[Image-SIG] OverflowError on image save

[Fredrik Lundh]

Does anyone have a (preferrably) small example, or a simple way to
create a broken file on a stock Windows XP machine?  An URL or an
off-list mail works fine.

</F>

On Fri, Mar 6, 2009 at 4:52 PM, Howard Lightstone
<howard at eegsoftware.com> wrote:
> This LOOKS like a bug in Windows XP which creates .BMP files via DirectX
> with an incorrect bitmap header size (54 vice 40).  Changing the 54 to 40
> makes the file readable again.  Most utilities seem to ignore this but
> Windows itself won't be able to 'read' it as a .BMP file.
>
> (using XP SP2 and DirectX 9.0c ... I haven't tried this on Vista yet)
>
> On Fri, Mar 6, 2009 at 5:50 AM, Wichert Akkerman <wichert at simplon.biz>
> wrote:
>>
>> The first image:
>>
>> >>> i=PIL.Image.open(open("/Users/wichert/Desktop/dont.bmp"))
>> >>> i
>> <PIL.BmpImagePlugin.BmpImageFile instance at 0x43f490>
>> >>> i.mode
>> 'RGB'
>> >>> i.size
>> (290, 4294967075L)
>> >>> i.tile
>> [('raw', (0, 0, 290, 4294967075L), 54, ('BGR', 872, -1))]
>>
>> and the second image:
>>
>> >>> i=PIL.Image.open(open("/Users/wichert/Desktop/dont2.bmp"))
>> >>> i.mode
>> 'RGB'
>> >>> i.size
>> (288, 4294967078L)
>> >>> i.tile
>> [('raw', (0, 0, 288, 4294967078L), 54, ('BGR', 864, -1))]
>>
>>
>> Regards,
>> Wichert.
>>
>> On 3/5/09 6:41 PM, Fredrik Lundh wrote:
>>>
>>> Can you print the following attributes for a broken file, before calling
>>> load:
>>>
>>>     pil_data.mode
>>>     pil_data.size
>>>     pil_data.tile
>>>
>>> </F>
>>>
>>> 2009/3/3 Wichert Akkerman<wichert at simplon.biz>:
>>>
>>>>
>>>> I have a small routine which tries to verify if an uploaded file is a
>>>> valid
>>>> image. It works like this:
>>>>
>>>>         image_data=StringIO(data)
>>>>         try:
>>>>             pil_data=PIL.Image.open(image_data)
>>>>         except IOError: # PIL abuses IOError to report parsing errors
>>>>             raise Invalid(self.message("bad_image", state),
>>>>                     value, state)
>>>>
>>>>         pil_data.load()
>>>>         (width,height)=pil_data.size
>>>>
>>>> For some images I get an OverflowError on the load() call:
>>>>
>>>> Module PIL.ImageFile:155 in load
>>>>
>>>>>>
>>>>>>   self.load_prepare()
>>>>>>
>>>>
>>>> Module PIL.ImageFile:223 in load_prepare
>>>>
>>>>>>
>>>>>>   self.im = Image.core.new(self.mode, self.size)
>>>>>>
>>>>
>>>> OverflowError: long int too large to convert to int
>>>>
>>>> I can not find any information as to what the problem might be. It seems
>>>> to
>>>> only occur for bmp files; jpeg and png appear to work correctly.
>>>>
>>>> This is using PIL 1.1.6 and Python 2.5 on a Linux system.
>>>>
>>>> Wichert.
>>>> <<                       self.map = None
>>>>
>>>>                self.load_prepare()
>>>>
>>>>                # look for read/seek overrides
>>>> <<           if not self.im or\
>>>>                   self.im.mode != self.mode or self.im.size !=
>>>> self.size:
>>>>                    self.im = Image.core.new(self.mode, self.size)
>>>>                # create palette (optional)
>>>>                if self.mode == "P":
>>>> _______________________________________________
>>>> Image-SIG maillist  -  Image-SIG at python.org
>>>> http://mail.python.org/mailman/listinfo/image-sig
>>>>
>>>>
>>>>
>>
>> _______________________________________________
>> Image-SIG maillist  -  Image-SIG at python.org
>> http://mail.python.org/mailman/listinfo/image-sig
>>
>
>
>
> --
> Howard Lightstone
> hlightstone at gmail.com
> howard at eegsoftware.com
>