  We introduce RaidaR, a rich annotated image dataset of rainy street scenes,
to support autonomous driving research. The new dataset contains the largest
number of rainy images (58,542) to date, 5,000 of which provide semantic
segmentations and 3,658 provide object instance segmentations. The RaidaR
images cover a wide range of realistic rain-induced artifacts, including fog,
droplets, and road reflections, which can effectively augment existing street
scene datasets to improve data-driven machine perception during rainy weather.
To facilitate efficient annotation of a large volume of images, we develop a
semi-automatic scheme combining manual segmentation and an automated processing
akin to cross validation, resulting in 10-20 fold reduction on annotation time.
We demonstrate the utility of our new dataset by showing how data augmentation
with RaidaR can elevate the accuracy of existing segmentation algorithms. We
also present a novel unpaired image-to-image translation algorithm for
adding/removing rain artifacts, which directly benefits from RaidaR.
