  Recently using convolutional neural networks (CNNs) has gained popularity in
visual tracking, due to its robust feature representation of images. Recent
methods perform online tracking by fine-tuning a pre-trained CNN model to the
specific target object using stochastic gradient descent (SGD)
back-propagation, which is usually time-consuming. In this paper, we propose a
recurrent filter generation methods for visual tracking. We directly feed the
target's image patch to a recurrent neural network (RNN) to estimate an
object-specific filter for tracking. As the video sequence is a spatiotemporal
data, we extend the matrix multiplications of the fully-connected layers of the
RNN to a convolution operation on feature maps, which preserves the target's
spatial structure and also is memory-efficient. The tracked object in the
subsequent frames will be fed into the RNN to adapt the generated filters to
appearance variations of the target. Note that once the off-line training
process of our network is finished, there is no need to fine-tune the network
for specific objects, which makes our approach more efficient than methods that
use iterative fine-tuning to online learn the target. Extensive experiments
conducted on widely used benchmarks, OTB and VOT, demonstrate encouraging
results compared to other recent methods.
