JPH10304176A - Image processing unit, method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To imbed additional information to image data by a proper method in response to the resolution of the image data by controlling an addition means so as to add a different specific pattern to the data in response to the resolution of the image data when the data are generated by a prescribed image forming means. SOLUTION: A PCLK corresponding to 300 dpi is given to a main scanning counter 307 and a BD corresponding to 300 dpi is given to a sub scanning counter 308 respectively in the case of 1st and 2nd changeover switches 311, 312 set to 300 dpi. On the other hand, in the case of requiring 600 dpi, the 1st and 2nd changeover switches 311, 312 are switched. A PCLKH whose frequency is a half of the frequency of the PCLK for 300 dpi is given to the main scanning counter 307 and a BDH whose frequency is a half of the frequency of the BD for 300 dpi is given to the sub scanning counter 308 respectively. Furthermore, the frequency is controlled by allowing a CPU 302 to recognize the resolution and to provide an output of a signal to a clock changeover device 310 based thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and method having a function of adding additional information to an input image, and a storage medium.

[0002]

2. Description of the Related Art In recent years, image recording apparatuses such as color printers and color copiers have been increasingly improved in performance and can provide high-quality images. As a result, it is becoming possible to form an image similar to that of securities such as banknotes.

[0003] However, the formation of such images is prohibited, and it is necessary to suppress such actions. As one of the measures, for example, when such an image is formed, a number unique to the image recording apparatus is assigned to the formed image so that the situation in which the image is formed based on the formed image can be determined. A method of embedding the indicated dot pattern (hereinafter referred to as an add-on method) is known.

The dot pattern of the add-on system is periodically embedded in the entire screen of the formed image by each image recording device, read by a decoding device different from these image recording devices, and the image is read from the read unique dot pattern. A recording device is specified.

[0005]

In recent image recording apparatuses, printing may be performed with different resolutions of image data for each model or for the same model due to a difference in use.
For example, text-based images are printed at high resolution,
Images mainly composed of natural images are printed at low resolution, and printing adapted to the type of each image is performed to improve image quality.

Conventionally, however, the position of the add-on dot pattern is shifted when the resolution changes, despite the fact that the add-on dot pattern represents the same information. Therefore, there is a problem that even if an attempt is made to read a formed image and decode a dot pattern embedded in the formed image, the dot pattern cannot be decoded properly.

The present invention has been made in view of the above conventional example, and has as its object to embed additional information by an appropriate method according to the resolution at which an image is formed.

It is an object of the present invention to ensure that embedded additional information can be decoded regardless of the resolution at which an image is formed.

[0009]

In order to solve the above-mentioned problems, an image processing apparatus according to the present invention comprises: a specific pattern output means for outputting a specific pattern indicating additional information as one of a plurality of resolutions; An adding unit that adds a specific pattern output from the specific pattern output unit to the input image data having a resolution that is difficult for human eyes to recognize, and an image data to which additional information is added by the adding unit. Output means for outputting to the predetermined image forming means, and control means for controlling the specific pattern added by the adding means to be different according to the resolution at the time of image formation by the predetermined image forming means. It is characterized by having.

[0010] Alternatively, a specific pattern output means for outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and an output from the specific pattern output means for input image data of any of a plurality of resolutions. An adding unit that adds the specific pattern that is difficult to recognize to the human eye, an output unit that outputs the image data to which the additional information has been added by the adding unit to a predetermined image forming unit, and an image that is output by the predetermined image forming unit. Irrespective of the resolution at the time of formation, control means for controlling such that the position at which the specific pattern indicating the same additional information is added to the input image data becomes substantially constant.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an apparatus applied to the present invention will be described.

FIG. 7 shows an image recording apparatus using the color electrophotographic technique. It is needless to say that the present invention is not limited to the color electrophotographic technique, but can be applied to an image forming apparatus such as an ink jet or a thermal transfer method.

In this configuration, the input density level is assumed to be sent as an image signal in 8 bits for each color of M (magenta), C (cyan), Y (yellow), and Bk (black), and is added to the image. The recognition signal is called an add-on dot.

In FIG. 1, a photosensitive drum 100 is first uniformly charged to a predetermined polarity by a charger 101, and the photosensitive drum 100 is exposed by a laser beam L.
A first latent image is formed on, for example, magenta. Next, in this case, a predetermined developing bias voltage is applied only to the magenta developing device Dm, so that the magenta latent image is developed and a first magenta toner image is formed on the photosensitive drum 100.

On the other hand, immediately before the transfer paper P is fed at a predetermined timing and the leading end thereof reaches the transfer start position, a transfer bias voltage (+1.8 KV) of the opposite polarity (for example, plus polarity) to the toner is applied to the transfer drum 102. Then, the photosensitive drum 100 is electrostatically attracted to the surface of the photosensitive drum 100. Thereafter, the first toner image on the photosensitive drum 100 is transferred to the transfer paper P, and at the same time, the transfer paper P is electrostatically attracted to the surface of the transfer drum 102. Subsequently, the magenta toner remaining on the photosensitive drum 100 is removed by the cleaner 103, and the photosensitive drum 100 is ready for the next color latent image forming and developing process.

Next, a second cyan latent image is formed on the photosensitive drum 100 by the laser beam L, and then a second latent image on the photosensitive drum 100 is formed by the cyan developing device Dc. Thus, a second toner image is formed.
Then, the second cyan toner image is transferred onto the transfer paper P in accordance with the position of the first magenta latent image previously transferred onto the transfer paper P. In the transfer of the second color toner image, a bias voltage of +2.1 KV is applied to the transfer drum 102 immediately before the transfer paper P reaches the transfer portion.

Similarly, the third of yellow and black,
Fourth latent images are sequentially formed on the photosensitive drum 100,
Each of the toner images is sequentially developed by the developing units Dy and Db, and the third and fourth toner images of yellow and black are sequentially transferred in accordance with the positions of the toner images previously transferred to the transfer paper P. The four color toner images are formed on P in an overlapping state.

FIG. 8 is a block diagram showing a processing flow. RGB image signals are sent in parallel from the host 201 and input to the controller 214. The controller 214 includes a color conversion processing unit 202 and a γ correction unit 20.
3. The halftone processing unit 204 is provided. RG input
The B signal is subjected to masking and UCR processing in the color conversion processing unit 202, color correction and undercolor removal are performed, and magenta (M), cyan (C), yellow (Y), and black (B
k) is converted into an image signal. As described above, M, C,
The color conversion processing unit 2 prints one screen each of Y and Bk colors.
From 02, the image data is output in the order of the screen, that is, the data of one screen of M, the data of one screen of C, the data of one screen of Y, and the data of one screen of Bk.

Next, the output density curve is corrected so as to be linear by the γ correction section, and the halftone processing section 204 performs halftone processing by a method such as the systematic dither method or the error diffusion method.

After the above processing is performed by the controller,
The M, C, Y, and Bk image signals are input to the engine 215. The engine 215 includes an add-on addition processing unit 205, P
It comprises a WM processing unit 206, a laser driving unit 207, an additional dot generation unit 212, an EEPROM 213, and the like.

The engine 215 includes an additional dot generation unit 21
2 generates encrypted information for adding information (model number, machine number, etc.) unique to the engine 215 stored in the EEPROM 213 to the image, and outputs the information to the add-on addition processing unit 205.

The add-on addition processing unit 205 encrypts the M, C, Y, and Bk image signals input from the controller 214, if necessary, according to the signal input from the additional dot generation unit 212. The embedded information (dot pattern) is output to the PWM processing unit 206. Normally, an add-on pattern is added to only the input yellow (Y) image signal and output.

This makes use of the characteristic that a yellow (Y) image is more difficult to identify to human eyes than an image of another color.

After that, the pulse is modulated by the PWM processing unit 206 and D / A converted, and then the laser driving unit 207 is processed.
Is input and printed.

The engine unit 215 includes a CPU 302
And controls each block in the engine unit and transmits / receives data to / from each block.

FIG. 9 shows the additional dot generating section 212 and the EEPR
It is a block diagram of OM213 and the add-on addition processing part 205. The CPU 302 inputs the unique information of the engine 215 stored in the EEPROM 213 to the encryption circuit 306, where the information is encrypted, the parity is checked by the parity check 306, and if an error occurs, the printing operation is stopped. .

The main scanning counter 307 sends ON at a position where an add-on dot is to be added in accordance with the clock signal PCLK in the main scanning direction of the image signal. Sub-scan counter 30
Numeral 8 performs a counting operation in accordance with the clock signal BD in the sub-scanning direction, and sends ON in add-on. The add-on dot generation circuit 309 receives the add-on dot shape parameter stored in the ROM 303 of the CPU, and turns on the add-on permission signal and the main scan counter 307 and the sub-scan counter 308 which are turned ON only when yellow data is transmitted.
Only when this is done, an add-on dot is generated, and Bk is turned on in the FF (highest density) area and WH is turned on in the 00 (lowest density) area, and sent. The add-on addition processing unit 205 in FIG. 7 forcibly modulates the image data at the position of the corresponding image to the highest density when Bk is input, and modulates it to the lowest density when WH is input.

FIG. 10 shows an example of an add-on dot. Dotted lines in the figure represent add-on lines (a to f), and 404 indicates each add-on dot. An add-on dot 405 is obtained by enlarging the add-on dot. The add-on dot is formed by the FF area 401 and the 00 areas 402 and 403 on both sides. This add-on dot appears periodically in the image.

The way in which information is represented by the add-on dot will be briefly described. The number of the information depends on the positional relationship between the add-on dot in the add-on line a and the dots of another add-on line included in one unit in the drawing. It can represent tens of bits of information.

Next, a state of embedding the above-mentioned add-on dot in an image will be described.

FIG. 11 is a diagram showing the state of add-on dots embedded when the conventional image forming apparatus switches the resolution.

In the figure, the upper half is when the image data is 300 dpi for both main scanning and sub-scanning, and the lower half is when the image data is 600 dpi.
The position of the add-on dot at the time of i is shown.

In the figure, A is one unit of a pattern composed of add-on dots at 300 dpi.
B is one unit of a pattern composed of add-on dots at 600 dpi. As you can see, 600d
In the case of “pi”, both the main scanning and the sub-scanning have a density twice that of 300 dpi, so that the size of one unit of the add-on dot pattern differs at each resolution.

(First Embodiment) FIG. 1 shows an additional dot generation unit 212 and an EEPROM 21 according to this embodiment.
3 is a block diagram of an add-on addition processing unit 205. FIG. In FIG. 1, the description of the same components as those in FIG. 4 described above is omitted.

In FIG. 1, the clock switching unit 3 located before the main scanning counter 307 and the sub-scanning counter 308
It is 10. The clock switch 310 divides the frequency of the input clock signal PCLK and outputs a clock signal PCLKH having a half frequency. The first frequency divider 313 divides the frequency of the input clock signal BD to half the frequency. Second frequency divider 314 that outputs changed clock signal BDH
And a first switch 311 for selecting either the clock signal PCLK or PCLKH, and a second switch 312 for selecting either the clock signal BD or BDH.

Referring to FIG.
The first and second selector switches 312 are in the switching state at the time of 300 dpi, and the main scanning counter 30
7, a PCLK corresponding to 300 dpi is input, and a BD corresponding to 300 dpi is input to the sub-scanning counter 308 at the same time.

On the other hand, at 600 dpi, the first switch 311 and the second switch 312 are switched. That is, the main scanning counter 307 has 300 dpi.
PCLKH of half the frequency of the PCLK at the time is input, and at the same time, 300 dpi
A BDH of half the frequency of the BD at the time is input.

The control of the frequency, that is, the process of controlling the position of the add-on pattern is performed by the CPU 302 recognizing the resolution to be printed and outputting a switching signal to the clock switch 310 as needed based on the recognized result. Done.

By the above switching process, the ON signal sent from the main scanning counter 307 and the sub-scanning counter 308 to the add-on dot generation circuit 309 is set to 300 dpi,
The add-on dot pattern can be printed at the same position of the print image regardless of the switching of 600 dpi.

FIG. 2 is a diagram showing the state of add-on dots embedded when the image forming apparatus switches the resolution in the present embodiment. In all of the embodiments of the present invention, the add-on dot is added with an add-on pattern only to a yellow (Y) image signal which is difficult to recognize by human eyes, and is output. Therefore, FIG. 2 shows a state of the dot arrangement of yellow. When these dots are added to the original image, each dot portion in FIG. 2 is forcibly modulated in the image on the yellow surface.

In the figure, the upper half shows the case where the image data is 300 dpi for both the main scanning and the sub-scanning, and the lower half shows the same when the image data is 600 dpi.
The add-on dot at the time of i is shown.

In the figure, A is one unit of a pattern composed of add-on dots at 300 dpi.
B is one unit of a pattern composed of add-on dots at 600 dpi. As you can see, 600d
Although the density is twice as high in the main scanning and the sub-scanning at 300 dpi, the position of one unit of the add-on dot pattern is the same.

As a result, the position at which the add-on dot pattern indicating the same additional information (model number, machine number, etc.) is added to the yellow input image becomes almost constant, so that the add-on dot pattern can be added based on the actually printed image. It is possible to decode the dot pattern with high accuracy.

(Second Embodiment) In the first embodiment, the present invention is applied to the case where the resolution is switched in both the main scanning direction and the sub-scanning direction. The present invention can be applied even when the switching is performed by switching.

The configuration of the device is the same as that of the first embodiment.

FIG. 3 is a diagram showing the state of add-on dots embedded when the image forming apparatus of the present embodiment switches the resolution only in the main scanning direction.

In the figure, the upper half shows the add-on dot pattern when image data is printed at 300 dpi in both the main scan and the sub-scan, and the lower half shows the main scan at 600 dpi and the sub-scan 300
The add-on dot pattern when printed in dpi is shown.

At this time, FIG. 1 shown in the first embodiment is used.
Switch 311 for main scanning at 600 dpi, that is, to output PCLKH.
The changeover switch 312 outputs the BD signal to the sub-scanning counter 308 at the frequency for 300 dpi.

In FIG. 3, A is one unit of a pattern composed of add-on dots at 300 dpi.
D is one unit of a pattern composed of add-on dots at the time of 600 dpi for main scanning and 300 dpi for sub-scanning.

As described above, in the lower half of FIG.
Despite having twice the density compared to dpi,
The printing position of one unit of the add-on dot pattern remains unchanged.

In this embodiment, similarly to the first embodiment, the position where the add-on dot pattern indicating the same additional information (model number, machine number, etc.) is added to the yellow input image becomes almost constant. Therefore, it is possible to accurately decode the add-on dot pattern based on the actually printed image.

In this embodiment, the case where the resolution is switched in the main scanning direction and the resolution is not switched in the sub-scanning direction has been described. However, the same applies to the case where there is no resolution switching and there is a resolution switching in the sub-scanning direction. By the operation described above, the effect of the present invention can be obtained.

(Third Embodiment) In the first and second embodiments, address control is performed to apply one fixed add-on pattern to each resolution.
The case where an add-on pattern suitable for each resolution is switched for each resolution is also included in the scope of the present invention. Specific examples are shown below.

FIG. 4 is a block diagram of the additional dot generation section 212, the EEPROM 213, and the add-on addition processing section 205 in the present embodiment. Description of components having the same functions as those in FIG. 1 used in the first and second embodiments and FIG. 7 used in the related art will be omitted. Hereinafter, only portions different from the above embodiment will be described.

In the first and second embodiments, the synchronous clocks PCLK and BD to the main scanning counter 307 and the sub-scanning counter 308 are connected as they are as shown in FIG. New encryption circuit 315 that performs encryption according to each resolution by SEL
Is different.

The operation of the encryption circuit 315 and the CPU 302 will be described with reference to the flowcharts of FIGS.

FIG. 5 shows a procedure for controlling the position of the dot pattern in the main scanning direction. First, at 501, the CPU 302
Is a signal S indicating the resolution at which the resolution to be printed is recognized.
EL is input. Then, the input signal SEL
Is determined to be 600 dpi.

If the input signal SEL does not indicate 600 dpi, that is, if it is 300 dpi, a dot pattern in which dots exist at positions corresponding to l, l + 1, l + 2,. It is generated and output to the parity check circuit 306. (502).

On the other hand, when the input signal SEL is 600 dp
If it indicates i, a dot pattern in which dots exist at positions corresponding to the even-numbered dots in the main scanning direction, k, k + 2, k + 4,... in FIG. I do. (503). Further, in 503, the position control in the sub-scanning direction is not possible.
It is assumed that the same dot pattern is generated as the add-on line.

FIG. 6 shows a procedure for controlling the position of the dot pattern in the sub-scanning direction. In the add-on line (sub-scanning direction), control is performed by an add-on permission signal from the CPU 302.

First, when the CPU 302 does not recognize that the resolution to be printed is 600 dpi (resolution SEL is 300 dpi) in 601, the add-on permission signal is turned on in all add-ons (60).
4).

On the other hand, if the CPU 302 recognizes in step 601 that the resolution to be printed is 600 dpi (the resolution SEL is 600 dpi), the line in the sub-scanning direction is an even-numbered add-on line, ie, m, m + in FIG.
An add-on permission signal is output to a position corresponding to 2, m + 4,... (602, 604).

If the line in the sub-scanning direction is an odd number (m + 1, m + 3,... In FIG. 2), the add-on permission signal is prohibited (603).

With the above control, similarly to the first and second embodiments, even when the printing resolution changes,
The position of one unit of the add-on dot pattern is the same.

As a result, the position at which the add-on dot pattern indicating the same additional information (model number, machine number, etc.) is added to the yellow input image becomes substantially constant, so that the add-on dot pattern can be added based on the actually printed image. It is possible to decode the dot pattern with high accuracy.

(Modification) The above embodiment is not limited to switching between two resolutions. In an image forming apparatus, it is possible to change the resolution in multiple stages. The case where the position of the add-on dot pattern is controlled by controlling the generated dot pattern is also included in the present invention.

The method of creating each dot is not limited to the method of forming the FF (highest density) area and the 00 (lowest density) area shown in FIG. In the area corresponding to, the density is increased by α, and 00
In the area corresponding to the (lowest density) area, dots can be created by decreasing the density by α, and such a method is also included in the scope of the present invention.

Further, the additional information added as the add-on dot pattern is not limited to the model number and the machine number, but may be any information representing the situation where the image is printed, such as the machine number of an externally connected device.

The present invention can be applied as a part of a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but can be applied to one device (for example, a copying machine, a facsimile machine).
May be applied to a part of the apparatus comprising:

Further, the present invention is not limited to only the apparatus and method for realizing the above-described embodiment, but includes a computer (CPU or MP) in the above-described system or apparatus.
U), a program code of software for realizing the above-described embodiment is supplied, and the computer of the system or the apparatus operates the various devices according to the program code to realize the above-described embodiment. It is included in the category of the present invention.

In this case, the program code of the software implements the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, specifically, A storage medium storing the above program code is included in the scope of the present invention.

As a storage medium for storing such a program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, ROM and the like can be used.

In addition to the case where the computer controls the various devices in accordance with only the supplied program code to realize the functions of the above-described embodiment, the program code operates on the computer. Such a program code is included in the scope of the present invention even when the above-described embodiment is realized in cooperation with an OS (Operating System) or other application software.

Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, the function expansion board or the function is stored based on the instruction of the program code. The case where the CPU or the like provided in the storage unit performs part or all of the actual processing, and the above-described embodiment is realized by the processing is also included in the scope of the present invention.

[0075]

As described above, according to the present invention, additional information can be embedded by an appropriate method according to the resolution at which an image is formed.

In particular, since the position where the specific pattern indicating the same additional information (model number, machine number, etc.) is added to the input image becomes substantially constant, the additional information embedded regardless of the resolution at which the image is formed can be used. It can be surely decoded.

[Brief description of the drawings]

FIG. 1 shows an additional dot generation unit 21 according to the first embodiment.
2. Block diagram of EEPROM 213 and add-on addition processing unit 205

FIG. 2 shows an example of an add-on dot when the resolution is switched in the first embodiment.

FIG. 3 shows an example of an add-on dot when the resolution is switched only in the main scanning direction.

FIG. 4 shows an additional dot generation unit 21 according to the third embodiment.
2. Block diagram of EEPROM 213 and add-on addition processing unit 205

FIG. 5 is a flowchart illustrating an operation of an encryption circuit 315 in Embodiment 3.

FIG. 6 is a flowchart illustrating the operation of an add-on permission signal in the sub-scanning direction according to the third embodiment.

FIG. 7 is a configuration example of an image recording apparatus using color electrophotographic technology.

FIG. 8 is a block diagram showing a processing flow;

FIG. 9 shows an additional dot generation unit 212 and an EEPROM 21;
3. Block diagram of add-on addition processing unit 205

FIG. 10 shows an example of an add-on dot.

FIG. 11 shows an example of an add-on dot when the resolution is switched.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 photosensitive drum 101 charging device 102 transfer drum 103 cleaner L laser beam light P transfer paper Dm magenta developing device Dc cyan developing device Dy yellow developing device Db black developing device 201 host 202 color conversion processing section 203 gamma correction section 204 halftone Processing unit 205 Add-on addition processing unit 206 PWM processing unit 207 Laser driving unit 212 Additional dot generation unit 213 EEPROM 214 Controller 215 Engine 302 CPU 305 Encryption circuit 306 Parity check 307 Main scanning counter 308 Sub-scanning counter 309 Add-on dot generation circuit 310 Clock Switch 311 First switch 312 Second switch 313 First frequency divider 314 Second frequency divider 315 Encryption circuit 401 FF area of add-on dot 00 area 404 addon dots 405 addon dots enlarged view of 402-403 addon dot: both sides

Claims (22)

[Claims] 1. A specific pattern output means for outputting a specific pattern indicating additional information as one of a plurality of resolutions, and a specific pattern output means for input image data of any one of a plurality of resolutions. An adding unit that adds the specific pattern that is difficult for the human eye to identify, an output unit that outputs the image data to which the additional information is added by the adding unit to a predetermined image forming unit, and an image that is output by the predetermined image forming unit. An image processing apparatus comprising: a control unit that controls a specific pattern added by the adding unit to be different according to a resolution at the time of formation. 2. The image processing apparatus according to claim 1, wherein the input image data is color image data composed of a plurality of colors, and the addition by the adding unit is performed only on the yellow image data. apparatus. 3. The image processing apparatus according to claim 1, wherein the control by the control unit is performed by changing a cycle of a timing signal for outputting the specific pattern by the specific pattern output unit. 4. The image processing apparatus according to claim 4, wherein the change of the cycle of the timing signal performed by the control unit can be performed independently in a main scanning direction and a sub-scanning direction. 5. The image processing apparatus according to claim 1, wherein the control by the control unit is performed by selectively outputting a plurality of types of specific patterns that can be generated by the specific pattern output unit. . 6. The image processing apparatus according to claim 1, wherein the specific pattern includes a plurality of dots. 7. The image processing apparatus according to claim 6, wherein the dots are composed of a plurality of pixels. 8. The image processing apparatus according to claim 6, wherein each of the dots has a different size at the different resolution. 9. The image processing apparatus according to claim 1, further comprising the predetermined image forming unit. 10. A specific pattern output step of outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and output in the specific pattern output step for input image data of any of a plurality of resolutions. An adding step of adding the specific pattern that is hard to be discerned by the human eye, an output step of outputting the image data to which the additional information has been added in the adding step to a predetermined image forming means, A control step of controlling the specific pattern added by the adding unit to be different according to the resolution at the time of formation. 11. A specific pattern output step of outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and output in the specific pattern output step for input image data of any of a plurality of resolutions An adding step of adding the specific pattern that is hard to be discerned by the human eye, an output step of outputting the image data to which the additional information has been added in the adding step to a predetermined image forming means, A control step of controlling the specific pattern added by the adding means to be different according to the resolution at the time of formation, in a state readable from a computer. 12. A specific pattern output means for outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and output from the specific pattern output means for input image data of any of a plurality of resolutions. An adding unit that adds the specific pattern that is difficult for the human eye to identify, an output unit that outputs the image data to which the additional information is added by the adding unit to a predetermined image forming unit, and an image that is output by the predetermined image forming unit. An image processing apparatus comprising: control means for controlling a position at which a specific pattern indicating the same additional information is added to the input image data, regardless of the resolution at the time of formation. . 13. The image processing apparatus according to claim 12, wherein the input image data is color image data composed of a plurality of colors, and the addition by the adding unit is performed only on the yellow image data. apparatus. 14. The image processing apparatus according to claim 12, wherein the control by the control unit is performed by changing a cycle of a timing signal for outputting the specific pattern by the specific pattern output unit. 15. The image processing apparatus according to claim 12, wherein the change of the cycle of the timing signal performed by the control unit can be performed independently in the main scanning direction and the sub-scanning direction. 16. The image processing apparatus according to claim 12, wherein the control by the control unit is performed by selectively outputting a plurality of types of specific patterns that can be generated by the specific pattern output unit. . 17. The image processing apparatus according to claim 12, wherein the specific pattern includes a plurality of dots. 18. The image processing apparatus according to claim 17, wherein the dots are composed of a plurality of pixels. 19. The method of claim 17, wherein each of the dots has a different size at the different resolution.
An image processing apparatus according to claim 1. 20. The image processing apparatus according to claim 12, further comprising the predetermined image forming unit. 21. A specific pattern output step of outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and output in the specific pattern output step for input image data of any of a plurality of resolutions An adding step of adding the specific pattern that is hard to be discerned by the human eye, an output step of outputting the image data to which the additional information has been added in the adding step to a predetermined image forming means, Irrespective of the resolution at the time of formation, a control step of controlling the position where a specific pattern indicating the same additional information is added to the input image data to be substantially constant. . 22. A specific pattern output step of outputting a specific pattern indicating additional information as any pattern of a plurality of resolutions, and output in the specific pattern output step for input image data of any of a plurality of resolutions An adding step of adding the specific pattern that is hard to be discerned by the human eye, an output step of outputting the image data to which the additional information has been added in the adding step to a predetermined image forming means, A control step of controlling a position where a specific pattern indicating the same additional information is added to the input image data to be substantially constant irrespective of the resolution at the time of formation. Storage means stored in.