Prajna: Towards Recognizing Whatever You Want from Images without Image Labeling

With the advances in distributed computation, machine learning and deep neural networks, we enter into an era that it is possible to build a real world image recognition system. There are three essential components to build a real-world image recognition system: 1) creating representative features, 2) designing powerful learning approaches, and 3) identifying massive training data. While extensive researches have been done on the first two aspects, much less attention has been paid on the third. In this paper, we present an end-to-end Web knowledge discovery system, Prajna. Starting from an arbitrary set of entities as inputs, Prajna automatically crawls images from multiple sources, identifies images that have reliably labeled, trains models and build a recognition system that is capable of recognizing any new images of the entity set. Due to the high cost of manual data labeling, leveraging the massive yet noisy data on the Internet is a natural idea, but the practical engineering aspect is highly challenging. Prajna focuses on separating reliable training data from extensive noisy data, which is a key to the capability of extending an image recognition system to support arbitrary entities. In this paper, we will analyze the intrinsic characteristics of Internet image data, and find ways to mine accurate and informative information from those data to build a training set, which is then used to train image recognition models. Prajna is capable of automatically building an image recognition system for those entities as long as we can collect sufficient number of images of the entities on the Web.