Text in images can be utilized in many image understanding applications due to the exact semantic information. In this paper, we propose a novel integrated k-shortest paths optimization based text line extraction method. Firstly, the candidate text components are extracted by the Maximal Stable Extremal Region (MSER) algorithm on gray, red, green and blue channels. Secondly, one integrated directed graph on red, green, and blue channels are constructed upon the candidate text components, which can effectively incorporate different channels into one framework. Then, the integrated directed graph is transformed guided by the extracted text lines in gray channel to reduced the computational complexity. Finally, we use the k-shortest paths optimization algorithm to extract the text lines by taking advantage of the particular structure of the integrated directed graph. Experimental results demonstrate the effectiveness of the proposed method in comparison with state-of-the-art methods.