1. A method for authentication, comprising: extracting a preliminary edge orientation pattern that fits in a first dimension from an input sketch of a user, the preliminary edge orientation pattern including a set of quantized orientation patterns; obtaining an input edge orientation pattern by scaling the preliminary orientation pattern that fits in the first dimension to fit into a second dimension that is smaller than the first dimension by blurring, the scaling reducing a corresponding size of each quantized orientation pattern; measuring an edge orientation similarity between the input edge orientation pattern and a template edge orientation pattern; and making an authentication decision at least partially based on the edge orientation similarity, wherein a size of the second dimension is selected to achieve a desired balance between a false acceptance rate and a false rejection rate of authentication, and wherein extracting the preliminary edge orientation pattern comprises: computing a gradient orientation of image intensity in the input sketch; quantizing the gradient orientation to each r th orientation of R number of quantized orientations, where r=1,2,. .. , R; and computing the preliminary edge orientation pattern from the quantized gradient orientation.