Three-dimensional noise reduction

A method comprising:

• receiving a current image of a sequence of images from an image sensor;
• combining the current image with a recirculated image to obtain a noise reduced image, where the recirculated image is based on one or more previous images of the sequence of images from the image sensor, and in which the current image is combined with the recirculated image using a set of mixing weights for respective image portions of the recirculated image;
• determining a noise map for the noise reduced image, where the noise map is determined based on estimates of noise levels for pixels in the current image, a noise map for the recirculated image, and the set of mixing weights;
• recirculating the noise map with the noise reduced image to combine the noise reduced image with a next image of the sequence of images from the image sensor;
• and
• storing, displaying, or transmitting an output image that is based on the noise reduced image.

A system comprising:

• an image sensor configured to capture image data using a plurality of selectable exposure times;
• and
• a processing apparatus that is configured to:
• receive a first image from the image sensor, where the first image is captured with a first exposure time;
• receive a second image from the image sensor, where the second image is captured with a second exposure time that is less than the first exposure time;
• determine a high dynamic range image based on the first image in a raw format and the second image in a raw format, in which an image portion of the high dynamic range image is based on a corresponding image portion of the second image when a pixel of a corresponding image portion of the first image is saturated;
• and
• store, display, or transmit an output image that is based on the high dynamic range image.