Measure Object Detection¶
Precision, Recall, and F1¶
\[ \begin{align}\begin{aligned}\begin{split}\begin{split}
&Precision &= \dfrac{TP}{\text{total detection}}&= \dfrac{TP}{TP+FP}\\
&Recall &= \dfrac{TP}{\text{total positive}} &= \dfrac{TP}{TP+FN}\\
&F1&=\dfrac{precision\cdot recall}{precision+recall}\\\end{split}\\\begin{split}&TP=\text{True Positive}\\
&TN=\text{True Negative}\\
&FP=\text{False Positive}\\
&FN=\text{False Negative}\\
\end{split}\end{split}\end{aligned}\end{align} \]
Intersection over union, IoU¶
consider area of Ground Truth and area of Prediction
\[IoU = \dfrac{\text{area of overlap}}{\text{area of union}}\]
It is used to define Positive or negative
Non-Maximum Suppression, NMS¶
To filter overlapped object
mean Average Precisiion, mAP¶
When The confident level threshold increase, the precision decrease and recall increase.
Average Precision is the area under the precision-recall curve, with a confident or IoU threshold
\[AP = \int_0^1p(r)dr\]
In Pascal VOC, an average for the 11-point interpolated AP is calculated. [0, 0.1, 0.2, 0.3, …1.0]