SYSTEM AND METHOD FOR PRINTING USING VARIABLE-DENSITY WHITE INK UNDER-PRINTED LAYER

• US 20090207458A1
• Filed: 02/18/2008
• Published: 08/20/2009
• Est. Priority Date: 02/18/2008
• Status: Active Grant

• Current Assignee: Cimpress Schweiz GmbH (Cimpress Plc)
• Original Assignee: Vistaprint Technologies Limited (Cimpress Plc)
• Inventors: Moody, Jay T., Hyman, Jacob A., Doggett, William K. III, Tsykora, Anatoliy V.
• Granted Patent: US 7,920,297 B2
• Time in Patent Office: Days
• US Class Current: 358/3.290
• CPC Class Codes: H04N 1/54 Conversion of colour picture signals to a plurality of signals some of which represent particular mixed colours, e.g. for textile printing

Abstract

Techniques for generated variable density mono-color under-print layer(s) for printing underneath an image on a substrate to improve the appearance of the printed image.

Claims

1. A computer-implemented method for generating a variable density mono-color under-print layer corresponding to an image to be printed, the method comprising:

receiving a printable image, the printable image comprising a plurality of first pixels;

generating a mono-color under-print layer, the mono-color under-print layer comprising a plurality of second pixels, each second pixel corresponding to a first pixel in a same corresponding position in the printable image and each second pixel having an associated opacity whose value is based on at least one color characteristic of its corresponding first pixel.

2. The method of claim 1, wherein the mono-color comprises white.

3. The method of claim 1, wherein the printable image is to be printed on a substrate of a known color, the known color comprising a non-white color, and wherein the mono-color comprises white.

4. The method of claim 1, wherein the step of generating the mono-color under-print layer comprises determining a level of luminosity of each first pixel and setting an opacity value of the corresponding second pixel based on the determined luminosity level.

5. The method of claim 4, wherein the step of setting the opacity value comprises setting the opacity value to a value that is a function of the determined luminosity level for determined luminosity levels within a predetermined range, and setting the opacity value to a pre-determined constant opacity for determined luminosity levels outside of the pre-determined range.

6. The method of claim 5, wherein the pre-determined constant opacity comprises full opacity.

7. The method of claim 5, wherein the predetermined range ranges from zero luminosity to a pre-determined threshold luminosity level.

8. The method of claim 1, wherein the step of generating the mono-color under-print layer comprises creating an alpha channel in an electronic document, copying the printable image into the alpha channel, loading the alpha channel into an empty layer in the electronic document, selecting the loaded alpha channel within the layer, filling the selected alpha channel with the mono-color, and saving the layer as the mono-color under-print layer.

9. The method of claim 10, further comprising;

merging the mono-color under-print layer with itself at least once to generate a denser mono-color under-print layer.

10. The method of claim 1, wherein the step of generating the mono-color under-print layer comprises copying the printable image, converting the copied printable image to grayscale, discretizing the grayscale into a reduced number of grayscale levels, setting all pixels outside of a predetermined range of grayscale levels to transparent, and saving the resulting image as the mono-color under-print layer.

11. The method of claim 1 wherein the step of generating the mono-color under-print layer comprises:

for each first pixel in the printable image, determining a difference in color characteristic between the first pixel and a known substrate color, the substrate color comprising the color of the substrate on which the printable image is to be printed, and setting the opacity of the second pixel corresponding to the first pixel based on the determined difference.

12. The method of claim 11, wherein the opacity of the second pixel is set relatively higher if the determined difference is relatively higher.

13. The method of claim 1, wherein the color characteristic comprises a color hue.

14. The method of claim 1, wherein the color characteristic comprises a color luminosity.

15. The method of claim 1 wherein the color characteristic comprises a color saturation.

16. The method of claim 1, further comprising generating at least one additional mono-color under-print layer specific to the received image.

17. The method of claim 1, comprising printing the mono-color under-print layer in a same position as the received image is to be printed on a substrate prior to printing the received image on the substrate.

18. A computer-readable medium comprising program instructions which, when executed by a computer, implement the method of claim 1.

19. A system for generating a variable density mono-color under-print layer corresponding to an image to be printed, the system comprising:

means for receiving a printable image, the printable image comprising a plurality of first pixels;

means for generating a mono-color under-print layer, the mono-color under-print layer comprising a plurality of second pixels, each second pixel corresponding to a first pixel in a same corresponding position in the printable image and each second pixel having an associated opacity whose value is based on at least one color characteristic of its corresponding first pixel.

20. A method for printing an image onto a substrate, the image comprising a plurality of areas of varying luminosity, the method comprising:

printing at least one variable density mono-color under-layer onto a substrate in a pre-determined position, areas of varying opacity of the mono-color in the under-layer corresponding to areas of varying luminosity in the image to be printed; and

printing the image over the under-layer at the pre-determined position on the substrate.

21. The method of claim 20, wherein the substrate comprises a non-white color.

22. The method of claim 20, wherein the variable density mono-color under-layer comprises a plurality of pixels, each of the plurality of pixels in the white ink under-layer corresponding to a pixel in a same corresponding position in the image and each having an associated opacity determined based on a luminosity level of its corresponding image pixel.

23. The method of claim 22, wherein the opacity of each under-layer pixel varies according to the luminosity level of its corresponding image pixel for luminosity levels within a pre-determined range, and which are set to full opacity outside of the pre-determined range.

24. The method of claim 23, wherein the pre-determined range ranges from zero luminosity to a pre-determined threshold luminosity level.