[Image-SIG] Information about PythonMagick
Don Rozenberg
don.rozenberg at gmail.com
Sun Sep 11 23:52:40 CEST 2005
Fredrik Lundh wrote:
> Don Rozenberg wrote:
>
>
>>My interest arises because I want to manipulate the image in ways that
>>are not canned in PIL; I think that I want to get at the pixels to
>>implement my own image transformations.
>
>
> slow:
>
> value = im.getpixel((x, y))
> im.putpixel((x, y), value)
>
> faster:
>
> values = im.getdata()
> im.putdata(values)
>
> fastest:
>
> http://effbot.org/zone/pil-numpy.htm
> http://effbot.org/imagingbook/imagemath.htm (in 1.1.6)
>
> (note that Python's not well-suited for writing pixel-by-pixel
> algorithms; the more you can build on existing primitives, the
> faster your program gets. on the other hand, you can always
> start in pure python, and migrate to C/C++ or Pyrex or Inline
> C when you're done experimenting)
>
> </F>
>
>
>
> _______________________________________________
> Image-SIG maillist - Image-SIG at python.org
> http://mail.python.org/mailman/listinfo/image-sig
>
Hi,
It was my intention to experiment in python and then go to a faster
implementation.
Following up your mention of 1.1.6, I downloaded and built
Imaging-1.1.6a0.tar.gz; however, when I ran 'python selftest.py' I got
two failures:
*****************************************************************
Failure in example: im = ImageMath.eval("float(im + 20)",
im=im.convert("L"))
from line #116 of selftest.testimage
Exception raised:
Traceback (most recent call last):
File "./doctest.py", line 499, in _run_examples_inner
exec compile(source, "<string>", "single") in globs
File "<string>", line 1, in ?
File "PIL/ImageMath.py", line 200, in eval
out =__builtin__.eval(expression, args)
File "<string>", line 0, in ?
TypeError: __float__ returned non-float (type instance)
*****************************************************************
Failure in example: im.mode, im.size
from line #117 of selftest.testimage
Expected: ('F', (128, 128))
Got: ('RGB', (128, 128))
1 items had failures:
2 of 57 in selftest.testimage
***Test Failed*** 2 failures.
*** 2 tests of 57 failed.
I am running python 2.4.1 on a Knoppix/Debian system. I installed
python from source. It seems that these failures involve exactly what I
want to do. I then tried using python 2.3.5 and '57 tests passed.'.
Is this a known problem in python 2.4.1? I guess that I can do my thing
on the older version of python.
Thanks for your help,
Don
--
Don Rozenberg
707-882-3601
don.rozenberg at gmail.com
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