1. An image processing system ( 1 ) for omnidirectional reading of optical patterns, said system comprising: an imaging system ( 2 ) for provision of image data; an analog/digital converter ( 4 ) for conversion of the image data to digital image data ( 12 ); a processing device ( 6 ) for processing of the digital image data ( 12 ); a computation device ( 8 ); and a plurality of convolvers for convolution of the digital image data; wherein a contour point ( 22 ) is entered in a contour point list ( 20 ) in a memory at least with the values X position, Y position and contrast value (P(X,Y, contrast value)) precisely when a) the convolution results (Fx_ 0 , Fx_ 1 ) of the operands which are associated with one convolver pair ( 54 ) have different mathematical signs and the difference between the operands in the predetermined direction exceeds a threshold value, or when b) one and only one operand is equal to zero, and the difference between the operands in the predetermined direction exceeds a threshold value (Fx_Threshold).