High dynamic range image sensor
First Claim
Patent Images
1. A method comprising:
- sampling a first pixel cell signal at a first time to produce a first sample;
sampling a second pixel cell signal at a second time to produce a second sample;
applying a first variable weighting factor to the first sample, wherein the first variable weighting factor is defined based on a first function;
applying a second variable weighting factor to the second sample, wherein the second variable weighting factor is defined based on a second function; and
combining the weighted first sample and the weighted second sample according to the equation;
SCOMBINED(i, j)=SLONG(i, j)*M(i, j)+n*SSHORT(i, j)*(1−
M(i, j))where SCOMBINED denotes the combination of the first sample, denoted by SSHORT, and the second sample, denoted by SLONG, for the pixel cell located at (i, j), n denotes a scalar value that is dependent on the difference in the time of exposure between the first time and the second time, and M(i, j) denotes the variable weighting factor.
1 Assignment
0 Petitions
Accused Products
Abstract
This disclosure describes techniques for producing high dynamic range images by applying a variable weighting factor to a sample prior to combining the sample with another sample. In one example, a method includes sampling a first pixel cell signal at a first time to produce a first sample, sampling a second pixel cell signal at a second time to produce a second sample, applying a variable weighting factor to the second sample, wherein the variable weighting factor is defined based on a function, and combining the first sample and the weighted second sample.
22 Citations
32 Claims
-
1. A method comprising:
-
sampling a first pixel cell signal at a first time to produce a first sample; sampling a second pixel cell signal at a second time to produce a second sample; applying a first variable weighting factor to the first sample, wherein the first variable weighting factor is defined based on a first function; applying a second variable weighting factor to the second sample, wherein the second variable weighting factor is defined based on a second function; and combining the weighted first sample and the weighted second sample according to the equation;
SCOMBINED(i, j)=SLONG(i, j)*M(i, j)+n*SSHORT(i, j)*(1−
M(i, j))where SCOMBINED denotes the combination of the first sample, denoted by SSHORT, and the second sample, denoted by SLONG, for the pixel cell located at (i, j), n denotes a scalar value that is dependent on the difference in the time of exposure between the first time and the second time, and M(i, j) denotes the variable weighting factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A system comprising:
-
an image sensor comprising; a plurality of pixel cells; and a controller that; samples, from at least one of the plurality of pixel cells, a first pixel cell signal at a first time to produce a first sample; and samples, from the at least one of the plurality of cells, a second pixel cell signal at a second time to produce a second sample; and a processor that; applies a first variable weighting factor to the first sample, wherein the first variable weighting factor is defined based on a first function; applies a second variable weighting factor to the second sample, wherein the second variable weighting factor is defined based on a second function; and combines the weighted first sample and the weighted second sample according to the equation;
SCOMBINED(i, j)=SLONG(i, j)*M(i, j)+n*SSHORT(i, j)*(1−
M(i, j))where SCOMBINED denotes the combination of the first sample, denoted by SSHORT, and the second sample, denoted by SLONG, for the pixel cell located at (i, j), n denotes a scalar value that is dependent on the difference in the time of exposure between the first time and the second time, and M(i, j) denotes the variable weighting factor. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A system comprising:
-
means for sampling a first pixel cell signal at a first time to produce a first sample; means for sampling a second pixel cell signal at a second time to produce a second sample; means for applying a first variable weighting factor to the first sample, wherein the first variable weighting factor is defined based on a first function; means for applying a second variable weighting factor to the second sample, wherein the second variable weighting factor is defined based on a second function; and means for combining the weighted first sample and the weighted second sample according to the equation;
SCOMBINED(i, j)=SLONG(i, j)*M(i, j)+n* SSHORT(i, j)*(1−
M(i, j))where SCOMBINED denotes the combination of the first sample, denoted by SSHORT, and the second sample, denoted by SLONG, for the pixel cell located at (i, j), n denotes a scalar value that is dependent on the difference in the time of exposure between the first time and the second time, and M(i, j) denotes the variable weighting factor. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
-
-
25. A computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to:
-
sample a first pixel cell signal at a first time to produce a first sample; sample a second pixel cell signal at a second time to produce a second sample; apply a first variable weighting factor to the first sample, wherein the first variable weighting factor is defined based on a first function; apply a second variable weighting factor to the second sample, wherein the second variable weighting factor is defined based on a second function; and combine the first sample and the weighted second sample according to the equation;
SCOMBINED(i, j)=SLONG(i, j)*M(i, j)+n* SSHORT(i, j)*(1−
M(i, j))where SCOMBINED denotes the combination of the first sample, denoted by SSHORT, and the second sample, denoted by SLONG, for the pixel cell located at (i, j), n denotes a scalar value that is dependent on the difference in the time of exposure between the first time and the second time, and M(i, j) denotes the variable weighting factor. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32)
-
Specification