Time multiplexed WAV Colour Standard

[AncientBrit]

>Dr.Z

Many thanks for the feedback,

Kind regards,

Graham

[gary]

>Gary,

I hadn't realised what a can of worms I was opening!!

There's more to this than I had imagined.

As a start if you could give me more info on the 10kHz FIR and decimation process (and pseudo code if available) it would tie in with my latest task. At the moment I soften the cropped Web image by a simple averaging process plus judicious de-focusing of the camera!

I too have found problems with lack of processing speed but VB was never known for speed (sorry C, C# etc is a black art for me!!).

I have used Safe Arrays in the past to improve plotting to screen, but pixel value computation still remains an issue.

The DLL would be extremely helpful but you of course you will need to know what to include and at the moment I can't advise since I'm feeling my way forward.

Thanks you for your prompt response and very helpful comments,


Kind regards,

Graham

I don't use C# either (too much like java for my liking), I actually use Visual C++.

Here is some VB code demonstrating the principles of bilinear image resizing and NBTV decimation and interpolation.

I have applied them to B&W here but they easily extend to colour (luminosity, R, G, B all processed separately)

This is my first ever VB app so it will probably look a little strange to you and is probably full of errors but the principles should be fairly obvious, and of course there are endless, and probably better, ways to do all of things...

I also attach your application modified a little to show how to use the CxImage library. Let me know if you want to pursue this method.

[AncientBrit]

>Gary,

That's very useful and helpful.

Many thanks.


I'm just getting my head around the concepts of DSP filtering. With little maths I rely on coded examples which I can adapt (bodge).


(I might be back for more help!)


Kind regards,


Graham

[AncientBrit]

>Gary,

Just a follow up now that I've had a chance to unpack and run the two software examples. In a word "amazing". The results are fantastic.

I can use your examples as a tutorial whilst I get my head around the principles.

You must have spent a considerable amount of time putting that together.
Again many thanks!

You'll be using Visual Basic from now on then! (I don't think!!)


Kind regards,


Graham

[gary]

I hope you find it useful Graham.

I must re-iterate that the low order of the windowed-sinc filter is down to Klaas, I was using a much higher order filter and getting marginally worse results (due to ringing) even though technically it was the correct approach. Reducing the order minimises the ringing, and if the penalty is some aliasing it doesn't seem to present itself as an artifact in the picture.

I don't mind knowing a bit of VB as there is a lot of source code out there in which it is written and it certainly helps to port it if you know the semantics. I have just never gotten around to it.

I am not a snob when it comes to programming languages, I spent many many hours programming in BASIC on my old System 80 (TRS 80 clone) and there is a lot you can do with it.

I have also written quite a lot in FORTRAN, PASCAL, Java, LISP, and even some C#. I love OOP and C++, but if an edict came down from on high that there must be only ONE language then I would choose straight C. There is nothing you can't do with it, you just need a little self discipline (in cleaning up after yourself). You can learn it in a day and you would never regret it.

Cheers

Gary

[AncientBrit]

>Gary,

You're a linguist!!

I'll make no further comparisons of language, it'll only provoke debate!!


Kind regards,


Graham