public void setLoopCount(int loopCount) {
    	this.loopCount = loopCount;
    }
This is intended to be called first when writing an animated GIF
frame by frame.

@param os OutputStream for the animated GIF
@param logicalScreenWidth width of the logical screen. If it is less than
       or equal zero, it will be determined from the first frame
@param logicalScreenHeight height of the logical screen. If it is less than
       or equal zero, it will be determined from the first frame
@throws Exception
subs/gif-revert/src/main/java/com/engineer/gif/revert/lib/AnimatedGIFWriter.java