In a method for identifying objects in a digital image which is included in a sequence of images, luminance values of a current digital image are compared with at least one threshold value in order to create a current binarized image on the basis of the comparison. A quality measure for the current binarized image is also calculated, whereupon said at least one threshold value is updated on the basis of the quality measure for use in binarization of a subsequent image. The method can be realized in the form of a computer program, a computer program product, a device, and a hand-held apparatus for position determination.