Hiding Auxiliary Data with Line Structure Modification

Abstract

The present disclosure relates generally to information hiding and digital watermarking. One claim recites a method of hiding auxiliary data in an image. The image includes line structures. The method include: receiving an image including line structures; identifying a frequency associated with the line structures; using a programmed processor modulating the frequency associated with the line structures to convey auxiliary data in the image, in which the presence of the auxiliary data is hidden from a human observer of the image, but the auxiliary data is machine-detectable. Other claims, implementations and embodiments are provided as well.

1 . A method of marking a signal to convey auxiliary data, wherein the signal including a plurality of elements, the method comprises:
 receiving a signal including a plurality of elements;   using a programmed processor selectively contorting or distorting the signal to provide relatively dense and sparse regions of elements, in which the dense and sparse regions collectively convey the auxiliary data.   
     
     
         2 . The method of  claim 1  in which the signal represents an image or video. 
     
     
         3 . The method of  claim 2  in which the contorting or distorting comprises at least one of resizing, scaling, stretching or warping. 
     
     
         4 . The method of  claim 1  in which auxiliary data is machine-readable from optical scan data corresponding to at least a portion of the signal. 
     
     
         5 . A non-transitory computer readable medium comprising instructions stored thereon to cause an electronic processor to perform the method of  claim 1 . 
     
     
         6 . A method of hiding auxiliary data in an image in which the image includes line structures, the method comprises:
 receiving an image including line structures;   identifying a frequency associated with the line structures;   using a programmed processor modulating the frequency associated with the line structures to convey auxiliary data in the image, in which the presence of the auxiliary data is hidden from a human observer of the image, but the auxiliary data is machine-detectable.   
     
     
         7 . The method of  claim 6  in which the auxiliary data comprises a plural bit message. 
     
     
         8 . The method of  claim 6  in which said modulating increases the frequency associated with the line structures. 
     
     
         9 . The method of  claim 6  in which said modulating decreases the frequency associated with the line structures. 
     
     
         10 . A non-transitory computer readable medium comprising instructions stored thereon to cause an electronic processor to perform the method of  claim 6 . 
     
     
         11 . A method of hiding auxiliary data in an image, in which the image includes line structures, the method comprises:
 receiving an image including line structures;   using a programmed processor: i) compressing the line structures in a first area to yield dense areas in the line structures; and ii) stretching the line structures in a second area to yield sparse areas in the line structures; in which the dense areas and the sparse areas convey auxiliary data, in which the presence of the auxiliary data is hidden from a human observer of the image, but the auxiliary data is machine-detectable.   
     
     
         12 . The method of  claim 11  in which the auxiliary data comprises a plural-bit payload. 
     
     
         13 . The method of  claim 11  in which the compressing and stretching are carried out to yield a spread-spectrum digital watermark carrying the auxiliary data. 
     
     
         14 . A non-transitory computer readable medium comprising instructions stored thereon to cause an electronic processor to perform the method of  claim 11 .