Abstract:
An image processing system is capable of proving that identification information is added to a print by providing a function ( 305  to  307 , particularly  307 , in FIG.  3  Flow chart) for detecting whether a printer has a function for adding the identification information to a printed matter when transferring image data from an electronic apparatus ( 201  in FIG.  1 ) which processes the image data to the printer to ensure positive addition of the identification information to the printed matter.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an image processing system and an electronic apparatus which are respectively an image processing system comprising an image processing device and an electronic apparatus for transmitting and receiving image data and an electronic apparatus which transmits and receives image data to/from the image processing device whereby the image processing device is authenticated by the electronic apparatus.  
         RELATED BACKGROUND ART  
         [0003]    Lately along with remarkable improvements of color copying machines and color printers, there have been reported these crimes of counterfeiting bank notes and securities by illegally using these color copying machines and color printers.  
           [0004]    To prevent these crimes, therefore, there have been proposed a technology for adding to an image print the information which permits to specify a serial number of a copying machine used or otherwise a technology for detecting a specified original and preventing this specified original from being copied.  
           [0005]    However, the conventional printers have not been furnished with means capable of accurately detecting whether a function for adding the identification information is provided.  
           [0006]    Accordingly, for transferring image data from electronic equipment such as an image scanner and a computer to a printer and printing the image data, it has not always been guaranteed that the identification information is added to the printed copies. When reading the original on the image input device and outputting the image from this image data input device, it has not been able to certify at the image output device that the image input device provides the function to determine the specified original.  
           [0007]    Therefore, when printing image data transferred from the image input device to the image output device, it has not always been guaranteed that the specified original is identified at the image input device and the output of image data is controlled.  
           [0008]    In addition, both image input and out devices could not certify that they are respectively provided with the specified original detecting function and the identification code addition function.  
         SUMMARY OF THE INVENTION  
         [0009]    It is an object of the present invention to provide an image processing system and an electronic apparatus for solving the above problems.  
           [0010]    It is another object of the invention to an image processing system capable of certainly certifying an image forming device and an image input device and an electronic device, which are respectively provided with specified functions, and an electronic apparatus.  
           [0011]    A preferable embodiment of the present invention for attaining the above objects is an image processing system for transferring image data from an electronic apparatus to an image forming device comprising:  
           [0012]    an electronic apparatus including;  
           [0013]    certifying means for certifying whether the image forming device has a function for adding identification information to a formed image according to those data received from the image forming device, and  
           [0014]    transfer means for transferring the image data to the image forming device according to the result of certification by means of the certifying means; and  
           [0015]    an image forming device including;  
           [0016]    receiving means for receiving image data from the electronic apparatus, and  
           [0017]    adding means for adding the identification information to the image data received.  
           [0018]    In addition, it is a further another object of the invention to provide an image processing system, which certifies an image forming device and an image input device by an indecipherable and safe certifying method, and an electronic apparatus.  
           [0019]    It is a further another object of the invention to provide an image processing system including a processing part for which an illegal modification is difficult, and an electronic apparatus.  
           [0020]    It is a further another object of the invention to provide an image processing system and an electronic apparatus which respectively have novel functions.  
           [0021]    Other objects and features of the present invention will be obvious from the description of the embodiments and drawings shown in the following sheets. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    [0022]FIG. 1 is a block diagram showing a flow of signals through an image scanner  201  and a printer  202 ;  
         [0023]    [0023]FIG. 2 is a schematic diagram of an apparatus according to a first embodiment of the present invention;  
         [0024]    [0024]FIG. 3 is a flow chart of the first embodiment;  
         [0025]    [0025]FIG. 4 is an error message display of an image scanner  201  according to the first embodiment;  
         [0026]    [0026]FIG. 5 is a block diagram showing a configuration of a patterning circuit  410  shown in FIG. 1;  
         [0027]    [0027]FIG. 6 is an example of a copying print;  
         [0028]    [0028]FIG. 7 is a block diagram showing a flow of signals through the image scanner  201  and the printer  202  of a second embodiment;  
         [0029]    [0029]FIG. 8 is a block diagram illustrating the second embodiment;  
         [0030]    [0030]FIG. 9 is a signal processing block diagram of an image scanner  2201  and a printer  2202 ;  
         [0031]    [0031]FIG. 10 is a flow chart illustrating a third embodiment;  
         [0032]    [0032]FIG. 11 is a display showing an error message in the third embodiment;  
         [0033]    [0033]FIG. 12 is a circuit diagram of a color space matching determination circuit;  
         [0034]    [0034]FIG. 13 is a circuit block diagram of color space determination circuits  240  to  247 ;  
         [0035]    [0035]FIG. 14 is a timing chart;  
         [0036]    [0036]FIG. 15 is a circuit block diagram of a real time correction signal generation circuit;  
         [0037]    [0037]FIG. 16 is a cricuit block diagram of a print signal generating circuit  1105 ;  
         [0038]    [0038]FIG. 17 is a circuit block diagram showing circuit configurations of smoothing circuits  1220  to  1227 ;  
         [0039]    [0039]FIG. 18 is graphical representations respectively showing a relationship between an input Xi and a smoothing calculated value Yi;  
         [0040]    [0040]FIG. 19 is an illustration showing a relationship between a shape of a specified original in a color space and a determining ROM  1204 ;  
         [0041]    [0041]FIG. 20 is an illustration showing a shape of a specified original A in a color space;  
         [0042]    [0042]FIG. 21 is an illustration showing a shape of a specified original B in a color space;  
         [0043]    [0043]FIG. 22 is an illustration showing a relationship between data of a plurality of originals stored in the determining ROM  1204  and the bit positions of the determining ROM  1204 ;  
         [0044]    [0044]FIG. 23 is an illustration showing a conceptional representation of determination of a similarity of a distribution of an input color image in a color space and a color distribution of specific original; and  
         [0045]    [0045]FIG. 24 is a flow chart illustrating mutual certification. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]    The present invention is described in detail, referring to the preferred embodiments.  
         [0047]    Though an example of a copying machine is described as an application example of the present invention in the following embodiments, the present invention is not limited to this application example and can apply to other various types of equipment.  
         [0048]    [0048]FIG. 1 shows a block diagram showing a signal flow in an image scanner  201  and a printer  202 .  
         [0049]    In FIG. 1, reference numerals  210 - 1 ,  210 - 2  and  210 - 3  respectively denote CCD (charge coupled device) sensors each having spectral sensitivity characteristics for red (R), green (G) and blue (B), and the image data is outputted as 8-bit output signals  0  to  255  after having been A/D converted.  
         [0050]    Those sensors  210 - 1 ,  210 - 2  and  210 - 3  used in this embodiment are equidistantly arranged and therefore a spatial deviation is corrected by means of delay devices  401  and  402 .  
         [0051]    Reference numerals  403 ,  404  and  405  are respectively logarithmic converters, each comprising a look-up table ROM or RAM, which convert luminance signals to density signals.  406  is a known masking UCR (under color removal) circuit for which a detailed description is omitted. The masking UCR circuit  406  outputs image data having a specified bit length such as, for example, 8 bits in plane sequence each time each signal of magenta (M), cyan (C), yellow (Y) and black (Bk) is read according to three signals entered.  
         [0052]    In this case, a CNO signal is a 2-bit plane sequential signal which designates an output color of color image data to be outputted in the plane sequence by the masking UCR circuit  406  and also a control signal for outputting 2-plane sequential color image signals in accordance with the sequence of transfer operations four times as shown in Table 1, thereby changing over the operating condition of the masking/UCR circuit  406 .  
                   TABLE 1                       CNO signal   print output                   0   Magenta (M)       1   Cyan (C)       2   Yellow (Y)       3   Black (Bk)                  
 
         [0053]    [0053] 407  denotes a known space filter circuit which corrects a space frequency of output signal.  408  is a density conversion circuit which corrects color image signals entered from the image scanner in accordance with a density characteristic of a printing part  202  and comprises ROMs or RAMs similar to the logarithmic converters  403  to  405 .  
         [0054]    [0054] 410  is an identification signal addition circuit described later in FIG. 5. This circuit enables to add the identification information such as a serial number of the printer in a color of light yellow to a copied output and therefore, if a full-color copying machine is illegally used to copy specified images such as bank notes, the machine used can be specified.  
         [0055]    [0055] 450  is a microprocessor which carries out processing of image signals of the image scanner  201  and certification processing of the printer. As in the present circuit configuration, in a case that an improvement of the certification processing such as stopping the supply, of clock signals to the microprocessor  450  by carrying out the control of the image signal processing circuit and certification processing of the printer in the same microprocessor, the control function of the image signal processing circuit does not operate and a strength of the equipment for vicious modification can be increased.  
         [0056]    ROM  451  is a read only memory in which a program of the microprocessor  450  is stored.  
         [0057]    RAM  452  is a random access memory used as a work area by the microprocessor  450 .  
         [0058]    A microprocessor  460  carries out image signal processing and certification processing of the printer  202 . Likewise the microprocessor  450 , the strength of the equipment for improvement can also be increased by carrying out the control and certification processing of the image signal processing circuit in the same microprocessor.  
         [0059]    ROM  461  and RAM  462 , as ROM  451  and RAM  452 , are respectively a read only memory which stores the program of the microprocessor  460  and a random access memory used as a work area by the microprocessor  460 .  
         [0060]    (Outline of the Equipment)  
         [0061]    A schematic diagram of a first embodiment of the present invention is shown in FIG. 2. In FIG. 2, 201 is an image scanner which reads the original and processes digital signals.  202  is a printing part which prints out an image corresponding to the original image read by the image scanner  201  on a printing paper in full colors.  
         [0062]    In the image scanner  201 ,  200  is a mirror surface impression plate, and an original  204  on an original rest glass (hereafter referred to as the “platen”) is irradiated by a lamp  205 , an irradiated light is guided to mirrors  206 ,  207  and  208 , focused on a  3 -line sensor (hereafter referred to as the “CCD”)  210  by a lens  209  and sent to a signal processing part  211  as red (R), green (G) and blue (B) components of full color information. The whole surface of the original is scanned (sub-scan) by 205 and 206, which mechanically move at a speed v, and 207 and 208, which also mechanically move at a speed ½v, respectively in a direction perpendicular to an electrical scanning direction (main scanning) of the line sensor, and the image signals are transferred to the signal processing part  211 .  
         [0063]    In the signal processing part  211 , image signals R, G and B, which have been read, an electrically processed after having been temporarily stored in the image memory (not shown), converted to magenta (M), cyan (C), yellow (Y) and black (Bk) color components and sent in plane sequence to the printing part  202 . Read-out operation from the above-described image scanner (not shown) is carried out four times with respect to the image data of the original which has been read in one scanning by the image scanner  201 , one of color components M, C, Y and Bk is generated in image processing and sent to the printing part in plane sequence, and thus one print-out operation is completed through reading and processing carried out four times.  
         [0064]    Image signals of M, C, Y and Bk sent from the image scanner  201  are sent to a laser driver  212 . The laser driver  212  modulation-drives a semiconductor laser  213  in response to image signals sent. The laser beam scans the surface of a photosensitive drum  217  through a polygon mirror  214 , a f-θ lens  215  and a mirror  216 .  
         [0065]    [0065] 218  is a rotary developer which comprises a magenta developing part  222 , a cyan developing part  220 , a yellow developing part  221  and a black developing part  222 , and these four developing parts alternately contact the photosensitive drum  217  and develop a static image formed on the photosensitive drum with a toner.  
         [0066]    [0066] 223  is a transfer drum which takes up a paper form to be supplied from a paper cassette  224  or  225  around it and transfers an image developed on the photosensitive drum onto s paper.  
         [0067]    After four colors M, C, Y and Bk have been thus transferred in sequence, the paper passes through a fixing unit  226 , the toner is fixed to the paper and the paper is ejected.  
         [0068]    [0068]FIG. 3 is a flow chart illustrating the processing of the image scanner which certifies that the printer  202  is provided with the identification signal addition function.  
         [0069]    In this processing, only the printer having the identification signal addition function identifies a confidential information T, which has been maintained, through the image scanner and implements the certification function.  
         [0070]    In this case, the fact that the printer  202  is maintaining the confidential information T can be checked by a method called “zero-knowledge interactive proof” without loading the confidential information T on the transmission channel and therefore safe certification can be realized.  
         [0071]    In FIG. 3, 301 to  310  are represents a flow chart related to the operation of the microprocessor  450  of the image scanner  201 .  
         [0072]    [0072] 320  to  329  represents a flow chart related to the operation of the microprocessor  460  of the printer  202 .  
         [0073]    At  310 , the microprocessor  460  sends out the certification start code (for example, ESC code) to the microprocessor  460 .  
         [0074]    When the microprocessor  460  receives the certification start code, the microprocessor generates a random number Rm at  321 , calculates X=R m   2 mod(n) at  322  and sends the resultant value to the microprocessor  450 , where n is a large predetermined composite number (a product of large prime numbers). The microprocessor  450  stores X data received in the internal RAM at  303 .  
         [0075]    A random number B m  is generated at  304 , where B m  is a value of 0 or 1. At  305 , the data of B m  is sent to the printer.  
         [0076]    The microprocessor  460  carries out the processing at  326  when the value of B m  received at  324  and  325  is 0 and the processing at  327  when the value of B m  is 1.  
         [0077]    At  326 , the data of Y=R m  is sent out to the image scanner. At  327 , the value of Y=TR m mod(n) is sent out to the image scanner.  
         [0078]    In this case, T is the confidential information owned only by the printer which has the identification signal addition function.  
         [0079]    At  306 , the microprocessor  450 , which has received the above-described Y data, checks a validity of the value Y at  307  by the following formulae.  
           X=Y   2   mod ( n ) if  B   m =0  (1)  
           ZX=Y   2   mod ( n ) if  B   m =1  (2)  
         [0080]    where X is a number stored in the RAM at  303  and Z is represented by Z=T 2 mod(n) . . . (3).  
         [0081]    If Y data received is valid, the processing at  301  to  309  and  320  to  328  is carried out. Only when this processing is repeated 1 times and all of processing is normally completed, image data is transferred at  310  and  329 .  
         [0082]    IF Y data is invalid at  307 , the microprocessor  450  stops after having displayed an error message shown in FIG. 4 at  308 .  
         [0083]    If Y data received by the microprocessor  450  is invalid when this processing is carried out, the power supply of the image scanner should be turned on/off to reset the operation of the microprocessor.  
         [0084]    (Patterning Circuit)  
         [0085]    [0085]FIG. 5 is a block diagram showing a configuration of the identification signal addition circuit  410  according to the embodiment. In FIG. 5, 901 is a sub-scan counter,  902  is a main scan counter,  903  is a look-up table ROM (hereafter referred to as the “LUT”),  905  is a flip-flop,  913  is an AND gate,  906  is a register,  910  is 4 to 1 selectors,  911  is an AND gate, and  912  is an adder, respectively.  
         [0086]    The sub-scan counter  901  repeatedly counts main scan sync. signals HSYNC and the main scan counter  902  repeatedly counts pixel sync. signals CLK, respectively in a 9-bit width and 512 cycles. In addition, the LUT  903  is a read only memory (hereafter referred to as the “ROM”) in which a pattern to be added is stored, and each lower 6 bits of respective counted values of the sub-scan counter  901  and the main scan counter  902  are entered into the LUT  903 . Only one bit of the output of the LUT  903  is referred, an AND value of respective upper three bits of the main scan counter  901  and the sub-scan counter obtained by an AND gate  913 , synchronization is made with a CLK signal at the flip-flop  905 , a logic operation of 2-bit plane sequential signals CNO “0” and CNO “1” is executed at the AND gate  91 , and the result is sent to the gate  911 . This is a signal which is valid only in the current printing in yellow (Y) with CNO=2 (refer to Table 1).  
         [0087]    On the other hand, a value PI is maintained in the register  906 . Data which has passed through the AND gate  913  is added to an adder  912  as a pattern after an AND value with PI has been obtained by the AND gate  911 . A result V′ of addition is outputted from the adder  912 . Accordingly, when printing is carried out with CNO=2, that is, in yellow, a pattern stored in the LUT  903  is repeatedly read out and added to the signal V to be outputted.  
         [0088]    In this case, the pattern is added only with a yellow toner so that it is difficult to identify the pattern or the pattern cannot be identified by human eyes. This utilizes the fact that the human eyes are weak in identification of the pattern drawn with the yellow toner.  
         [0089]    (Result of Copying)  
         [0090]    [0090]FIG. 6 shows an example of a result of copying according to the first embodiment. In FIG. 6, the added pattern is shown with  1001  and the contents stored in the LUT  903  is the added pattern. In the example shown in FIG. 6, a pattern to which “ABCD” and “1234” are arrayed in the sub-scan direction is added as a pattern of 64 pixels×64 pixels so as to be difficult to identify with human eyes and scanning is repeated for every  512  pixels for main scanning and  512  lines for sub-scanning. Therefore the copying machine used can be limited by judging a copied matter to which the pattern is added if the pattern is made as a specified serial number or a specified encoded serial number of the machine.  
         [0091]    Moreover, in a case that there is a high possibility of a specified original, which should not primarily be copied, included in an image to be read, a pattern varying in the density such as a high density can be added in accordance with a probability of a specified original.  
         [0092]    In addition, in this embodiment, a pitch for adding the pattern is specified to be  512  pixels (or lines) for the main scanning and therefore the pattern is added for every approximately 32.5 mm since the resolution is specified to be 400 dpi (dots/inch). On the other hand, the shorter side lengths of bank notes (issued by the Bank of Japan) are approximately 76 mm and the shorter side lengths of bank notes issued in the leading advanced countries are approximately 60 mm to 120 mm and therefore the pattern must be added to the copied matters of these bank notes if the bank notes are illegally copied. Accordingly, if a bank note or bank notes are copied on, for example, an A4 size paper and only copied bank notes are cut out for illegal use, the serial number of the copying machine used can be specified by checking the copied matter and reading the added pattern.  
         [0093]    The configuration shown in FIG. 1 is intended to provide the equipment with a strength for improvement by adapting the equipment to carry out the certification processing and the control of the image signal processing circuit by one microprocessor. A second embodiment of the present invention is intended to materialize a function which further prevents the illegal modification of the equipment than in the configuration shown in FIG. 1 by forming  701  and  702  parts shown in FIG. 7 with a single chip LSI.  
         [0094]    If the ROM simultaneously incorporates the calculation part and the ROM which stores the certification function control program in a single chip, a calculation processing regarding the certification processing cannot be traced from outside. If at least part of the image signal processing circuit control program is adapted to simultaneously exist in  701  or  702 , the image signal processing circuit does not normally operate and an illegal modification of the certification processing part can be prevented even though the microprocessor in which an improved microprocessor is built in is connected to actuate.  
         [0095]    (Second Embodiment)  
         [0096]    [0096]FIG. 8 is a diagram illustrating a second embodiment of the present invention.  
         [0097]    The first embodiment is adapted to transfer an image from the image scanner to the printer.  
         [0098]    The second embodiment is intended to transfer an image from the computer to the printer.  
         [0099]    In FIG. 8, 800 is, for example, an image memory device which receives image data from the computer and transfers it to the printer.  
         [0100]    [0100] 801  is a microprocessor which executes the certification operation of the image memory control circuit  803  and the printer  202 .  
         [0101]    The microprocessor  801  executes a processing equivalent to the certification operation of the microprocessor  450  shown in FIG. 1.  
         [0102]    The second embodiment of the present invention described above is intended to certify that the identification information is added to the print when the image data is transferred from an electronic device which processes image data to the printer by providing the function for detecting whether the printer has a function for adding the identification information.  
         [0103]    More specifically, a pass word (confidential) to be given only when the printer has a function for adding the identification information is certified by the so-called zero knowledge interactive method from an external equipment and, only when the external equipment determines that the printer has the function for adding the identification information, the image data is transferred to the printer.  
         [0104]    The above-described pass word can be certified without sending the ass word through the data transfer channel by using the means (zero knowledge interactive proof) and therefore a safe and accurate certification function can be realized.  
         [0105]    An example of certification is described by means of the zero knowledge interactive proof in the above embodiment and moreover the other cipher method (for example, an RSA method) can be used to certify that the printer has special confidential information.  
         [0106]    Though the printer is described as an example of the image forming apparatus in this embodiment, a display can be used as the image forming apparatus according to the present invention.  
         [0107]    As described above, the present invention enables to certainly add the identification information to an image-formed matter by providing means for certifying from the external equipment that the printer has the function for adding the identification information.  
         [0108]    The system can be more resistant to vicious modification of the equipment by adapting the microprocessor to simultaneously serve as a microprocessor for controlling the image signal processing circuit.  
         [0109]    The system which is highly resistant to illegal modification can be formed by the ROM for storing a program to execute the certifying operation and the microprocessor as a single-chip LSI.  
         [0110]    A third embodiment of the present invention is described below.  
         [0111]    (Signal Processing Block Diagram)  
         [0112]    [0112]FIG. 9 is a signal processing block diagram of the image scanner  2201  and the printer  2202 .  
         [0113]    In FIG. 9, 1101 is a CCD color sensor,  1102  is an analog amplifier,  1103  is an A/D converter, and  1104  is a shading correction circuit which corrects variations of the lightness depending on a reading position for image signals.  
         [0114]    [0114] 1106  is a color space matching determination circuit for calculating in real time the similarity of color distributions in the  3 -dimensional color space including the image data which has been read and a specified original such as a bank note or a security note.  
         [0115]    Distortions of the lightness and color depending on the position of the original are corrected by using color signals which have been corrected for shading and, therefore, the similarity of color components in the color space can be accurately determined. The shading correction circuit  1104  for the color image reader is not described in detail here since it is known.  
         [0116]    [0116] 1105  is a print signal generating circuit which converts input color signals R (red), G.(green), and B (blue) to Y (yellow), M (magenta), C (cyan) and Bk (black) signals. This circuit includes delay means for compensating a time required for the determination described later. Print signals are modulated with a real time correction signal f 1113 .  
         [0117]    [0117] 1107  is a circuit for generating the real time correction signal f 1113 .  
         [0118]    [0118] 1108  is a circuit block for generating read sync. signals HS 1109 , CLK 1110 , and VS 1112 . HS 1109  is a main scan range signal, CLK 1110  is a pixel read reference clock signal, and VS 1112  is a range signal which shows an effective range in the sub-scan direction for reading the original.  
         [0119]    The density conversion circuit  408 , the identification code addition circuit  410 , the microprocessors  450  and  460 , and RAMs  452  and  462  are of the same structure as those circuits described in FIG. 1. However, the contents of the program for ROMs  3451  and  3461  differs from those in FIG. 1 in order to carry out a processing in response to this embodiment.  
         [0120]    [0120]FIG. 10 is a flow chart which illustrates the processing where the printer  2202  certifies that the image scanner  2201  has the specified original determination function.  
         [0121]    In this processing, the certification function is implemented by adapting the printer to confirm that only the image scanner having the specified original determination function maintains the confidential information T.  
         [0122]    In this case, it can be confirmed that the image scanner  2201  has the confidential information T without loading the confidential information T of the transfer channel by using the means of zero knowledge interactive proof as in the first embodiment and therefore the certifying operation can be implemented in safety.  
         [0123]    The flow chart shown in FIG. 10 shows a flow of operations of the microprocessor  450  of the image scanner  2201  and the microprocessor  460  of the printer  2202  in certification processing.  
         [0124]    The microprocessor  450  of the image scanner  2201  generates a random number Rm at  301 , calculates X=Rm 2 mod(n) at  302  and sends out it to the microprocessor  460  of the printer  2202 .  
         [0125]    In this case, n is a large predetermined composite number (a product of large prime numbers).  
         [0126]    The microprocessor  460  stores X data received at  1310  in the internal RAM at  1311 , and generates the random number Bm at  1312 .  
         [0127]    Bm in this case is 1-bit data, that is, a value of 0 or 1.  
         [0128]    The microprocessor  450  which sends out the data of Bm to the image scanner at  1313  carries out the processing at  1306  when the Bm values received at  1304  and  1305  are 0 and the processing at  1307  when the Bm values are 1.  
         [0129]    Data of Y=Rm is sent out to the printer at  1306  and the value of Y=TRm mod (n) to the printer at  1307 .  
         [0130]    In this case, T is confidential information to be given only to the image scanner which has the specified original determination function.  
         [0131]    The microprocessor  460  which has received the above-described Y data at  1314  checks the validity of the value Y by using the following formulae (1) and (2).  
           X=Y   2   mod ( n ) if  Bm= 0  (1)  
           ZX=Y   2   mod ( n ) if  Bm= 1  (2)  
         [0132]    where, X is a number stored in the RAM at  1311  and Z is  
           Z=T   2   mod ( n )  (3)  
         [0133]    Even though the Y data received is determined valid, the certification can be more certainly carried out by carrying out the processing specified at  1301  to  1308  and  1310  to  1317  as many times as specified (1 times). It is determined that the image scanner  2201  has the specified original determination function only when the above processing has been normally finished 1 times, and the image data is transferred at  1309  and  1318 .  
         [0134]    If the Y data is invalid at  1315 , the microprocessor  460  stops after the error message shown in FIG. 11 has been displayed at  1316 .  
         [0135]    The microprocessor  460  is stopped by carrying out this processing when the Y data received by the microprocessor  460  is invalid and therefore the power supply of the printer  2202  should be turned on or off to reset the operation of the microprocessor  460 .  
         [0136]    (Color Space Matching Determination Circuit  1106 )  
         [0137]    [0137]FIG. 12 illustrates the color space matching determination circuit  1106 .  
         [0138]    In FIG. 12, R1201 is the data of upper five bits of eight bits of the R (red) signal from the shading correction circuit  1104 . Similarly, G1202 is a 5-bit G (green) signal and B1203 is a 5-bit B (blue) signal.  
         [0139]    [0139] 1204  is a ROM (read only memory) which stores the information related to colors of a plurality of types of specified originals. Colors of the specified originals carry particular color distributions on the color spaces, depending on the type of specified original, as shown in FIGS. 20 and 21. The ROM  1204  operates to enter the R, G and B signals into addresses A 0  to A 14  and outputs the determination signals which indicate that the R, G and B signals entered coincide with the colors of the plurality of types of specified originals to data D 0  to D 7 .  
         [0140]    The information related to the colors of the specified originals is stored in the data of the ROM  1204  as shown in FIG. 19 and 1 is outputted to D 0  to D 7 , respectively, when the signals coincide with the colors of the specified original and 0 is otherwise outputted. D 0  to D 7  correspond to eight types of specified originals of the 0th to 7th specified originals.  
         [0141]    [0141]FIG. 22 shows a relationship between the data related to the colors of the plurality of types of originals stored in the ROM  1204  and the bit positions of the ROM  1204 . Determining information related to the colors of eight different types of specified originals is outputted in parallel from D 0  to D 7  to the pixel data entered.  
         [0142]    Smoothing circuits  1220  to  1227  carry out smoothing operation shown in FIGS. 17 and 18 by using color determination signals X 0   210  to X 7   217 .  
         [0143]    [0143]FIG. 17 is a circuit block diagram showing the configuration of one of smoothing circuits  1220  to  1227 .  
         [0144]    In FIG. 17, 1701 and  1702  are respectively a multiplier,  1703  is an adder,  1704  is a latch circuit, and  1705  is a comparator. A specified original as shown in FIG. 18 can be determined in conjunction with the continuity of data by using a weighted mean of input data and the preceding data of multipliers  701  and  702  and the adder  703  for determination.  
         [0145]    [0145]FIG. 18 shows a relationship between input Xi and smoothed value Yi. If 1 continues as a value of input Xi, the value of Yi increases.  
         [0146]    When input R, G and B signals continuously coincide with the colors of the specified original, signals  1230  to  1237  become 1 and more accurate determination can be made without being affected by noise and others.  
         [0147]    In the color space determination circuits  240  to  247 , the similarity of the specified image data and the input color signals in R, G and B color spaces shown in FIG. 16 is calculated in real times and color space similarity determination signals MK 0   260  to MK 7   267  are calculated.  
         [0148]    [0148]FIG. 13 is a block diagram of one of color space determination circuits  1240  to  1247 .  
         [0149]    In this circuit configuration, data Dn from the SRAM  1209  and a signal Cn from the smoothing circuit are OR-calculated and stored in the RRAM  1209 . The counter  1301  is counted up only when data Dn is changed from 0 to 1. The counter  2301  is cleared at the rise of the sub-scanning range signal VS 1112 . An output value Zn of the counter  2301  and the constant  6 n of the register  302  compared in the comparator  2303 , MKn=1 is obtained at Zn&gt;δn and MKn=0 at Zn≦δn. A value of 1% of U ORG  in FIG. 16 is set as the value δn (1=90 in this embodiment).  
               δ                 n     =       1   100     ×     U   ORG               (   1   )                               
 
         [0150]    In this case, U ORG  is a value for a unit volume of a cube for which R, G and B coordinates are divided into 32 segments in FIG. 17.  
         [0151]    When the observation image data, that is, the data of input color signal string have an approximately identical shape to the specified image data in R, G and B color spaces according to the above-described processing, the color space similarity determination signals MK 0   1260  to MK 7   1267  are set to 1.  
         [0152]    Selectors  1271  and  1272  clear the SRAM  1209  when the sub-scan range signal VS 1112  is 0 (LOW). An address generator  1270  generates in sequence all addresses of the SRAM 1209 . When the VS 1112  is low, the SRAM 1209  is cleared to 0 according to the addresses signals generated by the address generator  1270 .  
         [0153]    [0153] 1205  is a timing signal generation circuit which generates the timing signals shown in FIG. 14.  
         [0154]    CLK 4  at  1206  is a clock signal obtained by quarterly dividing the reference clock CLK 1110 ,  1207  is a signal for controlling the write enable terminal of the SRAM 1209  and  1208  is a signal for controlling the output enable terminal of the SRAM 1209 .  
         [0155]    (Generation of Real Time Correction Signal)  
         [0156]    [0156]FIG. 15 is a circuit block diagram which illustrates the real time correction signal generation circuit  1107 .  
         [0157]    When one of a plurality of specified original data registered in the ROM  1204  is determined to coincide with the observation image data on the color space according to this circuit configuration, the real time correction signal f 1113  is set to 1 (High).  
         [0158]    (Print Signal Generation Circuit)  
         [0159]    [0159]FIG. 16 is a circuit block diagram which illustrates the print signal generation circuit  1105 .  
         [0160]    The masking UCR operation circuit A 1601  usually generates the print YMCBk signals from R, G and B signals entered.  
         [0161]    The masking UCR operation circuit B 1602  generates print Y′, M′, C′ and Bk′ signals varying in color tones (for example, intensified red tone) if it is determined that the input color signals coincide with the specified original.  
         [0162]    The color tone can be changed on the print only in the area where the color signals are determined to coincide with the specified original by selecting and outputting the signals of the circuits  1601  and  1602  by the selector  1603  according to the real time correction signal f 1113 .  
         [0163]    In the above embodiment, the determination referring to the color tone is exemplified as a method for determining the specified original. Clearly, however, the other determination method such as pattern matching can be used. In addition, though the above embodiment is described using the image processing apparatus provided between the image scanner and the printer, it is obvious that the present invention is not limited to this embodiment and various types of systems including an image processing system which comprises an image input device such as a camera and an electronic device such as a monitor can be used.  
         [0164]    [0164]FIG. 24 is a diagram illustrating mutual certification between the image scanner and the printer.  
         [0165]    At  2001 , the image scanner certifies for the printer that the image scanner has the identification code addition function.  
         [0166]    At  2002 , the printer certifies for the image scanner that the printer has the specified original detection function.  
         [0167]    An illegal use of color image input/output equipment can be more certainly prevented by mutual certification between the input and output equipment. Thus the present invention enables to prevent vicious and illegal use of electronic equipment or image forming apparatuses by certifying whether the image input apparatus or the external apparatus has a special function.  
         [0168]    In addition, certification is carried out between the image input and output apparatuses as to whether these apparatuses are discretely provided with the special function and therefore vicious and illegal use of image processing apparatuses can be prevented in high accuracy.