Random forest-based scheme using feature and decision levels information for multi-focus image fusion

Abstract

Often captured images are not focussed everywhere. Many applications of pattern recognition and computer vision require all parts of the image to be well-focussed. The all-in-focus image obtained, through the improved image fusion scheme, is useful for downstream tasks of image processing such as image enhancement, image segmentation, and edge detection. Mostly, fusion techniques have used feature-level information extracted from spatial or transform domain. In contrast, we have proposed a random forest (RF)-based novel scheme that has incorporated feature and decision levels information. In the proposed scheme, useful features are extracted from both spatial and transform domains. These features are used to train randomly generated trees of RF algorithm. The predicted information of trees is aggregated to construct more accurate decision map for fusion. Our proposed scheme has yielded better-fused image than the fused image produced by principal component analysis and Wavelet transform-based previous approaches that use simple feature-level information. Moreover, our approach has generated better-fused images than Support Vector Machine and Probabilistic Neural Network-based individual Machine Learning approaches. The performance of proposed scheme is evaluated using various qualitative and quantitative measures. The proposed scheme has reported 98.83, 97.29, 98.97, 97.78, and 98.14 % accuracy for standard images of Elaine, Barbara, Boat, Lena, and Cameraman, respectively. Further, this scheme has yielded 97.94, 98.84, 97.55, and 98.09 % accuracy for the real blurred images of Calendar, Leaf, Tree, and Lab, respectively.