Fast inpainting of railway freights images based on multiple direction interpolation

High resolution line-scan cameras produce images with missing information due to occlusion caused by foreign objects. In this paper, we propose a framework based on multiple direction interpolation for single image digital restoration to remove high tension wire (HTW) from images for railway loaded condition inspection (LCI) applications. The known region to be reconstructed is automatically segmented into smooth and edge sub-regions. The smooth regions are filled-in with bilinear interpolation based on the information in the neighborhood, which is the minimum among the gradient values in three directions. For the edge regions, the fill-in result is optimized using a data fusion method based on the information in three directions with bi-cubic interpolation. Inpainting is performed for each channel independently based on the HSI color space instead of RGB. Experimental results indicate that better restoration results can be obtained as compared with traditional Bertalmio-Sapiro-Caselles-Bellester (BSCB) and fast marching method (FMM) algorithms. The proposed algorithm can also effectively deal with inpainting of complex color images with high computational efficiency.