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Pixels array (Read 1152 times)
frogal31
Pixels array
Mar 25th, 2010, 3:06am  
Hi everyone, first I'm french so my english is not fluent.

I'm new with processing and i would like to create, a glitch generator.  
A program to modify images (jpg), like we want.

But, to start, I have a problem, i don't know how to use the "pixels array" in order to modify this image.

I found i could use "bytes" but it seems complicated.
So my goal is to create a pixel array or grid, and be able to choose the pixels i want. And then, modify the pixels.
(I would use load image and then load pixels.)

I came here to find help so if anyone could explain me how to do
I will be gratefull.

Thanks a lot.
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PhiLho 
Re: Pixels array
Reply #1 - Mar 25th, 2010, 4:50am  
Have you read the pixels[] page and the related ones You should take a look at the samples coming with Processing (use a search tool to find those using loadPixels) to get a feeling how it works.
Then if you are still stuck, try to explain what concept you don't get, exactly.
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frogal31
Re: Pixels array
Reply #2 - Mar 26th, 2010, 7:03am  
hi, thanks for answering.

I already read "pixels" and "loadpixels",
but I just don't understand, how do we select the pixels after this.
How can I see it worked and H
how can I use the pixel array once I made it, we can say.

I would like to duplicate pixels, shift them, change their color...
thanks again.
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PhiLho 
Re: Pixels array
Reply #3 - Mar 26th, 2010, 8:28am  
First note: a number of tasks can be done by Processing without needing to go down to pixel level. For example duplicating a bunch of pixels can be done with set()/get(), image(), etc.

You don't select pixels, you access them by their coordinates, flattened to a linear index (y * imageWidth + x).
Once you get the value of a pixel, you can use bit operations, for example, to alter them, then store the changed value back to the array.
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frogal31
Re: Pixels array
Reply #4 - Mar 27th, 2010, 12:37am  
okai, thank you.
I'm gonna take a look at set()/get(). I didn't know we could do that this way.
If I still have problems , I will post a new message here.

thanks again.
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