The fractional calculus is used in edge detection much more frequently due to its good performance in strengthening details

Among those studies

most are made in RGB color space. However

the brightness information and the chrominance information are related to each other in RGB color space. This defect prevents us from obtaining both the brightness edge and the chrominance edge simultaneously. Therefore

using fractional calculus in other color spaces whose brightness information and chrominance information are separated

is significant in theory and practice. In this paper

to make the most use of both brightness and color information

we propose a novel edge detection method by using fractional differentiation in CIE Lab color space for edge detection. Compared with detecting edges directly in the RGB color space

the edge extracted by the proposed method is much more consistent with human visual preception. Furthermore

the continuity and the anti-disturbance are better too. By contrast to other classical algorithms

the proposed method also has significant advantage.