# How to understand the common practices followed for writing a "bounding box" for an image in datasets?

For the image datasets, there may be a bounding box for each image at the dataset. It is an annotation for an image. It is a rectangular box intended for focusing on something inside the image.

I read about the following two types of representations for a bounding box.

1. using two points $$(x_1, y_1)$$ and $$(x_2, y_2)$$.

$$$$

1. Using a point $$(x_1, y_1)$$, width, and height. $$$$

How do understand both the representations, Specifically, does the point $$(x_1, y_1)$$ used to denote the top right or top left or bottom right or bottom left in both cases?

• In case 2 it could also be the centre, ie the box starts at (x - (w/2)) and end at (x+(w/2)) etc. Sep 20 at 10:39