Cutting an image into equal sized rectangular pieces.

I did some research for this and found several solutions to this.

1. Using BitMap
Using Bitmap 2

However, java doesn't seem to have the BitMap class, it seems to be ported from Android ?

2. Using CropImageFilter and FilteredImageSource

I don't understand what is the author doing with the code =/ .

Any explanations or new ideas on how to cut an image into equal sized rectangular pieces are appreciated