Whirl & Pinch Effect
"Whirl & Pinch" adds distortion effect to image/photo. It distorts the image by whirling and pinching, which are two common center-based, circular distortions. You can see samples behind.
Preview function is useful to preview the result.
![Whirl & Pinch Effect](images/whirl.png)
![Whirl & Pinch Effect](images/whirl2.png)
Samples:
![Whirl & Pinch Effect](images/whirl_a.png)
![Whirl & Pinch Effect](images/whirl_b.png)