Re-identification is generally carried out by encoding the appearance of a
subject in terms of outfit, suggesting scenarios where people do not change
their attire. In this paper we overcome this restriction, by proposing a
framework based on a deep convolutional neural network, SOMAnet, that
additionally models other discriminative aspects, namely, structural attributes
of the human figure (e.g. height, obesity, gender). Our method is unique in
many respects. First, SOMAnet is based on the Inception architecture, departing
from the usual siamese framework. This spares expensive data preparation
(pairing images across cameras) and allows the understanding of what the
network learned. Second, and most notably, the training data consists of a
synthetic 100K instance dataset, SOMAset, created by photorealistic human body
generation software. Synthetic data represents a good compromise between
realistic imagery, usually not required in re-identification since surveillance
cameras capture low-resolution silhouettes, and complete control of the
samples, which is useful in order to customize the data w.r.t. the surveillance
scenario at-hand, e.g. ethnicity. SOMAnet, trained on SOMAset and fine-tuned on
recent re-identification benchmarks, outperforms all competitors, matching
subjects even with different apparel. The combination of synthetic data with
Inception architectures opens up new research avenues in re-identification.

本文提出一种基于深度卷积神经网络（SOMAnet），能够识别个体的外观细节和身体结构特征等，通过使用 100K 的合成数据集 SOMAset 进行训练和微调，和 Inception 架构进行结合的重新识别方法，成功地提高了识别精度。

超越外表：用于深度卷积神经网络的合成训练数据在再识别中的应用

Looking Beyond Appearances: Synthetic Training Data for Deep CNNs in  Re-identification

Very deep convolutional networks have been central to the largest advances in
image recognition performance in recent years. One example is the Inception
architecture that has been shown to achieve very good performance at relatively
low computational cost. Recently, the introduction of residual connections in
conjunction with a more traditional architecture has yielded state-of-the-art
performance in the 2015 ILSVRC challenge; its performance was similar to the
latest generation Inception-v3 network. This raises the question of whether
there are any benefit in combining the Inception architecture with residual
connections. Here we give clear empirical evidence that training with residual
connections accelerates the training of Inception networks significantly. There
is also some evidence of residual Inception networks outperforming similarly
expensive Inception networks without residual connections by a thin margin. We
also present several new streamlined architectures for both residual and
non-residual Inception networks. These variations improve the single-frame
recognition performance on the ILSVRC 2012 classification task significantly.
We further demonstrate how proper activation scaling stabilizes the training of
very wide residual Inception networks. With an ensemble of three residual and
one Inception-v4, we achieve 3.08 percent top-5 error on the test set of the
ImageNet classification (CLS) challenge

本研究发现在 Inception 网络中加入残差连接有助于加速训练并提高图像识别性能，同时还提出了几种优化的网络结构，实验结果在 ILSVRC 2012 分类任务中取得了显著的性能提升。