On Wed, Aug 26, 2009 at 11:49 PM, Mark Wendell<mark.wend...@gmail.com> wrote:
> Figured this much out: if I do an np.copy of the original array to a
> new array, then I can edit individual 'color' values with impunity. So
> I guess the original array from the pil object still shares memory
> with that image object somehow, making it unwritable?
>
> thanks
> Mark
>
> On Wed, Aug 26, 2009 at 7:48 PM, Mark Wendell <mark.wend...@gmail.com> wrote:
>>
>> Hi all - I'm playing with editing image data converted from PIL objects, and
>> running into a situation where numpy tells me that an 'array is not
>> writable'. Not sure I understand what that means, or how to get around it.
>> Here's a sample interactive session:
>>
>> >>> import Image
>> >>> import numpy as np
>> >>> im = Image.open("rgb.0001.jpg")
>> >>> a = np.asarray(im)
>> >>> a.shape
>> (512, 512, 3)
>> >>> a.dtype
>> dtype('uint8')
>> >>> a[0,0,0]
>> 254
>> >>> a[0,0,0] = 10
>> Traceback (most recent call last):
>> File "<stdin>", line 1, in <module>
>> RuntimeError: array is not writeable
>>
>>
>> Any help appreciated. Thanks,
>> Mark
>>
>> PIL 1.1.6
>> numpy 1.2.1
>> Ubuntu 9.04
>>
Hi Mark,
I don't really know the specifics of why your array isn't writeable
(someone will have a better answer and will correct me if I'm wrong),
but you could try to check if it's writeable by doing:
>>> a.flags # or a.flags.writeable
And check the value of writeable. It might be as simple as setting
a.flags.writeable = True, but then again there might be a good reason
why it's unwriteable. I don't really know.
Skipper
_______________________________________________
NumPy-Discussion mailing list
NumPy-Discussion@scipy.org
http://mail.scipy.org/mailman/listinfo/numpy-discussion
