In this demo, we demonstrate "Real-time Food Category Change'' based on a Conditional Cycle GAN (cCycle GAN) with a large-scale food image data collected from the Twitter Stream. Conditional Cycle GAN is an extension of CycleGAN, which enables "Food Category Change'' among ten kinds of typical foods served in bowl-type dishes such as beef rice bowl and ramen noodles. The proposed system enables us to change the appearance of a given food photo according to the given category keeping the shape of the given food but exchanging its textures. For training, we used two hundred and thirty thousand food images which achieved very natural food category change among ten kinds of typical Japanese foods: ramen noodle, curry rice, fried rice, beef rice bowl, chilled noodle, spaghetti with meat source, white rice, eel bowl, and fried noodle.

In most of the cases, the estimated calories are just associated with the estimated food categories, or the relative size compared to the standard size of each food category which are usually provided by a user manually. In addition, in the case of calorie estimation based on the amount of meal, a user conventionally needs to register a size-known reference object in advance and to take a food photo with the registered reference object. In this demo, we propose a new approach for food calorie estimation with CNN and Augmented Reality (AR)-based actual size estimation. By using Apple ARKit framework, we can measure the actual size of the meal area by acquiring the coordinates on the real world as a three-dimensional vector, we implemented this demo app. As a result, it is possible to calculate the size more accurately than in the previous method by measuring the meal area directly, the calorie estimation accuracy has improved.

In this paper, we propose a conditional fast neural style transfer network. We extend the network proposed as a fast neural style transfer network by Johnson et al. [1] so that the network can learn multiple styles at the same time. To do that, we add a conditional input which selects a style to be transferred out of the trained styles. In addition, we show that the proposed network can mix multiple styles, although the network is trained with each of the training styles independently. The proposed network can also transfer different styles to the different parts of a given image at the same time, which we call "spatial style transfer". In the experiments, we confirmed that no quality degradation occurred in the multi-style network compared to the single network, and linear-weighted multi-style fusion enabled us to generate various kinds of new styles which are different from the trained single styles.

Because of the recent progress on deep learning studies, Convolutional Neural Network (CNN) based method have outperformed conventional object recognition methods with a large margin. However, it requires much more memory and computational costs compared to the conventional methods. Therefore, it is not easy to implement a CNN-based object recognition system on a mobile device where memory and computational power are limited. In this paper, we examine CNN architectures which are suitable for mobile implementation, and propose multi-scale network-in-networks (NIN) in which users can adjust the trade-off between recognition time and accuracy. We implemented multi-threaded mobile applications on both iOS and Android employing either NEON SIMD instructions or the BLAS library for fast computation of convolutional layers, and compared them in terms of recognition time on mobile devices. As results, it has been revealed that BLAS is better for iOS, while NEON is better for Android, and that reducing the size of an input image by resizing is very effective for speedup of CNN-based recognition.