1. A method of detecting a posture of at least one predetermined part of an object, comprising: extracting a first object shape from a first image taken by a first image sensor; computing a characteristic dimension value of said predetermined part within a predetermined region of said first object shape by: determining a plurality of segmentation boundaries based on a first set of thresholds; extracting said predetermined region from said first object shape based on said segmentation boundaries; identifying said at least one predetermined part within said predetermined region based on a second set of thresholds; measuring dimensional values of said at least one predetermined parts within said predetermined region; and calculating said characteristic dimension value based on said dimensional values of said predetermined parts within said predetermined region; constructing a mask based on said characteristic dimension value; extracting a profile of said predetermined part from said first object shape by applying said mask on said first object shape; and identifying at least one predefined feature point in said profile of said predetermined part; thereby detecting said posture of said predetermined part.