Table 3 The effect of sampling negative instances randomly versus a clustering approach. Under each sampling strategy, we compare various methods to handle class imbalance.

From: Overcoming the limitations of patch-based learning to detect cancer in whole slide images

Negative sampling

Weighing

Dice (% overlap)

Error in \(\sqrt{{d}_{1}{d}_{2}}\)

Confusion matrix

K-means

\(\propto \)

59

2.58

\(\left(\begin{array}{cc}5& 3\\ 0& 12\end{array}\right)\)

\(\frac{1}{\propto }\)

58

3.29

\(\left(\begin{array}{cc}3& 5\\ 0& 12\end{array}\right)\)

\(=\)

58

2.56

\(\left(\begin{array}{cc}3& 5\\ 0& 12\end{array}\right)\)

Minority oversam-pling

75

1.69

\(\left(\begin{array}{cc}6& 2\\ 0& 12\end{array}\right)\)

Random

\(\propto \)

64

1.90

\(\left(\begin{array}{cc}4& 4\\ 1& 11\end{array}\right)\)

\(\frac{1}{\propto }\)

61

3.55

\(\left(\begin{array}{cc}3& 5\\ 0& 12\end{array}\right)\)

\(=\)

58

2.21

\(\left(\begin{array}{cc}2& 6\\ 0& 12\end{array}\right)\)

Minority oversam-pling

57

3.18

\(\left(\begin{array}{cc}3& 5\\ 1& 11\end{array}\right)\)

None

\(\propto \)

30

15.37

\(\left(\begin{array}{cc}0& 8\\ 0& 12\end{array}\right)\)

\(\frac{1}{\propto }\)

30

14.58

\(\left(\begin{array}{cc}0& 8\\ 0& 12\end{array}\right)\)

\(=\)

26

16.33

\(\left(\begin{array}{cc}0& 8\\ 0& 12\end{array}\right)\)

Minority oversam-pling

30

15.25

\(\left(\begin{array}{cc}0& 8\\ 0& 12\end{array}\right)\)

  1. indicates using class weights in cross-entropy loss directly proportional to class distributions, = uses weights 1 for all classes. Each setting uses the EfficientNet-B0 framework, 256 as the tile stride, and only random cropping as data augmentation.