摘要:
A method and system implements a redistributive characteristic into an error diffusion process. A grey level value representing a pixel is received. A threshold circuit thresholds the received grey level value and generates an error value as a result of the threshold. A portion of the error value is diffused to adjacent pixels on a next scanline. All the error for a single pixel on the next scanline is accumulated. Since this accumulated error has a greater number of bits than can be stored in a buffer, a portion of the accumulated error is truncated and redistributed to a down stream pixel for inclusion in the downstream pixel's error accumulation process. The grey level value has a first resolution which corresponds to an original input resolution. In a high addressabilty environment, the received grey level value is interpolated to subpixel grey level values before thresholding.
摘要:
A method and system implements a dynamic error diffusion process. A grey level value representing a pixel is received. An image segmentation circuit determines an image characteristic of the pixel being processed. A threshold circuit thresholds the grey level value (pixel) and generates an error value as a result of the threshold process. A portion of the error value is diffused to adjacent pixels on a next scanline. The distribution of this error value is dynamic in that different sets of weighting coefficients are used based the image characteristic of the processed pixel. One set of coefficients are utilized in processing a pixel having a first image characteristic, and a second set of coefficients are utilized in processing a pixel having a second image characteristic.
摘要:
A printing system for rendering marks on a recording medium receives a multi-level grey scale pixel value representing a pixel having a first resolution. A screening circuit generates a screened multi-level grey scale pixel value equal to (G.sub.L -V.sub.i)+(S.sub.i -Th)*Dmp.sub.vi *Mod.sub.Eff wherein G.sub.L is the maximum grey level value of the pixel, V.sub.i is equal to the multi-level grey scale pixel value of the first resolution, S.sub.i is equal to a screen value corresponding to a position of the pixel, Th is the threshold value, Dmp.sub.vi is a video dependent dampening factor, and Mod.sub.Eff is a modulation multiplication factor. An interpolator converts the screened multi-level grey scale pixel value to a second resolution, the second resolution being higher than the first resolution, and a binarization circuit binarizes the converted multi-level grey scale pixel value so as to output a binary signal and an error value, the error value having a resolution equal to the first resolution. The error value is diffused to multi-level grey scale pixel values corresponding to pixels adjacent to the pixel having the first resolution, and the binary signal is converted into a mark on the recording medium.
摘要:
A method and system implements screening and a high addressability characteristic into an error diffusion process. A grey level value representing a pixel is received. The grey level value has a first resolution which corresponds to an original input resolution. The grey level value is then screened. A threshold circuit thresholds the grey level value and generates an error value as a result of the threshold. A portion of the error value is diffused to adjacent pixels on a next scanline. The screened grey level value can also be interpolated to generate subpixel grey level values which correspond to a second resolution. The second resolution is higher than the first resolution and corresponds to the high addressability characteristic. The threshold circuit would then threshold the grey level value and generate an error value having a resolution corresponding to the first resolution.
摘要:
A process eliminates pattern shifting artifacts in a printed image rendered using a hybrid high addressable error diffusion process by perturbing a threshold/image signal value relationship when a multi-level grey level is binarized. The process utilizes a programmable multi-level grey signal modifying circuit for modifying the multi-level grey signal by a predetermined value according to its grey level. The modified multi-level grey signal is binarized to a binary pixel signal according to a relationship between the modified multi-level grey signal and a threshold value. The process further generates an error corresponding to the relationship and diffuses the error to neighboring pixels. The multi-level grey signal is modified with either random noise multiplied by a grey level dependent coefficient or by a predetermined value from a checkerboard or vertical line pattern. The value from the pattern is dependent upon the grey level and pixel location of the image data.
摘要:
A method and system implements a high addressability characteristic into an error diffusion process. A grey level value representing a pixel is received: The grey level value has a first resolution which corresponds to an original input resolution. The grey level value is interpolated to generate subpixel grey level values which correspond to a second resolution. The second resolution is higher than the first resolution and corresponds to the high addressability characteristic. A threshold circuit thresholds the interpolated grey level value and generates an error value as a result of the threshold. The error value has a resolution corresponding to the first resolution. A portion of the error value is diffused to adjacent pixels on a next scanline.
摘要:
A method and system implements a dynamic error diffusion process. A grey level value representing a pixel is received. An image segmentation circuit determines an image characteristic of the pixel being processed. A threshold circuit thresholds the grey level value (pixel) and generates an error value as a result of the threshold process. A portion of the error value is diffused to adjacent pixels on a next scanline. The distribution of this error value is dynamic in that different sets of weighting coefficients are used based the image characteristic of the processed pixel. One set of coefficients are utilized in processing a pixel having a first image characteristic, and a second set of coefficients are utilized in processing a pixel having a second image characteristic.
摘要:
A process eliminates pattern shifting artifacts in a printed image by perturbing a threshold/image signal value relationship when a multi-level grey level is binarized. The process utilizes a programmable multi-level grey signal modifying circuit for modifying the multi-level grey signal by a predetermined value according to its grey level. The modified multi-level grey signal is binarized to a binary pixel signal according to a relationship between the modified multi-level grey signal and a threshold value. The process further generates an error corresponding to the relationship and diffuses the error to neighboring pixels. The multi-level grey signal is modified with either random noise multiplied by a grey level dependent coefficient or by a predetermined value from a checkerboard or vertical line pattern. The value from the pattern is dependent upon the grey level and pixel location of the image data.
摘要:
A method and system implements a high addressability characteristic into an error diffusion process. A grey level value representing a pixel is received. The grey level value is interpolated to generate subpixel grey level values which correspond to a second resolution. A threshold circuit thresholds the interpolated grey level value. In parallel to the interpolation circuit and threshold circuit is an error circuit which generates a plurality of possible error values. One of the plurality of possible error values is selected based on the number of subpixels exceeding a threshold value. A portion of the selected error value is then diffused to adjacent pixels on a next scanline.
摘要:
A printing system for rendering marks on a recording medium receives a multi-level grey scale pixel value representing a pixel having a first resolution. A screening circuit generates a screened multi-level grey scale pixel value equal to (G.sub.L -V.sub.i)+(S.sub.i -Th)*Dmp.sub.Vi *Mod.sub.Eff wherein G.sub.L is the maximum grey level value of the pixel, V.sub.i is equal to the multi-level grey scale pixel value of the first resolution, S.sub.i is equal to a screen value corresponding to a position of the pixel, Th is the threshold value, Dmp.sub.Vi is a video dependent dampening factor, and Mod.sub.Eff is a modulation multiplication factor. An interpolator converts the screened multi-level grey scale pixel value to a second resolution, the second resolution being higher than the first resolution, and a binarization circuit binarizes the converted multi-level grey scale pixel value so as to output a binary signal and an error value, the error value having a resolution equal to the first resolution. The error value is diffused to multi-level grey scale pixel values corresponding to pixels adjacent to the pixel having the first resolution, and the binary signal is converted into a mark on the recording medium.