Text in natural scene images usually carries abundant semantic information.However,due to variations of text and complexity of background,detecting text in scene images becomes a critical and challenging task.In this paper,we present a novel method to detect text from scene images.Firstly,we decompose scene images into background and text components using morphological component analysis (MCA),which will reduce the adverse effects of complex backgrounds on the detection results.In order to improve the performance of image decomposition,two discriminative dictionaries of background and text are leed from the training samples.Moreover,Laplacian sparse regularization is introduced into our proposed dictionary leing method which improves discrimination of dictionary.Based on the text dictionary and the sparse-representation coefficients of text,we can construct the text component.After that,the text in the query image can be detected by applying certain heuristic rules.The results of experiments show the effectiveness of the proposed method.