  A major challenge in scaling object detection is the difficulty of obtaining
labeled images for large numbers of categories. Recently, deep convolutional
neural networks (CNNs) have emerged as clear winners on object classification
benchmarks, in part due to training with 1.2M+ labeled classification images.
Unfortunately, only a small fraction of those labels are available for the
detection task. It is much cheaper and easier to collect large quantities of
image-level labels from search engines than it is to collect detection data and
label it with precise bounding boxes. In this paper, we propose Large Scale
Detection through Adaptation (LSDA), an algorithm which learns the difference
between the two tasks and transfers this knowledge to classifiers for
categories without bounding box annotated data, turning them into detectors.
Our method has the potential to enable detection for the tens of thousands of
categories that lack bounding box annotations, yet have plenty of
classification data. Evaluation on the ImageNet LSVRC-2013 detection challenge
demonstrates the efficacy of our approach. This algorithm enables us to produce
a >7.6K detector by using available classification data from leaf nodes in the
ImageNet tree. We additionally demonstrate how to modify our architecture to
produce a fast detector (running at 2fps for the 7.6K detector). Models and
software are available at
