Mask based toner reduction

A method comprising:

• receiving digitized pixels for an image comprising color planes of different colors into a print engine comprising a processor, said processor being specialized for processing image data, said digitized pixels comprising continuous image data;
• applying, using said processor, a halftone screen to said digitized pixels of said continuous image data, said halftone screen including separate halftone frequencies and different threshold values for each color plane of said image, said halftone frequencies and said threshold values having been set during calibration of said print engine, and said halftone frequencies being selected to reduce banding and image artifacts in a rendered image, said applying said halftone screen to said digitized pixels producing an array of pixel values, said array of pixel values comprising a threshold array;
• generating, by said processor, a mask to be applied to said halftone screen for each of said color planes of said image, said generating said mask comprising:
• grouping said pixel values for said threshold array into a selected number of clusters,
• arranging said clusters into a cluster array using one pixel value from each cluster, and
• identifying pixel values to remove from said threshold array, said identifying said pixel values comprising locating each said pixel value in said cluster array and selecting a pixel value from each cluster to be removed, said mask being controlled to avoid removing two consecutive pixels from said image;
• and
• translating, by said processor, said threshold array of pixel values to an image file;
• and
• applying, by said processor, said mask to said image file, removing selected pixels from said rendered image based on said mask.

A multifunction device comprising:

• a control system comprising a processor, said processor comprising a digital image processor;
• a user interface connected to said control system;
• and
• an image output device connected to said processor,
• said user interface providing user selection of a level of toner savings for said image output device,
• said processor receiving digitized pixels for an image comprising color planes of different colors, said digitized pixels comprising continuous image data,
• said digital image processor applying a halftone screen to said digitized pixels of said continuous image data, said halftone screen including separate halftone frequencies and different threshold values for each color plane of said image, said halftone frequencies and said threshold values having been set during calibration of a print engine associated with said image output device, and said halftone frequencies being selected to reduce banding and image artifacts in a rendered image according to said image output device,
• said digital image processor producing an array of pixel values using said halftone screen, said array of pixel values comprising a threshold array,
• said processor generating a mask to be applied to said halftone screen for each of said color planes of said image, said generating said mask comprising:
• grouping said pixel values for said threshold array into a selected number of clusters,
• arranging said clusters into a cluster array using one pixel value from each cluster, and
• identifying pixel values to remove from said threshold array, said identifying said pixel values comprising locating each said pixel value in said cluster array and selecting a pixel value from each cluster to be removed, said mask being controlled to avoid removing two consecutive pixels from said image,
• said processor translating said pixel values of said threshold array to an image file,
• said processor applying said mask to said image file, removing selected pixels from said rendered image, and
• said processor sending said image file to said image output device.

A method comprising:

• receiving digitized pixels for an image comprising color planes of different colors into a print engine comprising a processor, said processor being specialized for processing image data, said digitized pixels comprising continuous image data;
• applying, using said processor, a halftone screen to said digitized pixels of said continuous image data, said halftone screen including separate halftone frequencies and different threshold values for each color plane of said image, said halftone frequencies and said threshold values having been set during calibration of said print engine;
• producing, by said processor, an array of pixel values by applying said halftone screen, said array of pixel values comprising a threshold array;
• generating, by said processor, a mask to be applied to said halftone screen for each of said color planes of said image, said generating said mask comprising:
• grouping said pixel values for said threshold array into a selected number of clusters,
• arranging said clusters into a cluster array using one pixel from each cluster, and
• identifying pixel values to remove from said threshold array, said identifying said pixel values comprising locating each said pixel value in said cluster array and selecting a pixel value from each cluster to be removed, said mask being controlled to avoid removing two consecutive pixels from said image;
• and
• applying, by said processor, said mask to said threshold array, creating a modified threshold array, said modified threshold array corresponding to reduced toner usage for rendering said image.