High density ink-jet printing on a transparency

Abstract

A method for printing on transparent medium using an ink-jet printer. The method includes providing a grayscale image having a plurality of pixels, each pixel having a pixel value corresponding to a brightness of the pixel; converting each pixel value to an ink output value for the ink-jet printer using a conversion function, wherein the conversion function maps the darkest pixel value to an optical density of greater than 2.5 and maps all other pixel values to an appropriate output pixel value such that a resulting printed image is perceived to be linearly bright across the image.

1 . A system for printing with high density on a transparent medium, comprising:
 an ink-jet printer including a plurality of nozzles; and   an image processing module configured to convert pixel values of an image to a first ink output value corresponding to a black ink nozzle for the ink-jet printer, wherein converting includes mapping the darkest pixel value to an optical density of greater than 2.5 and wherein the conversion results in a perceived linear brightness of the printed image.   
     
     
         2 . The system of  claim 1 , wherein the image includes a grayscale image having a plurality of pixels, each pixel having a pixel value corresponding to a brightness of the pixel. 
     
     
         3 . The system of  claim 1 , wherein the image processing module is configured to convert by mapping the lightest pixel value to an optical density of less than 0.3. 
     
     
         4 . The system of  claim 1 , wherein the output value comprises an output value for one of a cyan, magenta, and yellow ink nozzle for the ink-jet printer. 
     
     
         5 . The system of  claim 1 , wherein the output value comprises an output value for a black ink nozzle. 
     
     
         6 . The system of  claim 5 , wherein the output value comprises an output value for cyan, magenta, and yellow ink nozzles for the ink-jet printer. 
     
     
         7 . A machine readable medium that stores instructions which when performed by a machine, causes the machine to perform operations, comprising:
 converting input pixel values into output ink values using a lookup table, wherein the lookup table comprises:   input pixel value 255, black output value about 251, cyan magenta and yellow output value about 102;   input pixel value 242, black output value about 234, cyan magenta and yellow output value about 84;   input pixel value 230, black output value about 220, cyan magenta and yellow output value about 72;   input pixel value 217, black output value about 206, cyan magenta and yellow output value about 64;   input pixel value 204, black output value about 193, cyan magenta and yellow output value about 57;   input pixel value 191, black output value about 181, cyan magenta and yellow output value about 51;   input pixel value 179, black output value about 170, cyan magenta and yellow output value about 45;   input pixel value 166, black output value about 159, cyan magenta and yellow output value about 41;   input pixel value 153, black output value about 148, cyan magenta and yellow output value about 36;   input pixel value 140, black output value about 137, cyan magenta and yellow output value about 32;   input pixel value 128, black output value about 127, cyan magenta and yellow output value about 29;   input pixel value 115, black output value about 117, cyan magenta and yellow output value about 25;   input pixel value 102, black output value about 106, cyan magenta and yellow output value about 22;   input pixel value 89, black output value about 96, cyan magenta and yellow output value about 19;   input pixel value 77, black output value about 85, cyan magenta and yellow output value about 16;   input pixel value 64, black output value about 74, cyan magenta and yellow output value about 13;   input pixel value 51, black output value about 62, cyan magenta and yellow output value about 10;   input pixel value 38, black output value about 50, cyan magenta and yellow output value about 7;   input pixel value 26, black output value about 36, cyan magenta and yellow output value about 5;   input pixel value 13, black output value about 20, cyan magenta and yellow output value about 3; and   input pixel value 0, black output value about 0, cyan magenta and yellow output value about 0.   
     
     
         8 . A method for printing an image, comprising:
 converting input pixel values of an input image into output ink values using a lookup table, wherein the lookup table comprises:   input pixel value 255, black output value about 251, cyan magenta and yellow output value about 102;   input pixel value 242, black output value about 234, cyan magenta and yellow output value about 84;   input pixel value 230, black output value about 220, cyan magenta and yellow output value about 72;   input pixel value 217, black output value about 206, cyan magenta and yellow output value about 64;   input pixel value 204, black output value about 193, cyan magenta and yellow output value about 57;   input pixel value 191, black output value about 181, cyan magenta and yellow output value about 51;   input pixel value 179, black output value about 170, cyan magenta and yellow output value about 45;   input pixel value 166, black output value about 159, cyan magenta and yellow output value about 41;   input pixel value 153, black output value about 148, cyan magenta and yellow output value about 36;   input pixel value 140, black output value about 137, cyan magenta and yellow output value about 32;   input pixel value 128, black output value about 127, cyan magenta and yellow output value about 29;   input pixel value 115, black output value about 117, cyan magenta and yellow output value about 25;   input pixel value 102, black output value about 106, cyan magenta and yellow output value about 22;   input pixel value 89, black output value about 96, cyan magenta and yellow output value about 19;   input pixel value 77, black output value about 85, cyan magenta and yellow output value about 16;   input pixel value 64, black output value about 74, cyan magenta and yellow output value about 13;   input pixel value 51, black output value about 62, cyan magenta and yellow output value about 10;   input pixel value 38, black output value about 50, cyan magenta and yellow output value about 7;   input pixel value 26, black output value about 36, cyan magenta and yellow output value about 5;   input pixel value 13, black output value about 20, cyan magenta and yellow output value about 3; and   input pixel value 0, black output value about 0, cyan magenta and yellow output value about 0.