https://community.intel.com/t5/Intel-Integrated-Performance/Result-of-alpha-composition/m-p/967584#M20314 Hello, <BR /><BR />I'm using AlphaComp_8uAC4R function. I want to be able to work in both modes : alpha-premultiplied mode and not premultiplied mode.<BR />From my tests, it seems that the results of the function with ippAlphaOver are alpha-premultiplied :<BR />I've the same results with <BR />AlphaPremul(im1);<BR />AlphaPremul(im2);<BR />AlphaComp(im1,im2,ippAlphaOverPremul)<BR />and <BR />AlphaComp(im1,im2,ippAlphaOver)<BR /><BR />Is it the expected behaviour ?<BR />Is there a inverse function for AlphaPremul I could use to transform the result ?<BR /><BR />Thanks<BR /><BR />Raphael Wed, 10 Mar 2004 01:19:49 GMT rdebeugny 2004-03-10T01:19:49Z https://community.intel.com/t5/Intel-Integrated-Performance/Result-of-alpha-composition/m-p/967584#M20314 Hello, <BR /><BR />I'm using AlphaComp_8uAC4R function. I want to be able to work in both modes : alpha-premultiplied mode and not premultiplied mode.<BR />From my tests, it seems that the results of the function with ippAlphaOver are alpha-premultiplied :<BR />I've the same results with <BR />AlphaPremul(im1);<BR />AlphaPremul(im2);<BR />AlphaComp(im1,im2,ippAlphaOverPremul)<BR />and <BR />AlphaComp(im1,im2,ippAlphaOver)<BR /><BR />Is it the expected behaviour ?<BR />Is there a inverse function for AlphaPremul I could use to transform the result ?<BR /><BR />Thanks<BR /><BR />Raphael Wed, 10 Mar 2004 01:19:49 GMT https://community.intel.com/t5/Intel-Integrated-Performance/Result-of-alpha-composition/m-p/967584#M20314 rdebeugny 2004-03-10T01:19:49Z https://community.intel.com/t5/Intel-Integrated-Performance/Result-of-alpha-composition/m-p/967585#M20315 <DIV>Dear Customer,<BR />If you would like further investigation on those Intel IPP functions, please submit an issue with details and test casesthrough Intel Premier Support at <A href="https://premier.intel.com" target="_blank">https://premier.intel.com</A>.</DIV> <DIV><BR />Thanks,<BR />Ying</DIV> <DIV>Intel IPP Support</DIV> Tue, 16 Mar 2004 05:50:57 GMT https://community.intel.com/t5/Intel-Integrated-Performance/Result-of-alpha-composition/m-p/967585#M20315 Ying_S_Intel 2004-03-16T05:50:57Z