This is currently possible by combining the following
transformations:

- Shift the image so that the centre is around the origin
- Rotate with N degrees
- Shift the image back

However, a single parameter would make this much easier! Would you
please file an issue on GitHub so that we can implement this?

In the meantime, the code:

```
from skimage import data
from skimage import transform
import numpy as np
import matplotlib.pyplot as plt
image = data.chelsea()
shift_y, shift_x = np.array(image.shape[:2]) / 2.
tf_rotate = transform.SimilarityTransform(rotation=np.deg2rad(30))
tf_shift = transform.SimilarityTransform(translation=[-shift_x, -shift_y])
tf_shift_inv = transform.SimilarityTransform(translation=[shift_x,
shift_y])
image_rotated = transform.warp(image, (tf_shift + (tf_rotate +
tf_shift_inv)).inverse)
plt.imshow(image_rotated)
plt.show()
```