[magick-users] Compositing using DissolveCompositeOp

[Elie Zedeck RANDRIAMIANDRIRAY]

Thanks Pete.

But all these C functions, I really don't know their equivalence in 
Magick++. What I did is scanning a PixelPacket, and then altering the 
.opacity member using the formula:

newOpacity = oldImagePixelPacket[column].opacity * (percent / 100);

Which I think is the same as what you said.

Pete Whatever wrote:
> Hi Elie,
>
>   
>> it requires a parameter for the dissolve factor.
>>     
>
> You can get around this as described by Anthony in
> http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=12014
>
> e.g. if you want to dissolve by 30%, you multiply the alpha channel by 30% and then do an Over composite:
>
> MagickEvaluateImageChannel(mw2,AlphaChannel,MultiplyEvaluateOperator,0.3);
> MagickCompositeImage(mw1,mw2, OverCompositeOp,0,0);
>
>
> Best Wishes
> Pete
>
>
> --- On Wed, 10/29/08, Elie Zedeck RANDRIAMIANDRIRAY <rez at eliezedeck.com> wrote:
>
>   
>> From: Elie Zedeck RANDRIAMIANDRIRAY <rez at eliezedeck.com>
>> Subject: [magick-users] Compositing using DissolveCompositeOp
>> To: magick-users at imagemagick.org
>> Date: Wednesday, October 29, 2008, 11:48 PM
>> Hi guys,
>>
>> I couldn't find in the Documentation any ways to use
>> the 
>> DissolveCompositeOp, as normally, it requires a parameter
>> for the 
>> dissolve factor.
>>
>> Anyone knows how to do this?
>>
>> Thanks,
>> Elie Zedeck.
>> _______________________________________________
>> Magick-users mailing list
>> Magick-users at imagemagick.org
>> http://studio.imagemagick.org/mailman/listinfo/magick-users
>>     
>
>
>       
>
>