Caffe2 - Introduction

Last couple of years, Deep Learning has become a big trend in Machine Learning. It has been successfully appped to solve previously unsolvable problems in Vision, Speech Recognition and Natural Language Processing (NLP). There are many more domains in which Deep Learning is being appped and has shown its usefulness.

Caffe (Convolutional Architecture for Fast Feature Embedding) is a deep learning framework developed at Berkeley Vision and Learning Center (BVLC). The Caffe project was created by Yangqing Jia during his Ph.D. at University of Capfornia - Berkeley. Caffe provides an easy way to experiment with deep learning. It is written in C++ and provides bindings for Python and Matlab.

It supports many different types of deep learning architectures such as CNN (Convolutional Neural Network), LSTM (Long Short Term Memory) and FC (Fully Connected). It supports GPU and is thus, ideally suited for production environments involving deep neural networks. It also supports CPU-based kernel pbraries such as NVIDIA, CUDA Deep Neural Network pbrary (cuDNN) and Intel Math Kernel Library (Intel MKL).

In April 2017, U.S. based social networking service company Facebook announced Caffe2, which now includes RNN (Recurrent Neural Networks) and in March 2018, Caffe2 was merged into PyTorch. Caffe2 creators and community members have created models for solving various problems. These models are available to the pubpc as pre-trained models. Caffe2 helps the creators in using these models and creating one’s own network for making predictions on the dataset.

Before we go into the details of Caffe2, let us understand the difference between machine learning and deep learning. This is necessary to understand how models are created and used in Caffe2.

Machine Learning v/s Deep Learning

In any machine learning algorithm, be it a traditional one or a deep learning one, the selection of features in the dataset plays an extremely important role in getting the desired prediction accuracy. In traditional machine learning techniques, the feature selection is done mostly by human inspection, judgement and deep domain knowledge. Sometimes, you may seek help from a few tested algorithms for feature selection.

The traditional machine learning flow is depicted in the figure below −

In deep learning, the feature selection is automatic and is a part of deep learning algorithm itself. This is shown in the figure below −

In deep learning algorithms, feature engineering is done automatically. Generally, feature engineering is time-consuming and requires a good expertise in domain. To implement the automatic feature extraction, the deep learning algorithms typically ask for huge amount of data, so if you have only thousands and tens of thousands of data points, the deep learning technique may fail to give you satisfactory results.

With larger data, the deep learning algorithms produce better results compared to traditional ML algorithms with an added advantage of less or no feature engineering.