How to write an Image without running out of memory in Java?

Question

final BufferedImage img = new BufferedImage(3500, 2480, BufferedImage.TYPE_BYTE_INDEXED);
final Graphics2D g2D = img.createGraphics();
g2D.setBackground(Color.white);
g2D.clearRect(0, 0, width, height);

(full code in this question).

This code results in a Java Heap Space exception although I've set the jvm attribute to 3GB. Could that be the problem?

Anyway isn't it possible to draw the image with less memory? I'm after an A4-size BMP for printing, only with text. Most of the time it's black-and-white only, while at some times I'll need to use blue, pink, and gray too.

Answer 1

Could you chunkify your picture? That is divide the creation of it into smaller chunks to keep the memory footprint down while processing. Finally, when you're ready to merge, you just merge smaller chunks one at a time. Then you'd be left with the originally sized picture without needing to worry about RAM caps.

Answer 2

There is something very fishy about the facts stated in your question. Unless I'm mistakened, that BufferedImage uses 1 byte per pixel, and therefore 3500 x 2480 bytes ... around 10Mbytes. But you claim to have set the heap size to 3Gbytes.

What JVM options did you actually use?