Table 2 Evaluation metrics.

From: Early gastric cancer detection and lesion segmentation based on deep learning and gastroscopic images

Evaluation metrics

Calculation formula

Evaluation meaning

Precision

\({\text{Precision}} = \frac{TP}{{TP + FP}}\)

The percentage of all predictive positive samples correctly recognized as positive

Recall/sensitivity

\({\text{Recall}} = \frac{TP}{{TP + FN}}\)

The percentage of all actual positive samples that are correctly recognized as positive

Specificity

\({\text{Specificity}} = \frac{TN}{{TN + FP}}\)

The percentage of all actual negative samples correctly recognized as negative

Accuracy

\({\text{Accuracy}} = \frac{TP + TN}{{TP + FP + TN + FN}}\)

The percentage of samples with correct recognition results among all samples

F1 score

\(F1{\text{ s}}core = \frac{{{2} \times TP}}{2 \times TP + FP + FN}\)

A measure of a test’s accuracy by calculating the harmonic mean of the precision and recall

Intersection over union (IoU)

\(IoU = \frac{A \cap B}{{A \cup B}}\)

Predicted bounding box overlap with real bounding box

Average precision (AP)

None

The average of per-class precision

Precision-recall curves (PR curve)

None

Relationship curves of Precision and Recall under different thresholds