# Flow Image Statistics

### From Endrov

In lack of a better name, these operations create local image statistics and features.

## Contents |

### Average, Rectangle

Calculate local average.

Complexity O(#pixels)

### Bilateral filter

Noise reducing Bilateral filter.

Complexity O(#pixels*pw*ph)

### Entropy circle/rectangle

Local entropy.

Complexity O(#pixels r^2) or O(#pixels*pw*ph)

### Kirsch filter

Edge detecting Kirsch operator.

Complexity O(#pixels)

### Kuwahara filter

Noise reducing Kuwahara filter.

Complexity O(#pixels)

### Percentile rectangle

Compute local percentile around every pixel. Percentile should be within [0,1] values outside will be clamped. Special cases:

- 0 Min
- 0.5 Median
- 1 Max

Complexity O(#pixels*pw*ph)

### Sum circle/rectangle

Local sum.

Complexity O(#pixels r^2) for circle and O(#pixels) for rectangle

### Variance circle/rectangle

Local variance.

Complexity O(#pixels r^2) for circle and O(#pixels) for rectangle