Embedded variable line patterns for images

Abstract

In some implementations, a system is capable of generating identifications that include distinctive line patterns corresponding to different portions of secure customer information. Data indicating an input image, and a dithering matrix representing a two-dimensional array of pixel values is obtained. Pixel values of pixels included in the input image are transformed using the dithering matrix. For each pixel within the input image, the transformation includes identifying a particular pixel value within the dithering matrix that represents a particular pixel within the input image, and adjusting an intensity value of the particular pixel based on attributes of the dithering matrix. A transformed image is generated based on the transformation and then provided for output.

What is claimed is: 
     
         1 . A method performed by one or more computers, the method comprising:
 obtaining data indicating (i) an input image, and (ii) a dithering matrix representing a two-dimensional array of pixel values;   transforming, using the dithering matrix, pixel values of pixels included in the input image, the transforming comprising, for each pixel within the input image:   identifying a particular pixel value within the dithering matrix that represents a particular pixel within the input image, the particular pixel value having a coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image;   adjusting an intensity value of the particular pixel based on attributes of the dithering matrix;   generating a transformed image based on transforming the pixel values of the pixels included in the input image, wherein at least a portion of the transformed image comprises a dithering pattern; and   providing the transformed image for output.   
     
     
         2 . The method of  claim 1 , wherein the dithering pattern comprises a vertical parallel line pattern. 
     
     
         3 . The method of  claim 1 , wherein the dithering pattern comprises a horizontal parallel line pattern. 
     
     
         4 . The method of  claim 1 , wherein the attributes of the dithering matrix comprise at least one of:
 horizontal and vertical dimensions of the two-dimensional array of pixel values, a range of pixel values included in the two-dimensional array of pixel values, and an arrangement of pixel values within the two-dimensional array of pixel values.   
     
     
         5 . The method of  claim 4 , wherein adjusting the intensity value of the particular pixel comprises:
 determining a scaling factor based on (i) a range of intensity values for pixels included in the input image, and (ii) the range of pixel values included in the two-dimensional array of pixel values;   adjusting the intensity value of the particular pixel based on the scaling factor to generate a scaled intensity value of the particular pixel;   combining the scaled intensity value of the particular pixel and the particular pixel value having the coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image to generate a combined value for the particular pixel; and   dividing the combined value by a value representing a horizontal dimension of the two-dimensional of the two-dimensional array of pixel values to generate an adjusted intensity value of the particular pixel.   
     
     
         6 . The method of  claim 4 , wherein:
 the transformed image is a monochrome image; and   adjusting the intensity value of the particular pixel further comprises setting the adjusted intensity value of the particular pixel to a value equal to either 0 or 1.   
     
     
         7 . The method of  claim 1 , further comprising:
 obtaining a color photograph of an individual;   converting pixel intensity values of pixels included in the color photograph to grayscale intensity values; and   generating the input image of the individual based on converting pixel intensity values of pixels included in the color photograph to grayscale intensity values.   
     
     
         8 . The method of  claim 1 , wherein the dithering pattern is included in an entire region of the transformed image. 
     
     
         9 . A system comprising:
 one or more computers; and   one or more storage devices storing instructions that, when executed by the one or more computers, cause the one or more computers to perform operations comprising:
 obtaining data indicating (i) an input image, and (ii) a dithering matrix representing a two-dimensional array of pixel values; 
 transforming, using the dithering matrix, pixel values of pixels included in the input image, the transforming comprising, for each pixel within the input image:
 identifying a particular pixel value within the dithering matrix that represents a particular pixel within the input image, the particular pixel value having a coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image; 
 adjusting an intensity value of the particular pixel based on attributes of the dithering matrix; 
 
 generating a transformed image based on transforming the pixel values of the pixels included in the input image, wherein at least a portion of the transformed image comprises a dithering pattern; and 
 providing the transformed image for output. 
   
     
     
         10 . The system of  claim 9 , wherein the dithering pattern comprises a vertical parallel line pattern. 
     
     
         11 . The system of  claim 9 , wherein the dithering pattern comprises a horizontal parallel line pattern. 
     
     
         12 . The system of  claim 9 , wherein the attributes of the dithering matrix comprise at least one of:
 horizontal and vertical dimensions of the two-dimensional array of pixel values, a range of pixel values included in the two-dimensional array of pixel values, and an arrangement of pixel values within the two-dimensional array of pixel values.   
     
     
         13 . The system of  claim 12 , wherein adjusting the intensity value of the particular pixel comprises:
 determining a scaling factor based on (i) a range of intensity values for pixels included in the input image, and (ii) the range of pixel values included in the two-dimensional array of pixel values;   adjusting the intensity value of the particular pixel based on the scaling factor to generate a scaled intensity value of the particular pixel;   combining the scaled intensity value of the particular pixel and the particular pixel value having the coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image to generate a combined value for the particular pixel; and   dividing the combined value by a value representing a horizontal dimension of the two-dimensional of the two-dimensional array of pixel values to generate an adjusted intensity value of the particular pixel.   
     
     
         14 . The system of  claim 12 , wherein:
 the transformed image is a monochrome image; and   adjusting the intensity value of the particular pixel further comprises setting the adjusted intensity value of the particular pixel to a value equal to either 0 or 1.   
     
     
         15 . The system of  claim 9 , wherein the operations further comprise:
 obtaining a color photograph of an individual;   converting pixel intensity values of pixels included in the color photograph to grayscale intensity values; and   generating the input image of the individual based on converting pixel intensity values of pixels included in the color photograph to grayscale intensity values.   
     
     
         16 . A non-transitory computer-readable storage device encoded with computer program instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:
 obtaining data indicating (i) an input image, and (ii) a dithering matrix representing a two-dimensional array of pixel values;   transforming, using the dithering matrix, pixel values of pixels included in the input image, the transforming comprising, for each pixel within the input image:
 identifying a particular pixel value within the dithering matrix that represents a particular pixel within the input image, the particular pixel value having a coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image; 
 adjusting an intensity value of the particular pixel based on attributes of the dithering matrix; 
   generating a transformed image based on transforming the pixel values of the pixels included in the input image, wherein at least a portion of the transformed image comprises a dithering pattern; and   providing the transformed image for output.   
     
     
         17 . The device of  claim 16 , wherein the dithering pattern comprises a vertical parallel line pattern. 
     
     
         18 . The device of  claim 16 , wherein the dithering pattern comprises a horizontal parallel line pattern. 
     
     
         19 . The device of  claim 16 , wherein the attributes of the dithering matrix comprise at least one of:
 horizontal and vertical dimensions of the two-dimensional array of pixel values, a range of pixel values included in the two-dimensional array of pixel values, and an arrangement of pixel values within the two-dimensional array of pixel values.   
     
     
         20 . The device of  claim 19 , wherein adjusting the intensity value of the particular pixel comprises:
 determining a scaling factor based on (i) a range of intensity values for pixels included in the input image, and (ii) the range of pixel values included in the two-dimensional array of pixel values;   adjusting the intensity value of the particular pixel based on the scaling factor to generate a scaled intensity value of the particular pixel;   combining the scaled intensity value of the particular pixel and the particular pixel value having the coordinate location within the two-dimensional array corresponding to a coordinate location of the particular pixel within the input image to generate a combined value for the particular pixel; and   dividing the combined value by a value representing a horizontal dimension of the two-dimensional of the two-dimensional array of pixel values to generate an adjusted intensity value of the particular pixel.