  We introduce G-CNN, an object detection technique based on CNNs which works
without proposal algorithms. G-CNN starts with a multi-scale grid of fixed
bounding boxes. We train a regressor to move and scale elements of the grid
towards objects iteratively. G-CNN models the problem of object detection as
finding a path from a fixed grid to boxes tightly surrounding the objects.
G-CNN with around 180 boxes in a multi-scale grid performs comparably to Fast
R-CNN which uses around 2K bounding boxes generated with a proposal technique.
This strategy makes detection faster by removing the object proposal stage as
well as reducing the number of boxes to be processed.
