Copy-forgery-inhibited pattern density parameter determination method, copy-forgery-inhibited pattern image generation method, and image processing apparatus

Abstract

A primary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a first pattern on the basis of a predetermined parameter is performed. The user selects one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the primary test printing process. A secondary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a second pattern on the basis of the parameter used to determine the print densities of the latent-image and background-image parts of the selected copy-forgery-inhibited pattern image is performed. The user selects one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the secondary test printing process, and the parameter of the selected copy-forgery-inhibited pattern image is determined as a copy-forgery-inhibited pattern density parameter.

1 . A copy-forgery-inhibited pattern density parameter determination method in an image processing apparatus for generating a copy-forgery-inhibited pattern image including a latent-image part and background-image part, comprising: 
 a step of performing a primary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a first pattern on the basis of a predetermined parameter;    a step of prompting a user to select one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the primary test printing process;    a step of performing a secondary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a second pattern on the basis of the parameter used to determine the print densities of the latent-image and background-image parts of the selected copy-forgery-inhibited pattern image; and    a step of prompting the user to select one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the secondary test printing process, and determining the parameter of the selected copy-forgery-inhibited pattern image as a copy-forgery-inhibited pattern density parameter.    
   
   
       2 . The method according to  claim 1 , wherein a change amount of the print density which is changed in the second pattern is set to be smaller than a change amount of the print density which is changed in the first pattern.  
   
   
       3 . The method according to  claim 1 , wherein the step of performing the secondary test printing process includes a step of storing a gray level value selected in the primary test printing process as the predetermined parameter, and using the stored parameter in the secondary test printing process when the step of performing the primary test printing process is skipped.  
   
   
       4 . The method according to  claim 1 , wherein when a copy-forgery-inhibited pattern image which has the latent-image and background-image parts with appropriate print densities is not selected from the plurality of copy-forgery-inhibited pattern images generated by the secondary test printing process, the step of performing the primary test printing process is repeated.  
   
   
       5 . The method according to  claim 1 , further comprising: 
 a step of generating a copy-forgery-inhibited pattern image on the basis of the determined copy-forgery-inhibited pattern density parameter;    a step of compositing the generated copy-forgery-inhibited pattern image to an input document image; and    a step of printing a composite image.    
   
   
       6 . A copy-forgery-inhibited pattern image generation method in an image processing apparatus for generating a copy-forgery-inhibited pattern image including a latent-image part and background-image part, comprising: 
 a step of performing a test printing process of copy-forgery-inhibited pattern images generated by changing only a print density that defines the latent-image part in one direction of a print paper sheet and by changing only a print density that defines the background-image part in the other direction;    a step of prompting a user to select a copy-forgery-inhibited pattern image in which the latent-image and background-image parts have equal densities, and a latent-image emerges after copying, on the basis of the copy-forgery-inhibited pattern images generated by the test printing process; and    a step of generating a copy-forgery-inhibited pattern image including the latent-image and background-image parts on the basis of the print density of the selected copy-forgery-inhibited pattern image.    
   
   
       7 . The method according to  claim 6 , wherein the print density in the one direction depends on the print density in the other direction.  
   
   
       8 . The method according to  claim 6 , wherein a change amount of the print density in the one direction depends on the print density in the other direction.  
   
   
       9 . The method according to  claim 6 , further comprising: 
 a step of compositing the input document image to the generated copy-forgery-inhibited pattern image; and    a step of printing a composite image.    
   
   
       10 . An image processing apparatus for generating a copy-forgery-inhibited pattern image including a latent-image part and background-image part, comprising: 
 means for performing a primary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a first pattern on the basis of a predetermined parameter;    means for prompting a user to select one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the primary test printing process;    means for performing a secondary test printing process of a plurality of copy-forgery-inhibited pattern images generated by changing one or both of print densities of the latent-image and background-image parts in a second pattern on the basis of the parameter used to determine the print densities of the latent-image and background-image parts of the selected copy-forgery-inhibited pattern image; and    means for prompting the user to select one copy-forgery-inhibited pattern image which has the latent-image and background-image parts with approximate print densities from the plurality of copy-forgery-inhibited pattern images generated by the secondary test printing process, and determining the parameter of the selected copy-forgery-inhibited pattern image as a copy-forgery-inhibited pattern density parameter.    
   
   
       11 . An image processing apparatus for generating a copy-forgery-inhibited pattern image including a latent-image part and background-image part, comprising: 
 means for performing a test printing process of copy-forgery-inhibited pattern images generated by changing only a print density that defines the latent-image part in one direction of a print paper sheet and by changing only a print density that defines the background-image part in the other direction;    means for prompting a user to select a copy-forgery-inhibited pattern image in which the latent-image and background-image parts have equal densities, and a latent-image emerges after copying, on the basis of the copy-forgery-inhibited pattern images generated by the test printing process; and    means for generating a copy-forgery-inhibited pattern image including the latent-image and background-image parts on the basis of the print density of the selected copy-forgery-inhibited pattern image.    
   
   
       12 . A program for making a computer execute a copy-forgery-inhibited pattern density parameter determination method of  claim 1 .  
   
   
       13 . A program for making a computer execute a copy-forgery-inhibited pattern density parameter determination method of  claim 6 .  
   
   
       14 . A computer-readable recording medium recording a program of  claim 12 .  
   
   
       15 . A computer-readable recording medium recording a program of  claim 13.