Alternate subsampling in colour filter arrays

1 . An imaging system comprising:

an image sensor comprising:

a plurality of photo-sensitive cells arranged on a photo-sensitive surface of the image sensor; and

a colour filter array comprising colour filters of at least three different colours; and

at least one processor configured to:

read out image data from the image sensor, wherein when reading out, the at least one processor is configured to employ subsampling in at least a region of the photo-sensitive surface, by:

reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array, wherein a given line in the first set comprises colour filters of each of the at least three different colours; and

skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, wherein the first set of lines comprises one of: odd lines in the colour filter array, even lines in the colour filter array, while the second set of lines comprises another of: the odd lines, the even lines;

obtaining information indicative of a gaze direction of a user;

determining a gaze region and a peripheral region in the photo-sensitive surface of the image sensor, based on the gaze direction; and

while reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array and skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, further employing the subsampling with a first subsampling density in the gaze region and with a second subsampling density in the peripheral region, the first subsampling density being higher than the second subsampling density;

the at least one processor further configured to process the image data to generate an image;

wherein the given line in the first set is a row of the colour filter array, and wherein another given line in the first set comprising colour filters of each of the at least three different colours is a column of the colour filter array.

2 . The imaging system of claim 1 , wherein the at least one processor is configured to select the first set of lines and the second set of lines as sets of at least one of: rows, columns, based on whether colour filters of each of the at least three different colours are arranged in rows, columns, or both rows and columns.

3 . A method comprising:

reading out image data from an image sensor, wherein the image sensor comprises a plurality of photo-sensitive cells arranged on a photo-sensitive surface of the image sensor, and a colour filter array comprising colour filters of at least three different colours, and wherein the step of reading out comprises employing subsampling in at least a region of the photo-sensitive surface, by:

reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array, wherein a given line in the first set comprises colour filters of each of the at least three different colours; and

skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, wherein the first set of lines comprises one of: odd lines in the colour filter array, even lines in the colour filter array, while the second set of lines comprises another of: the odd lines, the even lines;

obtaining information indicative of a gaze direction of a user;

determining a gaze region and a peripheral region in the photo-sensitive surface of the image sensor, based on the gaze direction; and

while reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array and skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, further employing the subsampling with a first subsampling density in the gaze region and with a second subsampling density in the peripheral region, the first subsampling density being higher than the second subsampling density; and

processing the image data to generate an image;

wherein the given line in the first set is a row of the colour filter array, and wherein another given line in the first set comprising colour filters of each of the at least three different colours is a column of the colour filter array.

4 . The method of claim 3 , further comprising selecting the first set of lines and the second set of lines as sets of at least one of: rows, columns, based on whether colour filters of each of the at least three different colours are arranged in rows, columns, or both rows and columns.

5 . An imaging system comprising:

an image sensor comprising:

a plurality of photo-sensitive cells arranged on a photo-sensitive surface of the image sensor; and

a colour filter array comprising sets of repeating rows or columns, wherein a given set of repeating rows or columns comprises N rows or columns that repeat consecutively; and

at least one processor configured to:

read out image data from the image sensor, wherein when reading out, the at least one processor is configured to employ subsampling in at least a region of the photo-sensitive surface, by:

reading out the image data from those photo-sensitive cells that correspond to at most N-1 rows or columns out of the N rows or columns in each set of repeating rows or columns; and

skipping read out from those photo-sensitive cells that correspond to a remainder of the N rows or columns in each set of repeating rows or columns;

obtaining information indicative of a gaze direction of a user;

determining a gaze region and a peripheral region in the photo-sensitive surface of the image sensor, based on the gaze direction; and

while reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array and skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, employing the subsampling with a first subsampling density in the gaze region and with a second subsampling density in the peripheral region, the first subsampling density being higher than the second subsampling density;

the at least one processor further configured to process the image data to generate an image.

6 . A method comprising:

reading out image data from an image sensor, wherein the image sensor comprises a plurality of photo-sensitive cells arranged on a photo-sensitive surface of the image sensor, and a colour filter array comprising sets of repeating rows or columns, wherein a given set of repeating rows or columns comprises N rows or columns that repeat consecutively, and wherein the step of reading out comprises employing subsampling in at least a region of the photo-sensitive surface, by:

reading out the image data from those photo-sensitive cells that correspond to at most N-1 rows or columns out of the N rows or columns in each set of repeating rows or columns; and

skipping read out from those photo-sensitive cells that correspond to a remainder of the N rows or columns in each set of repeating rows or columns;

obtaining information indicative of a gaze direction of a user;

determining a gaze region and a peripheral region in the photo-sensitive surface of the image sensor, based on the gaze direction, and

while reading out the image data from those photo-sensitive cells that correspond to a first set of lines in the colour filter array and skipping read out from those photo-sensitive cells that correspond to a second set of lines in the colour filter array, further employing the subsampling with a first subsampling density in the gaze region and with a second subsampling density in the peripheral region, the first subsampling density being higher than the second subsampling density; and

processing the image data to generate an image.