Question

There is a very large picture that could not load into memory once. Because it may cause out of memory exception. I need to zoom this picture to small size. So what should I do?

The simple thought is open an inputstream, and process a buffer size at a time. But the zoom algorithm?

Answer 1

There are a lot of different resizing algorithms which offer varying level of quality with the trade off being cpu time.

I believe with any of these you should be able to process a massive file in chunks relatively easily, however, you should probably try existing tools to see whether they can already just handle the massive file anyway.

Gd graphics library allows you to define how much working memory it can use I believe so it obviously already has logic for processing files in chunks.