Methods and apparatus for motion detection

A method comprising:

• activating an image capture device;
• performing, with the image capture device and after activation, a series of exposure adjustments;
• acquiring, during the exposure adjustments and with the image capture device, first and second images;
• producing a third image based on the first and second images, wherein first intensity values of pixels in the third image individually represent a magnitude of a difference in intensity between respective corresponding pixels in the first and second images;
• assembling a data set based on the third image, the data set specifying (i) the first intensity values of the pixels in the third image, and (ii) a number of pixels of the third image having individual first intensity values;
• determining, based on the data set, a threshold for motion detection;
• and
• identifying a region of motion based in part on applying the threshold to the third image.

A device comprising:

• a sensor;
• at least one processor;
• and
• a data storage device storing instructions that when executed by the at least one processor cause the device to
• produce a first image based on a plurality of previous images of a sequence, the first image including pixels with intensity values based on a magnitude of a difference in intensity values between a pair of pixels from the plurality, and the pair being one pixel from each of the plurality at the same locations within their respective previous images,
• assemble a data set from the first image, the data set specifying (i) the intensity values of the pixels in the first image and (ii) a number of pixels of the first image having individual intensity values, and
• produce a second image by application of a filter to the first image according to a threshold derived from the data set.