Colors changing when applying "transparent"

Colors changing when applying "transparent"

[Willi Egger]

Hi,

I would like to use transparnt colors in one of the documents. However the 
resulting color is different with transparent color. Could anyone try the 
following code twice setting the %-sign in front of the fill-statement:

\setupoutput[pdftex]
\starttext
\setupcolors[state=start]

\startuseMPgraphic{tBG}
         path p ;
         p := unitsquare xscaled \overlaywidth yscaled \overlayheight ;
         fill p withcolor \MPcolor{white}; % With normal colors, everything 
is fine (blue is really RGB(0,0,1)
         % fill p withcolor transparent("normal",.5,\MPcolor{white}); % 
This however results in fading of ALL of the colors...
\stopuseMPgraphic

\defineoverlay[textBG][\useMPgraphic{tBG}]

\setupbackgrounds[page][background=color,backgroundcolor=blue]
\setupbackgrounds[text][background=textBG]

\input tufte
\stoptext

I would expect that the optical appearance of blue shoud not change after 
application of the transparent color to the gray areq.

Regards Willi 

Re: Colors changing when applying "transparent"

[Hans Hagen]

At 09:20 25/11/2003, you wrote:
>\setupoutput[pdftex]
>\starttext
>\setupcolors[state=start]
>
>\startuseMPgraphic{tBG}
>         path p ;
>         p := unitsquare xscaled \overlaywidth yscaled \overlayheight ;
>         fill p withcolor \MPcolor{white}; % With normal colors, 
> everything is fine (blue is really RGB(0,0,1)
>         % fill p withcolor transparent("normal",.5,\MPcolor{white}); % 
> This however results in fading of ALL of the colors...
>\stopuseMPgraphic
>
>\defineoverlay[textBG][\useMPgraphic{tBG}]
>
>\setupbackgrounds[page][background=color,backgroundcolor=blue]
>\setupbackgrounds[text][background=textBG]
>
>\input tufte
>\stoptext

Looks like an acrobat bug to me; if you use gsview, it works ok; there are 
more problems with acrobat and transparencies, like

- no smoothing when a vector graphic is on top of a transparency
- disappearing characters (esp very big ones)
- funny flattener preview colors

One of the reasons for such problems is that there is no 'reset graphics 
state' operator and i guess that occasionally the acrobat graphic state 
stack gets messed up.

Hans



-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
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Re: Colors changing when applying "transparent"

[Willi Egger]

Hi Hans,

Indeed now I tried in Acrobat5 and the problem does not show up.

There is probably another bug to be reported:

I got a file, where with \startcombination ... \stopcombination two small 
pictures are placed next to each other. - When viewing the result in 
Acrobat6 everything looks ok. When printing the page, then the right 
picture will not show up on the print!

Kind regards Willi


At 10:37 25.11.2003, Hans wrote:
>At 09:20 25/11/2003, you wrote:
>>\setupoutput[pdftex]
>>\starttext
>>\setupcolors[state=start]
>>
>>\startuseMPgraphic{tBG}
>>         path p ;
>>         p := unitsquare xscaled \overlaywidth yscaled \overlayheight ;
>>         fill p withcolor \MPcolor{white}; % With normal colors, 
>> everything is fine (blue is really RGB(0,0,1)
>>         % fill p withcolor transparent("normal",.5,\MPcolor{white}); % 
>> This however results in fading of ALL of the colors...
>>\stopuseMPgraphic
>>
>>\defineoverlay[textBG][\useMPgraphic{tBG}]
>>
>>\setupbackgrounds[page][background=color,backgroundcolor=blue]
>>\setupbackgrounds[text][background=textBG]
>>
>>\input tufte
>>\stoptext
>
>Looks like an acrobat bug to me; if you use gsview, it works ok; there are 
>more problems with acrobat and transparencies, like
>
>- no smoothing when a vector graphic is on top of a transparency
>- disappearing characters (esp very big ones)
>- funny flattener preview colors
>
>One of the reasons for such problems is that there is no 'reset graphics 
>state' operator and i guess that occasionally the acrobat graphic state 
>stack gets messed up.
>
>Hans
>
>
>
>-------------------------------------------------------------------------
>                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
>                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
>  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
>-------------------------------------------------------------------------
>                        information: http://www.pragma-ade.com/roadmap.pdf
>                     documentation: http://www.pragma-ade.com/showcase.pdf
>-------------------------------------------------------------------------
>
>_______________________________________________
>ntg-context mailing list
>ntg-context@ntg.nl
>http://www.ntg.nl/mailman/listinfo/ntg-context

Re: Colors changing when applying "transparent"

[Hans Hagen]

At 12:46 25/11/2003, you wrote:

>Indeed now I tried in Acrobat5 and the problem does not show up.
>
>There is probably another bug to be reported:
>
>I got a file, where with \startcombination ... \stopcombination two small 
>pictures are placed next to each other. - When viewing the result in 
>Acrobat6 everything looks ok. When printing the page, then the right 
>picture will not show up on the print!

there are indeed some bugs with regard to xforms; you can try to print 'as 
image'

Hans

Re: Colors changing when applying "transparent"

[Willi Egger]

Hoi Hans,

Bedankt voor de link....

Het ziet er steeds gelikter uit.

Op pagina 156 staat "Haas'sche Schriftgiesserei" Het apostroofje is 
vervangen door een kapitaal S-caron. -  Dit is nogal raar omdat er op 
verschillende andere plekken in dit deel van het boek apostroven gebruikt 
worden. ??

Op pagina 164 laatste paragraaf: ... the single easiest way. - Ik denk, dat 
"single" weg kan.
De "common consensus" > TeX Live is commonly seen as the most easiest way 
to get up and running a TeX system.

Groet Willi

At 13:10 25.11.2003, Hans wrote:
>At 12:46 25/11/2003, you wrote:
>
>>Indeed now I tried in Acrobat5 and the problem does not show up.
>>
>>There is probably another bug to be reported:
>>
>>I got a file, where with \startcombination ... \stopcombination two small 
>>pictures are placed next to each other. - When viewing the result in 
>>Acrobat6 everything looks ok. When printing the page, then the right 
>>picture will not show up on the print!
>
>there are indeed some bugs with regard to xforms; you can try to print 'as 
>image'
>
>Hans
>
>_______________________________________________
>ntg-context mailing list
>ntg-context@ntg.nl
>http://www.ntg.nl/mailman/listinfo/ntg-context