Method for digitally rasterizing half-tone images with rasters of any width and angle

A method for digital rastering of an original image to generate a half-tone image with a desired raster having an arbitrary screen width and arbitrary screen angle, comprising the steps of:

• providing a threshold matrix for a given raster having a given screen width and screen angle, and having an input for receiving an access address and an output for outputting a threshold value corresponding to the input access address;
• providing addresses for said desired raster;
• generating a pixel address corresponding to a pixel to be recorded and reading an image value from the original image corresponding to said pixel address;
• for said generated pixel address, comparing a corresponding address of the desired raster with a corresponding access address of the threshold matrix, and, if a deviation is greater than a predetermined limit value, then correcting the access address of the threshold matrix;
• inputting said corresponding and sometimes corrected access address into the threshold matrix and outputting a corresponding threshold value;
• and
• comparing said threshold value with said read image value and, depending on the comparison, deciding how said pixel is to be recorded.

A method for digital rastering of an original image to generate a half-tone image with a desired raster having an arbitrary screen width and arbitrary screen angle, comprising the steps of:

• providing a threshold matrix for a given raster having a given screen width and screen angle, and having an input for receiving an access address and an output for outputting a threshold value corresponding to the input access address;
• providing addresses for said desired raster;
• generating a pixel address corresponding to a pixel to be recorded and reading an image value from the original image corresponding to said pixel address;
• for said generated pixel address, comparing a corresponding address of the desired raster with a corresponding access address of the threshold matrix, and, if a deviation is greater than a step of said access address, then correcting the access address of the threshold matrix;
• inputting said corresponding and sometimes corrected access address into the threshold matrix and outputting a corresponding threshold value;
• and
• comparing said threshold value with said read image value and, depending on the comparison, deciding how said pixel is to be recorded.

A method for digital rastering of an original image to generate a half-tone image with a desired raster having an arbitrary screen width and arbitrary screen angle, comprising the steps of:

• providing a threshold matrix for a given raster having a given screen width and screen angle, and having an input for receiving an access address and an output for outputting a threshold value corresponding to the input access address;
• for each image value that pixels of the original image can assume, generating and storing a bit pattern by comparing the threshold values of the threshold matrix with said image value, and depending on the comparison, deciding which bit value is to be stored in the bit pattern, the bit pattern having an input for receiving an x, y access address and an output for outputting a bit value corresponding to the input x, y access address;
• providing x, y addresses for said desired raster;
• generating an x, y pixel address corresponding to a pixel to be recorded and reading an image value from the original image corresponding to said x, y pixel address;
• for said generated x, y pixel address, comparing a corresponding x, y address of the desired raster with a corresponding x, y access address of the bit pattern stored for said image value, and if a deviation is greater than a predetermined limit value, then correcting the x, y access address of the bit pattern;
• inputting said corresponding and sometimes corrected x, y access address into said bit pattern and outputting a corresponding bit value;
• and
• depending on said bit value, exposing or not exposing said pixel to be recorded.

A method for digital rastering of an original image to generate a half-tone image with a desired raster having an arbitrary screen width and arbitrary screen angle, comprising the steps of:

• providing a threshold matrix for a given raster having a given screen width and screen angle, and having an input for receiving an access address and an output for outputting a threshold value corresponding to the input access address;
• for each image value that pixels of the original image can assume, generating and storing a bit pattern by comparing the threshold values of the threshold matrix with said image value, and depending on the comparison, deciding which bit value is to be stored in the bit pattern, the bit pattern having an input for receiving an access address and an output for outputting a bit value corresponding to the input access address;
• providing addresses for said desired raster;
• generating a pixel address corresponding to a pixel to be recorded and reading an image value from the original image corresponding to said pixel address;
• for said generated pixel address, comparing a corresponding address of the desired raster with a corresponding access address of the bit pattern stored for said image value, and if a deviation is greater than a predetermined limit value, then correcting the access address of the bit pattern;
• inputting said corresponding and sometimes corrected access address into said bit pattern and outputting a corresponding bit value;
• and
• depending on said bit value, exposing or not exposing said pixel to be recorded.