Annoying copyPixels problem, please help

Question

Hi
I have a problem using copyPixels command.
My task is following:
1) I have an image castmember with an png imported, that
contains some
number of image objects (for example 10 letters). This image
has alpha
channels
2) I need to create another image containing just a part of
this letters,
for example 2,4 and 8 letter
3) I create new image Object and use a copyPixels command to
copy the
letters i need from original to destination image
4) But, here the problem - if I copy the letters on empty
image (with no
backgroundimage) I get problem with alphachannels - they
became "broken", I
mean, alpha channels are not more transparent es they shell
be, but shey are
shown as white (grey) tattered spots under letters
5) when before copying the letters I copy to thtn new image
some background
image, and then copy letters - they are shown correct - the
alphachannelw
are OK
6) when I copy a background image, that is smaller then
letters, then the
part, where copied letter lies over background, is correkt,
and the part of
letter, copied over empty space is "not beautifull"
I tried to play with parameters of CopyPixels (maskImage,
maskOffset,
something with extractAlpha, useAlpha) but with no success
Can anyone help me with this
I need just a line of correct lingo-code?
Or is this a problem of Director?
Thanx in advance
ANY HELP WILL BE APPRECIATED
Jorg

Answer 1

Hi Ben.
Thank you very much vor your replay
but I still can get it
Here the code
on testAlphaChannels sourceImage, cNewWidth, cNewHeight,
pRects
cSourceAlphaImage=sourceImage.extractAlpha()
newImage = image(cNewWidth, cNewHeight, 32)
newImage.useAlpha = FALSE
newAlphaImage = image(cNewWidth, cNewHeight, 8)
repeat with i=1 to pRects.count
destRect=......
newImage.copyPixels(sourceImage, destRect, pRects
newAlphaImage.copyPixels(cSourceAlphaImage, destRect,
pRects,
[#ink:#darkest])
end repeat
newImage.useAlpha = TRUE
newImage.setAlpha(newAlphaImage)
textMember = new(#bitmap)
textMember.image=newImage
end
But the result is not correct. O my example
http://www.lvivmedia.com/fontPr/Fontproblems3.jpg
image to the left is
created on background image, and image to the right - with
code above
What is wrong in the code, I quoted above?
Any help will be appreciated
Jorg
"duckets" <[email protected]> wrote in
message
news:ekhekq$c6g$[email protected]..
> I think this is what you'll have to do:
>
>
>
> Do the copypixels command as per your 2nd result example
(where "no
background
> image is used") using destImage.useAlpha = false.
>
> Create a new image as a blank alpha channel image (8
bit, #greyscale)
>
> Repeat the same copypixels commands for each number, but
this time the
source
> image is 'sourceAlphaImage', and the dest Image is this
new alpha image.
And
> the crucial part, use: [#ink:#darkest] for these
operations. This is
because
> you are merging greyscale images which represent the
alpha channels of
each
> letter. The darker parts are more opaque, and the
lighter parts are more
> transparent, so you always want to keep the darkest
pixels with each
copypixels
> command.
>
> hope this helps!
>
> - Ben
>
>
>
>