Post RIP image rendering in an electrographic printer to minimize screen frequency sensitivity
View Patent ↗A method of printing multiple images with differing line screen frequencies with a printer is print sensitive to differing line screen frequencies, the method comprising the steps of: converting the images into a digital bitmap comprised of an array of pixels wherein each pixel is assigned a digital value representing marking information; defining each pixel as either a background pixel, interior pixel, or an edge pixel; reassigning the digital value of the interior pixels to a fixed interior pixel value; and reassigning the edge pixel values so as to minimize print sensitivity to differing line screen frequencies between images.
1. A method of printing images with differing line screen frequencies with a printer sensitive to differing line screen frequencies, the method comprising the steps of:
providing page description digital data (PDL data) defining a version of at least one image;
rasterizing the PDL data into instruction data (RIP data) defining a digital bitmap comprised of an array of Marked Pixels assigned a digital value representing marking information and Unmarked Pixels not assigned a value representing marking information;
storing the RIP data in memory;
rendering RIP data retrieved from memory into rendered data; and,
providing the rendered data to a writer interface for printing,
wherein the rendering step comprises defining Marked Pixels as either interior pixels or edge pixels and reassigning the digital value of the interior pixels and edge pixel values independently to minimize print sensitivity to differing line screen frequencies between images.
2. A method in accordance with claim 1 , wherein the rasterizing step comprises converting the image to a binary digital bitmap and the rendering step comprises reassigning the binary digital values to multi-bit digital values.
3. A method in accordance with claim 1 , wherein the rasterizing step comprises converting the image to a multi-bit digital bitmap and the rendering step comprises reassigning the binary digital values to multi-bit digital values.
4. A method in accordance with claim 1 , wherein the rendering step comprises increasing the value of edge pixels with respect to interior pixels.
5. A method in accordance with claim 1 , wherein the rendering step comprises decreasing the value of edge pixels with respect to interior pixels.
6. A method in accordance with claim 1 , further comprising performing the defining and rendering steps two or more times.
7. A method of printing images with differing line screen frequencies with a printer sensitive to differing line screen frequencies, the method comprising the steps of:
providing page description digital data (PDL data) defining at least one image;
interpreting the PDL data into a list of multiple objects within the image;
rasterizing the PDL data into instruction data (RIP data) defining a digital bitmap comprised of an array of Marked Pixels assigned a digital value representing marking information and Unmarked Pixels not assigned a value representing marking information;
storing the RIP data in memory;
rendering RIP data retrieved from memory into rendered data; and,
providing the rendered data to a writer interface for printing,
wherein the rendering step comprises defining Marked Pixels as either interior pixels or edge pixels and reassigning the digital value of the interior pixels and edge pixel values of each object independently to minimize print sensitivity to differing line screen frequencies between images.
8. A method in accordance with claim 7 , wherein the objects includes text and/or non-text objects.
9. A method in accordance with claim 7 , wherein the rasterizing step comprises converting the image to a binary digital bitmap and the rendering step comprises reassigning the binary digital values to multi-bit digital values.
10. A method in accordance with claim 7 , wherein the rasterizing step comprises converting the image to a multi-bit digital bitmap and the rendering step comprises reassigning the binary digital values to multi-bit digital values.
11. A method in accordance with claim 7 , wherein the rendering step comprises increasing the value of edge pixels with respect to intenor pixels.
12. A method in accordance with claim 7 , wherein the rendering step comprises decreasing the value of edge pixels with respect to interior pixels.
13. A method in accordance with claim 7 , further comprising performing the defining and rendering steps two or more times.