JP5256165B2 - Image reading apparatus and image reading system - Google Patents

Description

  The present invention relates to an image reading apparatus and an image reading system, and more particularly, to an apparatus having an OCR function.

  In an image reading apparatus comprising a scanner portion in an image forming apparatus such as a scanner used in a network or an MFP (Multi-Function Product / Printer / Peripheral), the OCR (Optical Character Recognition or optical character reading) is used. (Equipment: Optical Character Reader)) function is installed, character recognition is automatically performed from the scanned image, and character data can be created.

  For example, in Patent Document 1, in a facsimile, a portion that can be recognized as a character is output from the scanner read image by performing OCR processing, and a character code is output. If it is compatible, the character code and the image data are transmitted as they are, and if not compatible, the character code is again developed into a font and transmitted together with the image data.

JP 2000-348137 A

  In the above-described prior art, OCR processing is performed from image data with a fixed resolution output from the scanner. For example, the resolution is about 300 dpi. On the other hand, the performance of the scanner is improved with the particularly high-function MFP, and resolutions of 600 dpi and 1200 dpi have appeared.

  On the other hand, the OCR recognition rate does not improve much even if the resolution is increased in the case of characters of 10 to 12 points or more that are normally used. However, in the case of characters with a small number of points such as subscripts and notes, increasing the resolution is effective in improving the recognition rate. Therefore, when the resolution is generally increased, there is a problem that the processing amount of recognition increases dramatically, and the processing time greatly increases. For example, when the OCR process is performed in parallel with the copying operation, the OCR recognition process is hardly completed even when the print output is completed after the scanner reading.

  An object of the present invention is to provide an image reading apparatus and an image reading system capable of increasing the recognition rate without causing a large decrease in processing speed and a large increase in processing amount.

An image reading apparatus according to an aspect of the present invention includes an image reading unit that reads a document image, and a first image that performs image processing in a predetermined high resolution format on image data read by the image reading unit. A processing unit, a first storage unit that temporarily stores image data after processing by the first image processing unit, and image data stored in the first storage unit are read out, and a predetermined low resolution A second image processing unit that performs image processing in a format, a second storage unit that stores low-resolution image data processed by the second image processing unit, and a font size of characters, An OCR processing unit that determines the resolution in the second image processing unit in advance so that the resolution increases as the font size decreases, and the OCR processing unit is stored in the second storage unit. Read out image data and By performing processing and analyzing the font size of the character, the font of the leading edge character and the last character of the paragraph is included for each paragraph included in the image indicated by the image data read from the second storage unit. Check the size, and if a paragraph whose font size is less than or equal to a predetermined value appears, specify the position of the paragraph from the image data stored in the first storage unit. In addition, the resolution of the second image processing unit is increased to the resolution assigned to the font size of the leading edge character and the last character of the corresponding paragraph, and OCR processing is performed again with high resolution image data. Is performed on the corresponding paragraph.
An image reading apparatus according to another aspect of the present invention includes an image reading unit that reads a document image, and a first high-resolution image processing that is performed on image data read by the image reading unit. An image processing unit, a first storage unit that temporarily stores image data after processing by the first image processing unit, and image data stored in the first storage unit are read out, and a predetermined low resolution A second image processing unit that performs image processing in the format, a second storage unit that stores image data (to be output image data) after processing by the second image processing unit, and the second The image data stored in the storage unit is read out, OCR processing is performed, and, as a result of the processing, when characters with a low recognition rate appear, from among the image data stored in the first storage unit, Position the character and read it again Both enhance resolution in the second image processing unit, characterized in that it comprises a OCR processing unit that performs OCR processing anew high-resolution image data.

  According to the above configuration, it is realized as a network scanner, an MFP, and the like. The original image is read by the image reading unit, and the read image data is preliminarily processed by the first image processing unit, such as area separation and character extraction. The image processing is performed in a defined high resolution, for example, a gradation of 8 bits and a resolution of 600 dpi, and the processed image data is temporarily stored in the first storage unit, read out as appropriate, and the second image processing unit Image processing is performed in a predetermined low resolution such as double or edge enhancement for characters, for example, 1 bit gradation, 200 dpi resolution, and the processed image data to be output image data is stored in the second storage unit The OCR function is realized as follows in the image reading apparatus adapted to output appropriately.

  In other words, the OCR processing unit normally reads out the image data stored in the second storage unit, and uses the OCR processing data at a fixed resolution as output data as it is. As a result, when a character with a low recognition rate appears, the resolution is increased and the OCR process is performed again. In the re-processing, the OCR processing unit designates the corresponding character from the image data stored in the first storage unit, causes the character to be read again, and at the second image processing unit. The resolution is increased and OCR processing is performed again with high resolution image data.

  Therefore, since only the characters that could not be recognized by the first low-resolution OCR processing when the character size is small are re-recognized by the second high-resolution OCR processing, the processing speed is greatly reduced. The recognition rate can be increased without causing a significant increase in processing amount.

  In the image reading apparatus of the present invention, the OCR processing unit gradually increases the resolution in the second image processing unit until a predetermined recognition rate is obtained for the character.

  According to the above configuration, when a character with a low recognition rate appears by OCR processing, the resolution in the second image processing unit is increased little by little until a predetermined recognition rate is obtained for the corresponding character. Repeat the process to be performed.

  Therefore, an increase in the amount of recognition processing can be minimized.

  Furthermore, in the image reading apparatus according to the present invention, the OCR processing unit analyzes the font size of the character being recognized. As a result of the analysis, the recognition rate is low when the character is smaller than a predetermined size. It is determined that a character has appeared.

  According to the above configuration, when the character font size is not more than a predetermined size, such as a subscript or a note, the recognition rate in the OCR processing unit is reduced as described above, so when these characters appear, The OCR processing unit automatically performs OCR processing using the high-resolution data as described above.

  Therefore, accurate recognition can be performed from the beginning.

  In the image reading apparatus according to the present invention, the OCR processing unit may cause the second image processing unit to perform enlargement, smoothing, and noise removal when the font size is analyzed and the character is smaller than a predetermined size. OCR processing is performed after at least one image processing is performed.

  According to the above configuration, when it is determined that the character is equal to or smaller than the predetermined font size, appropriate image processing is performed and OCR processing is performed.

  Accordingly, OCR data with a high recognition rate can be completed and supplied to an external customer such as a personal computer.

  Furthermore, the image reading system of the present invention is configured such that the image reading apparatus includes an external device that uses data read by the image reading device, and the OCR processing unit is mounted on the external device side. It is characterized by that.

  According to the above configuration, as described above, it is possible to cause an external device such as a personal computer using the OCR data to perform the OCR processing that may cause the image data to be high resolution and processing heavy. it can.

  As described above, the image reading apparatus and the image reading system of the present invention read an original image by the image reading unit, perform high-resolution image processing on the read image data by the first image processing unit, and The processed image data is temporarily stored in the first storage unit, read out as appropriate, the second image processing unit performs low-resolution image processing, and the processed image data to be output image data is stored in the second storage. In the image reading apparatus that is stored in the unit and appropriately output, the OCR processing unit reads the image data in the second storage unit, and if a character having a low recognition rate appears as a result of the recognition process, the resolution is set. The OCR process is performed again.

  Therefore, since only the characters that could not be recognized by the first low-resolution OCR processing when the character size is small are re-recognized by the second high-resolution OCR processing, the processing speed is greatly reduced. The recognition rate can be increased without causing a significant increase in the processing amount.

1 is a block diagram of an MFP according to an embodiment of the present invention. It is a figure for demonstrating the procedure of the OCR process of one Embodiment of this invention. It is a figure for demonstrating the procedure of the OCR process in the image reading system of the other embodiment of this invention.

(Embodiment 1)
FIG. 1 is a block diagram of an MFP 1 according to an embodiment of the present invention. The MFP has a plurality of functions such as a printer, a scanner, and a facsimile in addition to the function as a copying machine. Therefore, the MFP 1 includes an image reading unit 2, an image processing unit 3, a first image storage unit 4, a second image storage unit 5, an image forming unit 6, a communication unit 7, and an input operation. Unit 8 and a system control unit 9.

  The image reading device 2 includes an image sensor, a scanning optical system, an automatic document feeder, and a control unit for controlling them. The image processing unit 3 includes an application specific integrated circuit (ASIC), the first storage unit 4 includes a semiconductor memory, and the second storage unit 5 includes a hard disk device. Details of these operations will be described later.

  The image forming unit 6 includes a recording paper conveyance system and a control unit for controlling them in addition to an electrophotographic image forming unit. The communication unit 7 has a function as a network interface when linked with a printer and a modem when performing facsimile communication. The input operation unit 8 includes an input unit 81 such as a numeric keypad or a touch panel, a display unit 82 including a liquid crystal display device, and a control unit 83 thereof. The system control unit 9 includes a microcomputer and its peripheral circuits, and controls the overall operation of the MFP 1.

  In this MFP 1, the part related to the image reading apparatus of the present invention is an image reading unit 2 and a processing unit for the read image. Specifically, in FIG. 1, the communication unit 7 and the image forming unit 6 are excluded. Part.

  The image processing unit 3 performs, as an input process on the read image data from the image reading unit 2, a predetermined multi-value and high resolution such as region separation and character cutout, for example, 8-bit gradation and resolution of 600 dpi. A first low-resolution image processing unit 31 that performs image processing in a format and a predetermined low resolution such as scaling or edge enhancement for characters as intermediate processing in the image data processed by the first image processing unit 31 For example, a second image processing unit 32 that performs image processing in a format of gradation 1 bit and resolution 200 dpi and creates output image data, and an image editing unit 33 that performs editing such as image composition as output processing A reference image creation unit 34 that creates a reference image (thumbnail), and an OCR processing unit that performs OCR processing as needed from the processed image data in the second image processing unit 32 5 and configured to include a.

  The image data processed by the first image processing unit 31 is temporarily stored in the first image storage unit 4 and appropriately read by the second image processing unit 32. Similarly, the image data processed by the second image processing unit 32 is stored in the second image storage unit 5 and is appropriately read out by the image forming unit 6 and the communication unit 7, and Used for OCR processing of the invention.

  In the MFP 1 configured as described above, it should be noted that the OCR processing unit 35 reads out image data stored in the second image storage unit 5 and performs OCR processing. When a character with a low recognition rate appears, the character is positioned from the image data stored in the first image storage unit 4 and read again, and the second image processing unit 32 is read out. The image processing is performed by increasing the resolution in the image processing, the OCR processing is performed again using the high-resolution image data after the image processing, and the result is inserted into the previous OCR processing result.

  FIG. 2 is a diagram for explaining the procedure of the OCR processing as described above. In the case of a normal copying operation, the read image data of the original image in the image reading unit 2 is taken in as indicated by reference numeral F1, and as described above, the first image processing unit 31 performs input processing. Then, image processing is performed in a predetermined multi-value and high resolution, for example, 8-bit 600 dpi format such as region separation and character cutout, and the intermediate image data is obtained.

  Subsequently, in the second image processing unit 32, image processing is performed on the intermediate image data as intermediate processing, such as scaling and edge enhancement for characters, in a predetermined low resolution, for example, 1 bit 200 dpi format. The output image is output from the image output unit 36 to the image forming unit 6 as indicated by reference numeral F2, printed on a recording sheet, and output.

  Further, during the scanner operation, the read image data of the original image by the image reading unit 2 is taken in as indicated by reference numeral F11, and the reference image creating unit 34 generates the reference image (thumbnail) as described above. Created and stored in the first image storage unit 4 as indicated by reference numeral F12. On the other hand, the read image data of the original image is taken in as indicated by reference numeral F21, and as described above, as the input processing, the first image processing unit 31 determines in advance such as region separation and character cutout. Image processing in multi-value and high resolution, for example, 8-bit 600 dpi format is performed, stored in the first image storage unit 4 in association with the reference image, and layout information or the like is stored by the image editing unit 33. Created.

  The original image data thus stored in the first image storage unit 4 is sequentially read out to the second image processing unit 32 as indicated by reference numeral F22, and as described above, as intermediate processing, scaling and character Image processing is performed in a predetermined low resolution, for example, 1 bit 200 dpi, such as edge enhancement for. The output image data obtained by the second image processing unit 32 is stored in the second image storage unit 5 and is sequentially read out from the second image storage unit 5 as indicated by reference numeral F23. In the file forming unit 37, the files are collected in a predetermined file format and output from the communication unit 7 to an external personal computer 10 or the like.

  When the OCR processing is selected by the input operation unit 8 or the personal computer 10 during the copying operation or by the input operation unit 8 or the personal computer 10 when reading the scanner, the OCR processing unit 35 Of the output image data stored in the second image storage unit 5, the data of the character area is sequentially read and the OCR process is executed. The obtained text data is output to the personal computer 10 or the like.

  At this time, normally, as indicated by the reference symbol F31, the OCR processing unit 35 reads out the image data stored in the second storage unit 5, and performs the OCR processing at a fixed resolution as the reference symbol F32. However, in this embodiment, when a character with a low recognition rate appears as a result of the processing, the resolution is increased and the OCR processing is performed again. Is to do.

  Specifically, in the re-processing, when the corresponding character appears in the image data stored in the first storage unit 4, the OCR processing unit 35 determines which position of the document the corresponding character appears. Therefore, the position of the document ID and the character of the corresponding character is designated as indicated by the reference symbol F33, and read again from the first storage unit 4 as indicated by the reference symbol F34. The resolution in the second image processing unit 5 is increased, for example, high resolution image data of 300 dpi is obtained, and OCR processing is performed again. If the recognition rate is still low, the OCR processing unit 35 increases the gradation and resolution to 400 dpi and 600 dpi, and repeats the OCR processing of the corresponding character.

  Therefore, when the character size is small, only characters that could not be recognized by the first low-resolution OCR process are re-recognized by the second high-resolution OCR process. The recognition rate can be increased without causing a significant increase in the processing amount. As a result, the extracted OCR data can be supplied to an external customer such as the personal computer 10 without greatly delaying the copying operation or the scanner reading operation.

  In the above description, it has been described that the OCR process is performed in parallel during the copying operation or the scanner reading, but only the OCR process may be performed alone.

  Preferably, when the font size of a character such as a subscript or a note is small, the recognition rate in the OCR processing unit 35 is sufficiently expected to be low. Therefore, the image editing unit 33 uses the character information as layout information. Using the fact that the font size is known, the font size of the currently recognized character is analyzed, and when a character with a low recognition rate such as a subscript or a note appears, the OCR processing unit 35 automatically Specifically, OCR processing is performed using high resolution data as described above.

  In this case, as described above, the resolution is not gradually increased. For example, in the case of a 12-point character, the normal 1-bit 200 dpi, in the case of a 10-point character, the 2-bit 300 dpi, and in the case of an 8-point character, 4 bits. In the case of 400 dpi, 6-point characters, the resolution may be determined in advance according to the number of points, such as 8-bit 600 dpi. As a result, the number of processes with a low recognition rate can be reduced. In addition, subscripts often appear sporadically, whereas notes and the like often appear together in a paragraph or the like. Therefore, the number of points between the most advanced character and the last character is confirmed for each paragraph, and in the case of a low point, the same high resolution is applied to the entire paragraph recognized by the image editing unit. You may make it do.

  Preferably, the OCR processing unit 35 sends at least one image of enlargement, smoothing, and noise removal to the second image processing unit 5 when the font size is analyzed and the character is a predetermined size or less. The OCR process is performed after the process is performed. In this way, OCR data with a high recognition rate can be completed by performing OCR processing after performing appropriate image processing on characters with a low number of points that are expected to have a low recognition rate.

(Embodiment 2)
FIG. 3 is a diagram for explaining the procedure of the OCR process in the image reading system according to another embodiment of the present invention. This FIG. 3 is similar to FIG. It should be noted that in this MFP, the OCR processing unit 35 is not provided in the image processing unit 3 ′, and instead, the OCR processing unit 35 is provided on the external personal computer 10 ′ side that uses the scanner read image. 'Is provided.

  Therefore, on the personal computer 10 'side, the image data processed by the first image processing unit 4 and the second image processing unit 5 is input via the communication unit 7 as indicated by reference numeral F23. The OCR processing unit 35 'sequentially performs OCR processing and the text data of the processing result is also stored in the storage unit 10a. At this time, when a character with a low recognition rate appears, the OCR processing unit 35 ′ outputs the image data of the corresponding character from the first image storage unit 4 as indicated by reference numerals F35 to F36, and The output image data in which the resolution of the second image processing unit 32 is increased is obtained, and the OCR process is performed again.

  With this configuration, when the number of characters having a low recognition rate increases, the OCR processing, which may cause the image data to be high resolution and heavy processing, can be performed on a personal computer 10 ′ or the like using this OCR data. The image processing unit 3 ′ on the MFP side can be used with an apparatus capable of performing almost the same processing as the conventional one not equipped with the OCR function. In addition, the amount of data transferred between the image processing unit 3 'and the personal computer 10' is not significantly increased because only the amount of re-queries for character data with a low recognition rate is increased.

1 MFP
2 image reading unit 3, 3 ′ image processing unit 31 first image processing unit 32 second image processing unit 33 image editing unit 34 reference image creation unit 35, 35 ′ OCR processing unit 36 image output unit 37 filing unit 4 1st image memory | storage part 5 2nd image memory | storage part 6 Image formation part 7 Communication part 8 Input operation part 81 Input part 82 Display part 83 Control part 9 System control part 10,10 'Personal computer 10a Memory | storage part

Claims (3)

An image reading unit for reading a document image;
A first image processing unit that performs image processing in a predetermined high-resolution format on image data read by the image reading unit;
A first storage unit for temporarily storing image data after processing by the first image processing unit;
A second image processing unit that reads out image data stored in the first storage unit and performs image processing in a predetermined low-resolution format;
A second storage unit for storing low-resolution image data processed by the second image processing unit;
Depending on the character of the font size, the more so the resolution is high is small font size, look including the OCR processing unit that defines the resolution at the second image processing unit in advance,
The OCR processing unit reads the image data stored in the second storage unit, performs OCR processing, and analyzes the font size of the character, thereby reading the image read from the second storage unit. For each paragraph included in the image indicated by the data, check the font size of the leading edge character and the last character of the paragraph, and if a paragraph whose font size is equal to or less than the predetermined value appears, From the image data stored in the first storage unit, the corresponding paragraph is positioned and read again, and at the resolution assigned to the font size of the leading edge character and the last character of the paragraph, An image reading apparatus, wherein the resolution of the second image processing unit is increased, and OCR processing with high-resolution image data is performed again on the corresponding paragraph . The OCR processing unit causes the second image processing unit to perform at least one of image processing for enlargement, smoothing, and noise removal in the case where the character size is not more than a predetermined size as a result of the font size analysis. The image reading apparatus according to claim 1 , wherein OCR processing is performed . The image reading apparatus according to claim 1 or 2, further comprising an external device that uses data read by the image reading device, and the OCR processing unit is mounted on the external device side. Image reading system .

Images