  Object detection is a task that performs position identification and label
classification of objects in images or videos. The information obtained through
this process plays an essential role in various tasks in the field of computer
vision. In object detection, the data utilized for training and validation
typically originate from public datasets that are well-balanced in terms of the
number of objects ascribed to each class in an image. However, in real-world
scenarios, handling datasets with much greater class imbalance, i.e., very
different numbers of objects for each class , is much more common, and this
imbalance may reduce the performance of object detection when predicting unseen
test images. In our study, thus, we propose a method that evenly distributes
the classes in an image for training and validation, solving the class
imbalance problem in object detection. Our proposed method aims to maintain a
uniform class distribution through multi-label stratification. We tested our
proposed method not only on public datasets that typically exhibit balanced
class distribution but also on custom datasets that may have imbalanced class
distribution. We found that our proposed method was more effective on datasets
containing severe imbalance and less data. Our findings indicate that the
proposed method can be effectively used on datasets with substantially
imbalanced class distribution.
