Patent attributes
Impact time between an image sensing circuitry and an object relatively moving at least partially towards, or away from, the image sensing circuitry can be computed. Image data associated with a respective image frame of a sequence (1 . . . N) of image frames sensed by said image sensing circuitry and which image frames are imaging said object can be received. For each one (i) of multiple pixel positions, a respective duration value (f(i)) indicative of a largest duration of consecutively occurring local extreme points in said sequence (1 . . . N) of image frames can be computed. A local extreme point is present in a pixel position (i) when an image data value of the pixel position (i) is a maxima or minima in relation to image data values of those pixel positions that are closest neighbors to said pixel position (i).