Re: error when using externalfigure

[Hans Hagen <pragma@wxs.nl>]

On 11/26/2012 11:00 AM, luigi scarso wrote:
> On Mon, Nov 26, 2012 at 10:50 AM, Hans Hagen <pragma@wxs.nl> wrote:
>> On 11/26/2012 10:36 AM, luigi scarso wrote:
>>>
>>> On Mon, Nov 26, 2012 at 10:20 AM, Pavel Dohnal <pavel.dohnal@twobits.cz>
>>> wrote:
>>>>
>>>> Hello,
>>>> I have a big context source file which contains pictures from different
>>>> sources. The problem is, that there are some pictures the context cannot
>>>> process. It displays an error message and ends. I run the context from
>>>> another script in batchmode. After finishing, the context creates a PDF
>>>> file, which contains this problematic picture but the pdf is broken. It
>>>> does
>>>> not have numbers in the table of contents and it is not arranged by
>>>> setup.
>>>> Here is a minimal example:
>>>> \starttext
>>>>
>>>> \externalfigure[http://cdn-locations-images.tripomatic.com/img-poi1295-5ZTynx-s.jpg][width=26.5mm]
>>>> \stoptext
>>>
>>>
>>>
>>> when I save the jpg  as eps from gimp
>>> I see
>>> width = 6096,00
>>> height=4064,00
>>>
>>> The first value is off for TeX.
>>
>>
>> if i print the values from the img object i get
>>
>> 17344.8pt
>> 11563.2pt
>>
>> so the problem is deep down in the jpg reader ... the image is crippled in
>> the sense that it has no valid resolution information
>>
>> something for hartmut to check in the img lib
>
> Hm, I'm not sure. It's an image that could be correct, but TeX cannot manage it.
> It has 240x160 pixels and 1ppi, so it's 6,096 meters x 4,06400meters
> and 6 meters are too much for TeX (which still has its limits around 5meters)
> It's ok to print poster maybe, but then  TeX  is not the right tool.

yes, but the 1,1 resolution prevents us from doing anything useful, i.e. 
we could for instance have something

if xresolution < 72 then xresolution = 72 end

but I'm not sure what the pdf backend will do as then the uses 
resolution for front and backend differ too much

i'll add an overflow check but keep in mind that in that case scaling is 
bases on the limited size

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                                           Hans Hagen | PRAGMA ADE
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