This lab activity is adapted from C++ for You++,Maria and Gary Litvin, Skylight Publishing, Andover, MA, 1998. An image is represented as a two-dimensional array of characters. Elements of the array, called pixels, (picture elements) have values '.' (white) and 'x' (black). An image may have a number of arbitrary shaped blobs, contours, isolated pixels, etc. With each white pixel in an image we can associate a certain white area called the connectivity component of that pixel. This is defined as the set of all white pixels that can be connected to the given pixel with a continuous chain of white pixels.

The AreaFill(..) function takes a specified white pixel in an image and fills the connectivity component of that pixel with black, as illustrated below. A pixel is said to be connected to pixels that are adjacent horizontally or vertically.

	     Before		     After
	.....xx........		.....xx........
	....x..xx......		....xxxxx......
	....x....xxxx..		....xxxxxxxxx..
	...x........xxx		....xxxxxxxxxxx
	..x...*........		..xxxxxxxxxxxxx
	...x........xx.		...xxxxxxxxxxxx
	...x..xxx...x.x		...xxxxxxxxxx.x
	...x..x..x.x...		...xxxx..xxx...
	...xxxx...x....		...xxxx...x....
	...............		...............

1. Write a program that will read in the matrix from a text file and display it to the screen. The main program should prompt the user for the image file name, load and display the image, then ask for the location of the starting pixel.

2. Write function AreaFill(..) that will change the matrix. Display the new matrix to the screen. In writing your recursive function, be sure you remain within the image boundaries and do not refil pixels that are already black.