Loading patent…
AssigneeInternational Business Machines Corporation
InventorsHo Chong Lee, Mikel J. Stanich, Gerhard R. Thompson, Jack L. Zable
Estimating the term…
A method of generating artifact-free threshold matrices for digital printing devices is provided. The method includes, for example, the steps of establishing a threshold matrix by examining at least one color level for artifacts and removing the color level from the threshold matrix if it has artifacts. The method further includes the steps of examining a range of color levels for artifacts and removing the color levels from the threshold matrix which have artifacts and evenly distributing the remaining color levels over a range of color levels from a first color level to a last color. The examination of color levels for artifacts may be implemented manually or through an automated computer controlled process. The automated process includes digitally acquiring the color level and performing a Fourier transform on the color level to determine its spectral components. The spectral components are analyzed to determine the presence or absence of artifacts. Color levels having artifacts may be removed from a threshold matrix via one of several removal procedures. Once the threshold matrix is defined by artifact-free color levels, it is then integrated or stored into a printer or display device.
A method of selecting artifact-free color levels for rendering images, the method comprising the steps of establishing a threshold matrix having a plurality of color levels by generating a plurality of color levels, examining at least one of the color levels for artifacts and removing the color level from the threshold matrix if it has artifacts.
A method of selecting artifact-free gray levels for rendering images, the method comprising the steps of establishing a threshold matrix having a plurality of gray levels by generating a plurality of gray levels, examining at least one gray level for an artifact and if the gray level has an artifact, identifying the gray level for removal from the threshold matrix and removing the gray level from the threshold matrix.
A method of selecting artifact-free gray levels for rendering images, the method comprising the steps of establishing a threshold matrix by examining the optical density power spectrum of at least one gray level for an artifact and if the gray level has an artifact, identifying the gray level for removal from the threshold matrix, wherein the step of examining the optical density power spectrum of the at least one gray level for an artifact further comprises the step of optically scanning the at least one gray level along a first dimensional component to arrive at a gray level optical density power spectrum.
Dependencies are inferred from the claim text.