topic Conversion from aRGB format in Intel® Integrated Performance Primitives

Conversion from aRGB format

photo_tom — Thu, 18 Feb 2010 18:35:10 GMT

I have an image in memorythat is sourced inaRGB format and I need use some of the functionality in IPP. However, I do not see an efficient way to covert between aRGB of my imageto RGB0 formatused by IPPwithout exporting from my aRGB image to a file and then re-importing into IPP.

After looking at the help files for IPP, there does not seem to be another way to do it. Are there any suggestions?

Conversion from aRGB format

renegr — Fri, 19 Feb 2010 14:42:27 GMT

ippiSwapChannels_8u_C4IR

- or do you mean Adobe RGB? Then you need ICC processing which isn't part of IPP

Conversion from aRGB format

photo_tom — Fri, 19 Feb 2010 15:11:08 GMT

That looks like I might be able to get it to work, but it I'm not sure. I'm not understanding the documentation well.

However, you gave me an idea to wonder if I could do this with a shift. After downloading another help file, I found ippsLShiftC_32s_I function. If I run this shift 32bits left for 8 bits, I should get the pattern I need.

Thnaks for suggestion.

Conversion from aRGB format

Naveen_G_Intel — Sat, 20 Feb 2010 07:09:20 GMT

Hi,

Use ippiCopy_8u_AC4C3R, refer to ippiman.pdf, refer to Image Data Exchange and Initialization Functions

http://software.intel.com/sites/products/documentation/hpc/ipp/pdf/ippiman.pdf

Regards,

Naveen Gv

Conversion from aRGB format

Tamer_Assad — Sat, 20 Feb 2010 20:58:11 GMT

Hi Tom,

You have received the best answer from Naveen Gv (Intel).

For additional information, I have an extended discussion with Artem Vorobiev (Intel) please read this thread:(ippiYCbCr444ToYCbCr420_8u_C2P3R) is there any? + Y211)

URL: http://software.intel.com/en-us/forums/showthread.php?t=71620&o=d&s=lr

Regards,

Tamer

Conversion from aRGB format

renegr — Mon, 22 Feb 2010 09:57:20 GMT

If I understood it right, the problem is that the alpha channel is on the first byte - but ippiCopy_8u_AC4C3R assumes the alpha channel on the fourth byte. The A0C4C3R channel format isn't supported in Copy function. Furthermore it can't be executed inplace. So I think shifting or swapping channels is the more correct way. And both can be done inplace if speed is needed. According to ps_ippi.exe SwapChannels seems to be a little bit faster than shifting.

Conversion from aRGB format

photo_tom — Mon, 22 Feb 2010 16:16:58 GMT

Thanks for update, that is sort of what I was wondering. I think I'm going to go with shift/swap channels, then copy in final program.