1. A computer implemented method comprising: receiving a data request indicating a vector associated with a pixel to be processed, the vector associated with the pixel to be processed being relative to a reference pixel having a known address, the pixels being of a plurality of pixels of an image, the plurality of pixels being associated with data stored at respective data addresses, each data address being linked by a bijective function to respective coordinates (X′, Y′) of an ordered image reference frame relating to a position of the associated pixel in the image; determining, by a computer processor, the coordinates of the reference pixel by applying the bijective function to the address of the data associated with the reference pixel; obtaining, by the computer processor, the coordinates of the pixel to be processed from the coordinates of the reference pixel and from the vector associated with the pixel to be processed; determining, by the computer processor, the address of the data associated with the pixel to be processed by applying an inverse function of the bijective function to the coordinates of the pixel to be processed; and providing, by the computer processor, the data read at the address of the data associated with the pixel to be processed, wherein, the image is divided into a plurality of macroblocks of pixels corresponding respectively to macroblocks of data, the data in each macroblock of data being in a first arrangement relative to the respective positions of the pixels in said corresponding macroblock of pixels, and the macroblocks of data being arranged in memory in a second arrangement relative to the respective positions of the corresponding macroblocks of pixels in the image, the ordered image reference frame is defined based, on spatial coordinates (X,Y) of the pixel to be processed in a spatial reference frame of the image and on the second arrangement, wherein the second arrangement is such that columns of 2 N macroblocks of data are stored one after another by successively scanning corresponding lines of columns of 2 N macroblocks of pixels in the image, where N is an integer, and wherein the ordered image reference frame comprises 2N macroblocks of pixels arranged along a vertical axis, and wherein the coordinates X′ and Y′ in the ordered image reference frame of a pixel having spatial coordinates X and Y in the image satisfy the following equations: 
 X′=X+[Y/P col-ref ×P line-image 
 Y′=Y mod P col-ref where mod corresponds to a modulus operation, P col-ref corresponds to the number of pixels per column in the ordered image reference frame, where P col-ref is equal to 2 N ×P col-MB , 2 N corresponds to the number of macroblocks per column in the ordered image reference frame, P col-MB corresponds to the number of pixels per column in a macroblock, and P line-image corresponds to the number of pixels per line in an image.