Method and system for digital image stabilization

A method for digital image stabilization for removing unwanted movements of a camera, in translation and/or rotation, called jitter, from a raw sequence of images generated by said camera and obtaining a stabilized sequence of images, the method comprising the following steps:

• a first step of estimation of global motion of said camera, comprising sub-steps of calculating block motion vectors for predetermined parts of said images, determining macro-blocks for each of said parts and matching said macro-blocks of a current image with the ones of a previous image, and deriving from said block motion vectors of a translation vector and a rotation angle vector representing the motion of said camera and 1-bit binary images are generated and divided in a predetermined number of areas and in order to simplify the number of candidate vector in each of said areas, an extended search area is only performed on the first motion vector for a line of said macro-blocks and a reduced search area is performed on the remaining macro-blocks, said reduced area being centered around a predictor motion vector taken from a preceding reliable block motion vector, each area comprising a predetermined number of said macro-blocks and computing a reliability measure for each of said macro-blocks by counting the number of pixel of images at a “1” logic level, and in that said macro-blocks having a too high or too low predetermined ratio of “1” logic levels compared to “0” logic levels are labeled as unreliable, no motion estimation being then performed on said unreliable macro-blocks;
• a second step of filtering and extracting said jitter by separating intentional motion from the unintentional one, comprising the sub-steps of translation vector filtering and rotational angle filtering;
• and
• a third step of jitter compensation, consisting in compensating said raw sequence of images according to said extracted jitter, in order to obtain said stabilized sequence of images.