* Usage: java edu.rit.image.test.Test02 height width
* filename
*
height = Image height (pixels)
*
width = Image width (pixels)
*
filename = PJG image file name
*
* @author Alan Kaminsky
* @version 06-Jul-2009
*/
public class Test02
{
// Prevent construction.
private Test02()
{
}
// Shared variables.
// Constants.
static final BigRational ZERO = new BigRational ("0");
static final BigRational ONE = new BigRational ("1");
static final BigRational ONE_THIRD = new BigRational ("1/3");
// Command line arguments.
static int C;
static int S;
static BigRational A;
static BigRational B;
static File filename;
// Old and new cell arrays.
static BigRational[] currCell;
static BigRational[] nextCell;
// Output image matrix.
static byte[][] matrix;
static PJGGrayImage image;
// Input image matrix.
static byte[][] matrix2;
static PJGGrayImage image2;
// Main program.
/**
* Main program.
*/
public static void main
(String[] args)
throws Exception
{
// Parse command line arguments.
if (args.length != 3) usage();
C = Integer.parseInt (args[1]);
S = Integer.parseInt (args[0]) - 1;
A = ONE_THIRD;
B = new BigRational ("9/10");
filename = new File (args[2]);
// Allocate storage for old and new cell arrays. Initialize all cells to
// 0, except center cell to 1.
currCell = new BigRational [C];
nextCell = new BigRational [C];
for (int i = 0; i < C; ++ i)
{
currCell[i] = new BigRational();
nextCell[i] = new BigRational();
}
currCell[C/2].assign (ONE);
// Allocate storage for output image.
matrix = new byte [S+1] [C];
image = new PJGGrayImage (S+1, C, matrix);
image.setInterpretation (PJGGrayImage.ZERO_IS_WHITE);
// Do S time steps.
for (int s = 0; s < S; ++ s)
{
// Calculate next state of each cell.
for (int i = 0; i < C; ++ i)
{
nextCell[i]
.assign (currCell[i])
.add (currCell[(i-1+C)%C])
.add (currCell[(i+1)%C])
.mul (A)
.add (B)
.normalize()
.fracPart();
}
// Write current CA state to image matrix.
writeCurrCell (s);
// Advance one time step -- swap old and new cell arrays.
BigRational[] tmp = currCell;
currCell = nextCell;
nextCell = tmp;
}
// Write final CA state to image matrix.
writeCurrCell (S);
// Write output image to PJG file.
PJGImage.Writer writer =
image.prepareToWrite
(new BufferedOutputStream
(new FileOutputStream (filename)));
writer.write();
writer.close();
// Read image from file into a different matrix.
image2 = new PJGGrayImage();
PJGImage.Reader reader =
image2.prepareToRead
(new BufferedInputStream
(new FileInputStream (filename)));
reader.read();
reader.close();
// Compare output matrix with input matrix.
matrix2 = image2.getMatrix();
for (int r = 0; r <= S; ++ r)
{
byte[] matrix_r = matrix[r];
byte[] matrix2_r = matrix2[r];
for (int c = 0; c < C; ++ c)
{
if (matrix_r[c] != matrix2_r[c])
{
System.out.print ("matrix[");
System.out.print (r);
System.out.print ("][");
System.out.print (c);
System.out.print ("] = ");
System.out.print (Hex.toString (matrix_r[c]));
System.out.print (", matrix2[");
System.out.print (r);
System.out.print ("][");
System.out.print (c);
System.out.print ("] = ");
System.out.print (Hex.toString (matrix2_r[c]));
System.out.println();
}
}
}
}
// Hidden operations.
/**
* Write the current cell array to the image file.
*
* @param s Step (image row) index.
*/
private static void writeCurrCell
(int s)
throws IOException
{
for (int i = 0; i < C; ++ i)
{
image.setPixel (s, i, currCell[i].floatValue());
}
}
/**
* Print a usage message and exit.
*/
private static void usage()
{
System.err.println ("Usage: java edu.rit.image.test.Test02