The log-normal distribution of the size of objects in daily meal images and its application to the efficient reduction of object proposals
In general, object-detection methods apply classifiers to pre-calculated object proposals. It is therefore important to minimize the number of proposals to achieve computational efficiency. In this paper, we show that the region size for food objects in recorded images of daily food follows a lognormal distribution, which is different from the distribution for widely used datasets collected by querying the names of dishes. We explain this characteristic using Gibrat's law, and construct a model for the region-size distribution of objects in images. We applied the model to the filtering of object proposals generated by selective search and edge boxes. We obtained a significant reduction of 40.6% in the number of hypotheses compared with a conventional selective search, despite a decrease of only 0.007 in the Mean Average Best Overlap.