JP2010161745A - Image processor, image reader, image transmission device, image formation device, image processing method, program, and recording medium of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly generate an image file of image data obtained by reading a document, and to make a device for displaying or printing the image data execute appropriate image processings. <P>SOLUTION: This image processor includes: a document detecting part 14 for detecting a region, corresponding to a document image in image data and a condition of image processing to be applied in displaying the document image based on the image data of the document image; a color compensating part 16 for converting colors in regions other than the region corresponding to the document image in the image data to predetermined colors; a drawing command generating part 43 for generating a drawing command for controlling a computer provided for a device in a transmission destination to execute display, after executing the image processing based on the condition in displaying the document image; and a formatting processing part 44 for generating an image file created by adding the drawing command to image data obtained by applying a compression process to the image data, before applying the image processing, after executing the conversion process. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an image reading apparatus, an image transmission apparatus, an image forming apparatus, an image processing method, a program, and a recording medium thereof that perform predetermined processing on image data read from a document and transmit the processed image data to another apparatus. It is.

  Conventionally, information written on a recording material such as paper is read by a scanner to generate image data, converted to an image file in TIFF format, GIF format, PDF format, bitmap format, etc., and attached to an e-mail For example, information on a recording material is electronically documented by transmitting the information to a server or computer connected via a network. (For example, refer to Patent Document 1).

JP 2002-215549 A (published on August 2, 2002) Japanese Laid-Open Patent Publication No. Hei 7-192086 (published July 28, 1995) Japanese Patent Laid-Open No. 6-189083 (published July 8, 1994)

  By the way, when reading an original with a scanner, the original may be read in an inclined state, or may be read with the top (vertical direction) of the original being reversed. Therefore, in the conventional technique, image files read from an original are subjected to processing such as tilt correction and vertical correction, and then an image file is performed.

  However, since rotation processing of image data requires interpolation processing to be performed many times, there is a problem that the load imposed on the arithmetic device is large and it takes time to process the image file after reading the document.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to quickly generate an image file of a predetermined format based on image data obtained by reading a document, and It is based on that the image corresponding to the image data can be drawn appropriately.

  In order to solve the above problems, an image processing apparatus according to the present invention includes an image processing unit that generates an image file in which image data of a document image obtained by reading a document is formatted into data of a predetermined format. An image area detection unit for detecting an area corresponding to the original image in the image data, and an image processing condition to be applied when drawing the original image based on the image data. A condition detection unit, a color conversion unit that converts a color of a region other than the region corresponding to the document image detected by the image region detection unit in the image data into a predetermined color, and when drawing the document image A drawing command generation unit that generates a drawing command for controlling the computer so as to perform drawing in a state where image processing based on the above conditions is performed. The formatting processing unit applies the drawing command to the image data that has been subjected to the compression processing on the image data after the conversion processing by the color conversion unit and before the image processing as the image file. It is characterized by generating an added image file.

  The image processing method of the present invention is an image processing method for generating an image file in which image data of a document image obtained by reading a document is formatted into data of a predetermined format in order to solve the above problems. An image area detecting step for detecting an area corresponding to the original image in the image data; a condition detecting step for detecting an image processing condition to be applied when the original image is drawn based on the image data; A color conversion step of converting a color of a region other than the region corresponding to the document image detected in the image region detection step in the image data into a predetermined color, and an image based on the condition when the document image is drawn A drawing command generation step for generating a drawing command for controlling the computer so that drawing is performed in the processed state; An image file generation step of generating an image file in which the drawing command is added to the image data obtained by performing compression processing on the image data before the image processing after the conversion processing in the color conversion step It is characterized by including.

  According to the image processing apparatus and the image processing method described above, an area corresponding to the document image in the image data is detected, and the color of the area other than the area corresponding to the document image is converted into a predetermined color. Further, the image processing condition to be applied when drawing the document image is detected based on the image data, and the computer is configured to perform drawing after performing image processing based on the condition when drawing the document image. Generate drawing commands to control. Then, after the conversion process, an image file is generated by adding the drawing command to the image data obtained by performing the compression process on the image data before the image process.

  In this way, by compressing the image data after converting the color of the region other than the region corresponding to the document image to a predetermined color, the compression efficiency of the image data is improved, and the compression of the image data after the compression processing is performed. Data size can be reduced.

  Further, by generating an image file based on the image data of the original image before the image processing, it is possible to quickly perform processing such as transmission and filing of the image file relating to the image data read from the original image. Further, when drawing a document image (for example, when displaying a document image on a display or printing on a recording material), the computer can be controlled so that the drawing is performed with image processing based on a drawing command.

  For example, the condition detection unit detects an inclination angle of the document image with respect to a reference direction of the image data as the condition, and the drawing command generation unit detects the document image based on the inclination angle detected by the condition detection unit. A drawing command may be generated for causing the computer to perform an inclination correction process for making the angle coincide with or approach the reference direction.

  In general, the inclination correction processing (rotation processing) of image data places a heavy load on the calculation means and increases the processing time. On the other hand, according to the above configuration, since the tilt correction process is not performed when the image file is generated, the processing time required for generating the image file can be shortened. Further, when drawing an image, the image can be drawn in a state in which an inclination correction process is performed.

  The condition detection unit detects a range of an area where an image corresponding to the document in the image data exists as the condition, and the drawing command generation unit detects the range detected by the condition detection unit from the image data. It is also possible to generate a drawing command for causing a computer to perform image extraction processing for extracting the image data.

  According to the above configuration, since the image extraction process is not performed when the image file is generated, the processing time required for generating the image file can be shortened. Further, when drawing an image, it is possible to extract and draw a region where an image corresponding to a document exists.

  The condition detection unit detects the orientation of the document image with respect to a reference direction of the image data based on the orientation of the character image included in the document image in units of 90 degrees, and the drawing command generation unit Based on the orientation of the original image detected by the detection unit, a drawing command for causing the computer to perform a top and bottom correction process for rotating the original image in units of 90 degrees so as to match the orientation of the original image with the reference direction. It is good also as composition to generate.

  According to the above configuration, since the top / bottom correction processing is not performed when the image file is generated, the processing time required for generating the image file can be shortened. In addition, when drawing an image, the image can be drawn in a state where the top and bottom correction processing is performed.

  The condition detection unit detects a magnification of a scaling process to be performed on the image data in order to draw an image corresponding to the image data with a predetermined size, and the drawing command generation unit includes the condition detection unit. A drawing command for causing a computer to perform a scaling process based on the magnification detected by the computer may be generated.

  According to the above configuration, since the scaling process is not performed when the image file is generated, the processing time required for generating the image file can be shortened. Further, when drawing an image, the image can be drawn in a state where a scaling process for drawing an image corresponding to the image data with a predetermined size is performed.

  The condition detection unit detects a range of an area where an image corresponding to a document in the image data is present as the condition, and extracts extracted image data obtained by extracting the image data in the range from the image data. The drawing command generation unit detects a magnification of a scaling process to be performed on the extracted image data in order to draw a corresponding image with a predetermined size, and the drawing command generation unit detects the image in the range detected by the condition detection unit from the image data. A drawing command for causing a computer to perform image extraction processing for extracting data and scaling processing for scaling the extracted image data obtained by the image extraction processing based on the magnification detected by the condition detection unit. It is good also as composition to generate.

  According to the above configuration, since the image extraction process and the scaling process are not performed when the image file is generated, the processing time required for generating the image file can be shortened. Further, when drawing an image, it is possible to extract a region where an image corresponding to a document exists and to draw the image of the extracted region by scaling processing to a predetermined size.

  In addition, a normal mode in which the formatting processing unit performs the image processing on the image data of the document image and then generates the image file; and the document image before the formatting processing unit performs the image processing. A simple mode for generating an image file in which the drawing command is added to the image data may be provided.

  According to the above configuration, the normal mode for generating the image file based on the image data after the image processing is performed, and the simple mode for generating the image file in which the drawing command is added to the image data before the image processing is performed, Can be used as needed.

  The formatting processing unit may be configured to generate an image file of any one of a PDF format, a TIFF format, and an EXIF standard JPEG format based on the image data.

  According to the above configuration, any one of the PDF format, the TIFF format, and the JPEG format of the EXIF standard can be generated based on the image data, and the drawing command can be included in the image file.

  An image reading apparatus of the present invention includes an image reading unit that reads a document and acquires image data of the document image, and any one of the image processing devices described above.

  According to the above configuration, it is possible to quickly perform processing such as transmission and filing of an image file relating to image data read from a document image. Further, when drawing a document image (for example, when displaying a document image on a display or printing on a recording material), the computer can be controlled so that the drawing is performed with image processing based on a drawing command.

  An image transmission apparatus according to the present invention includes any one of the above-described image processing apparatuses and a communication unit that transmits the image file generated by the formatting processing unit to another device connected to be communicable. It is characterized by.

  According to the above configuration, the image data of the original image can be transmitted without being subjected to the above image processing, so that the load from the image processing device is reduced and the processing from reading the image to transmitting it can be performed quickly. Can be done. In addition, when an image corresponding to image data is drawn in the transmission destination apparatus, the image can be drawn in a state where image processing based on the drawing command is performed, so that the document image can be drawn in an appropriate state.

  The image forming apparatus of the present invention reads any one of the above-described image processing apparatuses, a storage unit that stores the image file generated by the formatting processing unit, and an image file stored in the storage unit, An image processing unit that performs image processing based on the drawing command included in the file; and an image forming unit that prints an image corresponding to the image data subjected to the image processing on a recording material.

  According to the above configuration, the image data of the document image is stored in the storage unit without being subjected to the image processing, so that the processing from reading the document to storing it can be quickly performed. In addition, when printing an image according to the image data, the image can be printed after performing image processing based on a drawing command included in the image file read from the storage unit. Can be printed in an appropriate state.

  The image processing apparatus may be realized by a computer. In this case, an image processing program for causing the image processing apparatus to be realized by the computer by causing the computer to operate as the respective units, and the program are recorded. Computer-readable recording media are also included in the scope of the present invention.

  As described above, the image processing apparatus of the present invention is an image processing apparatus including a formatting processing unit that generates an image file in which image data of a document image obtained by reading a document is formatted into data of a predetermined format. An image area detecting unit for detecting an area corresponding to the document image in the image data, and a condition detecting unit for detecting a condition of image processing to be applied when drawing the document image based on the image data A color conversion unit that converts a color of a region other than the region corresponding to the document image detected by the image region detection unit in the image data to a predetermined color, and based on the condition when the document image is drawn A drawing command generation unit for generating a drawing command for controlling the computer so that the image processing is performed, and the above format The processing unit adds, as the image file, the drawing command to the image data that has been subjected to the conversion processing by the color conversion unit and then subjected to compression processing on the image data before the image processing is performed. Generate an image file.

  The image processing method of the present invention is an image processing method for generating an image file obtained by formatting image data of a document image obtained by reading a document into data of a predetermined format. An image region detecting step for detecting a corresponding region, a condition detecting step for detecting image processing conditions to be applied when the original image is drawn based on the image data, and the image region detecting step for the image data A color conversion step of converting the color of the area other than the area corresponding to the original image detected in step 1 into a predetermined color, and drawing with the image processing based on the above conditions when drawing the original image A drawing command generation step for generating a drawing command for controlling the computer, and the image conversion as the image file in the color conversion step. It was subjected to physical, and an image file generating step of generating an image file by adding the drawing command to the image data subjected to the compression process on before the image data subjected to the image processing.

  Therefore, the compression efficiency of the image data can be improved, and the data size of the image data after the compression process can be reduced. Further, it is possible to quickly perform processing such as transmission and filing of an image file relating to image data read from a document image. Further, when drawing a document image, the computer can be controlled so as to draw in a state where image processing based on a drawing command is performed.

It is a flowchart which shows the flow of a process in the image processing apparatus concerning one Embodiment of this invention. 1 is a block diagram illustrating a schematic configuration of an image processing apparatus (an image reading apparatus and an image forming apparatus) according to an embodiment of the present invention, and a data flow in an image forming mode. FIG. 3 is a block diagram illustrating a data flow in a normal transmission mode in the image processing apparatus illustrated in FIG. 2. FIG. 3 is a block diagram showing a data flow in a simple transmission mode in the image processing apparatus shown in FIG. 2. It is sectional drawing which shows the structural example of the image input device with which the image processing apparatus shown in FIG. 2 is equipped. FIG. 3 is a block diagram illustrating a schematic configuration of a document detection unit provided in the image processing apparatus illustrated in FIG. 2. FIG. 6 is an explanatory diagram illustrating an example of a relationship between a scan range and a document position at the time of scanning in the image input apparatus illustrated in FIG. 5. FIG. 3 is an explanatory diagram illustrating a relationship between a vertical direction of image data and a vertical direction of a document image in the image processing apparatus illustrated in FIG. 2. FIG. 3 is an explanatory diagram showing a method for determining a document image area in the image processing apparatus in the image processing apparatus shown in FIG. 2. 3 is a graph showing an example of a gamma curve used for halftone correction processing in the image processing apparatus shown in FIG. 2. FIG. 3 is an explanatory diagram illustrating a configuration of an image file transmitted in the simple transmission mode in the image processing apparatus illustrated in FIG. 2. (A) shows an example of description contents for the document catalog description part in the image file shown in FIG. 11, and (b) shows an example of description contents for the page description part in the image file shown in FIG. , (C) shows an example of description contents for the image data description part in the image file shown in FIG. (A) shows an example of image data read by the image input device shown in FIG. 2, and (b) shows the image data shown in (a) in the description of the image drawing description section shown in FIG. It is explanatory drawing which shows the image displayed based on. FIG. 3 is an explanatory diagram illustrating an example of description contents for an image drawing description portion in an image file transmitted in the simple transmission mode in the image processing apparatus illustrated in FIG. 2. (A) shows an example of the image data read by the image input device shown in FIG. 2, and (b) shows the image data shown in (a) in the description of the image drawing description section shown in FIG. It is explanatory drawing which shows the image displayed based on. FIG. 3 is an explanatory diagram illustrating an example of description contents for an image drawing description portion in an image file transmitted in the simple transmission mode in the image processing apparatus illustrated in FIG. 2. (A) shows an example of the image data read by the image input device shown in FIG. 2, and (b) shows the image data shown in (a) in the description of the image drawing description section shown in FIG. It is explanatory drawing which shows the image displayed based on. FIG. 3 is an explanatory diagram illustrating an example of description contents for an image drawing description portion in an image file transmitted in the simple transmission mode in the image processing apparatus illustrated in FIG. 2. (A) shows an example of image data read by the image input device shown in FIG. 2, and (b) shows the image data shown in (a) in the description of the image drawing description section shown in FIG. It is explanatory drawing which shows the image displayed based on. FIG. 3 is an explanatory diagram illustrating an example of description contents for an image drawing description portion in an image file transmitted in the simple transmission mode in the image processing apparatus illustrated in FIG. 2. It is a block diagram which shows the modification of the image processing apparatus shown in FIG. It is a block diagram which shows the modification of the image processing apparatus shown in FIG. It is a block diagram which shows the modification of the image processing apparatus shown in FIG. FIG. 3 is an explanatory diagram showing the relationship between the document placement direction, the reading resolution in the main scanning direction, and the reading resolution in the sub-scanning direction in the image processing apparatus shown in FIG. 2.

  An embodiment of the present invention will be described. In the present embodiment, an example in the case where the present invention is applied to a digital color multifunction peripheral will be mainly described.

(1) Overall Configuration of Digital Color Multifunction Device FIGS. 2 to 4 are block diagrams showing a schematic configuration of the digital color multifunction device 1 according to the present embodiment. The digital color multifunction peripheral 1 is (1) an image forming mode in which an image corresponding to image data read by the image input device 2 is formed on a recording material by the image output device 4, and (2) the image input device 2 reads the image. A normal transmission mode in which the image data is subjected to processing such as tilt correction and the processed image data is transmitted to the external device by the communication device 5; and (3) at the time of drawing detected from the image data read by the image input device 2. A simple transmission mode is provided in which information indicating the condition to be applied and the image data before image processing corresponding to the condition are transmitted to an external device by the communication device 5. 2 shows the data flow in the image forming mode, FIG. 3 shows the data flow in the normal transmission mode, and FIG. 4 shows the data flow in the simple transmission mode.

  As shown in FIGS. 2 to 4, the digital color multifunction peripheral 1 includes an image input device 2, an image processing device 3, an image output device 4, a communication device 5, and an operation panel 6.

  The image input device 2 reads an image of a document and generates image data. For example, a scanner unit (not shown) including a device that converts optical information such as a CCD (Charge Coupled Device) into an electrical signal. It is configured. In the present embodiment, the image input device 2 outputs the reflected light image from the document to the image processing device 3 as RGB (R: red, G: green, B: blue) analog signals.

  FIG. 5 is a cross-sectional view illustrating an example of the image input device 2. The image input apparatus 2 shown in this figure includes an upper housing 60 and a lower housing 61. The upper housing (original cover) 60 includes an original holding mat 57, an alignment roller pair 55, an original conveying path 56, an image sensor unit 53, an upper original conveying guide 58, and the like, and the lower casing 61 has a first contact. A glass (original table) 51, a second contact glass 52, a reading unit 70, a light shielding member 59, and the like are provided. Further, the upper housing 60 is configured to be openable and closable with respect to the lower housing 61.

  The image input device 2 includes (1) a stationary reading mode in which the reading unit 70 reads the lower surface side of the document placed on the first contact glass 51, and (2) travels (moves) on the second contact glass 52. The reading reading unit 70 reads the lower surface side of the original to be read, and (3) the lower surface side of the original traveling (moving) on the second contact glass 52 is read by the reading unit 70 and the upper surface side is read by the image sensor unit 53. A double-sided scanning mode is provided.

  The alignment roller pair 55 is for aligning the angle of the original so that the leading edge of the conveyed original is perpendicular to the conveyance direction in the traveling reading mode and the double-sided reading mode. When the leading edge of the conveyed document comes into contact with the nip portion of the alignment roller pair 55 in the rotation stopped state, a predetermined deflection is formed on the document, and then the orientation of the document is aligned by rotating the alignment roller pair 55. Then, it is conveyed downstream of the alignment roller pair 55.

  The image sensor unit 53 is for reading an image on the upper surface side of the document conveyed on the second contact glass 52 when the duplex mode is selected.

  The document pressing mat 57 is used to stabilize the position of the document by pressing the document placed on the first contact glass 51 against the first contact glass 51 when the stationary reading mode is selected.

  The reading unit 70 includes a first scanning unit 63, a second scanning unit 64, an imaging lens 65, and a CCD (Charge Coupled Device) 66.

  The first scanning unit 63 includes a light source (exposure lamp) 62 that exposes a reading surface of a document, and a first reflection mirror 67 that reflects reflected light from the document toward the second scanning unit 64.

  In the stationary reading mode, the first scanning unit 63 moves at a constant speed V by a distance corresponding to the document size from the position P in the drawing to the right in parallel with the first contact glass 51. A document placed on one contact glass 51 is exposed with light emitted from a light source 62, and reflected light from the document is reflected by a first reflection mirror 67 and guided to a second scanning unit 64. The document size described above is a result of detecting the size of the document placed on the first contact glass 51 by a document size detection unit (not shown) (for example, a document size detection unit including a photoelectric conversion element such as a phototransistor). Alternatively, it may be input by the user via the operation panel. In the present embodiment, the first contact glass 51 is formed in a size that can read a document of up to A3 size.

  The first scanning unit 63 also emits light emitted from the light source 62 at the predetermined position facing the second contact glass 52 in the traveling reading mode and the double-sided reading mode. The reflected light from the original is reflected by the first reflecting mirror 67 and guided to the second scanning unit 64.

  The second scanning unit 64 includes a second reflecting mirror 68 and a third reflecting mirror 69, and is configured to guide light incident from the first reflecting mirror 67 to the imaging lens 65 and the CCD 66 by these mirrors. ing. The second scanning unit 64 moves at a speed of V / 2 following the first scanning unit 63 in the stationary reading mode.

  The light shielding member 59 is for preventing the image sensor unit 53 from reading an image at an appropriate density due to the light of the light source 62 of the reading unit 54 entering the image sensor unit 53.

  The imaging lens 65 is for imaging the reflected light from the original incident from the third reflection mirror 69 on the CCD 66.

  The CCD 66 is for converting light incident through the imaging lens 65 into an analog electric signal. This electric signal is converted into digital image data by an image processing device 3 described later. In the double-sided reading mode, the image data on the lower surface side of the document read by the reading unit 70 is input to the image processing device 3 and processed, and then the image on the upper surface side of the document read by the image sensor unit 53. Data is input to the image processing apparatus 3 and processed. While the image data on the lower surface side of the document is being processed in the image processing device 3, the image data on the upper surface side of the document read by the image sensor unit 53 is temporarily stored in a memory (not shown) and is stored on the upper surface side of the document. When the processing for the image data is completed, it is read from this memory and sent to the image processing device 3 for processing.

  As shown in FIGS. 2 to 4, the image processing apparatus 3 includes an A / D conversion unit 11, a shading correction unit 12, an input processing unit 13, a document detection unit (condition detection unit, image area detection unit) 14, document correction. 15, color correction unit (color conversion unit) 16, black generation and under color removal unit 17, spatial filter processing unit 18, output tone correction unit 19, halftone generation unit (halftone generation unit) 20, region separation unit 21 A transmission data generation unit 22, a storage unit 23, and a control unit 24. The storage unit 23 is a storage unit that stores various data (image data and the like) handled by the image processing apparatus 3. The configuration of the storage unit 23 is not particularly limited, and for example, a hard disk or the like can be used. The control unit 24 is a control unit that controls the operation of each unit provided in the image processing apparatus 3. The control unit 24 may be provided in a main control unit (not shown) of the digital color multifunction peripheral 1, and is provided separately from the main control unit and performs processing in cooperation with the main control unit. It may be a thing.

  In the image forming mode, the image processing apparatus 3 outputs CMYK image data obtained by performing various image processing on the image data input from the image input apparatus 2 to the image output apparatus 4. In the normal transmission mode, the image data input from the image input device 2 is subjected to image processing such as tilt correction processing, document image region extraction processing, scaling processing, and rotation processing, and based on the image data after image processing. R'G'B 'image data (for example, sRGB data) suitable for the display characteristics of display devices that are widely used, and the generated R'G'B' image data is converted into a predetermined format. And output to the communication device 5. Further, in the simple transmission mode, based on the image data input from the image input device 2, a document image area corresponding to the document image in this image data is detected, and the color of the area other than the document image area is set to a predetermined color. Convert to color (eg white or black). Further, based on the image data obtained by converting the color of the area other than the original image area as described above, R′G′B ′ image data (for example, sRGB data) suitable for the display characteristics of a display device that is generally popular. ) And image data compressed in a predetermined format, and parameters relating to tilt correction processing, top correction processing, image extraction processing, and the like to be applied when the image data is displayed on an external device The drawing command is converted into a predetermined format and output to the communication device 5. Details of the image processing apparatus 3 will be described later.

  The image output device 4 outputs the image data input from the image processing device 3 onto a recording material (for example, paper). The configuration of the image output device 4 is not particularly limited, and for example, an image output device using an electrophotographic method or an inkjet method can be used.

  The communication device 5 is composed of a modem or a network card, for example. The communication device 5 performs data communication with another device (for example, a personal computer, a server device, a display device, another digital multifunction peripheral, a facsimile device, etc.) connected to the network via a network card, a LAN cable, or the like. . When transmitting the image data, the communication device 5 reads the image data compressed in a predetermined format from the memory, changes the compression format, etc. when the transmission state with the other party is ensured and the transmission is possible. Necessary processing is performed, and the data is sequentially transmitted to the other party via the communication line. Further, when receiving the image data, the communication device 5 performs a communication procedure, receives the image data transmitted from the other party, and inputs it to the image processing device 3. The received image data is subjected to predetermined processing such as expansion processing, rotation processing, resolution conversion processing, output gradation correction, gradation reproduction processing, and the like by the image processing apparatus 3 and is output by the image output apparatus 4. Note that the received image data may be stored in a storage device (not shown), and the image processing device 3 may read it out as necessary to perform the predetermined processing.

  The operation panel 6 includes, for example, a display unit such as a liquid crystal display and setting buttons (none of which are shown), and information corresponding to an instruction from a main control unit (not shown) of the digital color multifunction peripheral 1 is described above. While displaying on a display part, the information input from a user via the said setting button is transmitted to the said main control part. The user can input various information such as a processing mode, the number of printed sheets, a paper size, and a transmission destination address for the input image data via the operation panel 6.

  The main control unit includes, for example, a CPU (Central Processing Unit) and the like, and is based on programs and various data stored in a ROM (not shown) and the like, information input from the operation panel 6, and the like. To control the operation.

  Next, processing in each mode described above in each unit provided in the image processing apparatus 3 will be described.

(2) Outline of Processing in Image Processing Device 3 FIG. 1 is a flowchart showing a schematic processing flow in the image processing device 3. As shown in this figure, first, the control unit 24 accepts a processing mode selection instruction from the user input via the operation panel 6 (S1). Further, image data obtained by reading a document is acquired from the image input device 2 (S2).

  Thereafter, the control unit 24 causes the document detection unit (condition detection unit) 14 to detect the tilt angle (S3) and to determine the vertical direction (S4).

  Thereafter, the control unit 24 determines whether or not the processing mode selected and instructed in S1 is the image forming mode (S5). If it is determined that the image forming mode is selected, the document correction unit 15 is caused to perform an inclination correction process based on the detection result of the inclination angle in S2 (S6), and the document correction is performed based on the determination result of the vertical direction in S3. The unit 15 performs the top / bottom correction processing (S7), causes the image output device 4 to output the image data subjected to the tilt correction processing and the top / bottom correction processing (S8), and ends the processing.

  On the other hand, if it is determined in S5 that the image forming mode is not selected, the control unit 24 causes the document detection unit (image region detection unit) 14 to perform document image region detection processing in the image data (S9).

  Further, the control unit 24 determines whether or not the processing mode selected and instructed in S1 is the simple transmission mode (S10). If it is determined that the mode is not the simple transmission mode, the control unit 24 determines that the mode is the normal transmission mode, and causes the document correction unit 15 to perform tilt correction processing based on the detection result of the tilt angle in S2 (S11). Based on the determination result of the vertical direction in S3, the original correction unit 15 performs the vertical correction process (S12), and causes the original correction unit 15 to perform the image extraction process based on the determination result of the original image area in S9 (S13). ).

  The control unit 24 causes the transmission data generation unit 22 to perform character recognition processing (S14), generates transparent text based on the result of the character recognition processing (S15), and converts the image data and transparent text into a predetermined format. An image file formatted according to (in this embodiment, PDF format) is generated (S16), the formatted image file is output to the communication device 5 (S17), and the process is terminated.

  On the other hand, if it is determined in S10 that the simple transmission mode is set, the control unit 24 causes the color correction unit 16 to convert the color of each pixel belonging to an area other than the original image area in the image data to a predetermined color (S18). . The predetermined color is not particularly limited. For example, the predetermined color is replaced with white (255 for 8-bit image data) or black (0 for 8-bit image data). . In addition, the control unit 24 causes the transmission data generation unit 22 to extract the tilt angle detection result, the top / bottom determination result, and the document image area determination result by the document detection unit 14 (S19), and based on these extraction results, the external device A drawing command to be applied when displaying image data is generated (S20). In addition, the control unit 24 causes the transmission data generation unit 22 to perform character recognition processing (S21), and generates transparent text based on the result of the character recognition processing (S22). Then, the control unit 24 controls the transmission data generation unit 22 to compress the image data obtained by converting the color of the area other than the original image area into a predetermined color, the drawing command, and the transparent text into a predetermined format. An image file formatted according to (in this embodiment, PDF format) is generated (S23), the formatted image file is output to the communication device 5 (S17), and the process is terminated.

(3) Image Forming Mode Next, the operation of the image processing apparatus 3 in the image forming mode will be described in more detail. In the case of the image forming mode, as shown in FIG. 2, first, the A / D conversion unit 11 converts RGB analog signals input from the image input device 2 into digital signals and outputs them to the shading correction unit 12.

  The shading correction unit 12 performs a process of removing various distortions generated in the illumination system, the imaging system, and the imaging system of the image input device 2 on the digital RGB signal sent from the A / D conversion unit 11, The data is output to the input processing unit 13.

  The input processing unit (input gradation correction unit) 13 adjusts the color balance of the RGB signal from which various distortions have been removed by the shading correction unit 12 and is also used in the image processing apparatus 3 such as a density signal. The signal is converted into a signal that can be easily handled by an image processing system. Also, image quality adjustment processing such as background density removal and contrast is performed. Further, the input processing unit 13 causes the storage unit 23 to store the image data subjected to each of the above processes.

  A document detection unit (condition detection unit) 14 detects an inclination angle of the document image, a vertical direction, a document image region where a document image exists in the image data, and the like based on the image data. The document correction unit 15 performs an inclination correction process, a top-and-bottom correction process, an image extraction process, and the like on the image data based on the detection result of the document detection unit 14.

  FIG. 6 is a block diagram illustrating a schematic configuration of the document detection unit 14. As shown in this figure, the document detection unit 14 includes a signal conversion unit 31, a binarization processing unit 32, a resolution conversion unit 33, a document inclination detection unit 34, a document top / bottom determination unit 35, and an image region determination unit 36. ing.

  When the image data subjected to the above-described processes by the input processing unit 13 is a color image, the signal conversion unit 31 achromatically converts the image data into a lightness signal or a luminance signal.

  For example, the signal conversion unit 31 converts the RGB signal into the luminance signal Y by calculating Yi = 0.30Ri + 0.59Gi + 0.11Bi. Here, Y is a luminance signal of each pixel, R, G, and B are each color component in the RGB signal of each pixel, and the subscript i is a value assigned to each pixel (i is an integer of 1 or more). It is.

  Alternatively, the RGB signal may be converted into a CIE 1976 L * a * b * signal (CIE: Commission International de l'Eclairage, L *: brightness, a *, b *: chromaticity).

  The binarization processing unit 32 binarizes the image data by comparing the achromatic image data (brightness value (brightness signal) or brightness value (brightness signal)) with a preset threshold value. . For example, when the image data is 8 bits, the threshold value is set to 128. Or it is good also considering the average value of the density | concentration (pixel value) in the block which consists of a some pixel (for example, 5 pixels x 5 pixels) as a threshold value.

  The resolution conversion unit 33 converts the resolution of the binarized image data to a low resolution. For example, image data read at 1200 dpi or 600 dpi is converted to 300 dpi. The resolution conversion method is not particularly limited, and for example, a known nearest neighbor method, bilinear method, bicubic method, or the like can be used.

  The document tilt detection unit 34 detects the tilt angle of the document with respect to the scan range (normal document position) at the time of image reading, based on the image data converted to the low resolution by the resolution conversion unit 33. That is, as shown in FIG. 7, when the position of the document at the time of image reading is tilted with respect to the scan range (regular document position) in the image input device 2, this tilt angle is detected.

  The method for detecting the tilt angle is not particularly limited, and various conventionally known methods can be used. For example, the method described in Patent Document 2 may be used. In this method, a plurality of boundary points between black pixels and white pixels (for example, coordinates of white / black boundary points at the upper end of each character) are extracted from the binarized image data, and a point sequence of each boundary point is extracted. Find the coordinate data. And a regression line is calculated | required based on the coordinate data of this point sequence, and the regression coefficient b is computed based on following formula (1).

b = Sxy / Sx (1)
Sx and Sy are the residual sum of squares of the variables x and y, respectively, and Sxy is the sum of the products of the residual of x and the residual of y. That is, Sx, Sy, and Sxy are expressed by the following formulas (2) to (4).

  Then, the inclination angle θ is calculated based on the following equation (5) from the regression coefficient b calculated as described above.

tan θ = b (5)
The document inclination detection unit 34 detects the edge (edge portion) of the document, and coordinates P1 (X1, Y1), P2 (X2, Y2), P3 (X3, Y3), P4 of each corner of the document. (X4, Y4) is calculated, and based on the calculation result, a document image area which is a region corresponding to the document image in the image data is detected. As shown in FIG. 7, even when the corner of the document does not exist within the range of the image data, the coordinates of the edge are determined based on the detection result of the edge of the document and the detection result of the tilt angle. calculate.

  In the present embodiment, first, with respect to image data read by the image input device 2, the pixel value of the pixel of interest and the adjacent pixel is larger than a predetermined threshold value (for example, 40) for each line unit in the sub-scanning direction. Among them, the coordinates of the leftmost pixel and the coordinates of the rightmost pixel are calculated as edge coordinates. Next, from the edge coordinates calculated for all the lines of the image data, the edge coordinates that are the uppermost, lower, left, and right parts are extracted.

Accordingly, in the example illustrated in FIG. 7, the following coordinates are extracted as the edge coordinates that are the uppermost part, the lower part, the left part, and the right part.
Upper part: P2 (X2, Y2)
Lower part: p1 (x1, y1), p3 (x3, y1) where x1 <x2
Left part: P1 (X1, Y1)
Right part: p2 (x2, y2), p4 (x2, y4) where y2 <y4
As described above, when two points are extracted from any of the coordinates of the uppermost, lower, left, and right portions, in the present embodiment, these two points are connected to the coordinates of the other extracted portions. Based on the straight line, the coordinates of the corners of the document existing outside the reading range are calculated. If one point is extracted for each of the coordinates of the uppermost, lower, left, and right portions, these points may be calculated as the coordinates of the corners of the document.

  Specifically, in the case of FIG. 7, a straight line connecting point P1 and point p1, a straight line connecting P2 and p2, and a straight line connecting p3 and p4 are obtained. Then, the intersection point between the straight line connecting the points P1 and p1 and the straight line connecting p3 and p4 is calculated as P3, and the intersection between the straight line connecting P2 and p2 and the straight line connecting p3 and p4 is calculated as P4.

  It should be noted that the number of pixels between P1 and P2 and the number of pixels between P1 and p3 are obtained, and the relationship between the vertical and horizontal resolutions and the number of pixels in a document of a predetermined size stored in advance ( For example, the size of the original may be estimated based on Table 1), and the coordinates of the corners P1 to P4 may be obtained based on the estimation result.

  In Table 1, as shown in FIG. 24, when the original is placed so that the short side of the first contact glass (original table) 51 and the long side of the original are substantially parallel, A case where the original is placed so that the short side of the first contact glass (original table) 51 and the short side of the original are substantially parallel is referred to as horizontal placement. R1 in Table 1 indicates the reading resolution in the main scanning direction (the direction along the short side of the first contact glass (document table) 51), and R2 indicates the sub-scanning direction (first contact glass (document table). ) The reading resolution in the direction along the long side of 51).

  Further, in consideration of variations when calculating the edge of the document, the range of the document image may be calculated wider by a predetermined width (for example, about 10 mm) than the edge detection result.

  Further, when the simple transmission mode or the tilt correction mode is selected, the image input device 2 reads the document so that the entire document can be read even when the document is placed on the document table in a tilted state. An area wider than the maximum possible size document may be read. For example, in the example shown in FIG. 7, the entire length in the vertical direction of the document table is read in the main scanning direction, and the long side of the A3 size, which is the maximum size that can be read by the image input device 2 in the sub-scanning direction. A range corresponding to this may be read. Further, the entire area of the document table may be read in both the main scanning direction and the sub-scanning direction.

  The document top / bottom determination unit 35 determines the top / bottom direction (vertical direction) of the document based on the image data binarized by the binarization processing unit 32 and reduced in resolution by the resolution conversion unit 33.

  It should be noted that the document correction unit 15 performs a tilt correction process on the image data based on the detection result of the document tilt detection unit 34, and the signal conversion unit 31, the binarization processing unit 32, and the resolution conversion unit 33 perform the image after the tilt correction. The signal conversion process, the binarization process, and the resolution conversion process are performed on the data, and the document top / bottom determination unit 35 performs the signal conversion process, the binarization process, and the resolution conversion process on the image data after the inclination correction. The top / bottom determination processing may be performed based on the applied image data.

  Further, the determination method of the vertical direction of the original is not particularly limited, and various conventionally known methods can be used. For example, the method described in Patent Document 3 may be used.

  In the method of Patent Document 3, character recognition processing is performed based on image data, each character in the document is cut out for each character, and each character is patterned. This process is performed using image data that has been binarized and reduced in resolution to 300 dpi. In addition, it is not always necessary to perform the character recognition process for all characters, and for example, a predetermined number of characters may be extracted and performed.

  Thereafter, matching (comparison) between the character pattern characteristics and the character pattern information stored in the database in advance is performed. As a matching method, the character pattern cut out from the image data is superimposed on the character pattern created in the database and the black and white for each pixel is compared, and the characters in the image data are all of the character patterns created in the database. It is determined that the character pattern matches the character. When there is no character pattern that matches all, the character in the image data is determined as the character pattern having the largest number of matching pixels. However, if the ratio of the number of matching pixels does not reach a predetermined matching ratio, it is determined that the discrimination is impossible.

  Then, the character recognition process is performed for each of the image data rotated by 90 °, 180 °, and 270 °. Thereafter, for each of 0 °, 90 °, 180 °, and 270 °, the number of distinguishable characters is calculated, and the rotation angle with the largest number of distinguishable characters is the character direction, that is, the normal vertical direction of the document. Judge as. Then, the rotation angle for matching the vertical direction of the document image in the image data with the normal vertical direction is determined. Specifically, the angle in the clockwise direction with respect to the normal vertical direction is positive, and the vertical direction (reference direction) of the document image in the image data matches the normal vertical direction as shown in FIG. Is 0 °, and when the vertical direction of the original image in the image data is −90 ° different from the normal vertical direction, the rotation angle is 90 °, and the vertical direction of the original image in the image data is normal vertical. The rotation angle is 180 ° when it is different by −180 ° with respect to the direction, and the rotation angle is 270 ° when the vertical direction of the original image in the image data is −270 ° different from the normal vertical direction. To do.

  The image region determination unit 36 determines a document image region (region where a document image is drawn) included in the image data binarized by the binarization processing unit 32 and reduced in resolution by the resolution conversion unit 33. The determination result is output to the document correction section 15.

  The method for determining the document image area is not particularly limited, and various conventionally known methods can be used. For example, as shown in FIG. 9, a histogram relating to black pixels is created for each of the main scanning direction and the sub-scanning direction, and the coordinates of image data existing at the leftmost, rightmost, uppermost, and lowermost positions are determined based on this histogram. Can be used.

  The document correction unit 15 performs a tilt correction process on the image data based on the tilt angle detection result of the document tilt detection unit 34. At this time, when a part of the document protrudes from the image data, as shown by the hatched portion in FIG. 7, that is, when a part of the document is out of the scanning range, Replace with a predetermined color (for example, white (255 in the case of 8-bit image data)).

  Further, based on the determination result of the document top / bottom determination unit 35, the top / bottom correction is performed so that the top / bottom direction of the image data matches the top / bottom direction of the document image included in the image data for the image data after the inclination correction processing. Processing (90 ° unit rotation processing) is performed.

  The document correction unit 15 extracts image data corresponding to the document image area determined by the image area determination unit 36 from the image data subjected to the inclination correction process and the top / bottom correction process, and the extraction. A scaling process (enlargement or reduction process) is performed so that the obtained image data has a predetermined size (for example, a size corresponding to the size of the recording material used in the image output device 4). Further, the document correction unit 15 outputs the image data subjected to each of the above processes to the color correction unit 16 and the region separation unit 21.

  Note that the image data that has been subjected to the above-described processes by the document correction unit 15 may be managed as filing data. In this case, the image data is compressed into a JPEG code based on, for example, a JPEG compression algorithm and stored in the storage unit 23. When a copy output operation or print output operation is instructed for this image data, a JPEG code is extracted from the storage unit 23 and transferred to a JPEG decompression unit (not shown), and subjected to a decoding process to obtain RGB data. Is converted to When a transmission operation is instructed for the image data, a JPEG code is extracted from the storage unit 23 and transmitted from the communication device 5 to an external device via a network or communication line.

  The color correction unit 16 performs a process of removing color turbidity based on spectral characteristics of CMY (C: cyan, M: magenta, Y: yellow) color materials including unnecessary absorption components in order to realize faithful color reproduction. Is. In the simple transmission mode, the color correction unit 16 performs processing for converting the color of each pixel belonging to an area other than the document image area in the image data into a predetermined color.

  The black generation and under color removal unit 17 generates black (K) signals from the CMY three-color signals after color correction, and subtracts the K signals obtained by black generation from the original CMY signals to generate new CMY signals. The process to generate is performed. As a result, the CMY three-color signal is converted into a CMYK four-color signal.

  The spatial filter processing unit 18 performs spatial filter processing (enhancement processing and / or smoothing processing) using a digital filter on the image data of the CMYK signal input from the black generation and under color removal unit 17 based on the region identification signal. And correct the spatial frequency characteristics. As a result, blurring of the output image and deterioration of graininess can be reduced.

  Similar to the spatial filter processing unit 18, the halftone generation unit 20 performs predetermined processing on the image data of the CMYK signal based on the region identification signal. For example, the region separated into characters by the region separating unit 21 has a large high frequency enhancement amount by sharp enhancement processing in the spatial filter processing by the spatial filter processing unit 18 in order to improve the reproducibility of black characters or color characters in particular. Is done. At the same time, the halftone generation unit 20 selects the binarization or multi-value processing on the high-resolution screen suitable for reproducing the high frequency. Further, with respect to the region separated into halftone dot regions by the region separation unit 21, the spatial filter processing unit 18 performs low-pass filter processing for removing the input halftone component. The output tone correction unit 19 performs an output tone correction process for converting a signal such as a density signal into a halftone dot area ratio that is a characteristic value of the image output device 4. In particular, gradation reproduction processing (halftone generation) is performed in which an image is separated into pixels and processed so that each gradation can be reproduced. For the area separated into photographs by the area separation unit 21, binarization or multi-value processing is performed on the screen with an emphasis on gradation reproducibility.

  The region separation unit 21 separates each pixel in the input image into any one of a black character region, a color character region, a halftone dot region, and a photographic paper photograph (continuous tone region) region based on the RGB signal. Based on the separation result, the region separation unit 21 outputs a region separation signal indicating to which region the pixel belongs to the black generation and under color removal unit 17, the spatial filter processing unit 18, and the halftone generation unit 20. .

  The transmission data generation unit 22 includes an information extraction unit 41, a character recognition unit 42, a drawing command generation unit 43, and a formatting processing unit 44. The transmission data generation unit 22 does not operate in the image forming mode. Details of the transmission data generation unit 22 will be described later.

  The image data subjected to the above-described processes is temporarily stored in a memory (not shown), read out at a predetermined timing, and input to the image output device 4.

(4) Normal transmission mode (normal mode)
Next, the operation of the image processing apparatus 3 in the normal transmission mode will be described in more detail with reference to FIG. Note that the processes of the A / D conversion unit 11, the shading correction unit 12, the input processing unit 13, the document correction unit 15, and the region separation unit 21 in the normal transmission mode are the same as those in the image forming mode. The region separation unit 21 outputs the region separation signal to the spatial filter processing unit 18 and the halftone generation unit 20.

  The document detection unit 14 performs the same operation as that in the image forming mode, and outputs the binarized and reduced resolution image data to the transmission data generation unit 22.

  The color correction unit 16 converts the RGB image data input from the document correction unit 15 into R′G′B ′ image data (for example, sRGB data) suitable for display characteristics of a display device that is generally popular. And output to the black generation and under color removal unit 17. In the normal transmission mode, the black generation and under color removal unit 17 outputs (through) the image data input from the color correction unit 16 to the spatial filter processing unit 18 as it is.

  The spatial filter processing unit 18 applies spatial filter processing (enhancement processing and / or smoothing) to the R′G′B ′ image data input from the black generation and under color removal unit 17 based on the region identification signal. And output to the output tone correction unit 19. The output tone correction unit 19 outputs (through) the image data input from the spatial filter processing unit 18 to the halftone generation unit 20 as it is in the normal transmission mode.

  The halftone generation unit 20 performs a predetermined process on the R′G′B ′ image data input from the output tone correction unit 19 based on the region identification signal, and outputs the processed data to the transmission data generation unit 22. For example, the halftone generation unit 20 performs correction using a gamma curve indicated by a solid line in FIG. 10 for a character region, and applies a gamma curve indicated by a broken line in FIG. 10 to a region other than the character region. Perform the corrections used. As the gamma curve for the area other than the character area, for example, a curve corresponding to the display characteristics of the display device provided in the external device of the transmission destination is set so that the gamma curve in the character area can clearly display characters. It is preferable to set.

  The R′G′B ′ image data output from the halftone generation unit 20 is input to the formatting processing unit 44 of the transmission data generation unit 22.

  The information extraction unit 41 of the transmission data generation unit 22 outputs (through) the image data input from the document detection unit 14 to the character recognition unit 42 as it is.

  The character recognizing unit 42 extracts the feature amount of the character included in the image data based on the image data input from the information extracting unit 41, compares the extraction result with the dictionary data, and performs character recognition. Then, the character recognition result is output to the drawing command generation unit 43. The character recognition processing method is not particularly limited, and various conventionally known methods can be used.

  Further, as indicated by a broken line in FIG. 3, the document detection unit 14 outputs the binarized and reduced resolution image data to the document correction unit 15 instead of outputting it to the transmission data generation unit 22, and the document correction unit 15 outputs the image data obtained by performing the inclination correction processing on the binarized and low-resolution image data to the transmission data generation unit 22, and the character recognition unit 42 of the transmission data generation unit 22 performs the inclination correction. Character recognition processing may be performed using the image data. Thereby, the accuracy of character recognition can be improved compared with the case where character recognition is performed based on image data before inclination correction.

  The drawing command generation unit 43 generates a transparent text based on the character recognition result by the character recognition unit 42 and outputs it to the formatting processing unit 44. Here, the transparent text is data for superimposing (or embedding) recognized characters as text information in a form that is not apparently visible. For example, in a PDF file, an image file in which transparent text is added to image data is generally used.

  The formatting processor 44 compresses the image data input from the halftone generator 20 in a predetermined format, and based on the compressed image data and the transparent text generated by the drawing command generator 43. An image file of a predetermined format is generated and output to the communication device 5. In the present embodiment, the image data (R′G′B ′ image data) subjected to display image processing input from the halftone generation unit 20 is changed to the PDF format, and based on the character recognition result. The generated transparent text is embedded in the image drawing description part (command description part) of each image file. Details of the image file will be described later.

  In this embodiment, the transparent text is added to the image data for transmission. However, the present invention is not limited to this, and the formatting processing unit 44 converts the image data input from the halftone generation unit 20 to a predetermined value. You may make it transmit to a format, without adding a transparent text. If no transparent text is added, data output from the document detection unit 14 to the transmission data generation unit 22 may not be performed.

  The communication device 5 transmits the image file input from the formatting processing unit 44 to an external device that is communicably connected via a network. For example, the communication device 5 transmits the image file attached to an electronic mail by a mail processing unit (job device) (not shown).

(4) Simple transmission mode (simple mode)
Next, the operation of the image processing apparatus 3 in the simple transmission mode will be described in more detail with reference to FIG. In the simple transmission mode, the A / D conversion unit 11, the shading correction unit 12, the input processing unit 13, the document detection unit 14, the color correction unit 16, the black generation and under color removal unit 17, the spatial filter processing unit 18, and the output gradation The processes of the correction unit 19, the halftone generation unit 20, and the region separation unit 21 are the same as those in the normal transmission mode.

  The document detection unit 14 sends the binarized and reduced resolution image data, the tilt angle detection result, the determination result of the top-and-bottom direction, and the determination result of the document image region to the transmission data generation unit 22. The document detection unit 14 outputs the R, G, and B image data input from the input processing unit 13 to the document correction unit 15 as it is. Alternatively, the document detection unit 14 may store the R, G, B image data input from the input processing unit 13 in the storage unit 23, and the document correction unit 15 may read the image data from the storage unit 23. Good.

  The document correction unit 15 outputs (through) the R, G, and B image data to the color correction unit 16 and the region separation unit 21 as they are. That is, in the simple transmission mode, the document correction unit 15 does not perform the inclination correction process, the top / bottom correction process, and the image extraction process for the R, G, and B image data.

  The color correction unit 16 converts the RGB image data input from the document correction unit 15 into R′G′B ′ image data (for example, sRGB data) suitable for display characteristics of a display device that is generally popular. At the same time, a process of converting the color of each pixel belonging to an area other than the original image area in the image data into a predetermined color (for example, white) is output to the black generation and under color removal unit 17. The black generation and under color removal unit 17 outputs (through) the image data input from the color correction unit 16 to the spatial filter processing unit 18 as it is in the simple transmission mode.

  The spatial filter processing unit 18 applies spatial filter processing (enhancement processing and / or smoothing) to the R′G′B ′ image data input from the black generation and under color removal unit 17 based on the region identification signal. And output to the output tone correction unit 19. The output tone correction unit 19 outputs (through) the image data input from the spatial filter processing unit 18 as it is to the halftone generation unit 20 in the simple transmission mode.

  The halftone generation unit 20 performs the same processing as that in the normal transmission mode on the R′G′B ′ image data input from the output tone correction unit 19 and outputs the processed image data to the transmission data generation unit 22. The R′G′B ′ image data output from the halftone generation unit 20 is input to the formatting processing unit 44 of the transmission data generation unit 22.

  The information extraction unit 41 of the transmission data generation unit 22 receives information indicating the tilt angle detection result, the top / bottom direction determination result, and the document image region determination result (coordinates of the document region) from the data input from the document detection unit 14. Each document is extracted and output to the character recognition unit 42 together with the binarized and reduced resolution image data.

  The character recognition unit 42 performs character recognition processing based on the image data input from the information extraction unit 41, and draws the character recognition result, the inclination angle detection result, the top / bottom direction determination result, and the document image region determination result. The data is output to the generation unit 43.

  The drawing command generation unit 43 is output from the halftone generation unit 20 based on the character recognition result, the tilt angle detection result, the top / bottom direction determination result, and the document image area determination result input from the character recognition unit 42. A rendering command for displaying the image data by causing the computer provided in the external device of the transmission destination to execute the inclination correction process, the top and bottom correction process, and the image extraction process is generated and output to the formatting processing unit 44. Further, the drawing command generation unit 43 generates a transparent text based on the character recognition result by the character recognition unit 42 and outputs it to the formatting processing unit 44.

  The formatting processing unit 44 compresses the image data input from the halftone generation unit 20 in a predetermined format, the compressed image data, the drawing command generated by the drawing command generation unit 43, and transparent text Based on the above, an image file of a predetermined format is generated and output to the communication device 5. In the present embodiment, the image data subjected to display image processing input from the halftone generation unit 20 is changed to the PDF format, and the drawing command and the transparent text generated by the drawing command generation unit 43 are changed to each image. An image file embedded in an image drawing description part (command description part) corresponding to the data is generated.

  FIG. 11 is an explanatory diagram showing the configuration of a PDF image file generated by the formatting processor 44. As shown in this figure, the image file is composed of a header part, a body part, a cross reference table, and a trailer part.

  The header portion includes a character string indicating that this file is a PDF file and a version number. The body part includes information to be displayed and page information. The cross-reference table describes address information for accessing the contents of the body part. In the trailer section, information indicating where to read first is described.

  The body part includes a document catalog description part, a page description part, an image data description part, and an image drawing description part (command description part). A page description part, an image data description part, and an image drawing description part are provided corresponding to each page.

  In the document catalog description section, reference information for an object composed of each page is described. FIG. 12A shows an example of description contents for the document catalog description part. Information such as a display range for each page is described in the page description portion. FIG. 12B shows an example of description contents for the page description part. In the example shown in this figure, the description “/ MediaBox [0.00000 0.00000 593.28003 842.88000]” defines the display range. Image data is described in the image data description section. FIG. 12C shows an example of description contents for the image data description part. In the image drawing description part, conditions to be applied when drawing the corresponding page are described. In the present embodiment, drawing commands related to tilt correction processing, top and bottom correction processing, and image extraction processing are described in this image drawing description section.

  FIG. 13A shows an example of image data read by the image input apparatus 2. FIG. 14 shows an example of description contents for the image drawing description part, and shows conditions applied when drawing the image data shown in FIG. In the example shown in this figure, the part “0.985 -0.174 0.174 0.985 -139.003 65.609 cm” indicates the contents relating to the inclination correction process and the parallel movement process. As a result, a clockwise rotation process (tilt correction process) of 10 degrees is performed, and a parallel movement is performed to match the coordinates of the lower left corner of the document image with the coordinates (origin) of the lower left corner of the displayed image. It is like that. “737.28 0.00 0.00 894.24 0.00 0.00 cm” indicates a display setting according to the image size and the image resolution, and the image is displayed in a desired size. FIG. 13B shows an image displayed when the image data of FIG. 13A is drawn by applying the conditions of FIG. In this example, the process of extracting the document image area is not performed, but since the page display range is set to the same size as the document, an image having a size corresponding to the document is displayed as a result. In this example, the lower left portion of the document is not included in the scan range of the image input apparatus 2 and there is no image data, so this portion is displayed in white.

  FIG. 15A shows an example of image data read by the image input apparatus 2. FIG. 16 shows an example of description contents for the image drawing description section, and shows conditions applied when drawing the image data shown in FIG. In the example shown in this figure, a document image area is extracted from image data, and only the image of the extracted area is displayed. “55.44 81.84 593.28 842.88 re W n” in FIG. 16 indicates the contents related to the document image region extraction processing. In the example shown in this figure, the lower left coordinates, the horizontal width, and the height in the rectangular extraction region are defined. FIG. 15B shows an image displayed when the image data of FIG. 15A is drawn by applying the conditions of FIG. As shown in this figure, the area outside the original image area is displayed in white.

  FIG. 17A shows an example of image data read by the image input apparatus 2. FIG. 18 shows an example of description contents for the image drawing description part, and shows conditions applied when drawing the image data shown in FIG. In the example shown in this figure, an area of a document image is extracted from image data, and the image of the extracted area is subjected to tilt correction processing and displayed. In FIG. 18, “101.00 270.00 593.28 842.88 re W n” indicates the content related to the document image area extraction processing, and “0.985 -0.174 0.174 0.985 -111.402 80.185 cm” indicates the content related to the tilt correction processing and the parallel movement processing. Yes. FIG. 17B shows an image displayed when the image data of FIG. 17A is drawn by applying the conditions of FIG. In the example shown in this figure, an area of a document image is extracted, and a 10 degree rotation process (tilt correction process) is performed clockwise around the center of the document. An area outside the original image area is displayed in white.

FIG. 19A shows an example of image data read by the image input apparatus 2. FIG. 20 shows an example of description contents for the image drawing description section, and shows conditions applied when drawing the image data shown in FIG. In the example shown in this figure,
The portion “0.985 -0.174 0.174 0.985 -211.402 -190.185 cm” indicates the contents related to the tilt correction process and the parallel movement process, and indicates that the rotation process (tilt correction process) is performed 10 degrees clockwise. FIG. 19B shows an image displayed when the image data of FIG. 19A is drawn by applying the conditions of FIG. In the example shown in this figure, the document image extraction process is not performed, but the display area is set to the same size as the document, so that an image outside the range of the document image is not displayed.

  The communication device 5 transmits the image file input from the formatting processing unit 44 to an external device that is communicably connected via a network. For example, the communication device 5 transmits the image file attached to an electronic mail by a mail processing unit (job device) (not shown). The external device displays the received image file with reference to a drawing command embedded in the image drawing description part (command description part). Accordingly, it is possible to display the image data that has been subjected to the tilt correction process, the top and bottom correction process, and the image extraction process in the external device. In addition, search processing, audio output processing, and the like can be performed using transparent text embedded in an image file.

  In the present embodiment, the drawing commands related to the tilt correction process, the top and bottom correction process, and the image extraction process are embedded in the image file and transmitted, but the present invention is not limited to this.

  For example, a drawing command related to any one or more of tilt correction processing, top and bottom correction processing, and image extraction processing may be embedded in an image file and transmitted.

  In addition to the above-described processes or instead of the above-described processes, drawing commands relating to other image processes may be embedded in the image file and transmitted. For example, a drawing command for displaying the image data by scaling (reducing or enlarging) the image data at a predetermined scaling factor may be embedded in the image file and transmitted. Further, for example, a magnification calculating unit (not shown) for calculating a magnification ratio for making the image of the document image area extracted by the image extraction process a predetermined size is provided in the document detection unit 14 or the transmission data generation unit 22. The drawing command generation unit 43 may generate a drawing command corresponding to the magnification ratio calculated by the magnification calculation unit, and the formatting processing unit 44 may embed the drawing command in the image file.

  In this embodiment, the transparent text based on the character recognition result is transmitted by being embedded in the image file. However, the present invention is not limited to this, and the transparent text may be omitted. When the transparent text is omitted, it is not necessary to perform character recognition processing, so that the document detection unit 14 may not output the binarized and reduced resolution image data to the transmission data generation unit 22. When the transparent text is omitted, the character recognition unit 42 may output (through) the data input from the information extraction unit 41 to the drawing command generation unit 43 as it is.

  When performing the character recognition processing, as indicated by a broken line in FIG. 4, the document detection unit 14 outputs the binarized and reduced resolution image data and the inclination angle of the document image to the document correction unit 15. The document correction unit 15 performs an inclination correction process on the binarized and low-resolution image data and outputs the image data to the transmission data generation unit 22, and the character recognition unit 42 of the transmission data generation unit 22 performs the inclination correction. Character recognition processing may be performed using the image data. Thereby, the accuracy of character recognition can be improved compared with the case where character recognition is performed based on image data before inclination correction.

  As described above, in the digital color multifunction peripheral 1 according to the present embodiment, the document detection unit 14 determines the area corresponding to the document image in the image data and the image processing conditions to be applied when displaying the document image. Based on the image data of the document image, the color correction unit 16 converts the color of the region other than the region corresponding to the document image in the image data into a predetermined color, and the drawing command generation unit 43 displays the document image. At this time, a drawing command for controlling a computer included in the transmission destination apparatus is generated so that display is performed after image processing based on the above conditions is performed. Then, after the conversion processing is performed, the formatting processing unit 44 generates an image file in which a drawing command is added to image data obtained by performing compression processing on the image data before performing the image processing.

  In this way, by compressing the image data after converting the color of the region other than the region corresponding to the document image to a predetermined color, the compression efficiency of the image data is improved, and the compression of the image data after the compression processing is performed. Data size can be reduced.

  Even if the image data read by the image input device (scanner) is, for example, a white area is read, the pixel value is constant due to various factors such as unevenness in the way the light strikes, the presence of irregularities, and dust adhesion. Not a value. That is, the area other than the area corresponding to the document image is originally uniform in color, but is not uniform in the image data, resulting in variations in pixel values. Therefore, by replacing pixel values in areas other than the area corresponding to the original image, that is, areas that do not contain necessary information with specific values, the compression efficiency is improved without losing necessary information. The size of the image data can be reduced. For example, when image data having a size of 5300 pixels × 700 pixels obtained by reading a uniform white backboard with an image input device (scanner) is directly subjected to JPEG compression, the size of the compressed image data is 180 Kbytes. On the other hand, when JPEG compression is performed at the same compression rate after converting all pixel values to the same value, the size of the compressed image data is reduced to about 40 Kbytes.

  Further, according to the above configuration, the image data of the document image can be transmitted without being subjected to the image processing, so that the processing from image reading to transmission can be quickly performed. In addition, when displaying a document image, a computer provided in the transmission destination apparatus can perform image processing based on the drawing command, so that the document image can be displayed in an appropriate state in the transmission destination apparatus. it can.

  In this embodiment, an example in which the formatting processing unit 44 generates a PDF image file has been described. However, the present invention is not limited to this, and is applied when drawing image data and the image data. Any image file having a format including power conditions may be used.

  For example, in the TIFF format or the JPEG format of the EXIF standard, a value may be set for a condition applied at the time of rendering to a tag corresponding to an item of correction processing. For example, when performing top-and-bottom correction processing (rotation processing), a value corresponding to a desired rotation angle may be set in a 0 × 112 tag that is a tag indicating rotation information. Specifically, the value 1 is set when the rotation angle is 0 degree, the value 6 is set when the rotation angle is 90 degrees, the value 3 is set when the rotation angle is 180 degrees, and the value 8 is set when the rotation angle is 270 degrees. do it.

  In this embodiment, the image file is transmitted to the external device connected via the network in the normal transmission mode and the simple transmission mode. However, the present invention is not limited to this. For example, the transmission destination of the image file may be the storage unit 23 provided in the digital color multifunction peripheral 1, and the image file may be filed in the storage unit 23.

  When the image file is filed in the storage unit 23 of the digital color multifunction peripheral 1 using the simple transmission mode, the main control unit of the digital color multifunction peripheral 1 monitors the operation state of the digital color multifunction peripheral 1 and does not operate. The state in which job processing (image reading processing in the image input device 2, various processing in the image processing device 3, image output processing in the image output device 4, and transmission / reception processing in the communication device 5) has not been performed for a predetermined time or more When it is detected that the image file has been continued, the image file filed in the simple transmission mode stored in the storage unit 23 is read out, and the document correction unit 15 is read based on the drawing command embedded in the image file. Inclination correction processing, top / bottom correction processing, and image extraction processing are performed, and the results of these processing are stored. Or it is stored in 23, or may be or to perform the image forming process is sent to the image output apparatus 4.

  In this embodiment, the character recognition unit 42 performs character recognition processing based on the binarized and low-resolution image data input from the document detection unit 14 or the document correction unit 15. However, it is not limited to this. For example, as shown in FIG. 21, the region separation signal output from the region separation unit 21 is input to the character recognition unit 42, and the character recognition unit 42 is determined as a character region (character edge based on the region separation signal. A text map indicating an image area including pixels) may be generated, and the character recognition process may be performed only on the character area.

  Alternatively, as shown in FIG. 22, a document type automatic determination unit 25 for determining the document type based on the image data is provided, and a document type determination signal output from the document type automatic determination unit 25 is sent to the character recognition unit 42. The character recognition unit 42 performs the character recognition processing only when the document type determination signal indicates that the document type determination signal indicates a document including characters (for example, a character document, a character printed photo document, a character photographic paper photo document, etc.). Also good. The document type discrimination method in the document type automatic discrimination unit 25 is not particularly limited as long as it can discriminate between a document including at least characters and a document not including characters. Various conventionally known methods are used. be able to.

  In this embodiment, the case where the present invention is applied to a digital color multifunction peripheral has been described. However, the present invention is not limited to this, and may be applied to a monochrome multifunction peripheral. Further, the present invention is not limited to a multifunction machine, and may be applied to, for example, a single image reading apparatus.

  FIG. 23 is a block diagram showing a configuration example when the present invention is applied to an image reading apparatus. An image reading apparatus 100 shown in this figure includes an image input device 2, an image processing device 3b, a communication device 5, and an operation panel 6. Since the configurations and functions of the image input device 2, the communication device 5, and the operation panel 6 are substantially the same as those of the digital color multifunction peripheral 1 described above, the description thereof is omitted here.

  The image processing apparatus 3b includes an A / D conversion unit 11, a shading correction unit 12, an input processing unit 13, a document detection unit 14, a document correction unit 15, a color correction unit 16, a transmission data generation unit 22, a storage unit 23, and a control. The unit 24 is provided. The transmission data generation unit 22 includes an information extraction unit 41, a character recognition unit 42, a drawing command generation unit 43, and a formatting processing unit 44.

  Note that the image forming mode is not provided, and the color correction unit 16 outputs the image data after the color correction processing to the formatting processing unit 44, and the formatting processing unit 44 inputs the image data from the color correcting unit 16. Except for generating an image file to be transmitted to an external device based on the data, the functions of each unit provided in the image processing device 3b are substantially the same as those of the digital color multifunction peripheral 1 described above. The image file generated by performing the above-described processes in the image processing apparatus 3b is transmitted by the communication apparatus 5 to a computer or a server that is communicably connected via a network.

  In each of the above embodiments, each unit (each block) provided in the digital color multifunction peripheral 1 and the image reading apparatus 100 may be realized by software using a processor such as a CPU. In this case, the digital color multifunction peripheral 1 and the image reading apparatus 100 expand a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and the program. A random access memory (RAM), and a storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is to enable the computer to read the program code (execution format program, intermediate code program, source program) of the control program for the digital color multifunction peripheral 1 and the image reading apparatus 100 which are software for realizing the functions described above. This is achieved by supplying the recording medium recorded in (1) to the digital color multifunction peripheral 1 and the image reading apparatus 100, and the computer (or CPU or MPU) reads and executes the program code recorded on the recording medium.

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The digital color multifunction peripheral 1 and the image reading apparatus 100 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The blocks of the digital color multifunction peripheral 1 and the image reading apparatus 100 are not limited to those realized using software, but may be constituted by hardware logic, and hardware that performs a part of the processing. Hardware and arithmetic means for executing software for performing control of the hardware and remaining processing may be combined.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention can be applied to an image processing apparatus, an image reading apparatus, and an image forming apparatus that perform predetermined processing on image data read from a document and transmit the image data to another apparatus.

1 Digital color MFP (image processing device, image forming device, image reading device)
2 Image input device 3, 3 b Image processing device 4 Image output device 5 Communication device 6 Operation panel 14 Document detection unit (condition detection unit, image area detection unit)
15 Document Correction Unit 16 Color Correction Unit (Color Conversion Unit)
21 region separation unit 22 transmission data generation unit 23 storage unit 24 control unit 31 signal conversion unit 32 binarization processing unit 33 resolution conversion unit 34 document inclination detection unit 35 document top / bottom determination unit 36 image region determination unit 41 information extraction unit 42 character Recognizing unit 43 Drawing command generating unit 44 Formatting processing unit 100 Image reading device (image processing device, image reading device)

Claims (14)

An image processing apparatus including a formatting processing unit that generates an image file in which image data of a document image obtained by reading a document is formatted into data of a predetermined format,
An image area detection unit for detecting an area corresponding to the document image in the image data;
A condition detection unit for detecting image processing conditions to be applied when drawing the document image based on the image data;
A color conversion unit that converts a color of a region other than a region corresponding to the document image detected by the image region detection unit in the image data into a predetermined color;
A drawing command generation unit that generates a drawing command for controlling the computer so that the image is drawn in a state where image processing based on the above conditions is performed when drawing the document image;
The formatting processing unit, as the image file, performs the drawing command on the image data subjected to the compression processing on the image data after the conversion processing is performed by the color conversion unit and before the image processing is performed. An image processing apparatus that generates an image file to which is added. The condition detection unit detects an inclination angle of the document image with respect to a reference direction of the image data as the condition,
The drawing command generation unit generates a drawing command for causing the computer to perform an inclination correction process for making the angle of the document image coincide with or approach the reference direction based on the inclination angle detected by the condition detection unit. The image processing apparatus according to claim 1, wherein: The condition detection unit detects, as the condition, a range of an area where an image corresponding to the document in the image data exists.
The drawing command generation unit generates a drawing command for causing a computer to perform image extraction processing for extracting the image data in the range detected by the condition detection unit from the image data. 2. The image processing apparatus according to 2. The condition detection unit detects the orientation of the document image with respect to a reference direction of the image data based on the orientation of the character image included in the document image in units of 90 degrees.
The drawing command generation unit performs a top and bottom correction process for rotating the document image by 90 degrees so that the direction of the document image matches the reference direction based on the direction of the document image detected by the condition detection unit. The image processing apparatus according to claim 1, wherein a drawing command for causing a computer to execute is generated. The condition detection unit detects a magnification of a scaling process to be performed on the image data in order to draw an image according to the image data with a predetermined size,
5. The drawing command generation unit according to claim 1, wherein the drawing command generation unit generates a drawing command for causing a computer to perform a scaling process based on the magnification detected by the condition detection unit. Image processing apparatus. The condition detection unit detects a range of an area where an image corresponding to a document in the image data exists as the condition, and according to the extracted image data obtained by extracting the image data of the range from the image data. Detecting a scaling factor to be applied to the extracted image data in order to draw an image with a predetermined size,
The drawing command generation unit detects an image extraction process for extracting the image data in the range detected by the condition detection unit from the image data, and the condition detection unit detects the extracted image data obtained by the image extraction process. The image processing apparatus according to claim 1, wherein a drawing command is generated for causing a computer to perform a scaling process for scaling based on the magnification. A normal mode for causing the formatting processing unit to generate the image file based on image data obtained by performing the image processing on the image data of the document image;
7. A simple mode for causing the formatting processing unit to generate an image file in which the drawing command is added to image data of the original image before the image processing is performed. The image processing apparatus according to claim 1.   8. The image processing apparatus according to claim 1, wherein the formatting processing unit generates an image file of any one of a PDF format, a TIFF format, and an EXIF standard JPEG format based on the image data. The image processing apparatus according to item. An image reading unit that reads the document and obtains image data of the document image;
An image reading apparatus comprising the image processing apparatus according to claim 1. The image processing apparatus according to any one of claims 1 to 8,
An image transmission device comprising: a communication unit that transmits the image file generated by the formatting processing unit to another device connected to be communicable. The image processing apparatus according to any one of claims 1 to 8,
A storage unit for storing the image file generated by the formatting processing unit;
An image processing unit that reads an image file stored in the storage unit and performs image processing based on the drawing command included in the image file;
An image forming apparatus comprising: an image forming unit that prints an image corresponding to image data subjected to the image processing on a recording material. An image processing method for generating an image file in which image data of a document image obtained by reading a document is formatted into data of a predetermined format,
An image area detecting step for detecting an area corresponding to the original image in the image data;
A condition detection step of detecting image processing conditions to be applied when drawing the document image based on the image data;
A color conversion step of converting a color of a region other than the region corresponding to the document image detected in the image region detection step in the image data into a predetermined color;
A drawing command generation step for generating a drawing command for controlling the computer so that the image is drawn in a state where image processing based on the above conditions is performed when drawing the document image;
As the image file, after performing the conversion process in the color conversion step, an image file in which the drawing command is added to the image data obtained by compressing the image data before the image process is generated. And an image file generating step.   A program for operating the image processing apparatus according to any one of claims 1 to 8, wherein the program causes a computer to function as each unit described above.   A computer-readable recording medium on which the program according to claim 13 is recorded.

Images