Systems and method for reducing fixed pattern noise in image data
The present disclosure generally relates to systems and methods for image data processing. In certain embodiments, an image processing pipeline may be configured to receive a frame of the image data having a plurality of pixels acquired using a digital image sensor. The image processing pipeline may then be configured to determine a first plurality of correction factors that may correct each pixel in the plurality of pixels for fixed pattern noise. The first plurality of correction factors may be determined based at least in part on fixed pattern noise statistics that correspond to the frame of the image data. After determining the first plurality of correction factors, the image processing pipeline may be configured to configured to apply the first plurality of correction factors to the plurality of pixels, thereby reducing the fixed pattern noise present in the plurality of pixels.
1. A method for processing image data comprising: receiving an image frame comprising a plurality of pixels; determining a first plurality of correction factors configured to correct each pixel in the plurality of pixels for fixed pattern noise, wherein the first plurality of correction factors is determined based at least in part on fixed pattern noise statistics that correspond to the frame of image data; and applying the first plurality of correction factors to the plurality of pixels;
wherein determining the first plurality of correction factors comprises: retrieving a first offset value from an offset look-up table comprising a plurality of offset values, wherein the offset look-up table is indexed according to a fixed pattern noise frame for a respective pixel; retrieving a second offset value from the offset look-up table; applying a first weighting factor to the first offset value, thereby generating a first weighted offset value; applying a second weighting factor to the second offset value, thereby generating a second weighted offset value and adding the first weighted offset value and the second offset weighted value, thereby generating an offset value for the respective pixel;
wherein the first offset value corresponds to least significant bits of the fixed pattern noise frame, and wherein the second offset value corresponds to a number of bits after the least significant bits in the fixed pattern noise frame.
2. An image signal processing system comprising: fixed pattern noise reduction circuitry configured to:
receive a frame of image data comprising a plurality of pixels; determine a first plurality of correction factors configured to correct each pixel in the plurality of pixels for fixed pattern noise, wherein the first plurality of correction factors is determined based at least in part on fixed pattern noise statistics that correspond to the frame of image data; and
determine a second plurality of correction factors configured to correct each row of pixels in the plurality of pixels for row fixed pattern noise; or determine a third plurality of correction factors configured to correct each column of pixels in the plurality of pixels for column fixed pattern noise; and
apply the first plurality and the second plurality of correction factors or the third plurality of correction factors to the plurality of pixels;
wherein the fixed pattern noise reduction circuitry is further configured to apply one or more global offset values to the plurality of pixels before applying the first plurality of correction factors and the second plurality of correction factors or the third plurality of correction factors to the plurality of pixels.
3. An image signal processing system comprising:
image processing hardware configured to reduce fixed pattern noise in image data by:
receiving a frame of the image data comprising a plurality of pixels acquired using a digital image sensor; determining a first plurality of correction factors configured to correct each pixel in the plurality of pixels for fixed pattern noise, wherein the first plurality of correction factors is determined based at least in part on fixed pattern noise statistics that correspond to the frame of the image data and a temperature value of the digital image sensor, an integration time of the digital image sensor, or any combination thereof; and
applying the first plurality of correction factors to the plurality of pixels, thereby reducing the fixed pattern noise present in the plurality of pixels.
4. The image signal processing system of claim 3 , wherein determining the first plurality of correction factors comprises retrieving an offset value and a gain value for each pixel in the plurality of pixels from a look-up table that corresponds to the temperature value.