<p>The integer coordinates refer to the top-left corner of a pixel. Adding 0.5 to both x and y gives you the center location of a pixel instead.</p>

CC BY-SA 4.0
2020-04-28T08:46:18.707Z
2020-04-28T08:46:18.707Z
GPhilo
<p>In the paper <a href="https://arxiv.org/abs/1512.02325" rel="nofollow noreferrer">SSD: Single Shot MultiBox Detector</a>, under section 2.2 - (4), why do we add an offset of <strong>0.5</strong> to x, y in generating the anchor boxes across feature maps? </p>

<computer-vision><object-detection><papers>
Why do we set offset (0.5) in single shot detector?
147956
# Why do we set offset (0.5) in single shot detector?

(Asked by: username_0 on 2020-04-28)

In the paper [SSD: Single Shot MultiBox Detector](https://arxiv.org/abs/1512.02325), under section 2.2 - (4), why do we add an offset of **0.5** to x, y in generating the anchor boxes across feature maps?

**Tags:** computer-vision, object-detection, papers


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## 1 answers

### Answer by username_1 on 2020-04-28. Score: 0 | Accepted answer

The integer coordinates refer to the top-left corner of a pixel. Adding 0.5 to both x and y gives you the center location of a pixel instead.


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