Photo resizer using Java

I'm planning to make a simple Photo Resizer since I usually find myself having to resize huge images being sent to me. I know that there are a lot of online services and tools out there that already do this but I was thinking that it would be a good time to improve my Java and build something useful at the same time.

The problem is that I 开发者_开发知识库don't know where to start. I've looked around and mostly saw similar projects made in C# and C++.

Any tips on how to start this?

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I did this some years ago to generate thumbnails. IIRC, you can use the ImageIO classes to read the image in as one format, and then write it back out as a different format/resolution.

edit: Oh, and here's Sun's tutorial on working with images. http://java.sun.com/docs/books/tutorial/2d/images/index.html