How can I avoid memory errors when using obscenely large images?

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kelson.ba..

How can I avoid memory errors when using obscenely large images?

in General Discussion • Other • 2 months ago

I am looking to load and view an arbitrarily large image by breaking it up into 1000x1000 blocks and loading the ones immediately around a PVector "camera." The problem is I need to be able to get rid of images from the memory that are no longer in use. Are loaded files handled automatically by the garbage collector, or is there any additional memory handling that I need to use?

Replies(3)

paulr451

Re: How can I avoid memory errors when using obscenely large images?

2 months ago

You can nudge the garbage collector with System.gc();

But you shouldn't normally need to, except perhaps in cases like these. In your case you are allocating 4M (megabyte) images (1000 x 1000 x 4 bytes). The question is how many and how quickly. As a reference I made the following program and watched the process's memory size:

void setup(){size(600,600);}
class item {
int[] ints1 = new int[4000000];
}

void draw(){
item I = new item();
item J = new item();
item K = new item();
item L = new item();
item M = new item();
println(I);
//System.gc();
}

If I run it without invoking the GC it climbs to around 600M then bounces up and down a little. I let it run for 20 minutes without any errors. When I run the GC to stays steady around 130M, so clearly it helps. But you may have other issues, what error are you getting exactly.

dimkir

Re: How can I avoid memory errors when using obscenely large images?

2 months ago

There used to be a memory PImage memory leak problem earlier in processing (as discussed in:

https://forum.processing.org/topic/pimage-memory-leak-example

However it seems to be fixed (at lest in 2.0.1):

I tried running the test-code which was leaking memory and it seems to run fine even with heap limited to 64Mb.

(Code originally by PhiLho from this post:

https://forum.processing.org/topic/pimage-memory-leak-example#25080000001807647 )

void setup()
{
size(640, 480);
}
void draw()
{
PImage img = createImage(width, height, RGB);
image(img, 0, 0);
println(frameCount);
}

So it seems that if you only have transient references to your "temporary" images, then garbage collector should be able to sort things out by himself.

GoToLoop

Re: How can I avoid memory errors when using obscenely large images?

2 months ago

However it seems to be fixed (at least in 2.0.1):

Processing 2 stable was officially launched only after devs fixed the leaked bug! So even v2.0.0 had no such bug!

Actually I believe even latest betas had it fixed already!

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