  Most previous bounding-box-based segmentation methods assume the bounding box
tightly covers the object of interest. However it is common that a rectangle
input could be too large or too small. In this paper, we propose a novel
segmentation approach that uses a rectangle as a soft constraint by
transforming it into an Euclidean distance map. A convolutional encoder-decoder
network is trained end-to-end by concatenating images with these distance maps
as inputs and predicting the object masks as outputs. Our approach gets
accurate segmentation results given sloppy rectangles while being general for
both interactive segmentation and instance segmentation. We show our network
extends to curve-based input without retraining. We further apply our network
to instance-level semantic segmentation and resolve any overlap using a
conditional random field. Experiments on benchmark datasets demonstrate the
effectiveness of the proposed approaches.
