1. An apparatus for semi-automatically segmenting an image object from the remainder of the image, comprising: (a) a processor configured for image processing of captured color digital images and receiving a user selection input as a user selected location within a color image from said captured color digital images for identifying an object to which segmentation is to be applied; and (b) a memory storing instructions; (c) said instructions when executed by the processor performing segmenting of the object as a foreground from its background in said color image, comprising: (i) downscaling said color image into a downscaled color image at the start of segmenting the object, and selecting one or more finer resolutions as segmentation proceeds; (ii) performing expectation-maximization (EM) with a joint Bayes classifier for classifying pixels nearby the user selected location for identifying an object to which segmentation is to be applied in the downscaled color image as foreground or background, and simultaneously estimating class parameters and an object mask for the object, in response to utilizing pixel color values for each pixel; (iii) refining the object mask by performing a binary search for determining a best size of an initial mask while performing said segmenting of the object at finer resolutions, and checking stopping criteria during said segmenting of the object, with successful segmentation being completed in response to EM convergence; and (iv) generating an object mask for the object as a result of said binary search.