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From: Paul A Bristow (pbristow_at_[hidden])
Date: 2007-01-10 13:39:26

>-----Original Message-----
>From: boost-bounces_at_[hidden]
>[mailto:boost-bounces_at_[hidden]] On Behalf Of Kevin Lynch
>Sent: 10 January 2007 16:56
>To: boost_at_[hidden]

>Paul A Bristow wrote:
>> This case suggests that we should try harder to ensure that
>ALL the Boost files contain the license terms. I see from the reports
>> that there are thousands of Boost files that do not have
>this (.png, xml?). How can one embed copyright into .png files?
>It's certainly possible with the ImageMagick toolkit, if the
>file format
>supports embedded comments:
>There are probably other ways, but I know that ImageMagick is portable
>to Unix and Windows boxes, has a set of standard command line
>tools, and
>also has a C++ binding (although I've never used it myself)

On further investigation, I find that there is provision in the specification:

Portable Network Graphics (PNG) Specification (Second Edition)
Information technology - Computer graphics and image processing - Portable Network Graphics (PNG): Functional specification. ISO/IEC
15948:2003 (E)
W3C Recommendation 10 November 2003 Introduction

PNG provides the tEXt, iTXt, and zTXt chunks for storing text strings associated with the image, such as an image description or
copyright notice. Keywords are used to indicate what each text string represents. Any number of such text chunks may appear, and
more than one with the same keyword is permitted. Keywords and text strings

The following keywords are predefined and should be used where appropriate.
Title Short (one line) title or caption for image
Author Name of image's creator
Description Description of image (possibly long)
Copyright Copyright notice
Creation Time Time of original image creation
Software Software used to create the image
Disclaimer Legal disclaimer
Warning Warning of nature of content
Source Device used to create the image
Comment Miscellaneous comment

It would be nice to complete many of these items for Boost documentation.

In theory, Adobe Photoshop Elements 2.0 (used to convert from .ps) has boxes for this information: File info and if I complete them,
it can be read back and a c symbol appears with the filename on the Window banner, and if I save as a pdf it can be saved and

BUT - bad news - if I save as .png and re-open, the info is lost :-((

(If anyone can confirm that this feature works on later versions, I'd like to know).

So it looks as though we need to use another tool to copyright our graphs :-(


Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
+44 1539561830 & SMS, Mobile +44 7714 330204 & SMS

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