Method for generating non-printing dots in a screened representation of an image
A method for generating a bitmap from an image for image reproduction, the bitmap having both screened and non-screened data, includes the steps of: generating a set of contiguous microdots of the bitmap, wherein the set is selected from the group of a set of contiguous microdots forming an image dot being part of the screened data and a set of contiguous microdots forming an entity of contiguous microdots being part of the non-screened data; generating a non-printing dot in the set of contiguous microdots, depending on a specific characteristic selected from a characteristic of the image and a characteristic of the set of contiguous microdots; and applying a morphological filter to the set of contiguous microdots for preserving fine details in the reproduction of the image.
1 . A method for generating a bitmap from an original image for printing a reproduction of said original image, wherein said bitmap includes data selected from the group of screened data and non-screened data, the method comprising the steps of:
generating a set of contiguous microdots of said bitmap, wherein said set of contiguous microdots is selected from the group of a set of contiguous microdots forming an image dot being part of said screened data and a set of contiguous microdots forming an entity of contiguous microdots being part of said non-screened data;
generating a non-printing dot in said set of contiguous microdots, depending on a specific characteristic selected from a characteristic of said original image and a characteristic of said set of contiguous microdots; and
applying a morphological filter to said set of contiguous microdots for preserving fine details in said reproduction of said original image.
2 . The method according to claim 1 further comprising the steps of:
determining a possible location in said set of contiguous microdots for said non-printing dot;
checking if said possible location fulfills a condition, wherein said condition depends on said specific characteristic; and
generating said non-printing dot only if said condition is fulfilled.
3 . The method according to claim 1 wherein said specific characteristic is said characteristic of said original image.
4 . The method according to claim 1 wherein said specific characteristic is said characteristic of said set of contiguous microdots.
5 . The method according to claim 4 wherein said specific characteristic is a dot size of said image dot and wherein the method further comprises the step of:
generating said non-printing dot in said image dot only if said dot size of said image dot is larger than a predetermined minimum size.
6 . The method according to claim 1 further comprising the step of:
determining said set of contiguous microdots by a raster image processor having a frame buffer.
7 . (canceled)
8 . The method according to claim 6 further comprising the step of:
applying said morphological filter to said set of contiguous microdots in said frame buffer.
9 . The method according to claim 1 further comprising the step of:
applying a second morphological filter to said bitmap for preserving fine details in said reproduction of said original image.
10 . The method according to claim 1 further comprising the step of:
exposing a printing plate precursor in accordance with said bitmap.
11 . The method according to claim 10 wherein said exposure is a direct-to-plate exposure.
12 - 13 . (canceled)
14 . A printing plate obtained by the method according to to claim 1 .
15 . A data processing system comprising means for carrying out the steps of the method according to claim 1 .
16 . A computer program comprising computer program code means adapted to perform the method according to claim 1 when said program is run on a computer.
17 . A computer readable medium comprising program code adapted to carry out the method according to claim 1 when run on a computer.
18 . A method for generating a bitmap from an original image for printing a reproduction of said original image, wherein said bitmap includes data selected from the group of screened data and non-screened data, the method comprising the steps of:
generating, in a raster image processor having a frame buffer, a set of contiguous microdots of said bitmap for storage into the frame buffer, wherein said set of contiguous microdots is selected from the group of a set of contiguous microdots forming an image dot being part of said screened data and a set of contiguous microdots forming an entity of contiguous microdots being part of said non-screened data;
generating a non-printing dot in said set of contiguous microdots, depending on a specific characteristic selected from a characteristic of said original image and a characteristic of said set of contiguous microdots; and
applying a morphological filter to said set of contiguous microdots in said frame buffer for preserving fine details in said reproduction of said original image.
19 . The method according to claim 18 further comprising the step of applying a second morphological filter to said bitmap for preserving fine details in said reproduction of said original image.
20 . A method for generating a bitmap from an original image for printing a reproduction of said original image, wherein said bitmap includes data selected from the group of screened data and non-screened data, the method comprising the steps of:
generating a set of contiguous microdots of said bitmap, wherein said set of contiguous microdots is selected from the group of a set of contiguous microdots forming an image dot being part of said screened data and a set of contiguous microdots forming an entity of contiguous microdots being part of said non-screened data;
generating a non-printing dot in said set of contiguous microdots, depending on a specific characteristic selected from a characteristic of said original image and a characteristic of said set of contiguous microdots;
applying a morphological filter to said set of contiguous microdots for preserving fine details in said reproduction of said original image; and
exposing a printing plate precursor in accordance with said bitmap wherein said exposure is a direct-to-plate exposure.
21 . The method according to claim 20 further comprising the step of applying a second morphological filter to said bitmap for preserving fine details in said reproduction of said original image.
22 . A method for generating a bitmap from an original image for printing a reproduction of said original image, wherein said bitmap includes data selected from the group of screened data and non-screened data, the method comprising the steps of:
generating a set of contiguous microdots of said bitmap by a raster image processor having a frame buffer, wherein said set of contiguous microdots is selected from the group of a set of contiguous microdots forming an image dot being part of said screened data and a set of contiguous microdots forming an entity of contiguous microdots being part of said non-screened data;
generating a non-printing dot in said set of contiguous microdots, depending on a specific characteristic selected from a characteristic of said original image and a characteristic of said set of contiguous microdots;
applying a morphological filter to said set of contiguous microdots in said frame buffer for preserving fine details in said reproduction of said original image; and
exposing a printing plate precursor in accordance with said bitmap wherein said exposure is a direct-to-plate exposure.
23 . The method according to claim 22 further comprising the step of applying a second morphological filter to said bitmap for preserving fine details in said reproduction of said original image.