POV-Ray : Newsgroups : povray.advanced-users : Write to image metadata Server Time
16 Apr 2024 16:37:16 EDT (-0400)
  Write to image metadata (Message 1 to 5 of 5)  
From: Mike Horvath
Subject: Write to image metadata
Date: 8 Feb 2015 13:27:04
Message: <54d7aa78$1@news.povray.org>
I think this was asked already a while ago, but are there any plans on 
letting people write to image metadata from within POVray?

Thanks!


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From: Le Forgeron
Subject: Re: Write to image metadata
Date: 8 Feb 2015 14:15:36
Message: <54d7b5d8$1@news.povray.org>
Le 08/02/2015 19:27, Mike Horvath a écrit :
> I think this was asked already a while ago, but are there any plans on
> letting people write to image metadata from within POVray?
> 
> Thanks!

Available room in metadata (including number of bytes and encoding)
varies a lot from one format to another.

So far, povray writes to metadata, its own choice of data, as something
like 4 lines, up each to 80 characters (no line feed, no tab). (that's
kind of least common form for all formats that support metadata)

First two lines are used for platform & compiler, but the last 2 lines
are kind of opened, if you compile with METADATA_COMMENT_3 and
METADATA_COMMENT_4 to be either a constant string or (more interesting)
what ever string-returning-function(s) that you want.

That is for the comment part.
Other metadata such as software, date and render time might get inside
the part written, but sometime there is no such place for such info.

So, you're just one custom compilation away from something you might
want. Or you want to be more precise about your metadata.

(All above only for 3.7 and onwards)


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From: Mike Horvath
Subject: Re: Write to image metadata
Date: 8 Feb 2015 14:23:53
Message: <54d7b7c9$1@news.povray.org>
On 2/8/2015 2:15 PM, Le_Forgeron wrote:
> Le 08/02/2015 19:27, Mike Horvath a écrit :
>> I think this was asked already a while ago, but are there any plans on
>> letting people write to image metadata from within POVray?
>>
>> Thanks!
>
> Available room in metadata (including number of bytes and encoding)
> varies a lot from one format to another.
>
> So far, povray writes to metadata, its own choice of data, as something
> like 4 lines, up each to 80 characters (no line feed, no tab). (that's
> kind of least common form for all formats that support metadata)
>
> First two lines are used for platform & compiler, but the last 2 lines
> are kind of opened, if you compile with METADATA_COMMENT_3 and
> METADATA_COMMENT_4 to be either a constant string or (more interesting)
> what ever string-returning-function(s) that you want.
>
> That is for the comment part.
> Other metadata such as software, date and render time might get inside
> the part written, but sometime there is no such place for such info.
>
> So, you're just one custom compilation away from something you might
> want. Or you want to be more precise about your metadata.
>
> (All above only for 3.7 and onwards)
>
>


OK, thanks. Yes, I meant the comment part. I just checked a Windows 7 
PNG file and don't see anything besides besides color depth, format, 
dimensions, etc.. XnView doesn't show the comment either.


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From: Le Forgeron
Subject: Re: Write to image metadata
Date: 9 Feb 2015 02:44:19
Message: <54d86553$1@news.povray.org>
Le 08/02/2015 20:24, Mike Horvath a écrit :
> On 2/8/2015 2:15 PM, Le_Forgeron wrote:
>> Le 08/02/2015 19:27, Mike Horvath a écrit :
>>> I think this was asked already a while ago, but are there any plans on
>>> letting people write to image metadata from within POVray?
>>>
>>> Thanks!
>>
>> Available room in metadata (including number of bytes and encoding)
>> varies a lot from one format to another.
>>
>> So far, povray writes to metadata, its own choice of data, as something
>> like 4 lines, up each to 80 characters (no line feed, no tab). (that's
>> kind of least common form for all formats that support metadata)
>>
>> First two lines are used for platform & compiler, but the last 2 lines
>> are kind of opened, if you compile with METADATA_COMMENT_3 and
>> METADATA_COMMENT_4 to be either a constant string or (more interesting)
>> what ever string-returning-function(s) that you want.
>>
>> That is for the comment part.
>> Other metadata such as software, date and render time might get inside
>> the part written, but sometime there is no such place for such info.
>>
>> So, you're just one custom compilation away from something you might
>> want. Or you want to be more precise about your metadata.
>>
>> (All above only for 3.7 and onwards)
>>
>>
>
>
> OK, thanks. Yes, I meant the comment part. I just checked a Windows 7
> PNG file and don't see anything besides besides color depth, format,
> dimensions, etc.. XnView doesn't show the comment either.

Now testing the windows binary of povray 3.7: the comments are there, at 
least gimp shows them in Image/Property/Comments :

Render Date: 2015-02-09 07:36:43Z
Platform: i686-pc-win-sse2
Compiler: msvc 10

Within XnView, I can "Edit"/"Edit comment" and see that it is there too 
(but on 2 lines instead of 3...or rather a single line: in fact 
line-feed are not displayed correctly, the small-rectangle glyph is 
displayed instead)

-- 
Just because nobody complains does not mean all parachutes are perfect.


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From: Mike Horvath
Subject: Re: Write to image metadata
Date: 9 Feb 2015 14:59:45
Message: <54d911b1$1@news.povray.org>
On 2/9/2015 2:44 AM, Le_Forgeron wrote:
> Now testing the windows binary of povray 3.7: the comments are there, at
> least gimp shows them in Image/Property/Comments :
>
> Render Date: 2015-02-09 07:36:43Z
> Platform: i686-pc-win-sse2
> Compiler: msvc 10
>
> Within XnView, I can "Edit"/"Edit comment" and see that it is there too
> (but on 2 lines instead of 3...or rather a single line: in fact
> line-feed are not displayed correctly, the small-rectangle glyph is
> displayed instead)
>

I checked another file and the comment was present in that one.


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