App takes a project as an input and produces an “Interactive coexistence matrix” that has the following dimensions: row_number = number of classes, col_number = number of classes. Each cell of the matrix shows how often a pair of classes (say person and car) appears together (how many images that simultaneously contain at least 1 person and at least 1 car). Each cell is clickable to open corresponding images
(1) An app is good for data exploration since it allows to see a big picture (co-occurrence statistics) as well as to navigate to the images of interest
(2) An App might be used to find “suspicious annotations”. If annotator has confused the class, we might see it as an “unexpected value” in the cell of “coexistence matrix”.
(3) Gradient based colors of the matrix’ cells might be useful
The image below illustrates the idea