading condition (step 104), and image data is generated / Transmit (step 105).

  On the other hand, when the resolution determined by the preliminary reading exceeds the resolution of the current reading condition (YES in step 103), the resolution of the reading condition is changed to the resolution determined by the preliminary reading (step 106), and the changed reading condition is used. The original is normally read (step 104), and image data is generated and transmitted (step 105).

  Note that after preliminary reading, the character in the character area determined to be the minimum character may be displayed on the operation panel or the like to ask for user confirmation.

  Further, when changing the resolution of the reading condition, the resolution value to be changed may be displayed on an operation panel or the like, and confirmation by the user may be requested.

  Furthermore, it is possible to set the upper limit and lower limit of the resolution to be changed based on the preliminary reading, and when the resolution determined by the preliminary reading exceeds the setting, the upper limit and lower limit setting values may be used as the resolution by the preliminary reading. .

  In addition, when the resolution determined by the preliminary reading exceeds the upper limit and lower limit of the resolution that can be read by the image reading unit, the upper limit and the lower limit may be used as the resolution of the reading condition.

  In addition, when normal reading is performed by changing the resolution of the reading condition, the resolution of the reading condition may be changed to a value before the change after the normal reading.

  Further, when the image reading unit includes an automatic document feeder (ADF), preliminary reading is performed on all the documents set on the ADF, and then normal reading is performed after the document is set on the ADF again. In this case, normal reading may be performed by changing the reading condition for each document.

  As described above, according to the present invention, it is possible to read and digitize the original with an optimum resolution in accordance with the character size of the original and the density difference between characters and symbols and the background.

  Further, since the document can be digitized under the optimum conditions, it is possible to reduce the burden on the user due to re-reading and to prevent the image data from becoming excessively large.

It is a schematic functional block diagram which shows an example of a structure of the image input device which concerns on this invention. It is a figure which shows an example of the relationship between the value of character size and contrast, and resolution. It is a flowchart which shows an example of the flow of a process in an image input device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image reading part 20 ... Image processing part 21 ... Switching part 22 ... Character area determination part 23 ... Minimum character size determination part 24 ... Character contrast determination part 25 ... Resolution determination part 26 ... Image compression part 27 ... Image memory 30 ... Reading Condition setting unit 40 ... transmission unit

Claims (5)

Image reading means for scanning a document and reading an image;
Reading condition setting means for setting image reading conditions when reading the image;
Image processing means for processing the image,
The image processing means includes
Determining the character size and contrast of the document based on the image;
Determine the resolution based on the result of the determination,
The reading condition setting means changes the image reading condition according to the resolution,
The image input device, wherein the document reading unit scans the document again based on the changed image reading condition and reads an image.   2. The image input apparatus according to claim 1, further comprising display means for displaying a character determined by the image processing means as the minimum character size of the document. Further comprising automatic document conveying means for sequentially conveying a plurality of documents to the image reading means,
The document set on the automatic document feeder is scanned by the document reader to obtain an image, the resolution of each document is determined by the image processor, and the image reading condition is set according to the resolution. The document is changed by a reading condition setting unit, and the original set on the automatic document conveying unit is scanned again by the original reading unit based on the changed image reading condition, and an image is read. The image input apparatus according to claim 1 or 2. In an image input method of scanning an original with an image reading unit to read an image, and processing the image with an image processing unit,
Scan the original with the image reading means to perform preliminary reading of the image,
The image processing means determines the character size and contrast of the document from the image,
A resolution is determined by the image processing means based on the result of the determination,
In accordance with the resolution, the reading condition when the original is scanned by the image reading unit to perform normal reading is changed by the reading condition setting unit,
An image input method, wherein normal reading is performed by rescanning the original with the original reading unit based on the changed reading condition. In an image input program that scans an original with an image reading unit, reads an image, and causes the image input device to execute processing for processing the image with the image processing unit.
Scanning the original with the image reading means to perform preliminary reading of an image;
Determining the character size and contrast of the document from the image by the image processing means;
Determining a resolution by the image processing means based on the result of the determination;
In accordance with the resolution, the reading condition when the original is scanned by the image reading unit to perform normal reading is changed by the reading condition setting unit,
An image input program causing the image input device to execute a step of performing normal reading by rescanning the original with the original reading unit based on the changed reading condition.

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