An image filter called the pseudosphere filter is presented in this paper. An edge-preserving parameter is introduced besides a scale parameter in the pseudosphere filter, and thus a better trade-off between image smoothing and edge locating can be obtained by using it. A pseudosphere-based edge detector is built by replacing the Gaussian filter in the classic Canny edge detector with the pseudosphere filter. Experimental results show that, by comparing with the classic Canny edge detector, in the case of having the same smoothness, pseudosphere-based edge detector offers a better precision for edge locating.