JP7746071B2 - Inspection method and device - Google Patents

Description

The present invention relates to a method and apparatus for inspecting the print quality of printed materials.

Recently, printing systems have become known in which an inspection device inspects printed sheets printed by a printing device while the sheets are being transported. In this inspection, the inspection device reads an image of the transported sheet and analyzes the read image to determine whether printing on the sheet was performed correctly. Such inspection devices can detect missing characters or barcodes printed on the printout, missing images, printing defects, missing pages, color misalignment, and more. If a printed sheet is determined to be defective, the defective sheet is ejected to a different destination from normal sheets. This prevents defective sheets from being mixed in with normal sheets and allows the operator to discard the defective sheets.

In such systems, when checking whether a character string has been printed correctly, an inspection device is known that performs character recognition processing on the area where the character string is printed and compares the recognition results with correct data. In systems like the one described above, when switching the paper output destination, the character recognition and comparison processes must be completed during sheet transport between reading the printed sheet and switching the output destination, making it necessary to achieve both speed and accuracy in the character recognition process. Patent Document 1 describes performing a layout analysis on a document, and performing character recognition processing that prioritizes recognition accuracy in areas where misrecognition must be avoided, and character recognition processing that prioritizes processing speed in areas where a certain degree of misrecognition is acceptable.

Japanese Patent Application Laid-Open No. 2001-43316

However, image analysis itself, such as layout analysis to determine the character recognition processing method, also incurs processing time overhead, and in some cases the desired inspection speed cannot be achieved.

In order to solve the above problem, the inspection device of the present invention is an inspection device having an inspection means that inspects a read image obtained by a reading unit reading the image on a recording material that has been transported from a transport means that receives and transports a recording material on which an image has been printed from a printing device that has printed the image on the recording material, and is characterized in that it has a registration means that registers a font and a character recognition processing method in association with each other before performing the inspection by the inspection means, and a setting means that sets an inspection area in which a character string is to be inspected and a font to be used in the inspection area, and the inspection means determines the character recognition processing method to be applied to the inspection area based on the font to be used in the inspection area that has been set by the setting means and the character recognition processing method associated with that font by the registration means, and performs character recognition processing of an image in the read image that corresponds to the inspection area.

By determining the character recognition processing method prior to inspection, inspection speed can be improved.

FIG. 1 is a schematic diagram showing the configuration of an information processing device, an inspection device, and a printing device. FIG. 1 is a block diagram showing the configurations of an information processing device, an inspection device, and a printing device. FIG. 2 is a diagram showing the internal configuration of an information processing device, an inspection unit, a printing device, and a large-capacity stacker. Flowchart of the entire test. FIG. 10 is a diagram showing a font registration screen. FIG. 10 is a diagram showing a character segmentation screen. 10 is a flowchart for font registration. FIG. FIG. 1 is a flowchart of the test setup. Inspection flowchart. 10 is a flowchart of an inspection setting according to the second embodiment.

The following describes embodiments of the present invention with reference to the accompanying drawings. However, the following embodiments do not limit the scope of the invention as claimed, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

First Embodiment
1 is a schematic diagram showing the configuration of an information processing apparatus, an inspection apparatus, and an image forming apparatus in this embodiment. Note that, although the image forming apparatus in this embodiment will be described using an electrophotographic image forming apparatus, the image forming apparatus in this embodiment may be an image forming apparatus of a different image forming method, such as an inkjet method or an offset method.

The image forming apparatus 0101 is connected to an information processing apparatus 0109 via a communication cable 0112. The information processing apparatus 0109 is connected to a client computer 0110 and an inspection apparatus 0108 via a network 0113. The image forming apparatus 0101 is equipped with a UI panel 0102, a paper feed deck 0103, and a paper feed deck 0104. In addition, an optional deck 0105 consisting of three paper feed decks is connected. The image forming apparatus 0101 is, for example, an electrophotographic image forming apparatus. The UI panel 0102 is, for example, a user interface equipped with a capacitive touch panel.

The image forming apparatus 0101 also includes an inspection unit 0106 and a large-capacity stacker 0107. The inspection unit is connected to the inspection device 0108 via a communication cable 0114. The large-capacity stacker 0107 includes a main tray and a top tray, and the main tray can hold several thousand sheets of paper at a time.

A print job is generated by the client computer 0110, sent to the information processing device 0109 via the network 0113, and managed by the information processing device 0109. The print job is then sent from the information processing device 0109 to the image forming device 0101 via the communication cable 0112, and the image forming device 0101 performs printing on paper based on the received print job. Note that the print job may also be generated and managed by the information processing device 0109, sent to the image forming device 0101 via the network 0112, and managed by the image forming device 0101.

The client computer 0110, information processing device 0109, and inspection device 0108 may also be connected to a cable 0112 to communicate with the image forming device 0101. In other words, the connection configuration of the image forming device 0101, information processing device 0109, and client computer 0110 shown in this embodiment is just one example, and it goes without saying that there are various other connection configurations besides those shown in this embodiment.

Figure 2 is a block diagram showing the control configuration of the image forming apparatus 0101, inspection apparatus 0108, large-capacity stacker 0107, information processing apparatus 0109, and client computer 0110 in this embodiment.

The CPU (Central Processing Unit) 0201 controls and performs calculations for each component within the image forming device 0101 via the system bus 0212. The CPU 0201 functions as a processing unit that executes each process described below by executing programs stored in the computer-readable storage unit 0205 and loaded into the RAM (Random Access Memory) 0202. The RAM 0202 is a type of general volatile storage device that can be accessed directly by the CPU 0201 and is used as a work area for the CPU 0201 or other temporary data storage area. The storage unit 0205 also functions as a temporary storage area and work memory when the image forming device is operating. The engine I/F 0209 communicates with the printer engine 0210. The paper feed deck I/F 0204 communicates with the paper feed deck 0211. The paper feed deck 0211 collectively refers to the paper feed decks 0103, 0104, and optional deck 0105 as hardware components, and functions as a processing unit that executes the processes described below. The UI panel 0203 is the hardware component of the UI panel 0102, and is a user interface for performing general operations on the image forming apparatus 0101. In this embodiment, the UI panel 0203 is equipped with a capacitive touch panel.

The network interface (hereinafter referred to as NW I/F) 0207 is connected to the NW I/F 0238 of the information processing device 0109 via communication cable 0213 and is used for communication between the information processing device 0109 and the image forming device 0101. In this example, the interfaces (0207, 0238) connected to the system bus (0212, 0239) are directly connected to each other, but this is not limited to this. For example, the information processing device 0109 and the image forming device 0101 may also be connected via a network such as a LAN; the connection type is not limited to this. The video I/F 0206 is connected to the video I/F 0233 via video cable 0241 and is used for communication of image data between the information processing device 0109 and the image forming device 0101. The connection interface between the information processing device 0109 and the image forming device 0101 may also be a combination of the functions of the NW I/F 0238 and the video I/F 0233. Furthermore, the connection interface between the image forming apparatus 0101 and the information processing apparatus 0109 may be a form that integrates the functions of the NW I/F 0207 and video I/F 0206.

The accessory I/F 0208 is connected to the accessory I/F 0214 and the accessory I/F 0220 via the communication cable 0225. That is, the image forming apparatus 0101 can communicate with the inspection unit 0106 and the large-capacity stacker 0107 via the accessory I/Fs 0208, 0214, and 0220.

The CPU 0216 controls and performs calculations for each component within the inspection unit 0106 via the system bus 0219. The CPU 0216 functions as a processing unit that executes each process described below by executing programs stored in the computer-readable memory unit 0247 and loaded into the RAM 0217. The RAM 0217 is a type of general volatile memory device that can be accessed directly by the CPU 0216 and is used as the CPU 0216's work area or other temporary data storage area. The memory unit 0247 functions as a temporary storage area and work memory when the inspection device is operating. The inspection device I/F 0215 is connected to the inspection device unit I/F 0231 via the communication cable 0248. That is, the inspection unit 0106 is used to communicate with the inspection device 0108 via the inspection device I/F 0215 and the inspection device unit I/F 0231. The photographing unit 0218 has a photographing function (scanning function) equipped with, for example, a contact image sensor (hereinafter referred to as CIS), and transmits images generated by photographing (reading and scanning) paper passing through the inspection unit to the inspection device 0108 via the inspection device I/F 0215. Note that the CIS equipped in the photographing unit 0218 is an example of a sensor, and other types of sensors such as a CCD image sensor may also be used, and the photographing method (scanning method) is not limited thereto.

The CPU 0220 controls and performs calculations for each unit within the large-capacity stacker 0107 via the system bus 0224. The CPU 0220 functions as a processing unit that executes each process described below by executing programs stored in the computer-readable memory unit 0248 and loaded into the RAM 0222. The RAM 0222 is a type of general volatile memory device that can be accessed directly by the CPU 0221, and is used as a work area for the CPU 0221 or as other temporary data storage areas. The paper discharge unit 0223 monitors and controls the paper discharge operation to the main tray and top tray, and the loading status of each of the main tray and top tray.

The CPU 0226 of the inspection device 0108 controls and performs calculations for each component within the inspection device 0108 via the system bus 0230. The CPU 0226 functions as a processing unit that executes the various processes described below by executing programs stored in the computer-readable storage unit 0228 and loaded into the RAM 0227. The RAM 0227 is a type of general-purpose volatile storage device that can be accessed directly by the CPU 0226 and is used as a work area or other temporary data storage area for the CPU 0226. The storage unit 0228 functions as a temporary storage area and work memory when the inspection device is operating. The PDL analysis unit 0229 reads PDL data such as PDF, PostScript, and PCL received from the client computer 0110 or the information processing device 0109 and performs interpretation processing. The display unit 0245 is, for example, an LCD display connected to the inspection device, and accepts user input to the inspection device and displays the status of the inspection device.

The CPU 0234 of the information processing device 0109 controls and performs calculations for each component within the information processing device 0109 via the system bus 0239. The CPU 0234 functions as a processing unit that executes each process described below by executing programs stored in the computer-readable memory unit 0236 and loaded into the RAM 0235. The RAM 0235 is a type of general volatile memory device that can be accessed directly by the CPU 0234 and is used as a work area for the CPU 0234 or other temporary data storage area. The memory unit 0236 functions as a temporary storage area and work memory when the information processing device is operating. The network interface (hereinafter referred to as NW I/F) 0237 is connected to the NW I/Fs 0232 and 0240 via a network. The information processing device 0109 communicates with the inspection device 0108 via the NW I/Fs 0237 and 0232. In addition, the information processing device 0109 communicates with the client computer 0110 via the NW I/F 0237 and NW I/F 0240.

The CPU 0243 of the client computer 0110 controls and performs calculations on each component within the client computer 0110 via the system bus 0246. The CPU 0243 functions as a processing unit that executes each process described below by executing programs stored in the computer-readable storage unit 0245 and loaded into the RAM 0242. The RAM 0242 is a type of general volatile storage device that can be accessed directly by the CPU 0243, and is used as a work area for the CPU 0243 or other temporary data storage area. The storage unit 0244 functions as a temporary storage area and work memory when the client computer is operating.

Figure 3 shows the internal configuration of the printing device 0101, inspection unit 0106, and large-capacity stacker 0107. The printing device 0101 accepts user input via the UI panel 0102 and displays printing and device status. The paper feed decks 0103 and 0104 can store various types of paper. Each paper feed deck can separate only the topmost sheet of paper stored and transport it to the paper transport path 0305. 0301 to 0304 are development stations where toner images are formed using Y, M, C, and K color toners, respectively, to form color images. The toner images formed here are primarily transferred to the intermediate transfer belt 0306. The intermediate transfer belt 0306 rotates clockwise in the figure, and the toner image is transferred to the paper transported from the paper transport path 0305 at the secondary transfer position 0307. The fixing unit 0308 is equipped with a pressure roller and a heating roller, and as the paper passes between these rollers, the toner is melted and pressed, fixing the toner image to the paper. After passing through the fixing unit 0308, the paper is transported to 0312 via paper transport path 0309. If further melting and pressing are required for fixing depending on the type of paper, after passing through the fixing unit 0308, the paper is transported to the second fixing unit 0310 using the upper paper transport path, where additional melting and pressing is performed, and then transported to 0312 via paper transport path 0311. If the image formation mode is double-sided, the paper is transported to the paper reversal path 0313, inverted at 0313, and then transported to the double-sided transport path 0314, where the image on the second side is transferred at the secondary transfer position 0307.

CISs 0315 and 0316 are arranged facing each other within the inspection unit 0106. CIS 0315 is a sensor for reading the top surface of the paper, and CIS 0316 is a sensor for reading the bottom surface of the paper. The inspection unit 0106 scans the paper using CISs 0315 and 0316 when the paper transported along the paper transport path 0317 reaches a predetermined position. The image generated by the scan is sent to the inspection device 0108 via the inspection device I/F 0215 and inspection unit I/F 0231. The CPU 0226 of the inspection device 0108 determines whether the received image contains defects and notifies the inspection unit 0106 of the determination result via the inspection unit I/F 0231 and inspection device I/F 0215. The inspection unit CPU 0216 notifies the large-capacity stacker 0107 of the received determination result via the accessory I/Fs 0214 and 0220.

The large-capacity stacker 0107 is capable of loading a large volume of paper. It has a main tray 0324 as a tray for loading paper. Paper that has passed through the inspection unit 0106 enters the large-capacity stacker 0107 via paper transport path 0319. Paper that is determined to have been printed correctly by the inspection device 0108 is transported from paper transport path 0319 to paper transport path 0322 and then stacked on the main tray 0324. The large-capacity stacker 0107 also has a top tray 0320 as a paper output tray. The CPU 0221 controls the ejection of paper that has been detected as defective by the inspection device 0108 to the top tray 0320. When outputting to the top tray 0320, the paper is transported from paper transport path 0319 to the top tray 0320 via paper transport path 0321. 0323 is an inversion unit for inverting the paper. This inversion unit 0323 is used when loading paper onto the main tray 0324. When loading paper onto the main tray 0324, the inversion unit 0323 inverts the paper once so that the orientation of the incoming paper is the same as the orientation of the paper when loaded. When transporting paper to the top tray 0320, the paper is discharged as is without being flipped when loaded, so the inversion unit 0323 does not perform an inversion operation.

The following describes the processing that characterizes this invention using flowcharts and example screens. The image forming apparatus program related to this flow is stored in the memory unit 0205 of the image forming apparatus 0101, read into RAM 0202, and executed by the CPU 0201. The inspection apparatus program related to this flow is stored in the memory unit 0228 of the inspection apparatus 0108, read into RAM 0227, and executed by the CPU 0226. The information processing apparatus program related to this flow is stored in the memory unit 0236 of the information processing apparatus 0109, read into RAM 0235, and executed by the CPU 0234. The client computer program related to this flow is stored in the memory unit 0245 of the client computer 0110, read into RAM 0242, and executed by the CPU 0243.

The overall process from font registration before the start of inspection to inspection of the target image is explained using the flowchart in Figure 4.

First, in font registration in step S401, the user creates and registers font data to be registered. The font data to be registered is data that associates character shape images with character codes, which are required for character recognition (OCR) performed during data inspection. Here, the inspection device 0108 begins reading the font registration image, and the client computer 0110 executes a print job for font registration. In this embodiment, the print job for font registration is a job that prints a font with the same character shape and size as the font used in the printed material to be inspected, and is printed on the same paper as the printed material to be inspected. The inspection unit then reads the printed material and sends the generated image to the inspection device. The inspection device can create data that associates each character image in the received image with its corresponding character code. When registering the font, the character recognition method to be applied is also determined. Details will be described later.

Next, in step S402, the user registers a reference image that will serve as the basis for inspection. First, the client computer 0110 executes a print job for registering the reference image and generates a reference image by reading the printed paper. The inspection device 0108 then reads and registers the generated reference image. Note that an RIP image generated by rasterizing the print job may be received from the information processing device 0109 or client computer 0110 and used as the reference image.

Next, in step S403, the user configures the inspection settings, including various inspection parameters, inspection areas, and inspection levels. Details will be described later.

Next, in step S404, the printout printed by the image forming apparatus 0101 is inspected by the inspection device 0108. That is, a print job for producing the printout to be inspected is generated by the client computer 0110 and sent to the information processing device 0109 for management. Furthermore, when the image forming apparatus 101 executes this print job and outputs printed paper, the inspection unit 0106 detects the transport of the printed paper and scans the paper using the CIS 0315 and 0316, saving the scanned image in the RAM 303 of the inspection device 0108. The inspection device compares the saved scanned image with a reference image to inspect whether the printing was successful and outputs the inspection results. The inspection is performed based on the settings specified by the user in the inspection settings. Based on the inspection results, the large-capacity stacker 0107 ejects printed paper determined to be defective to a separate tray.

Next, details of font registration in S401 will be explained using the UI diagrams in Figures 5 and 6, and the flowchart in Figure 7.

Figure 5 is an example of a font registration screen displayed on the UI panel 0102 and accepting a user's operation to register a font. 501 is a button to start reading the scanned image. 502 is a character area selection button. After the user presses the character area selection button 502, the character area selection operation is accepted by clicking with the mouse on the frame 505 indicating the character area displayed on the scanned image. 503 is a character area placement button. After the user presses the character area placement button 503, the character area placement operation is accepted by selecting by dragging the mouse on the preview display. The user selects a character area to include a character string containing the characters for which font registration is desired. 504 is a preview display area in which the scanned image is previewed. 505 is a frame indicating the character area placed on the previewed scanned image. 506 is a setting field for setting the direction of the character string in the selected character area. Button 507 starts character extraction. When the user presses button 507, individual characters are extracted from the arranged character area 505, and the screen transitions to the character extraction screen of Figure 6. Button 508 is a completion button for completing the font registration process.

Figure 6 shows the character segmentation screen displayed on the UI panel 0102. Reference numeral 601 denotes a screen that previews an image of the character area and the segmentation position of each character. A preview of the character area set by the user on the font registration screen is displayed, and a frame indicating the coordinates of the segmentation process results for each character is displayed on the preview. Reference numeral 602 denotes an input field for the font name of the registered font. Reference numeral 603 denotes an input field for the font size of the registered font. Reference numeral 604 denotes a text box for inputting character segmentation images segmented character by character from the character area and characters (character codes) to be associated with the character segmentation images. Reference numeral 605 denotes a registration button. When the user presses the registration button, the association between each character image and character code in 604, as well as the font name in 602 and the size in 603, are saved, the segmentation screen in Figure 6 closes, and the screen transitions to the font registration screen in Figure 5.

Figure 7 is a flowchart showing the processing executed by the inspection device 0108 when a font registration operation is performed on the inspection device 0108. In response to operations on the font registration screen and character extraction screen displayed on the UI panel 0102, the CPU 0226 executes various processes to set up the inspection.

At S701, the CPU 0226 accepts an operation to start reading a scanned image from the font registration screen. In this embodiment, the operation to start reading a scanned image is the user pressing the scan image reading start button 501. When the CPU 0226 accepts the pressing of the scan image reading start button 501, it transitions to a state in which it waits to receive a scanned image of the printed material. Thereafter, when a print job is executed, the image scanned by the inspection unit 0106 is read into the font registration screen.

In S702, the user executes a print job for font registration on the client computer 0110. The CPU 0226 of the inspection device 0108 receives an image of the printout scanned by the inspection unit 0106 from the inspection unit 0106 via the inspection device I/F 0215 and the inspection unit I/F 0231. The CPU 0226 then displays the scanned image on the preview display screen 504 of the font registration screen.

At S703, the CPU 0226 ends the wait state for receiving the scanned image of the printed material.

At S704, the CPU 0226 accepts a character area setting operation from the font registration screen. The user sets the character area on the preview of the loaded image using the character area selection button 502, character area placement button 503, and character string direction setting field 506.

At S705, the CPU 0226 accepts a character segmentation operation from the font registration screen. In this embodiment, the character segmentation operation is the user pressing button 507, which starts character segmentation. Upon accepting the pressing of button 507, which starts character segmentation, the CPU 0226 executes segmentation of individual characters from within the set character area and transitions to the character segmentation screen. The character segmentation process is, for example, a process of calculating a pixel value histogram for the image of the character area and segmenting the area where this pixel value histogram stands out as a character segmentation image. This character segmentation method is one example, and other methods may be used to extract each character image.

In S706, the CPU 0226 accepts, on the character extraction screen, an input operation for the character (character code) to be associated with each character extraction image extracted in S705. In this embodiment, the user inputs the character (character code) in the text box 604.

At S707, the CPU 0226 accepts input of the font name and font size on the character extraction screen. The input of the font name and font size is input by the user into the input field 602 for the font name of the registered font and the input field 603 for the font size.

At S708, the CPU 0226 determines whether to perform character recognition processing that prioritizes accuracy or that prioritizes speed when performing character recognition using the currently registered font. In this embodiment, if the font size received at S707 is smaller than a specified value, it determines to perform character recognition processing that prioritizes accuracy; if it is larger, it determines to perform character recognition processing that prioritizes speed. This is because characters with larger font sizes tend to have better recognition accuracy even when using character recognition processing that prioritizes speed. Note that the method of determining the character recognition processing method to be performed is just one example, and there are various other methods besides the one shown in this embodiment. For example, the determination may be made using the resolution of the extracted character image, the number of registered characters, the character color, the font name, etc. Making this determination during the font registration process rather than during the inspection process can reduce overhead during the inspection process. Furthermore, if initialization processing corresponding to the determined character recognition process is also performed at this time, overhead during the inspection process can be further reduced. An example of initialization processing corresponding to the character recognition process is instance generation processing.

In S709, the CPU 0226 calculates parameters to be used in pre-processing before performing character recognition using the currently registered font. Parameters to be used in pre-processing are, for example, binarization thresholds used when binarizing a scanned image. By calculating these parameters during the font registration process rather than during the inspection process, overhead during the inspection process can be reduced.

At S710, the CPU 0226 accepts a registration operation from the character extraction screen. In this embodiment, the registration operation is the user pressing the registration button 605. The CPU 0226 then saves the font name, font size, character extraction image, associated character code, character recognition processing method to be used, and pre-processing parameters as registration font data in the memory unit 0228, and terminates the font registration process. In other words, the font data is registered in association with the character recognition processing method and pre-processing parameters to be applied.

Next, the details of the inspection settings will be explained using the UI diagrams in Figures 8 and 9, and the flowchart in Figure 10. Inspection settings begin by selecting a reference image (a standard image) registered during reference registration.

Figures 8 and 9 show examples of the inspection setting screen displayed on the UI panel 0102, which accepts the user's operation to execute the inspection settings. On the inspection setting screen, the user specifies the position of the inspection area on the preview-displayed reference image, and then makes individual settings for each inspection area.

Reference numeral 801 denotes a preview display screen on which a reference image is displayed as a preview. If the reference image was generated based on a multi-page print job, the reference image for each page can be displayed sequentially by switching the reference image displayed as a preview.

Reference numerals 802 and 803 indicate frames that indicate inspection areas placed on the preview. Inspection areas are placed using the inspection area placement button 805, and the user can change their size and position by dragging the mouse. Reference numeral 802 shows an example of a pattern inspection area. Reference numeral 803 shows an example of a character string inspection area.

804 is an inspection area selection button. After the user presses the inspection area selection button 804, the user can select the inspection area by clicking the frames 802 and 803 that indicate the inspection area with the mouse.

805 is the inspection area placement button. After the user presses the inspection area placement button 805, they select the type of inspection area from the pull-down menu that appears, and then drag the mouse to select the area they want to specify as the inspection area on the preview display, thereby accepting the placement operation for the inspection area.

806 is a setting item for selecting data for comparison testing using a file selection method. Comparison testing data is a reference CSV file for data testing that is compared when performing a data test. The reference CSV file is a file that the user must prepare in advance, and is a file that lists the correct strings for string testing and the correct strings when decoded for barcode testing. In other words, when performing a data test to check the contents of a scanned string or the decoded contents of a code image (barcode or 2D code), the OCR results of the string image in the string testing area and the string resulting from decoding the code image are compared with the correct strings listed in the reference CSV file.

807 is the setting item for the selected area, and individual setting values for the inspection area selected after pressing the inspection area selection button 505 are displayed.

808 is the page range setting item. By pressing each button, the user can specify the range of pages on which inspection will be performed using the selected inspection area. If nothing is selected, the selected inspection area will be placed only on the page currently displayed on the preview display screen. If "Same side as current page" is selected, the selected inspection area will also be placed on other pages on the same side (front or back) depending on whether the selected inspection area is placed on the front or back of the sheet. If "All pages" is selected, the selected inspection area will be placed on all pages, regardless of whether they are on the front or back.

809 in Figure 8 and 901 in Figure 9 are setting items for each type of inspection area, and setting items corresponding to the type of inspection area selected using the inspection area selection button 804 are displayed.

In Figure 8, 809 indicates the pattern inspection setting items that are displayed when the pattern inspection area 802 is selected. The pattern inspection setting items include items such as what type of defects are inspected when inspecting printed matter and the level at which minute defects can be detected. The pattern inspection setting items include items such as what type of defects are inspected when inspecting printed matter and the level at which minute defects can be detected. Inspection items include, for example, round defects (hereinafter referred to as "dots") and linear defects (hereinafter referred to as "streaks"). There are five inspection levels, for example, from level 1 to level 5, with level 5 being able to detect thinner and smaller defects than level 1. In addition, a level can be set for each inspection item, such as inspection level 5 for dots and level 4 for streaks.

901 in Figure 9 is the setting item for the string inspection that is displayed when the string inspection area 803 is selected. For each inspection area, you can set the angle of the inspection area, the font of the string, whether to perform a comparison inspection, and which column in the reference CSV to compare with if a comparison inspection is performed. An item for selecting the font of the string to be used in the inspection area is displayed, and the font selection from the user is accepted. A font that was registered in S401 can be selected and the information of the selected font can be associated with the desired inspection area and saved.

810 is the test setting completion button. When the user presses the completion button, the test setting is completed, the settings are saved in the memory unit 0228, and the test setting process ends. If there is an inconsistency in the settings, the test setting completion button 810 may be disabled so that it cannot be pressed. An example of a setting inconsistency is when an inspection area exists for performing a comparison test, but the setting item 806 for the comparison test data has not been set. 811 is the test setting cancellation button. When the user presses it, the settings are discarded and the test setting process ends.

Figure 10 shows the processing in the inspection device 0108 when an inspection setting start operation is performed on the inspection device 0108. In response to an operation on the inspection setting screen displayed on the UI panel 0102, the CPU 0226 of the inspection device 0108 executes various processes to set up the inspection.

In S1001, the CPU 0226 accepts a setting operation for the verification test data from the test setting screen. In this embodiment, the setting operation for the verification test data is an operation by the user on the setting item 507 for the verification test data.

In S1002, the CPU 0226 accepts an inspection area placement operation from the inspection setting screen. In this embodiment, the inspection area placement operation is the user's operation of the inspection area placement button 805.

In S1003, the CPU 0226 accepts an inspection area selection operation from the inspection setting screen. In this embodiment, the inspection area selection operation is an operation in which the user presses the inspection area selection button 804 and selects one of the inspection areas arranged in the preview display area.

In S1004, the CPU 0226 accepts setting operations for each type of inspection area from the inspection setting screen. In this embodiment, setting operations for each inspection area refer to the user's operation of the setting items for each type of inspection area (setting operations for each setting item 809 in Figure 8 and 901 in Figure 9).

In S1005, the CPU 0226 determines whether the user has pressed the Complete button 810, which indicates completion of the test settings, and if the Complete button has been pressed, proceeds to S1006. If the test settings are not complete, the process returns to S1003 and the user continues setting up the test.

At S1006, the CPU 0226 saves the settings in the memory unit 0228 and ends the test setting process.

Next, the details of the inspection will be explained using the flowchart in Figure 11. The CPU 0226 of the inspection device 0108 executes various processes to perform the inspection.

At S1101, the CPU 0226 loads the inspection settings from the memory unit 0228 into the RAM 0227 and transitions to a state where it waits to receive a scanned image of the printout to be inspected. After this, when a print job is executed, the scanned image sent from the inspection unit 0106 can be processed as the inspection target.

In S1102, the user instructs the client computer 0110 to execute the print job to be inspected, and the image forming device executes printing based on the print job. The CPU 0226 receives the image generated by scanning the printout to be inspected by the inspection unit 0106 via the inspection device I/F 0215 and the inspection unit I/F 0231.

In S1103, the CPU 0226 cuts out and acquires an image of the inspection area specified by the inspection settings read in S1101 from the scanned image received from the inspection unit 0106 in S1102.

In S1104, the CPU 0226 determines whether the inspection area acquired in S1103 is an area set for pattern inspection or for character string inspection in the inspection settings loaded in S1101. If it is a pattern inspection area, the process proceeds to S1105; if it is a character string inspection area, the process proceeds to S1106.

In S1105, the CPU 0226 compares the image of the inspection area acquired in S1103 with a reference image of the image to be printed in that area to inspect whether there are any defects in the printed image. If a difference is detected, it is determined that a defect exists in the printed matter and the inspection result for that inspection area is NG; if no difference is detected (or the difference is within the allowable range), the inspection result is OK.

At S1106, the CPU 0226 performs preprocessing such as background removal and binarization on the inspection area where the string inspection will be performed. Font information is set for the inspection area for the string inspection, as described in Figure 9. Therefore, in this preprocessing, the preprocessing parameters to be used can be determined based on the font information set for the inspection area and the preprocessing parameters that were previously saved in association with the registered font data in S709 of Figure 7. This eliminates the need to analyze the image and calculate the preprocessing parameters when performing the inspection, reducing overhead during the inspection process.

In S1107, the CPU 0226 determines whether the character recognition processing method previously stored in association with the registered font data prioritizes speed or accuracy. Here, the CPU 0226 determines whether to apply speed-oriented character recognition processing or accuracy-oriented character recognition processing based on the font information previously set for the inspection area in FIG. 9 and the character recognition processing method information previously associated with the registered font data in S708 of FIG. 7. Therefore, since there is no need to analyze the image of the inspection area to determine the character recognition processing method, overhead during inspection processing can be reduced. If speed is prioritized, proceed to S1108; if accuracy is prioritized, proceed to S1109.

At S1108, the CPU 0226 performs speed-focused character recognition processing on the image of the inspection area using the registered font data set for the inspection area.

At S1109, the CPU 0226 performs precision-focused character recognition processing on the image of the inspection area using the registered font data set for the inspection area.

In S1110, the CPU 0226 compares the character string written in the reference CSV file with the character recognition results obtained in S1108 or S1109. If the comparison results in a mismatch, the inspection result for that inspection area is deemed NG; if the comparison results in a match, the inspection result for that inspection area is deemed OK.

In S1111, the CPU 0226 determines whether inspection of the inspection area specified in the inspection settings has been completed. If it has been completed, proceed to S1112; if it has not been completed, proceed to S1103.

In S1112, the CPU 0226 determines the results of the inspection. If the inspection of all inspection areas in the scanned image is successful, proceed to S1113; if the inspection of even one area is unsuccessful, proceed to S1114.

At S1113, the CPU 0226 instructs the large-capacity stacker 0107 to output printed materials that passed inspection to the main tray of the paper output unit 0223 of the large-capacity stacker 0107.

At S1114, the CPU 0226 instructs the large-capacity stacker 0107 to output the printouts that failed inspection to the top tray of the paper output unit 0223 of the large-capacity stacker 0107.

In S1115, the CPU 0226 determines whether inspection of all printed materials to be inspected has been completed. If not, proceed to S1102; if completed, proceed to S1116.

At S1116, the CPU 0226 ends the wait state for receiving the scanned image of the printed material. The CPU 0226 then ends the inspection process.

As described above, according to this embodiment, when font data is registered, information on the character recognition process and preprocessing to be applied to the character image of the font size to be registered are associated with the font data and registered (S708-S710 in FIG. 7). Furthermore, when a character string inspection area is set, information on the font to be printed in the inspection area is set (901 in FIG. 9). This makes it easy to determine the preprocessing and character recognition processing method to be applied when scanning a printed material to inspect the print quality, thereby improving inspection speed and accuracy. Furthermore, overhead can be further reduced by individually generating and initializing instances according to the character recognition method and parameter combination prior to inspection.

Second Embodiment
In the second embodiment, an example in which the character recognition processing to be applied is also determined and saved when the inspection area is set will be described with reference to Fig. 12. Note that the description will omit parts common to Fig. 10 of the first embodiment.

Figure 12 shows the processing of the second embodiment in the inspection device 0108 when an inspection setting start operation is performed on the inspection device 0108. In response to an operation on the inspection setting screen displayed on the UI panel 0102, the CPU 0226 executes various processes for setting up the inspection.

The processing of steps S1001 to S1004 is the same as that described above in Figure 10, so detailed description will be omitted.

In S1201, the CPU 0226 determines whether the type of inspection area selected in S1003 is a string inspection area, and if it is a string inspection area, proceeds to S1202; if it is not a string inspection area, proceeds to S1005.

In S1202, the CPU 0226 determines whether the character recognition process to be applied to the currently set character string inspection area is character recognition process that emphasizes accuracy or character recognition process that emphasizes speed. In this embodiment, if the size of the characters (or the number of pixels of the characters) printed in the character string inspection area set on the reference image is smaller than a specified value, it determines to perform character recognition process that emphasizes accuracy, and if it is equal to or greater than the specified value, it determines to perform character recognition process that emphasizes speed. The method of determining the character recognition to be performed is just one example, and there are various other forms in addition to the one shown in this embodiment. By determining this character recognition process while setting the inspection area, it is possible to reduce overhead during subsequent inspection processing. The determined character recognition method is saved in the memory unit 0228 as an inspection setting in S1006.

In S1203, the CPU 0226 calculates parameters to be used in preprocessing when performing character recognition on the currently set character string inspection area. Parameters to be used in preprocessing include, for example, the brightness of the background part in the scanned image and the binarization threshold. By performing this calculation while the inspection area is being set rather than during the inspection process, it is possible to reduce overhead during subsequent inspection processes. Furthermore, by performing initialization processing according to the determined character recognition processing at this time, it is possible to reduce overhead during inspection processes. The calculated parameters to be used in preprocessing are saved in the memory unit 0228 as inspection settings in S1006.

By following the above steps, in this embodiment, the character recognition process is determined and initialization processing corresponding to the character recognition process is performed prior to testing, thereby reducing overhead during testing and improving testing speed and accuracy.

Other Examples
The present invention can also be realized by executing the following process: software (program) that realizes the functions of the above-described embodiments is supplied to a system or device via a network or a computer-readable storage medium, and the computer (or CPU, MPU, etc.) of the system or device executes the program.

Claims (17)

An inspection device having an inspection means for inspecting a read image obtained by reading an image on a recording material conveyed from a conveying means that receives the recording material on which an image has been printed from a printing device that has printed the image on the recording material, the read image being read by a reading unit, the read image being conveyed from the recording material,
a registration means for registering a font and a character recognition processing method in association with each other before the inspection is performed by the inspection means ;
a setting means for setting an inspection area in which a character string is inspected and a font to be used in the inspection area ;
The inspection device is characterized in that the inspection means determines a character recognition processing method to be applied to the inspection area based on the font used in the inspection area set by the setting means and the character recognition processing method associated with the font by the registration means, and performs character recognition processing on an image in the read image corresponding to the inspection area using the determined character recognition processing method. The inspection device described in claim 1, characterized in that the character recognition processing method registered in association with a font by the registration means is either character recognition processing that emphasizes accuracy or character recognition processing that emphasizes speed. the registration means registers the font, the character recognition processing method, and information on pre-processing executed before the character recognition processing in association with each other;
The inspection device described in claim 1, characterized in that the inspection means performs pre-processing associated with the font on an image corresponding to the inspection area in the read image based on the font used in the inspection area set by the setting means, the character recognition processing method associated with the font by the registration means, and the pre-processing information, and uses the determined character recognition processing method to perform character recognition processing on the image corresponding to the inspection area in the read image after the pre-processing has been performed. 4. The inspection apparatus according to claim 3, wherein the information on the pre-processing is information on surface preparation. 4. The inspection apparatus according to claim 3, wherein the pre-processing information is a parameter used when binarizing the read image. 6. The inspection device according to claim 1 , wherein the inspection means further executes an inspection to compare the result of the character recognition processing with a correct character string. An inspection device having an inspection means for inspecting a read image obtained by reading an image on a recording material conveyed from a conveying means that receives the recording material on which an image has been printed from a printing device that has printed the image on the recording material, the read image being read by a reading unit, the read image being conveyed from the recording material,
a setting means for setting an inspection area in which a character string is to be inspected in the displayed reference image based on a user's instruction, and for setting a character recognition processing method to be applied to the inspection area based on the character size within the set inspection area before the inspection is performed by the inspection means;
The inspection device is characterized in that the inspection means performs character recognition processing on an image corresponding to the inspection area in the read image using the character recognition processing method set by the setting means. 8. The inspection device according to claim 7, wherein the character recognition processing method registered by the setting means in association with a font is either character recognition processing that emphasizes accuracy or character recognition processing that emphasizes speed. the setting means registers the character size, the character recognition processing method, and information on pre-processing to be executed before the character recognition processing in association with each other;
The inspection device described in claim 7, characterized in that the inspection means performs preprocessing associated with the character size on an image corresponding to the inspection area in the read image based on the character size used in the inspection area set by the setting means, the character recognition processing method associated with the character size used in the inspection area, and the preprocessing information, and uses the set character recognition processing method to perform character recognition processing on the image corresponding to the inspection area in the read image after the preprocessing has been performed. 10. The inspection apparatus according to claim 9, wherein the information on the pre-processing is information on surface preparation. 10. The inspection apparatus according to claim 9, wherein the pre-processing information is a parameter used when binarizing the read image. 12. The inspection device according to claim 7, wherein the inspection means further executes an inspection to compare the result of the character recognition processing with a correct character string. A program for causing a computer to function as the inspection device according to any one of claims 1 to 12 . A control method for an inspection device having an inspection means for inspecting a read image obtained by reading an image on a recording material conveyed from a conveying means that receives a recording material on which an image has been printed from a printing device that has printed an image on the recording material, the read image being read by a reading unit, the read image being conveyed from the recording material, the control method comprising:
a registration step of registering a font and a character recognition processing method in association with each other before the execution of the inspection ;
a setting step of setting an inspection area in which a character string is inspected and a font to be used in the inspection area;
an inspection step of determining a character recognition processing method to be applied to the inspection area based on the font used in the inspection area set in the setting step and the character recognition processing method associated with the font in the registration step, and performing character recognition processing on an image in the read image corresponding to the inspection area using the determined character recognition processing method;
A control method for an inspection apparatus, comprising: 1. A control method for an inspection device that inspects a read image obtained by a reading unit reading an image on a recording material that has been conveyed from a conveying means that receives and conveys a recording material on which an image has been printed from a printing device that has printed the image on the recording material, the method comprising:
a step of setting an inspection area for inspecting a character string based on a user's instruction in a reference image displayed before the inspection is performed , and setting a character recognition processing method to be applied to the inspection area based on the size of the characters in the set inspection area;
performing character recognition processing on an image corresponding to the inspection area in the read image using the set character recognition processing method;
A control method for an inspection apparatus, comprising: The inspection device described in claim 1, characterized in that before the inspection is performed, it is before the read image is obtained by the reading unit. The inspection device described in claim 7, characterized in that before the inspection is performed, it is before the read image is obtained by the reading unit.