Notes on image annotation
This work addresses the difficulty of obtaining reliable annotations for scene understanding datasets, which is crucial for computer vision research.
The paper describes the challenges and process of creating consistent image annotations for the SUN database, based on an expert annotator's experience segmenting and labeling tens of thousands of images.
We are under the illusion that seeing is effortless, but frequently the visual system is lazy and makes us believe that we understand something when in fact we don't. Labeling a picture forces us to become aware of the difficulties underlying scene understanding. Suddenly, the act of seeing is not effortless anymore. We have to make an effort in order to understand parts of the picture that we neglected at first glance. In this report, an expert image annotator relates her experience on segmenting and labeling tens of thousands of images. During this process, the notes she took try to highlight the difficulties encountered, the solutions adopted, and the decisions made in order to get a consistent set of annotations. Those annotations constitute the SUN database.