Magneto-optical Kerr effect (MOKE) imaging is a versatile technique for probing a surface magnetization of magnetic materials. Here, we investigate the influence of the polarizers' rotation on the resulting magnetooptical contrast of thin magnetic wires with cylindrical geometry. Employing MOKE microscopy, we image the magnetooptical contrast change and quantify the contribution of the spatially curved cylindrical surface to the overall magnetic contrast. The calculated magnetooptical contrast difference for various extinction angles between polarizer and analyzer provide an estimation of the surface magnetization orientation at curved surfaces. The magnetooptical analysis scheme can be extended to other non-planar magnetic surfaces.