Patent Publication Number: US-2023156126-A1

Title: Image processing apparatus and method for controlling the same

Description:
BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates to an image processing apparatus and a method for controlling the image processing apparatus. 
     Description of the Related Art 
     Some available image processing apparatuses support a book scan mode in which a double-page spread document, such as a book, is read page by page as images of two pages by two reading processes (see Japanese Patent Application Laid-Open No. 2021-111907). In the book scan mode, the document is generally placed such that a short-side direction of the document is parallel to a line sensor and a long-side direction of the document is perpendicular to the line sensor. In a case where the document is placed in such a manner, the document is divided at a center in the long-side direction of the document. In a first reading process, the document is read in the short-side direction as a main scanning size, and the document from an origin to a position corresponding to ½ of the size in the long-side direction is read as a sub-scanning size. In a second reading process, the document is read in the short-side direction as a main scanning size as in the first reading process, and the document from the position corresponding to ½ of the size to a trailing edge of the document in the long-side direction is read in a sub-scanning direction. As a result, the double-page spread document is read. 
     A scanner of a pressing plate type of the existing image processing apparatus scans the document with the above-described reading method because a length in the sub-scanning direction in which reading is performable is greater than a length in the main scanning direction in which reading is performable. 
     By contrast, a scanner in which a moving distance of the line sensor is made small, and the length in the main scanning direction in which reading is performable is made greater than the length in the sub-scanning direction in which reading is performable in order to reduce a scanning time is considered. In such a scanner, the document is placed on a platen such that the long-side direction of the document is parallel to the line sensor. Therefore, the document cannot be read in the book scan mode as discussed in Japanese Patent Application Laid-Open No. 2021-111907. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a technique by which appropriate scanning is performable in the book scan mode in the scanner of the pressing plate type in which the length in the main scanning direction in which reading is performable is greater than the length in the sub-scanning direction in which reading is performable. 
     According to embodiments of the present disclosure, an image processing apparatus including a sensor unit having a length in a main scanning direction greater than a length in a sub-scanning direction in which reading is performable by movement of the sensor unit. The image processing apparatus includes an execution unit configured to execute, twice, processing of moving the sensor unit from a reference position to a predetermined position and reading an image of a document, based on one execution instruction input by a user, to generate first image data and second image data, and an output unit configured to output first extraction data generated by executing first extraction processing on the first image data, as one piece of page data, and to output second extraction data generated by executing second extraction processing on the second image data, as one piece of page data. 
     Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a sectional view of an image processing apparatus. 
         FIG.  2    is a block diagram of a control unit of the image processing apparatus. 
         FIG.  3    is a sectional top view of a scanner. 
         FIG.  4    is a conceptual diagram of book scanning. 
         FIG.  5    is a conceptual diagram of image processing and reading control in a book scan mode. 
         FIG.  6    is a flowchart in the book scan mode. 
         FIG.  7    is a conceptual diagram of image processing and reading control in a book scan mode  2 . 
         FIG.  8    is a flowchart of the book scanning. 
         FIG.  9    is a flowchart in the book scan mode  2 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Some exemplary embodiments of the present disclosure are described below with reference to accompanying drawings. Configurations described in the following exemplary embodiments are merely illustrative, and the present disclosure is not limited to illustrated configurations. 
     In a first exemplary embodiment, an image processing apparatus specialized in processing for an A4-size document will be described as a premise; however, a configuration to which a large-size document, such as A3 size and B4 size, is also adoptable. 
       FIG.  1    is a sectional view of a multifunctional peripheral (MFP) that is the image processing apparatus according to the present exemplary embodiment. The MFP has functions of a copying apparatus, a printer, and a facsimile (FAX). In  FIG.  1   , the MFP includes a document reading apparatus that includes a scanner  101  and a document feeder (ADF)  102 , a printing unit  103  for print recording, including drums of four colors, and sheet feeding decks  118 . In the present exemplary embodiment, detailed descriptions of the document feeder  102 , the printing unit  103 , the sheet feeding decks  118 , and the like are omitted because of low relevance. Details of a hardware configuration of a controller that controls a scanner unit, a printer unit, and a network interface unit of the MFP will be described with reference to  FIG.  2   . 
       FIG.  2    is a block diagram of a control unit  215  configuring the MFP according to the present exemplary embodiment. Configuration units of the control unit  215  are connected to a system bus  201  and an image bus  210 . A read only memory (ROM)  202  stores a boot program of a system. Further, system software realizing the units of the present exemplary embodiment is stored in the ROM  202  or a storage memory  205 , and is executed by a central processing unit (CPU)  203 . 
     A random access memory (RAM)  204  is a system work memory area for the CPU  203  to execute software, and is also an image memory temporarily storing image data when the image data is processed. The storage memory  205  is used as an internal storage. Data read by a reading unit, image data, the system software, and the like are stored in the storage memory  205 . The storage memory  205  includes a hard disk drive (HDD) or a solid-state drive (SSD). The storage memory  205  is divided into a plurality of sections, and can store a read document in each of the sections. 
     A local area network (LAN) interface (I/F) unit  206  is used for connection with a LAN, and performs input/output of information with each of apparatuses connected to a LAN. The above-described devices are disposed on the system bus  201 . A line I/F unit  207  for connection with a wide area network (WAN) is also provided. 
     An input-output (IO) control A unit  209  is a bus bridge that connects the system bus  201  and the image bus  210  transferring image data at high speed, and converts a data structure of the system bus  201 . The image bus  210  includes a general-purpose bus, such as a peripheral component interconnect (PCI) bus, an Institute of Electrical and Electronics Engineers (IEEE) 1394 bus, and a PCI-Express (PCIEx) bus. The following devices are disposed on the image bus  210 . A reading unit  212  serving as an image input/output device, a printer unit  213 , and an image processing unit  211  are connected to perform synchronization/asynchronization conversion of the image data. A communication bus for exchange of a control instruction to execute control operation of the printer unit  213  and/or the reading unit  212 , issued from the control unit  215  is connected between the printer unit  213  and the reading unit  212 . 
     The reading unit  212  is a module including the scanner  101  and the document feeder  102  in  FIG.  1   . 
     The communication bus is realized by using a general-purpose communication protocol, such as Universal Asynchronous Receiver/Transmitter (UART) (or recommended standard 232 (RS-232C)) and a universal serial bus (USB), or a dedicated communication protocol. The image processing unit  211  performs image processing, such as resolution conversion, compression/decompression, binary/multi-value conversion, and trimming, on input image data and output image data. In addition, the image processing unit  211  receives image data from the reading unit  212 , and transfers the received image data to the RAM  204  through the image bus  210  and the system bus  201 . 
     The processing of the image processing unit  211  is realized by image processing application specific integrated circuits (ASIC), which is hardware, and the software that is executed by the CPU  203  controlling the image processing ASIC. The image processing ASIC includes a register to set a format of data to be processed and processing details, and the image processing unit  211  performs the image processing by causing the control software that is executed by the CPU  203  to perform setting of the register of the image processing ASIC. 
     An IO control B unit  208  is an I/F unit for interface with an operation unit  214  (user interface [UI]), and outputs image data to be displayed on the operation unit  214 , to the operation unit  214 . The IO control B unit  208  transfers information input by a user through the operation unit  214 , to the CPU  203 . The IO control B unit  208  is an I/F unit used for software to control the operation unit  214  mounted with a display device and a keypad device. In the present exemplary embodiment, the operation unit  214  includes a liquid crystal display (LCD) touch panel, interprets a video graphics array (VGA) signal output from the IO control B unit  208 , and display the resultant. 
     Next, a configuration and operation of the scanner are described with reference to  FIG.  3   .  FIG.  3    is a sectional top view illustrating a schematic configuration of the scanner  101  in  FIG.  1   . As illustrated in  FIG.  3   , the scanner  101  includes a frame body  301 , and a sensor unit  302  including a base and a sensor mounted on the base. The sensor unit is, for example, a line sensor including a plurality of pixels arranged in a line. 
     The frame body  301  include a reference shaft  303  that is a reference of movement of the sensor unit  302  in a sub-scanning direction (direction of arrow A). In the present exemplary embodiment, a length of the sensor unit  302  is greater than a moving range of the sensor unit  302  in the sub-scanning direction. 
     In other words, a length in a main scanning direction in which reading is performable is greater than a length in the sub-scanning direction in which reading is performable. Driving force from a flatbed (FB) reading stepping motor  305  (hereinafter, stepping motor) is transmitted to a belt  304  via a gear group  306 . Further, the sensor unit  302  is moved along the reference shaft  303  by the belt  304 . The frame body  301  includes a platen glass (platen)  307  on which a document is to be placed, and a DF reading window  308  for DF scan. The DF reading window  308  is made of a material that allows light of a light-emitting diode serving as a light source to pass therethrough, as with the platen glass  307 . 
     The sensor unit  302  can be freely moved in an area of the platen glass  307  and the DF reading window  308 . More specifically, the sensor unit  302  can be moved by a predetermined amount by controlling the number of driving input pulses to the stepping motor  305 . A length of the sensor unit  302  in the main scanning direction is greater than a length in the sub-scanning direction in which reading is performable by movement of the sensor unit  302 . 
     The document reading apparatus having received a scan instruction from the CPU  203  drives the stepping motor  305 , and drives the belt  304  via the gear group  306 . This moves the sensor unit  302  in the sub-scanning direction along the reference shaft  303 , thereby reading the document placed on the platen glass  307 . The scanner  101  includes a mechanism for detecting a size of the document placed on the platen glass  307 . There are various methods for such a detection, and illustrations and detailed descriptions of the detection methods are omitted. 
     The scanner  101  notifies the control unit  215  of the detected document size. The control unit  215  controls reading operation of book scanning based on the notified document size. The sensor unit  302  performs reading in the main scanning direction with the maximum width of the sensor unit  302 , irrespective of the size of the document in the main scanning direction. The image processing unit  211  of the control unit  215  performs trimming processing on the image read with the maximum width, to extract a necessary area. 
     While illustrations and detailed descriptions are not provided in the present exemplary embodiment, in a case where trimming is performed in the sub-scanning direction, only an area to be used can be extracted by designating a start position and an end position in the sub-scanning direction in a reading instruction issued to the scanner  101 . In such a case, the scanner  101  drives the belt  304  to reduce an area where the sensor unit  302  is moved, thus reading an area smaller than the document size, starting from a leading edge. To perform trimming from partway to the trailing edge in the sub-scanning direction, the scanner  101  does not output image signals from the leading edge to a designated position. The trimming is realized by moving the sensor unit  302  to a designated trimming start position, and then performing reading and output of image signals. 
     Placement of a double-page spread document in the present exemplary embodiment is described with reference to  FIG.  4   .  FIG.  4    is a diagram illustrating an example of a method of placing the double-page spread document. 
     A document  401  is a schematic diagram of a double-page spread document, such as a book. In the present exemplary embodiment, pages of the double-page spread document progress in order from left to right; however, the configuration of the double-page spread document to which the present exemplary embodiment is applicable is not limited thereto. For example, pages of the double-page spread document may progress in order from right to left. A placement example  402  illustrates a case where the double-page spread document is placed on the platen glass  307 . In the scanner  101 , a reference point ( 403 ) of a reading position is located at an upper left position of the platen glass  307 . When the control unit  215  instructs coordinates from the reference point, the scanner  101  reads a designated area, and sequentially transfers the read image to the control unit  215 . Determination of the reading position from the above-described reference point  403  and the instruction to the scanner  101  are realized by control software operating on the CPU  203  of the control unit  215 . The reference point  403  may be set by the user via the operation unit  214 . 
     In the book scan mode, the reading instruction to the scanner  101 , the image processing to be applied to the read image, and the read image are described with reference to  FIG.  5    and a flowchart in  FIG.  6   . 
       FIG.  6    is a flowchart illustrating an example of processing in the book scan mode. The flowchart in  FIG.  6    is realized by a control application that is stored in the ROM  202  and operates on the CPU  203 . In the present exemplary embodiment, a scanner control unit that is connected to the reading unit  212  and controls the scanner  101  interprets the reading instruction, and drives the sensor unit  302  and the stepping motor  305  to read an image. A control instruction and configuration information, such as a size readable by the scanner, are exchanged between the scanner control unit and the control unit  215  through communication using a communication standard, such as RS-232C. 
     In the present exemplary embodiment, only the double-page spread document with pages to be turned over from right to left is described; however, application of the present exemplary embodiment is not limited to the double-page spread document with pages to be turned over from right to left. 
     Initially, in step S 601 , size information about a document  501  placed on the platen glass  307  is acquired using the document size detection sensor mechanism of the scanner  101 . The acquired document size information is stored as a main scanning direction size and a sub-scanning direction size in variables of OrgX/OrgY secured in the RAM  204 , respectively. Thereafter, in step S 602 , the number of times of reading is initialized to one. The number of times of reading is a variable similarly held in the RAM  204 . In steps S 603  to S 606 , an area to be read by the scanner  101  is designated. Since the sensor unit  302  does not include a trimming mechanism in the main scanning direction, StartX and EndX are designated for convenience, but image data corresponding to an entire width of the sensor unit  302  is transmitted to the control unit  215 . In the sub-scanning direction, an entire area is read. In the book scan mode according to the present exemplary embodiment, while an image of one document is read through two processes, images read through the two processes are the same as each other. Image data  502  generated by scanning the document is transmitted to the control unit  215 . 
     At this point, the reading instruction is not issued. Thus, the scanner  101  does not operate. After calculation of the reading position ends, the number of times of reading is checked in step S 607 . At this point, the scanning is a first scan process (YES in step S 607 ). Thus, the processing proceeds to step S 608 . In step S 608 , the number of times of reading is incremented for next document process. In steps S 609  to S 612 , calculating setting for trimming and mirror image determination to be performed on the image read by the scanner  101  is performed. In the first scan process, a trailing edge in the main scanning direction is read. Thus, in step S 609 , a trimming start position (TrmStartX) is set to a position indicated by Org/2. A center part of the double-page spread document is set to a head position of an effective image. Subsequently, in step S 610 , a trimming end position (TrmEndX) is set to OrgX. In steps S 611  and S 612 , a trimming start position and a trimming end position in the sub-scanning direction are similarly set. In the sub-scanning direction, the entire document size is to be read. Thus, TrmStartY is set to zero, and TrmEndY is set to OrgY. The trimming setting of the image ends in step S 612 , and the image read with the setting becomes a trimming image (extracted data)  503  of a first page in  FIG.  5   . It is found from  FIG.  5    that the image is in a mirror image state relative to the orientation of the double-page spread document. 
     To correct the mirror image state, mirror-image-inversion image processing is turned on in step S 613 . An image having been subjected to the mirror-image-inversion image processing becomes a mirror-image inverted image 1 ( 504 ). After the trimming position is calculated and the determination of the mirror-image-inversion image processing being turned on, setting is performed on the image processing ASIC that configures the image processing unit  211  which actually performs the image processing. 
     After the setting is performed, the reading instruction is issued to the scanner  101  in step S 615 . The above-described information about StartX/EndX and StartY/EndY are included in the reading instruction. The scanner control unit having received the reading instruction reads an image as designated, and transmits the read image to the control unit  215 . 
     At this time, StartX and EndX are designated for convenience, but the scanner  101  reads the designated area only in the sub-scanning direction because the scanner  101  cannot perform image trimming in the main scanning direction. As a result of the reading instruction, the image is input to the image processing unit  211  via the reading unit  212 , and the trimming of the image and the mirror image determination for determining whether the image is the mirror image are performed in accordance with preset image processing setting, in step S 616 . 
     The image to be finally output is one as indicated by the output image 1 ( 504 ), and in step S 617 , the output image 1 ( 504 ) is stored as the image data in the storage memory  205 . 
     In the present exemplary embodiment, to simplify the description, only the trimming and the mirror-image-inversion image processing are applied; however, application of the present exemplary embodiment is not limited only to the above-described two image processing. For example, other image processing such as background deletion, rotation, and magnification, or compression of image data to reduce a capacity in the storage memory  205  may be performed. 
     At a time when step S 617  ends, only the first page of the document has been read. To continuously read the second page, the processing returns to step S 607 . Since the number of times of reading has been set to two in step S 608 , the processing proceeds to step S 618 . While steps S 618  to S 621  are steps of determining the trimming position, unlike the first page, StartX is set to zero, and EndX is set to OrgX/2. Such setting is performed because, as for the second page, it is sufficient to read the document from the reference point to a position corresponding to half of the main scanning direction size OrgX, in the main scanning direction. 
     In the sub-scanning direction, the trimming position is calculated with the entire area serving as a read target, as with the first page. The second page is also read in the mirror image state. Thus in step S 622 , the mirror-image-inversion image processing is turned on. 
     In a manner similar to the first page, the image processing setting in step S 623  and the reading instruction in step S 624  are performed, and the trimming and the mirror-image-inversion image processing are performed on the image read by the scanner. In the reading of the second page, the same image (read image data  502 ) is obtained by the scanner. In other words, the process of reading the image of the document is performed twice by moving the sensor unit  302  from the reference position to the predetermined position based on a single execution instruction input by the user, thus generating the first image data and the second image data. 
     Here, since the trimming start position is different, the leading-edge side in the main scanning direction is trimmed (image  505 ), unlike the first page. The mirror-image-inversion image processing is similarly performed, and an output image  506  is stored in the storage memory  205 . In this process, a portion corresponding to a portion not extracted in the trimming for the first page is trimmed from the image of the second image data. 
     In other words, the first extraction data generated by performing the first extraction process on the first image data can be output as one piece of page data. The second extraction data generated by performing the second extraction process on the second image data can be output as one piece of page data. More specifically, the “output” here means that the image based on the first extraction data is printed on one sheet and the image based on the second extraction data is printed on one sheet different from the sheet for the first extraction data. 
     Such processing enables provision of the book scan mode even in the image processing apparatus in which the length of the sensor unit in the main scanning direction is greater than the length in the sub-scanning direction in which an image is readable by movement of the sensor unit. In the present exemplary embodiment, the double-page spread document with pages to be turned over from right to left is described. In a case of the document with pages to be turned over from left to right, the reading in the book scan mode can be similarly performed by changing the order of steps S 609  to S 612  and steps S 618  to S 621 . 
     A second exemplary embodiment of the present disclosure will be described. Use of the existing scanner (in which length of sensor unit  302  in main scanning direction is less than length in sub-scanning direction in which reading is performable by movement of sensor unit  302 ) is advantageous in a production cost because the sensor unit  302  is small. Thus, an image processing apparatus in which either the scanner according to the first exemplary embodiment or the existing scanner is connectable and a model configuration is selectable depending on whether priority is given to productivity or cost, may be provided. In such a configuration, the control unit  215  switches and operates the book scan mode  1  (operation in first exemplary embodiment) and a book scan mode  2 . 
     In other words, the control unit  215  appropriately issues the reading instruction to the scanner control unit based on the connected scanner, which makes it possible to provide the appropriate book scan mode with either the scanner according to the first exemplary embodiment or the existing scanner. It is possible to determine which of the scanner according to the first exemplary embodiment and the existing scanner is connected, by exchanging configuration information illustrated in Table 1 between the control unit  215  and the scanner control unit. Table 1 and Table 2 each illustrate an example of the configuration information. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Example of Configuration Information (Scanner 
               
               
                 in First Exemplary Embodiment) 
               
            
           
           
               
               
               
            
               
                   
                 Configuration Information Name 
                 Value 
               
               
                   
                   
               
               
                   
                 Feed Direction 
                 Long Edge Feed 
               
               
                   
                 Readable Width in Main Scanning Direction 
                 297 mm 
               
               
                   
                 Readable Width in Sub-Scanning Direction 
                 210 mm 
               
               
                   
                 . . . 
                 . . . 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Example of Configuration Information (Existing Scanner) 
               
            
           
           
               
               
               
            
               
                   
                 Configuration Information Name 
                 Value 
               
               
                   
                   
               
               
                   
                 Feed Direction 
                 Short 
               
               
                   
                   
                 Edge Feed 
               
               
                   
                 Readable Width in Main Scanning Direction 
                 210 mm 
               
               
                   
                 Readable Width in Sub-Scanning Direction 
                 297 mm 
               
               
                   
                 . . .  
                 . . . 
               
               
                   
                   
               
            
           
         
       
     
     The configuration information is stored in the scanner control unit, and is exchanged between the scanner control unit and the control unit  215  before start of scanning, for example, during startup processing of the image processing apparatus. 
     An example of the existing scanner according to the present exemplary embodiment is described with reference to  FIG.  7   . A conceptual diagram  707  illustrates a case where the scanner is disposed parallel to the short-side direction, and the main scanning direction and the sub-scanning direction are replaced with each other. At this time, a double-page spread document  701  is disposed on the platen in such a manner that the sensor unit and a long-side direction of the document are orthogonal to each other. An origin  702  of the reading position in this configuration is an upper right reference point of the document. 
     In the book scan mode  2 , in the first scan process, the entire document is read in the main scanning direction, and the document from the origin to a half position in the long-side direction is read in the sub-scanning direction. In the second scan process, the entire document in the main scanning direction and the document from the half position in the long-side direction to the trailing edge in the sub-scanning direction are to be read. The first scan process and the second scan process may be performed in a reversed order. Determination of the reading position and the like at this time are described in detail with reference to flowcharts in  FIG.  8    and  FIG.  9   . 
     Initially, in response to the user issuing an instruction to perform book scanning, the scanner configuration information is acquired in step S 801 . In step S 802 , it is determined in which of the book scan modes the operation is to be performed, based on the acquired configuration information. 
     If it is determined in step S 802  that the line sensor length, namely, the length in the main scanning direction in which reading is performable is greater than a maximum length in the sub-scanning direction in which reading is performable (YES in step S 802 ), the processing proceeds to step S 803 . In step S 803 , the operation in the book scan mode  1  is performed. If the maximum length in the sub-scanning direction in which reading is performable is greater than or equal to the line sensor length (NO in step S 802 ), the processing proceeds to step S 804 . In step S 804 , the reading processing in the book scan mode  2  is performed. In the present exemplary embodiment, it is determined which of the reading processing is to be performed, based on the maximum length in each of the main scanning direction and the sub-scanning direction in which reading is performable; however, information indicating greater one of the maximum reading length in the main scanning direction and the maximum reading length in the sub-scanning direction may be received as “Feed direction” information in the configuration information, and the information may be used for the determination. In the present exemplary embodiment, an example in which the book scan modes  1  and  2  are switched based on the type of the scanner is described; however, the configuration is not limited thereto. For example, the book scan modes  1  and  2  (first mode and second mode) may be switched based on the orientation of the document placed on the platen. More specifically, even for the scanner  101  illustrated in  FIG.  4   , in a case where a length of the placed document in the long-side direction is less than or equal to the length of the scanner  101  in the sub-scanning direction, the user can place the document either vertically or horizontally. In this case, even for the scanner  101  illustrated in  FIG.  4   , in a case where the book scan mode  1  is constantly operated, the scan may not be appropriately performed. Thus, a sensor that detects the direction of the document placed on the platen may be provided in the platen, the direction of the document may be specified by using the sensor, and processing of switching the book scan modes  1  and  2  may be performed based on the direction. The book scan modes  1  and  2  may be switched based on the direction and the size of the document. 
     In step S 803 , operation in the book scan mode  1  is performed. The operation is similar to the operation in the flowchart of  FIG.  6   . In a case where it is determined in step S 802  that the existing scanner is connected, a sub-routine in the book scan mode  2  is performed in step S 804 . The sub-routine in the book scan mode  2  is described with reference to the flowchart in  FIG.  9   . 
       FIG.  9    is a flowchart illustrating an example of the processing in the book scan mode  2 . As in the book scan mode  1 , in step S 901 , the information about the document sizes OrgX and OrgY is acquired from the scanner  101 . The length of the document in the short-side direction can be acquired as OrgX, and the length of the document in the long-side direction can be acquired as OrgY. 
     In step S 902 , the number of times of reading is initialized as in step S 602 . In step S 903 , the document start position in the main scanning direction (StartX) is designated as zero corresponding to the origin. Further, in step S 904 , the document end position in the main scanning direction (EndX) is designated as OrgX. 
     The document in the main scanning direction is read with the same size without change, in the two scan processes. 
     Thereafter, in steps S 905  and S 906 , the start position and the end position in the sub-scanning direction are calculated. In the first scan process, in the sub-scanning direction, the document from the leading edge in the sub-scanning direction to the half position of the document length OrgY in the sub-scanning direction, namely, to the position OrgY/2 is read to obtain an image  703 . Thus, StartY is set to zero, and EndY is set to OrgY/2. Thereafter, in step S 907 , a comparison is performed to determine whether the number of times of reading is one. At this point, the scanning is a first scan process (YES in step S 907 ). Thus, the processing proceeds to step S 908 . In step S 908 , the number of times of reading is incremented by one for reading of a second page. At this point, the image is read in a direction rotated by 270 degrees from the direction of the document, and the image  703  in a mirror image state is obtained. In step  909 , the setting for execution of rotation and mirror-image-inversion processing is performed. In step S 910 , the setting of the image processing unit  211  is performed. Thereafter, in step S 911 , the reading instruction is issued. The image is acquired from the scanner  101  and is then subjected to the rotation and the mirror-image-inversion processing by the image processing unit  211 . The resultant image is then written to the RAM  204  and is further stored as a first-page image  704  in the storage memory  205 . Thereafter, the processing returns to step S 907 . In step S 907 , the comparison for the number of times of reading is performed (to determine whether the number of times of reading is one). At this point, the number of times of reading is not one (NO in step S 907 ), and the processing proceeds to step S 914 . In steps S 914  and S 915 , the reading position in the second scan process is determined. In the second scan process, the document is read from the position OrgY/2 to OrgY in the sub-scanning direction. Therefore, StartY is set to OrgY/2, and EndY is set to OrgY. In other words, the control unit  215  performs the processing of moving the sensor unit from the reference position to the predetermined position and reading the image of the document, and the processing of moving the sensor unit from the reference position to a position different from the predetermined position and reading the image of the document, thus generating third image data and fourth image data. 
     Thereafter, in step S 916 , the setting for execution of rotation and mirror-image-inversion processing is performed. In step S 917 , the setting of the image processing unit  211  is performed. After the setting of the image processing unit  211  is performed, the reading instruction is issued in step S 918 . In the reading instruction at this time, StartX is designated as zero, EndX is designated as OrgX, StartY is designated as OrgY/2, and EndY is designated as OrgY. The scanner control unit having received the instruction initially drives the stepping motor  305 , and moves the sensor unit  302  to the position OrgY. 
     After the scanner control unit moves the sensor unit  302  to the position OrgY, the scanner control unit issues an image reading start signal to the control unit  215 , to notify the control unit  215  of start of image reading. In response to receiving the reading start signal, the control unit  215  receives image data of a designated size from the scanner  101  with this timing as a start point. The received image is a mirror image rotated by 270 degrees, as with a read image  705 . Thus, the rotation and the mirror-image-inversion processing are performed by the image processing unit  211  in a manner similar to that performed for the first page. A resultant image is output to the RAM  204 , and is then stored as a second-page image  706  in the storage memory  205 . 
     By performing the above-described control flow, it is possible to provide operation in the appropriate book scan mode even with either the scanner according to the first exemplary embodiment or the existing scanner connected. 
     OTHER EMBODIMENTS 
     Embodiment(s) of the present disclosure can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present disclosure includes exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2021-186700, filed Nov. 16, 2021, which is hereby incorporated by reference herein in its entirety.