How can I draw a sprite without drawing the background color of it on another picture ?

Hi everyone,

I've been programmed in java for sometime. Here is my question: How can I draw a sprite without touching the background color of it? I know Java support GIF89 format, with this, I can draw a sprite without touching the background color of it, and thus, I take care the transparecy well.

Yet, not every picture we have on hand is saved in GIF89 format, so we need

to do the transparecy ourselve, I know there are some methods in the java.awt.image.* can do the jobs for me. Can someone please tell me what method I should use?

I know how to transform an image into an array of integer values, but when I print out those value, all the values are negative. If there is a way to change these values, so when the array is transformed back to image, they will carry the same value of the applet's background color, how to change these value ?

AN EXAMPLE SHOWING SOME CODE WILL BE EXTREMELY HELPFUL !


I here say " thanks " in advance. Please, I really need your help !!!!!!