In the last few years, several works have been proposed to solve the problem of determining the hysteresis thresholds in an unsupervised way. In this paper, a novel method to solve this problem is proposed. Given a set of candidates for hysteresis thresholds, the basic idea of the proposed method is to combine gradient information with information obtained when the linking process is applied to all candidates. Using the same dataset and the same evaluation methodology already proposed by other works, the results obtained by our method show a performance better than that of the previous methods. The results obtained by the proposed method have been validated only for the Canny edge detector, but there are no restrictions on applying the proposed method to any other edge detector whose strategy is based on the hysteresis mechanism.