Methods and systems for improving display resolution in achromatic images using sub-pixel sampling and visual error filtering

A method for removing low-frequency chromatic artifacts created through sub-pixel sampling of an achromatic, higher-resolution image, said method comprising the acts of:

• performing sub-pixel sampling on said higher-resolution image;
• transforming said sub-pixel sampled image into an opponent color domain image with a segregated luminance channel and chrominance channels;
• performing high-pass filtering on said chrominance channels to remove low frequencies which developed during sub-pixel sampling thereby creating filtered chrominance channels;
• and
• combining said luminance channel and said filtered chrominance channels thereby creating a filtered opponent color domain image.

A method for converting an achromatic, higher-resolution image to a lower-resolution image with reduced visible errors, said method comprising the acts of:

• copying said achromatic, higher-resolution image into separate color channels;
• low-pass filtering said separate channels;
• combining said filtered channels into a filtered additive color domain image;
• performing sub-pixel sampling on said filtered additive color domain image;
• converting said sampled and filtered additive color domain image into an opponent color domain image;
• dividing said opponent color domain image into separate luminance and chrominance channels;
• high-pass filtering said chrominance channels;
• and
• combining said luminance, and said high-pass filtered chrominance channels into a filtered opponent color domain image.

A method for converting an achromatic, higher-resolution image to a lower-resolution image with reduced visible errors, said method comprising steps for:

• separating said achromatic, high-resolution image into separate color channels;
• low-pass filtering said separate channels;
• combining said filtered channels into a filtered additive color domain image;
• performing sub-pixel sampling on said filtered additive color domain image;
• converting said sampled and filtered additive color domain image into an opponent color domain image;
• dividing said opponent color domain image into separate luminance and chrominance channels;
• high-pass filtering said chrominance channels
• combining said luminance, and said high-pass filtered chrominance channels into a filtered opponent color domain image.

A system for converting an achromatic, higher-resolution image to a lower-resolution image with reduced visible errors, said system comprising:

• a first copier for copying said higher-resolution image into separate color channels;
• a low-pass filter for filtering said separate channels;
• a first combiner for combining said filtered channels into a filtered additive color domain image;
• a sampler for performing sub-pixel sampling on said filtered additive color domain image;
• a converter for converting said sampled and filtered additive color domain image into an opponent color domain image;
• a second divider for dividing said opponent color domain image into separate luminance and chrominance channels;
• a high-pass filter for filtering said chrominance channels
• a second combiner for combining said luminance, and said high-pass filtered chrominance channels into a filtered opponent color domain image.

A computer readable medium comprising instructions for converting an achromatic, higher-resolution image to a lower-resolution image with reduced errors, said instructions comprising the acts of:

• separating said higher-resolution image into separate color channels;
• low-pass filtering said separate channels;
• combining said filtered channels into a filtered additive color domain image;
• performing sub-pixel sampling on said filtered additive color domain image;
• converting said sampled and filtered additive color domain image into an opponent color domain image;
• dividing said opponent color domain image into separate luminance and chrominance channels;
• high-pass filtering said chrominance channels;
• and
• combining said luminance, and said high-pass filtered chrominance channels into a filtered opponent color domain image.

A computer data signal embodied in an electronic transmission, said signal having the function of converting an achromatic, higher-resolution image to a lower-resolution image, said signal comprising instructions for:

• copying said high-resolution image into separate color channels;
• low-pass filtering said separate channels;
• combining said filtered channels into a filtered additive color domain image;
• performing sub-pixel sampling on said filtered additive color domain image;
• converting said sampled and filtered additive color domain image into an opponent color domain image;
• dividing said opponent color domain image into separate luminance and chrominance channels;
• high-pass filtering said chrominance channels
• combining said luminance, and said high-pass filtered chrominance channels into a filtered opponent color domain image.

A method for re-sampling an image having chromatic information and luminance information comprising the steps of:

• (a) re-sampling said luminance information using a first re-sampling process and attenuating at least a portion of lower frequency chromatic information with respect to at least a portion of higher frequency chromatic information resulting from said re-sampling of said luminance information;
• (b) re-sampling said chromatic information of said image using a second re-sampling process, at least one of:
• (i) re-sampling of said luminance information is different than said re-sampling of said chromatic information;
• and
• (ii) said second process processes pixels of said image in a manner different than said first process;
• (c) combining said re-sampled luminance information, said re-sampled chromatic information, and at least a portion of said higher frequency chromatic information into a re-sampled image.