Comments for Ananth's very own blog

Comment on OpenCL.Net published! by Vio

Vio — Thu, 02 Sep 2010 12:05:34 +0000

Thank you for your answer,
I still have some question,is not very clear to me how to do the query.
I have created 2 DataParallelArray2D, one for each bitmap:

arrayNo1 = new DataParallelArray2D(provider, values)
arrayNo2 = new DataParallelArray2D(provider, values2)

(where values and values2 are byte[,] variables containing the bitmap ).

So at this point I have to create the query which compares the 2 arrays( and returns true/false) but is not very clear to me how to do it…

Comment on OpenCL.Net published! by ananth

ananth — Wed, 01 Sep 2010 20:15:32 +0000

Yes, you can definitely compare two bitmaps. All you’d need to do is to copy the data into a DataParallelArray2D using LockBits and Scan0 (look for Bitmap manipulation, you should find plenty of tips there) and then write a the comparison query as usual. Look at the Game of Life sample which, processes 2D images and extrapolate to compare two images like so: from p1 in image from p2 in image2 select (some similarity metric) – would process corresponding pixels in both images. Hope that helps.

Comment on OpenCL.Net published! by Vio

Vio — Mon, 30 Aug 2010 11:28:42 +0000

Hi,
I have a question for you. In my current project at work place I have to compare bitmaps, and it has to be very fast so I am thinking of doing it on the GPU. Searching for solutions i came around Brahma.
My question is, can i compare 2 bitmaps on the GPU using this framework? And if so, cand u point me an example or something?I saw in the samples of the framework that u compared floats and some vectors.
Any help is really appreciated.
Thanks

Comment on OpenCL.Net published! by ananth

ananth — Mon, 16 Aug 2010 19:46:06 +0000

AFAIK, C# 4.0 only has classes that allow creation of an expression tree from multi-line lambdas (BlockExpressions and stuff), but the C# 4.0 compiler will not accept a multiline lambda and implicitly convert it into an expression tree, which is what I envision. "The C# and Visual Basic compilers can generate expression trees only from expression lambdas (or single-line lambdas). It cannot parse statement lambdas (or multi-line lambdas). For more information about lambda expressions in C#, see Lambda Expressions (C# Programming Guide); for Visual Basic, see Lambda Expressions (Visual Basic)." from MSDN. I did consider workarounds like the one outlined here, but dropped it for the time-being, opting to wait for the C# team to add it in, hopefully in C# 5.0.

Comment on OpenCL.Net published! by Fahad

Fahad — Mon, 16 Aug 2010 05:35:14 +0000

For multi-line lambda, have you checked C# 4.0? The dynamic languages are interpreted with the new LINQ Expressions V2.

-Fahad

Comment on General by ananth

ananth — Tue, 10 Aug 2010 15:56:03 +0000

Sure, have PM’ed you my info.

Comment on OpenCL.Net published! by ananth

ananth — Tue, 10 Aug 2010 15:54:04 +0000

Yes, I am working on Brahma as I work on these bindings. Unfortunately, I spent a lot of time debating if I wanted to move Brahma to F# (to use quotations) – and delayed the release, but I’ve decided it’s not quite time yet. I can still do a lot with LINQ.

I only wish the C# team had seen it fit to add expression from multiline lambda support. If anyone reading this has pull with that team, I would urge you to help make it happen. Brahma can REALLY go places then.

Comment on General by Andy

Andy — Mon, 09 Aug 2010 02:15:27 +0000

Hey Ananth, This is Andy from the .Net User Group. I’ve got a possible speaking opportunity for you to talk about Brahma if you’re interested.

Thanks,
-Andy

Comment on OpenCL.Net published! by tom berg

tom berg — Thu, 05 Aug 2010 00:50:58 +0000

I’ve been watching your work eagerly! Do you have Brahma using these bindings yet?

Comment on OpenCL.Net published! by serge

serge — Thu, 29 Jul 2010 05:31:25 +0000

Nice work man. Just what I was looking for. Thank you!