초록 ▼

Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processe

Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processes the associated tone values in a manner that increases performance (including data compressibility) without sacrificing output quality. The selection process is computationally simple and fast. Reliability is ensured because the combinations of halftoning algorithms are tabulated as a result of analysis of test samples of the printed output.

대표청구항 ▼

1. A method for selecting among different halftoning algorithms to apply to pixel tone value data, which data include at least two components, the method comprising the steps of:combining the components to form an index; andmatching the index with one of a plurality of stored indices, each of the st

1. A method for selecting among different halftoning algorithms to apply to pixel tone value data, which data include at least two components, the method comprising the steps of:combining the components to form an index; andmatching the index with one of a plurality of stored indices, each of the stored indices being correlated to predetermined combinations of at least two halftoning algorithms, the predetermined combinations representing halftoning algorithms to apply to each component of the pixel tone value data in rendering the data to a display device. 2. The method of claim 1 wherein the matching step comprises:producing beforehand a number of different portions of an image on the display device by using several halftoning algorithm combinations to produce the portions; andtabulating for each of the stored indices a selected halftoning algorithm combination, thereby to provide the predetermined combinations. 3. The method of claim 2 wherein the halftoning algorithm combinations include a first class and second class of halftoning algorithms, and wherein the first class of halftoning algorithms is selected from a group of halftoning algorithms that can render the pixel tone value data more rapidly than the second class of halftoning algorithms of the group, and wherein the tabulating step includes the step of:determining the selected combinations from the first and second classes of halftoning algorithm. 4. The method of claim 3 including the step of assigning error diffusion-type halftoning algorithms to the first class of algorithms. 5. The method of claim 3 including the step of assigning matrix-based or ordered-dither type halftoning algorithms to the second class of algorithms. 6. The method of claim 1 wherein the combining step includes the step of concatenating the most significant four bits of data bytes that represent the components of the pixel tone value data. 7. The method of claim 1 wherein the stored indices that are correlated to predetermined combinations of at least two halftoning algorithms are stored prior to the matching step. 8. A method for selecting among at least two halftoning algorithms to apply to pixel tone value data streams that represent the tone values of two or more colorants to be applied to pixels in rendering a colored image, the method including the steps of:comparing, for a given pixel, the tone values of at least two of the colorants;noting the results of the comparison; andbased upon the results of the comparison, selecting for each colorant tone value a halftoning algorithm to apply to the colorant tone values for the given pixel.