JP6950298B2 - Image forming device, image forming method and program - Google Patents

Description

The present invention relates to an image forming apparatus, an image forming method and a program.

In the recent usage scene of multifunction devices, there is increasing interest in the risk of information leakage. Paper media or portable media, which are the media handled by multifunction devices, account for a large proportion of information leakage routes. Therefore, a technique related to document tracing using a digital watermark is required, and as an existing technique, a technique using a frequency (for example, Patent Document 1) and a technique related to pattern replacement (for example, Patent Document 2) are known. Further, a technique capable of stably detecting a digital watermark in an embedded image and suppressing deterioration of image quality due to a digital watermark pattern is already known (for example, Patent Document 3).

However, the conventional digital watermark embedding and detection technology has a problem that it is necessary to increase the resolution of the printer at the time of embedding and the resolution of the scanner at the time of detection in order to improve the detection rate while making the embedding inconspicuous. rice field.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the cost of a device by suppressing the resolution of a scanner while improving the detection rate of a digital watermark.

Therefore, in order to solve the above problems, the image forming apparatus includes an acquisition unit that reads an image and acquires image data, a generation unit that embeds electronic watermark data in the acquired image data to generate print data, and the generation unit. It has a printing unit that prints on a print medium based on the printed data, and the generation unit determines a resolution for embedding electronic watermark data when the acquired image data has a predetermined resolution or higher. The electronic watermark data embedded in the print data, which is lower than the resolution of the above, is embedded by making one or more pixels of the image data whose color is equal to or less than a predetermined brightness or less than a predetermined brightness to be white. ing.

While improving the detection rate of digital watermarks, the resolution of the scanner can be suppressed and the cost of the device can be reduced.

It is a figure which shows the hardware configuration example of the image forming apparatus 1 in embodiment of this invention. It is a figure which shows the functional structure example of the image forming apparatus 1 in embodiment of this invention. It is a flowchart which shows the procedure of embedding the digital watermark data in the RGB component in embodiment of this invention. It is a figure which shows the example of embedding the digital watermark data by the white outline in embodiment of this invention. It is a figure which shows the embedding example of the digital watermark data by multiple values in embodiment of this invention. It is a figure which shows the embedding example of the digital watermark data which changed the resolution in embodiment of this invention. It is a figure which shows the example of embedding the digital watermark data by the combination of a plurality of methods in embodiment of this invention. It is a figure which shows the example of embedding the digital watermark data in the single-sided document in embodiment of this invention. It is a flowchart which shows the procedure of embedding the digital watermark data in the luminance component in embodiment of this invention. It is a flowchart which shows the scanning procedure of the digital watermark data in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a hardware configuration example of the image forming apparatus 1 according to the embodiment of the present invention. As shown in FIG. 1, the image forming apparatus 1 includes a controller 60, an operation panel 70, an FCU80 (Facsimile Control Unit), a USB (Universal Serial Bus) 90, an MLB100 (Media Link Board), and an engine 110. Further, the controller 60 includes a CPU 61 (Central Processing Unit), a memory 62, an ASIC64 (Application Specific Integrated Circuit), an HDD 63 (Hard Disk Drive), and a TPM (Trusted Platform Module) chip 66.

The operation panel 70 is connected to the ASIC 64 of the controller 60. Further, the MLB100, the FCU80, the USB90, and the engine (including the scanner / plotter engine) 110 are connected to the ASIC64 of the controller 60 by the data transfer bus 65.

The CPU 61 controls the entire image forming apparatus 1. The CPU 61 executes a program stored in the memory 62 or the HDD 63 to realize the function of the image forming apparatus 1. For example, the CPU 61 includes functional units NCS21 (Network Control Service), OCS22 (Operation panel Control Service), FCS23 (Facsimile Control Service), MCS24 (Memory Control Service), ECS25 (Engine Control Service), and DCS26 (DCS26) shown in FIG. Delivery Control Service), CCS27 (Certification and Charge Control Service), LCS28 (Log Control Service), UCS29 (User information Control Service), SCS30 (System Control Service), SRM31 (System Resource Manager), FCUH41 (Facsimile Control Unit Handler) , IMH42 (Image Memory Handler) and MEU43 (Media Edit Utility) are started and executed as processes on the OS (Operating System), respectively, and the printer 11, copy 12, fax 13, scanner 14 and the like forming the application layer 5 are formed. The net file 15 is started and executed (details will be described later in FIG. 2).

The TPM chip 66 is a chip that realizes security-related functions by hardware. The operation panel 70 provides the user with an input / output interface. The FCU80 is hardware that controls the fax function. The USB 90 is an interface for connecting to an external USB device. The MLB 100 is hardware that converts an image format or the like. The engine 110 is hardware including a scanner and a printer (also referred to as a plotter).

FIG. 2 is a diagram showing a functional configuration example of the image forming apparatus 1 according to the embodiment of the present invention. The image forming apparatus 1 includes a software group 2, an engine unit 3, and a hardware unit 4 as a functional configuration.

The image forming apparatus 1 activates the application layer 5 and the platform 8. For example, the image forming apparatus 1 reads the programs of the application layer 5 and the platform 8 from the non-volatile memory constituting the memory 62 or the HDD 63 shown in FIG. 1, an external storage device corresponding to the external storage means, and the like. Is transferred to the RAM (Random Access Memory) area included in the memory 62 and started. The engine unit 3 has a scanning function and a printer function. The scanning function includes a function of determining whether the scanned image is an achromatic image or a chromatic image. The hardware unit 4 is a functional unit having a data exchange function or various functions with the engine unit 3 realized by the ASIC 64 shown in FIG.

Further, the software group 2 includes an application layer 5 and a platform 8 running on an operating system (hereinafter, referred to as “OS”) such as UNIX (registered trademark). The application layer 5 includes a program that performs processing unique to each user service related to image formation, such as the printer 11, the copy 12, the fax 13, and the scanner 14.

Further, the platform 8 manages the control service layer 6 that interprets the processing request from the application layer 5 and generates the acquisition request of the hardware unit 4, and the control service layer 6 that manages one or more hardware units 4. It includes a system resource manager (hereinafter referred to as “SRM”) 31 that mediates the acquisition request from SRM 31, and a handler layer 7 that manages the hardware unit 4 in response to the acquisition request from SRM 31.

The control service layer 6 includes a network control service (hereinafter referred to as “NCS”) 21, an operation panel control service (hereinafter referred to as “OCS”) 22, a fax control service (hereinafter referred to as “FCS”) 23, and a memory. Control service (hereinafter referred to as "MCS") 24, engine control service (hereinafter referred to as "ECS") 25, delivery control service (hereinafter referred to as "DCS") 26, certification and charge control service (hereinafter referred to as "DCS") Hereinafter, it is referred to as "CCS" 27, a log control service (hereinafter referred to as "LCS") 28, a user information control service (hereinafter referred to as "UCS") 29, and a system control service (hereinafter referred to as "SCS"). ) 30 mag, configured to include one or more service modules.

The platform 8 has a GW-API 51 that can receive a processing request from the application layer 5 provided by a predefined function. The OS executes each software of the application layer 5 and the platform 8 in parallel as a process. A process is also a functional unit that realizes a function based on the processing of the process.

The process of NCS21 provides a service that can be commonly used for applications that require network I / O, distributes the data received by each protocol from the network side to each application, and distributes the data from each application. Mediates when sending to the network side.

The OCS22 process controls the operation panel, which is a means of transmitting information between the operator and the main body control.

The FCS23 process involves sending and receiving faxes from the application layer 5 using the PSTN (Public Switched Telephone Network) network or ISDN (Integrated Services Digital Network) network, registering / quoting various fax data managed by backup memory, and faxing. Provide API (Application Programming Interface) for reading, receiving and printing faxes.

The process of MCS24 performs memory control such as acquisition and release of memory and use of HDD 63.

The process of ECS25 controls the engine unit 3 such as the engine unit 3 and the hardware unit 4.

The DCS26 process controls the distribution of stored documents and the like. CCS27 controls authentication and billing. The LCS 28 manages and retains log information. UCS29 manages user information.

The process of SCS30 performs processing such as application management, operation unit control, system screen display, LED display, hardware unit 4 management, and interrupt application control.

The process of SRM31 controls the system and manages the hardware unit 4 together with SCS30. For example, the process of SRM 31 mediates and controls execution according to an acquisition request from a higher layer using a plotter included in the engine unit 3, a hardware unit 4, or the like.

Specifically, the process of SRM31 determines whether the hardware unit 4 requested to be acquired is available, that is, whether it is not used by another acquisition request, and if it is available, the hardware requested to be acquired. Notify the upper layer that the wear unit 4 is available. Further, the process of SRM31 performs scheduling for using the hardware unit 4 in response to an acquisition request from an upper layer, and requests contents such as paper transfer and image drawing operation by a printer engine, memory allocation, file generation, and the like. Is directly implemented.

Further, the handler layer 7 includes a fax control unit handler (hereinafter referred to as “FCUH”) 41 that manages the fax control unit included in the hardware unit 4, and memory allocation to the process and management of the memory allocated to the process. It includes an image memory handler (hereinafter, referred to as “IMH”) 42 that performs the above-mentioned operations, and a media editing utility (hereinafter, referred to as “MEU”) 43 that controls electronic watermarks and image conversion-related controls. The SRM 31 and FCUH 41 make a processing request to the hardware unit 4 by using an engine I / F 52 that enables transmission of a processing request to the hardware unit 4 by a predefined function.

Here, as an example, an operation case of the printer 11 will be described.

The user transmits a print request from the PC to the image forming apparatus 1 through the printer driver. The image forming apparatus 1 uses the printer 11 through the NCS 21.

Upon receiving a request from the printer 11, the MCS 24 acquires the memory and uses the IMH 42 and the hardware unit 4 to hold the received data.

After acquiring all the data, the printer 11 makes a print request to the ECS 25 and passes the process to the lower service layers, for example, the SCS 30 and the SRM 31. The SRM 31 communicates with the engine unit 3 through the engine I / F 52, while the output data to the engine unit 3 is digitally read from the hardware unit 4 by the IMH 42 according to a user's instruction or setting. The processing of the watermark is requested from the MEU 43, and the digital watermark is embedded in the image under the control of the IMH42 by the MEU 43. After that, the image with a digital watermark under the control of IMH42 is passed to the engine unit 3 and printed on a printing medium such as paper.

FIG. 3 is a flowchart showing a procedure for embedding the digital watermark data in the RGB component according to the embodiment of the present invention.

In step S11, the image forming apparatus 1 reads an image. The scanner 14 shown in FIG. 2 reads through the engine 110 shown in FIG. Note that the image data already stored in the PC or the like may be used without the scanner 14 reading the image.

In step S12, the engine unit 3 determines whether the image read in step S11 is an achromatic image or a chromatic image. If it is an achromatic image, the process proceeds to step S13a (YES in S12), and if it is a chromatic image, the process proceeds to step S13b (NO in S12).

In step S13a, an RGB image is created from the achromatic image read by the IMH42. The created image is written in the memory 62 shown in FIG.

In step S13b, an RGB image is created from the chromatic image read by the IMH42. The created image is written in the memory 62 shown in FIG. 1 in the same manner as in step S13a.

In step S14, the IMH 42 embeds the digital watermark data via the MEU 43 in the RGB component of the image created in step S13a or step S13b. By embedding the digital watermark data in the RGB component, it is possible to eliminate the need for conversion of the image data to be embedded in the digital watermark data. The IMH 42 reads an image from the memory 62 included in the hardware unit 4 according to a user's instruction or setting, and requests the MEU 43 to process a digital watermark. The MEU 43 embeds a digital watermark in an image managed by IMH42. Hereinafter, in FIGS. 4 to 8, an example of digital watermark embedding by MEU43 will be described.

FIG. 4 is a diagram showing an example of embedding digital watermark data in white in the embodiment of the present invention. As shown in FIG. 4, the MEU 43 can embed the digital watermark inconspicuously by whitening the pixels for embedding the digital watermark in the black background portion of the image data. Here, the black background of the image data is a set of pixels whose color is equal to or less than a predetermined brightness or a predetermined brightness or less.

FIG. 5 is a diagram showing an example of embedding digital watermark data with multiple values according to the embodiment of the present invention. As shown in FIG. 5, the MEU 43 can embed the digital watermark inconspicuously by embedding the digital watermark data having a multi-valued gradation in the image data. The reading and detection of the digital watermark data may be performed with multi-valued gradation.

FIG. 6 is a diagram showing an example of embedding digital watermark data in which the resolution is changed in the embodiment of the present invention. FIG. 6 shows an example in which digital watermark data having a resolution lower than that of the image data is embedded. For example, when the resolution of the image data is 200 dpi, the digital watermark data may be embedded with pixels having twice the size of the pixels of the image data, that is, at 100 dpi, which is half the resolution. Further, for example, when the resolution of the image data is 600 dpi, the digital watermark data may be embedded at a resolution of 300 dpi.

Further, when the image data has a fine resolution equal to or higher than a predetermined resolution, the resolution for embedding the digital watermark data may be lower than the resolution of the image data. By lowering the resolution of the digital watermark data than the resolution of the image data, it is possible to improve the detection rate of the digital watermark data even when the resolution of the scanner is not high.

FIG. 7 is a diagram showing an example of embedding digital watermark data by a combination of a plurality of methods according to the embodiment of the present invention. As shown in FIG. 7, the method of embedding the digital watermark data by whitening the black background portion of FIG. 4, the method of embedding the multi-valued digital watermark data of FIG. 5, and the resolution of the digital watermark data of FIG. Digital watermark data is embedded in the image data by combining all the methods of reducing the watermark. By combining the methods of embedding a plurality of digital watermark data, it is possible to make the digital watermark inconspicuous, and it is possible to improve the detection rate even when the scanner resolution is low.

FIG. 8 is a diagram showing an example of embedding digital watermark data in a single-sided document according to the embodiment of the present invention. As shown in FIG. 8, by embedding the digital watermark data on the back surface in the case of a single-sided document, the digital watermark data can be embedded without affecting the image data on the front surface.

Return to FIG. Subsequently, the IMH 42 generates R'G'B'image data in which the digital watermark data is embedded. That is, the generated image data is written in the memory 62. (S15).

FIG. 9 is a flowchart showing a procedure for embedding the digital watermark data in the luminance component according to the embodiment of the present invention. When you want to embed the digital watermark data in the brightness component, by using the flowchart, you can embed the digital watermark data in the brightness component so that the embedded data is less noticeable than the method of embedding in the area without an image. be able to.

In step S21, the image forming apparatus 1 reads an image. The scanner 14 shown in FIG. 2 reads through the engine 110 shown in FIG. Note that the image data already stored in the PC or the like may be used without the scanner 14 reading the image.

In step S22, the engine unit 3 determines whether the image read in step S21 is an achromatic image or a chromatic image. If it is an achromatic image, the process proceeds to step S23a (YES in S22), and if it is a chromatic image, the process proceeds to step S23b (NO in S22).

In step S23a, an RGB image is created from the achromatic image read by the IMH42. The created image is written in the memory 62 shown in FIG.

In step S23b, an RGB image is created from the chromatic image read by the IMH42. The created image is written in the memory 62 shown in FIG. 1 in the same manner as in step S23a.

In step S24, the IMH42 converts the RGB image created in step S23a or step S23b into a YCbCr image.
The conversion formula from RGB to YCbCr is, for example, as follows.
Y = 0.2989 * R + 0.5866 * G + 0.1145 * B
Cb = -0.1687 * R-0.3312 * G + 0.5000 * B
Cr = 0.5000 * R-0.4183 * G-0.0816 * B
Subsequently, the IMH 42 reads an image from the memory 62 included in the hardware unit 4 according to a user's instruction or setting, and requests the MEU 43 to process the digital watermark. The MEU 43 embeds the digital watermark in the Y (luminance) component of the image managed by the IMH 42 (S25). The MEU 43 represents the Y component as an integer value from 0 to 255, and embeds the digital watermark data in the Y component of each dot. For embedding the digital watermark data, the digital watermark data embedding method of FIGS. 4 to 8 may be used as in the flowchart shown in FIG.

Subsequently, the IMH 42 generates Y'CbCr image data in which the digital watermark data is embedded. That is, the generated image data is written in the memory 62. (S26).

FIG. 10 is a flowchart showing a procedure for scanning digital watermark data according to the embodiment of the present invention.

In step S31, the image forming apparatus 1 reads an image. The scanner 14 shown in FIG. 2 reads through the engine 110 shown in FIG. Note that the image data already stored in the PC or the like may be used without the scanner 14 reading the image.

Subsequently, the scanner 14 or the IMH42 determines whether or not the digital watermark detection function is ON (S32), and if the digital watermark detection function is ON (YES in S32), the process proceeds to step S33. When the digital watermark detection function is OFF (NO in S32), the process proceeds to step S38, and normal reading is executed (S38).

Steps S33 to S36 are loop processing for reading the digital watermark. When the loop process of reading the digital watermark is started (S33), in step S34, the MEU 43 executes the digital watermark detection. Subsequently, the MEU 43 determines whether or not the digital watermark detected in step S34 is valid (S35). In step S36, it is determined whether or not the digital watermark reading / detection / determination of steps S33 to S35 has been completed a predetermined number of times, for example, 10 times, and if completed, the process proceeds to step S37.

In step S37, the MEU 43 makes a comprehensive determination on the reading result of the digital watermark executed in the loop processing of steps S33 to S36. The comprehensive determination may be determined by accumulating the results determined for each loop process, or may determine the result obtained by synthesizing the detections or determinations of a plurality of loop processes.

If the digital watermark reading / detection / determination is completed during the loop processing of steps S33 to S36, the loop processing is terminated and the process proceeds to step S37 without performing the loop processing a predetermined number of times. The procedure for scanning the digital watermark data may be completed.

As described above, according to the embodiment of the present invention, the image forming apparatus 1 reduces the resolution at which the digital watermark data is embedded when the image data has a fine resolution equal to or higher than a predetermined resolution. By lowering the resolution of the digital watermark data from the image data, it is possible to improve the detection rate of the digital watermark data even when the resolution of the scanner is not high. That is, it is possible to reduce the cost of the device by suppressing the resolution of the scanner while improving the detection rate of the digital watermark.

In the embodiment of the present invention, the engine unit 3 or the scanner 14 is an example of the acquisition unit. The R'G'B'image data or the Y'CbCr image data is an example of print data. IMH42 or MEU43 is an example of a generator. The engine unit 3 or the printer 11 is an example of a printing unit.

Although the examples of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications are made within the scope of the gist of the present invention described in the claims.・ Can be changed.

1 Image forming device 60 Controller 61 CPU
62 Memory 63 HDD
64 ASIC
65 Data transfer bus 66 TPM chip 70 Operation panel 80 FCU
90 USB
100 MLB
110 Engine 2 Software group 3 Engine part 4 Hardware part 5 Application layer 6 Control service layer 7 Handler layer 8 Platform 11 Printer 12 Copy 13 Fax 14 Scanner 15 Net file 21 NCS
22 OCS
23 FCS
24 MCS
25 ECS
26 DCS
27 CCS
28 LCS
29 UCS
30 SCS
31 SRM
41 FCUH
42 IMH
43 MEU
51 GW-API
52 Engine I / F

Japanese Unexamined Patent Publication No. 2009-201069 Japanese Unexamined Patent Publication No. 2009-253854 JP-A-2002-344720

Claims (9)

An acquisition unit that reads an image and acquires image data,
A generator that generates print data by embedding digital watermark data in the acquired image data,
It has a printing unit that prints on a printing medium based on the generated print data.
When the acquired image data has a predetermined resolution or higher, the generation unit lowers the resolution at which the digital watermark data is embedded to be lower than the predetermined resolution .
The digital watermark data embedded in the print data is an image forming apparatus in which one or a plurality of pixels of the image data whose color is a predetermined brightness or less or a predetermined brightness or less is white. The image forming apparatus according to claim 1, wherein the digital watermark data embedded in the print data is embedded in a luminance component of the image data. The image forming apparatus according to claim 1, wherein the digital watermark data embedded in the print data has a multi-valued gradation. The image forming apparatus according to claim 1, wherein the digital watermark data embedded in the print data is embedded in the luminance component of the image data with a multi-valued gradation. The method according to any one of claims 1 to 4, wherein the digital watermark data embedded in the print data is embedded in one or a plurality of pixels of the image data whose color is equal to or less than a predetermined brightness or a predetermined brightness or less. Image forming device. The image forming apparatus according to claim 1 or 3, wherein when the image is read from the front surface of the single-sided original, the digital watermark data embedded in the print data is embedded in the back surface of the single-sided original. The image forming apparatus according to any one of claims 1 to 6 , wherein the acquisition unit reads the printed print medium a predetermined number of times to detect the digital watermark data. The acquisition procedure to read the image and acquire the image data,
A generation procedure for embedding digital watermark data in the acquired image data to generate print data, and
A printing procedure for printing on a printing medium based on the generated print data, and
If the acquired image data is equal to or higher than a predetermined resolution, to perform a procedure for the resolution of embedding electronic watermark data Ru is lower than the predetermined resolution,
The digital watermark data embedded in the print data is an image forming method in which one or a plurality of pixels of the image data whose color is a predetermined brightness or less or a predetermined brightness or less is white. An image forming device is an executable program
The acquisition procedure to read the image and acquire the image data,
A generation procedure for embedding digital watermark data in the acquired image data to generate print data, and
Based on the print data said generated and printing procedures for printing on the print medium,
If the acquired image data is equal to or higher than a predetermined resolution, the resolution of embedding electronic watermark data than the predetermined resolution is performed a procedure Ru was reduced to the image forming apparatus,
The digital watermark data embedded in the print data is a program in which one or a plurality of pixels of the image data whose color is a predetermined brightness or less or a predetermined brightness or less is white.

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