Feature extraction is an important step before object detection and pattern recognition are conducted. In this paper, we endeavor to find a new way of feature extraction. As well known, the fundamental of computerized tomography (CT) is image reconstruction from projections. And a famous image reconstruction algorithm is filtered back-projection. Since the filtered projections can reconstruct the original object, it can be inferred that they can also represent the object. One of the contribution of this paper is that the idea image reconstruction from projections is adopted. To reduce the pattern dimensionality without loss of the ability of characterizing the object, the fractal dimensions of all the filtered projections are computed. These fractal dimensions form a feature vector from which pattern recognition can be done easily. Preliminary results have demonstrated that the proposed approach is a promising method for feature extraction.