Patent ID: 8350922

Claim:
Method to create a video sequence of a plurality of resultant images from images originating from a rolling shutter acquisition sensor, said method comprising the steps of: acquiring a plurality of images, each image being acquired at a known instant in time for a known possibly varying acquisition duration, all images being of width W and height H when expressed in pixel units, selecting a given image, described hereafter as the current image, with corresponding acquisition start time t 1 and acquisition duration Δt 1 , to be processed and a reference image, with corresponding acquisition start time t 0 and acquisition duration Δt 0 , said reference image being either a previously acquired image or a subsequent acquired image, decomposing the current and the reference images into blocks and calculating for each block of the current image, of given coordinates (x 1 ,y 1 ), the relative motion vector (u,v) from the current image to the reference image, leading to a corresponding block of coordinates (x 0 ,y 0 )=(x 1 +u,y 1 +v) in the reference image, each block being acquired at a block acquisition time due to the rolling shutter technology, computing for each block of the said reference image the corresponding block acquisition time t(x 0 ,y 0 ) given the coordinates (x 0 ,y 0 ) of the block in the reference image, the image acquisition start time t 0 and the image acquisition duration Δt 0 , using a linear dependence of the block acquisition time on the block position given by the formula t ⁡ ( x 0 , y 0 ) = y 0 × W + x 0 W × H ⁢ Δ ⁢ ⁢ t 0 + t 0 , computing for each block of the said current image the corresponding block acquisition time t(x 1 ,y 1 ) given the coordinates (x 1 ,y 1 ) of the block in the current image, the image acquisition start time t 1 and the image acquisition duration Δt 1 , using a linear dependence of the block acquisition time on the block position given by the formula t ⁡ ( x 1 , y 1 ) = y 1 × W + x 1 W × H ⁢ Δ ⁢ ⁢ t 1 + t 1 , selecting a time t* , hereafter reconstruction time and corresponding to the resultant image without rolling shutter effects in the output sequence, recomposing the resultant image, being part of the said video sequence at said reconstruction time t* and corrected from the rolling shutter effect, from the current image by moving each block of the current image in a three dimensional space defined by the image spatial coordinates plus time, the direction of the displacement being given by the line joining the three dimensional position of the block (x 1 ,y 1 ,t(x 1 ,y 1 )) according to the current image and its previous three dimensional position (x 0 =x 1 +u,y 0 =y 1 +v,t(x 0 ,y 0 )) according to the reference image, until it meets the plane of constant time equal to the reconstruction time t* in the said three dimensional space.