[pdftex] Image transparency

Hans Hagen pragma at wxs.nl
Thu Jun 21 15:51:09 CEST 2001

At 08:36 AM 6/21/01 -0300, George N. White III wrote:
>On Wed, 20 Jun 2001, Prof Brian D Ripley wrote:
>> On Wed, 20 Jun 2001, Wendy McKay wrote:
>> > What is wrong with jpegs or gifs?
>> gifs: patent issues.
>> jpeg: blurring and artefacts if used on line drawings or block colour
>>   diagrams.
>JPEG 2000, http://www.jpeg.org/JPEG2000.htm, uses wavelets and
>has greatly reduced the problem of artifacts.  I think it is very
>close to becoming official -- how long does it take Adobe to
>implement a new image standard?

interesting; do they reach a similar compression as djvu? 

>It is easy to generate PNG images with the same color LUT and pixel values
>as the GIF, but the colors using pdftex are not at all the same as those

are there better png libraries than the one currently used in pdftex? 

>Rather than trying to improve support for images in pdftex I would
>prefer to see better tools to generate PDF files with images that
>can be placed into pdftex documents.  It is useful to have the
>current basic PNG support for less demanding applications, but
>it would be difficult to provide access to the full image capabilities
>of PDF from pdeftex, and these capabilities are likely to change in
>the future to support things like JPEG 2000.

the number of compression schemes in pdf is not that large so it should be
possible to develop a decent set of filters, how good is the free stuff
that cna be used for that? Is there for instance real good [complete] and
free tiff->pdf conversion available? 

                                  Hans Hagen | PRAGMA ADE | pragma at wxs.nl
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