Transparent for WMF

rbuser

If i use a wmf-grafic with a transparent background (i controlled in
delphi), and set the transparent property of the graphics-object in RB, its
not handled correct. On the printer its printed with white backround (tested
on Postscript, also pcl-printer) and on the screen its in mixed color if the
underlaying area is a color instead of white.

any idea?

chris

digitalmetaphors

In general, WMFs do not support transparency. Use Bitmaps instead.

--
Cheers,

Alexander Kramnik
Digital Metaphors

rbuser

i could send you an transparent wmf (with no background).
Made in Powerpoint. The benefit is, that those graphics are very small
instead of bitmaps with 150 DPI. Also Bitmaps are depending on the
resoulution of the target device, so the printerdriver always resamples the
bitmap to scale it.

chris

"Alexander Kramnik (Digital Metaphors)" schrieb
im Newsbeitrag news:3d1c871f$1@dm500....

digitalmetaphors

Sure, send it to support@digital-metaphors.com and I'll be happy to try it
out.

--
Cheers,

Alexander Kramnik
Digital Metaphors

rbuser

i had send the WMF (J0251301.WMF) to the RB supportmail-address.
thank you
chris


"Alexander Kramnik (Digital Metaphors)" schrieb

digitalmetaphors

WMFs do not store alpha values so it is not possible to do true
transparency. The way PowerPoint handles this, I think, is it uses the first
pixel in the array as the transparent color, in this case white. It then
creates a mask (in this case the mask would surround all the non-white
pixels in the image), and gives the bits in the mask an alpha of zero and
the bits outside the mask an alpha of one, thus creating an illusion of a
transparent background when rendered. You can take a look at the Draw method
of TBitmap which does essentially the same thing. Unfortunately, RB does not
do anything this elaborate. RB handles transparency by simply rendering the
image to the canvas using the SrcAnd operator which in essence treats the
pixel values themselves as alpha values (they play a double role). Therefore
in instances like this you do not get the expected behavior like you are
seeing in PowerPoint.

--
Cheers,

Alexander Kramnik
Digital Metaphors

rbuser

I have a situation where I am trying to print a transparent bitmap and
everything works fine. The preview looks great but when I try to print the
program hangs. I have to forcibly exit the application.

Any suggestions? Thanks.

"Alexander Kramnik (Digital Metaphors)" wrote
in message news:3d1c871f$1@dm500....

digitalmetaphors

Most printers do not support transparency very well, if at all. Install the
latest pritner driver available and try toggling DirectDraw to true on the
TppImage component.


Cheers,

Jim Bennett
Digital Metaphors