Spatio-temporal color luminance dithering techniques

Abstract

Systems and methods are disclosed to enable the creation and the display of spatio-temporal dithered images. Embodiments include techniques that use color-shifting and luminance. In one embodiment, adjacent pixels are color-shifted with respect to each other and the color values of the adjacent pixels are temporally alternated with color values of pixels in the group. In another embodiment, the luminance of group of adjacent pixels is determined and the luminance of the group is made more homogenous spatially and temporally by distributing color variations over a larger number of pixels so as to reduce the luminance difference between the pixel with the least luminance and the pixel with the greatest luminance. Individual color components (e.g., red, green, blue) may also be separated and used so that the color-shifts associated with each color component may be simultaneously present in different pixels.

1 . A method comprising:
 decomposing a source image comprising a plurality of pixels into Red (R), Green (G), and Blue (B) color components corresponding to each pixel;   creating a red source image group, a green source image group, and a blue source image group by assigning the respective RGB color components of each pixel to the red, green and blue source image groups;   deriving a matrix based on the red, green, and blue source image groups;   determining a luminance difference between cells in the matrix, each cell including a red component, a green component, and a blue component, wherein determining the luminance difference includes determining a luminance amplitude of the matrix, the luminance amplitude of the matrix equal to the difference in luminance between a cell of the matrix having the highest luminance and a cell of the matrix having the lowest luminance based on their respective red, green, and blue components; and   reducing the luminance amplitude of the matrix.   
     
     
         2 . The method of  claim 1 , comprising temporally dithering at least one of the red, green, or blue components of two or more cells in the matrix. 
     
     
         3 . The method of  claim 2 , wherein the temporally dithering the at least one of the red, green, or blue components of the two or more cells in the matrix comprises a clockwise or counterclockwise temporal dithering of the cells in the matrix. 
     
     
         4 . The method of  claim 1 , wherein the deriving the matrix comprises deriving a lower pixel depth value from a higher pixel depth value of the red, green, or blue source image groups. 
     
     
         5 . The method of  claim 4 , wherein the deriving the matrix includes spatially dithering at least one of the RGB color components. 
     
     
         6 . The method of  claim 1 , wherein the reducing the luminance amplitude of the matrix comprises a color-shifting of at least one of the red, green, or blue components by distributing the color components spatially across one or more cells in the matrix such that the luminance amplitude between the most and least luminescent cells of the matrix following the color-shifting is less than the luminance amplitude between the most and least luminescent cells of the matrix before the color-shifting. 
     
     
         7 . A non-transitory computer-readable medium comprising code adapted to:
 decompose a source image comprising pixels into Red (R), Green (G), and Blue (B) color components corresponding to each pixel;   create an individual color component source image group by assigning the R, G, or B color component of each pixel to one or more adjacent cells of the source image group;   create a first most significant bit (MSB) matrix by using the most significant bits of each cell of the source image group;   create a least significant bit (LSB) matrix by using the least significant bits of each cell of the source image group;   select a dither pattern from a plurality of dither patterns by using the LSB matrix;   create a modification matrix by using the selected dither pattern and the LSB matrix;   add the modification matrix to the first MSB matrix to create a second MSB matrix; and   provide visual output to a display based on the second MSB matrix.   
     
     
         8 . The non-transitory computer-readable medium of  claim 7 , wherein the code adapted to select the dither pattern by using the LSB matrix comprises code adapted to use a magnitude of a value of a cell in the LSB matrix to select the dither pattern. 
     
     
         9 . The non-transitory computer-readable medium of  claim 7 , wherein the code adapted to select the dither pattern by using the LSB matrix comprises code adapted to temporally dither the selected dither pattern. 
     
     
         10 . The non-transitory computer-readable medium of  claim 7 , wherein the code adapted to create the modification matrix by using the selected dither pattern and the LSB matrix comprises code adapted to use a row and column position of a first cell of the LSB matrix to select a value in a second cell of the selected dither pattern, the second cell of the selected dither pattern having the row and column position of the first cell. 
     
     
         11 . The non-transitory computer-readable medium of  claim 7 , comprising code adapted to temporally dither the second MSB matrix. 
     
     
         12 . The non-transitory computer-readable medium of  claim 11 , wherein the code adapted to temporally dither the second MSB matrix comprises code adapted to perform a clockwise or counterclockwise temporal dithering of the second MSB matrix. 
     
     
         13 . An electronic device comprising:
 a display comprising a plurality of pixels; and   a processor configured to transmit signals representative of image data to the plurality of pixels of the display, wherein the processor is adapted to decompose an area of a source image into Red (R), Green (G), and Blue (B) color components; create a source image group by assigning the RGB color components of the area to one or more adjacent cells of the source image group; create a most significant bit (MSB) matrix by using the source image group; derive a matrix based on the RGB colors of each cell of the MSB matrix; determine a luminance difference of the cells in the matrix; and reduce the luminance amplitude of the matrix.   
     
     
         14 . The electronic device of  claim 13 , wherein the area of the source image comprises a single pixel. 
     
     
         15 . The electronic device of  claim 13 , wherein the processor is adapted to create the MSB matrix using only the most significant bits of the source image group. 
     
     
         16 . A method comprising:
 decomposing a source image comprising pixels into Red (R), Green (G), and Blue (B) color components corresponding to each pixel;   creating an individual color source image group by assigning the R, G, or B color component of each pixel to one or more adjacent cells of the source image group;   creating a first most significant bit (MSB) group by using the source image group;   creating a least significant bit (LSB) group by using the source image group;   selecting a spatial dither pattern from a plurality of spatial dither patterns by using the LSB group;   creating a modification matrix by using the dither pattern and the LSB group;   creating a second MSB group by using the modification matrix and the first MSB group;   creating a reduced-amplitude luminance matrix based on the second MSB group; and   temporally dithering the reduced-amplitude luminance matrix.   
     
     
         17 . The method of  claim 16 , comprising temporally dithering the selected spatial dither pattern. 
     
     
         18 . The method of  claim 17 , wherein the temporally dithering of the selected spatial dither pattern comprises a clockwise temporal dithering or a counterclockwise temporal dithering. 
     
     
         19 . The method of  claim 17 , wherein the temporally dithering of the selected spatial dither pattern comprises dividing the spatial dither pattern into a plurality of quadrants and then performing either a clockwise shifting of bit values in each quadrant or a counterclockwise shifting of the bit values in each quadrant. 
     
     
         20 . The method of  claim 16 , comprising temporally dithering the second MSB group. 
     
     
         21 . A non-transitory computer-readable medium comprising code adapted to:
 create a first most significant bit (MSB) group by selecting most significant bits from an area of a source image;   create a least significant bit (LSB) group by selecting least significant bits from the area of the source image;   select a dither pattern;   create a modification matrix by using the LSB group; and   create a second MSB group by adding the modification matrix to the first MSB group.   
     
     
         22 . The non-transitory computer-readable medium of  claim 21 , wherein the code adapted to select the dither pattern comprises code adapted to use the LSB group to select the dither pattern. 
     
     
         23 . The non-transitory computer-readable medium of  claim 22 , wherein the code adapted to use the LSB group to select the dither pattern comprises code adapted to select the dither pattern based on a magnitude of a value of a cell in the LSB group. 
     
     
         24 . The non-transitory computer-readable medium of  claim 21 , wherein the code adapted to create the second MSB group by adding the modification matrix to the first MSB group comprises code adapted to add a first value corresponding to a first cell in the first MSB group to a second value corresponding to a second cell in the modification matrix.