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Hello everybody,
I do have a question about reading image data from avi-files using C#.
I have to do some image processing on the image data. Thus, I need the image data itself and not just a Media Player. I already found some code "C# Wrapper" that uses the avifil32.dll that works quite well. However, the .dll seems to be limited to quite a few numbers of avi-codecs. The dll often fails.
I found the "DirectShow Media Player in C#" that works well. It reads in all kinds of avi-codecs using the QuartzTypeLib.dll. However, I do not understand how I reach the image-data itself. It seems to be capsuled within the dll. Even there is the IBasicVideo2.GetCurrentImage-Function I don't know how to use it.
Does anyone know, how I can reach the RGB-values of avi-files that are created by different codecs?
Maybe anyone has an idea?
Joerg
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Write an article 
Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
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What does it say about programming questions (in red) when you write a message?
Go to the correct forum.
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I'm not really asking something about programming. I'm asking if there's something similar around like a simple image processing tool that can do this.
Wout
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Hhhaaaa... 
There is something horrible in your code!
But I can't tell you otherwise that would make it a programing question!
mmhh....
No it's just too horrible, I tell you anyway!
Get rid of these evil
1. for (int x = 0; x < image.Width; x++)
2. image.GetPixel(x, y)
3. newImage.SetPixel
.Width, .GetPixel .SetPixel are perfomance killer.
cache the height & width and use BitmapData
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Performance was least of my worries, I just needed something that works quick! I don't need to transform thousands of images per second at the moment. My first goal is usually understandable code, and when it's not fast enough I'll revisit the thing and tune it. But that time has still to come!
Wout
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Premature performance optimization is not smart usually. But I'll compromise this time.
White is the reference color in this case. Next step would be making the reference color configurable!
What will edge detection do for me? I haven't felt the need for it yet.
Basically the algorithm works as follows now: the closer the input pixel color is to the reference color, the more transparent the output pixel can be.
Wout
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wout de zeeuw wrote: Basically the algorithm works as follows now: the closer the input pixel color is to the reference color, the more transparent the output pixel can be.
Anyway this is a very bad algorithm.....
Have you tried it?
Your whole picture is translucent... 
With edge detection you could fill the outside area and perhaps mix transparency around the edges...
In fact before writing an article I think you should have a working prototype...
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Works splendidly for me! But ofcourse it's not fool proof yet, it's basically in prototype stage that works good enough for my current purposes. Send me your image, I'm curious why it doesn't work on your image.
Wout
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Just any image with 4 million colors should do.
Sure enough white become transparent.
And your shape border become translucent. But so does all the pixels!!!
You can't see that with picture with just a few color with full saturation. but try on CodeProject Bob for example.... (using Orange as the reference color)
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Yep, for non-white ref color the algorithm needs some tweaking. The blending color for 255 is 0. But for any other value it can be either 0 or 255, depending on which target to blend to. Gimme half an hour to work that out!
Wout
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I think you misunderstood the gravity of the problem...
Or possibly I didn't explain it well...
Or possibly I'm plain wrong...
I just don't believe you will be happy of the result except with some color poor pictures.
Try to remove the blue cloudless sky from a picture this way (or grey cloudfull sky): I predict utter failure of the algorithm.
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This is not too bad but:
1. get rid of GetPixel / SetPixel / Width / Height , this is too damn slow!
2. Haven't you noticed that Bob is transparent as well?
It's what I'm trying to say since 4 posts!!! 
Now it might be okay with you, but you haven't aknowledged the fact yet....
Otherwise works nicely, indeed 
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Yes, I'm aware of that. That's part of the algorithm's philosophy. If the color is close to the reference color, then the pixel can be made very transparent. Basically it tries to make each pixel as transparent as it can be. When putting the orange background behind it, it will look the same as the original again (or very close to it, disregarding rounding errors).
I'll take care of the GetPixel/SetPixel stuff, didn't bother to look for quicker alternatives yet. If you can tell me from the top of your mind that'd be great 
Wout
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Yeah, I tried several times to make that point, but my posts kept timing out.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
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Christian Graus wrote: but my posts kept timing out.
I know what you mean
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Btw, the clr should be smart enough to inline simple property getters, so I don't think any performance is gained there. Will try it out though out of curiosity.
Wout
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Well the CLR does.
But I didn't say to cache the value of any property.
I said to cache Width and Height in particular.
Test it, you'll see...
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wout de zeeuw wrote: Btw, the clr should be smart enough to inline simple property getters
In other words, who said Weight and Height are simple property getter? 
Anyway Reflector and ANTS profiler told me they are not! :->
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In that case you have a good case. I'll cache those when turning this thing into an article.
Wout
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hi all,
i have 12 panel and 12 buttons on my form. each button shows a panel and hides the rest. (do i have to hide each panel one by one ???)
but i wanna know if there is an efficient method to hide the rest 11 panel with a for loop ? like :
for(int i=0;i <11;i++)
panel[i].visible=false;
//or panel{i}.visible=false;
//or panel(i).visible=false;
these codes do not work  how can i correct the for part ?
help me please.
thanks in advance, bye.
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private void HidePanels(Panel panelToShow)
{
foreach(Control control in this.Controls)
if(control is Panel)
if(!control.Equals(panelToShow))
control.Hide();
else
control.Show();
}
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