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Index › Programming Questions & Help › Syntax Questions › mapping what happens on screen to a matrix
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mapping what happens on screen to a matrix (Read 701 times)
intellijel
mapping what happens on screen to a matrix
Jul 21st, 2009, 2:21pm  
I am using processing to control a hardware matrix of rgb leds. Each led is basically addressed with an X,Y coordinate and an RGB value.

I making different graphic apps in Processing that I want to map to this hardware rgb matrix.

I am not sure what the terminology is for what I want to do.

I basically want to quantize what is happening on screen and at a higher resolution (like video) to a lower resolution and store all the values.

My initial matrix is only 5x5 so I just need to constantly store a new set of 25 rgb values and then transmit them to the device.

any tips for doing this?

I am guessing I can use the pixels[] array to get the screen values but what is a good algorithm for reducing the resolution in an efficient way?
What I mean is if a square in the original is 50x50 pixels and this would be reduced to one pixel in the matrix, how do I determine the color to use from within that square of 50x50? Take an average of all the other values?
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« Last Edit: Jul 21st, 2009, 9:22pm by intellijel »  
 
PhiLho 
Re: mapping what happens on screen to a matrix
Reply #1 - Jul 22nd, 2009, 1:01am  
You can cook your own quantization algorithm, there are lot of different methods available. Or you can start by just using image() with width & height parameters.
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intellijel
Re: mapping what happens on screen to a matrix
Reply #2 - Jul 22nd, 2009, 7:02am  
PhiLho  wrote on Jul 22nd, 2009, 1:01am:
You can cook your own quantization algorithm, there are lot of different methods available. Or you can start by just using image() with width & height parameters.


I thought about using image but then if I have an animation I would have to save the frame to disk each time I wanted to read it as an image and scale it down. Is there a way I can do this in ram instead
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Cedric
Re: mapping what happens on screen to a matrix
Reply #3 - Jul 22nd, 2009, 8:07am  
You dont have to save it to disk, you can use http://processing.org/reference/PGraphics.html instead...
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... twitter.com/CedricKiefer
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PhiLho 
Re: mapping what happens on screen to a matrix
Reply #4 - Jul 22nd, 2009, 8:47am  
Dices thread can be inspiring too...
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