Relating Cascaded Random Forests to Deep Convolutional Neural Networks for Semantic Segmentation
We consider the task of pixel-wise semantic segmentation given a small set of labeled training images. Among two of the most popular techniques to address this task are Random Forests (RF) and Neural Networks (NN). The main contribution of this work is to explore the relationship between two special forms of these techniques: stacked RFs and deep Convolutional Neural Networks (CNN). We show that there exists a mapping from stacked RF to deep CNN, and an approximate mapping back. This insight gives two major practical benefits: Firstly, deep CNNs can be intelligently constructed and initialized, which is crucial when dealing with a limited amount of training data. Secondly, it can be utilized to create a new stacked RF with improved performance. Furthermore, this mapping yields a new CNN architecture, that is well suited for pixel-wise semantic labeling. We experimentally verify these practical benefits for two different application scenarios in computer vision and biology, where the layout of parts is important: Kinect-based body part labeling from depth images, and somite segmentation in microscopy images of developing zebrafish.
READ FULL TEXT