Method for generating relief prints

摘要

A method for generating a relief print on a substantially flat substrate, wherein palpable differences exist between a height of various parts of the relief print, by a printer configured to print a relief print in a number of passes includes defining a rasterized relief image, comprising customary color channels for indicating a color of each pixel and a height channel for indicating a height of each pixel of the rasterized relief image, determining a low spatial frequency height component in the height value of a pixel of the rasterized relief image, subtracting the determined low spatial frequency height component from the relative height value of a pixel of the rasterized relief image, resulting in a relative reduced height value, and printing the rasterized relief image by using the relative reduced height value. A printing system is configured to execute the method.

主权项

1. A method for generating a relief print on a substantially flat substrate, wherein palpable differences exist between a height of various parts of the relief print, by a printer configured to print a relief print in a number of passes, the method comprising the steps of:
a) defining a rasterized relief image, comprising customary color channels for indicating a color of each pixel and a height channel for indicating a height of each pixel of the rasterized relief image; b) determining a low spatial frequency height component in the height value of a pixel of the rasterized relief image by applying a filter operation by means of a convex kernel; c) subtracting the determined low spatial frequency height component from the height value of a pixel of the rasterized relief image resulting in a reduced height value; and d) printing the rasterized relief image by using the reduced height value, wherein the step of determining the low spatial frequency height component comprises the sub-steps of: b1) moving the convex kernel over a plurality of positions in the rasterized relief image; b2) for each position of the plurality of positions, determining a minimum height difference between the image height and the kernel height; and b3) for each position of the plurality of positions, setting the low spatial frequency height component to the minimum height difference determined in step b2).