Image sensor calibration
AssigneeBoston Scientific Scimed, Inc.
InventorsJohn Kummailil, Nathaniel McCaffrey
Life of this patent
Estimating the term…
Abstract
A method of calibrating an image sensor may include detecting a response from a pixel of the image sensor as a result of light having an intensity impinging on the pixel, and measuring the actual standard deviation of the response of the pixel at the intensity of light. The method may also include determining an averaging number for the pixel at the intensity. The averaging number may be a number of responses of the pixel at the intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value. The method may further include determining the average response of the pixel using the determined averaging number.
Claims18
A method of calibrating an image sensor, comprising:
- detecting a response from a pixel of the image sensor as a result of light having an intensity impinging on the pixel;
- receiving an actual standard deviation of the response of the pixel at the intensity of light;
- determining an averaging number for the pixel at the intensity, the averaging number being a number of responses of the pixel at the intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value;
- and
- determining the average response of the pixel using the determined averaging number,
- wherein determining the averaging number includes rounding the determined averaging number to the closest higher power of two.
A control system for an image sensor, comprising:
- the image sensor including a plurality of pixels arranged thereon, each pixel of the plurality of pixels being configured to output a response indicative of an intensity of light incident thereon;
- a memory including a database, the database including an averaging number for at least one pixel of the plurality of pixels at multiple intensities, the averaging number being indicative of a number of responses of the pixel at an intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value;
- and
- a processor operatively coupled to the image sensor and the memory, the processor being configured to determine the average response of the pixel based on the determined averaging number and the intensity of light incident on the pixel,
- wherein the database includes the averaging number rounded to the closest higher power of two.
A method of operating an image sensor, comprising:
- detecting a response from a pixel of the image sensor as a result of light having a first intensity impinging on the pixel;
- obtaining an actual standard deviation of the response of the pixel at the first intensity, the actual standard deviation being a number indicative of an expected variation in the response of the pixel;
- determining a number n at the first intensity, wherein the number n is the number of frames at the first intensity to be averaged to attain a target standard deviation for the response at the first intensity, wherein determining the number n includes determining the number n using the equation
- n
- =
- ceil
-
- (
- σ
- actual
- σ
- target
- )
- 2
- ,
- where n=the number n, σactual=the actual standard deviation at the first intensity, σtarget=the target standard deviation and ceil is a ceiling function that rounds a result of (σactual/σtarget)2 to the next integer greater than or equal to the result of (σactual/σtarget)2;
- and
- averaging n number of responses from the pixel at the first intensity to obtain an average response from the pixel at the first intensity.
Dependencies are inferred from the claim text.