Hi Aman,

Could you post a minimal example? I've tried the following and it seems to work fine on my machine:

```python

>>> import numpy as np

>>> im = np.random.rand(5, 5)

>>> im[0, 0] = -1

>>> im[1, 1] = 1

>>> from skimage import morphology as mor, filter as fil

>>> selem = mor.disk(2)

>>> med = fil.rank.median(im, selem)

>>> med

array([[220, 220, 180, 216, 166],

[220, 180, 216, 200, 200],

[126, 180, 171, 180, 200],

[119, 126, 155, 171, 216],

[104, 119, 126, 171, 171]], dtype=uint8)

```

Also, please post the version of scikit-image you're using.

But anyway, off the top of my head, no, I don't have any clear idea of what's going wrong!

Juan.

On Sat, Feb 1, 2014 at 9:15 AM, Aman Thakral <aman.thakral@gmail.com> wrote:

Hi all,

I'm currently trying to use a median filter on my data, an am getting an error that I can't seem to debug.

I'm taking the difference of two images (both numpy.float64), scaling them between -1 and 1, and trying to apply a median filter. My image satisfies the conditions for being between -1 and 1 when I do the following test:

print diff.min()/dmax < -1.0 -> returns False (LHS evals to -1.0)
print diff.max()/dmax > 1.0 -> returns False (LHS evals to 0.663919388648)

The statement causing the error:

filtered = fltr.median(diff/dmax, selem)

where diff is my difference, and dmax is my scaling adjustment, selem is a disk of radius 2

This gives me the following traceback.

Traceback (most recent call last):

File "/home/clustering.py", line 138, in image_ratio
filtered = fltr.median(diff/dmax/2.+0.5, selem, mask=m.astype(np.bool))
File "/usr/local/lib/python2.7/dist-packages/skimage/filter/rank/generic.py", line 369, in median
out=out, mask=mask, shift_x=shift_x, shift_y=shift_y)

File "/usr/local/lib/python2.7/dist-packages/skimage/filter/rank/generic.py", line 71, in _apply
out_dtype)
File "/usr/local/lib/python2.7/dist-packages/skimage/filter/rank/generic.py", line 34, in _handle_input

image = img_as_ubyte(image)
File "/usr/local/lib/python2.7/dist-packages/skimage/util/dtype.py", line 358, in img_as_ubyte
return convert(image, np.uint8, force_copy)
File "/usr/local/lib/python2.7/dist-packages/skimage/util/dtype.py", line 191, in convert
raise ValueError("Images of type float must be between -1 and 1.")
ValueError: Images of type float must be between -1 and 1.

Has anyone else experienced this problem before? I tried searching in the groups, but couldn't find anything relevant.

Any help would be greatly appreciated!

Thanks,
Aman

--
You received this message because you are subscribed to the Google Groups "scikit-image" group.
To unsubscribe from this group and stop receiving emails from it, send an email to scikit-image+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.