ArrayIndexOutOfBounds error

This program takes as input an image, scans it and highlights circles in red. However I get an ArrayOutOfBounds exception at the last method when I call drawCircle(). I dont know how to fix it.

public class Assig1 {

    public static void main(String[] args) {
        try {
            // arg 0 is the input image name
            BufferedImage img = ImageIO.read(new File(args[0]));

            // arg 1 is the min radius
            int minr = Integer.parseInt(args[1]);
            // arg 2 is the max radius
            int maxr = Integer.parseInt(args[2]);

            // if present, arg 3 is the max width we consider
            int w = (args.length>3) ? Integer.parseInt(args[3]) : img.getWidth();
            // if present, arg 4 is the max height we consider
            int h = (args.length>4) ? Integer.parseInt(args[4]) : img.getHeight();

            
            findCircle(minr,img, w, h);
            
            //----
            // write out the image
            File outputfile = new File("outputimage1.png");
            ImageIO.write(img, "png", outputfile);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // Bresenham's algorithm to draw a circle
    // requires circle center and radius, as well as the
    // image and Graphics2D object with drawing colour already set.
    static void drawCircle(int cx,int cy,int r,BufferedImage img,Graphics2D g) {
        int f = 1-r;
        int ddF_x = 1;
        int ddF_y = -2 * r;
        int x = 0;
        int y = r;

        // draw cardinal points
        g.drawLine(cx,cy+r,cx,cy+r);
        g.drawLine(cx,cy-r,cx,cy-r);
        g.drawLine(cx+r,cy,cx+r,cy);
        g.drawLine(cx-r,cy,cx-r,cy);

        // draw 1/8 of the circle, taking advantage of symmetry
        while(x < y) {
            if(f >= 0) {
                y--;
                ddF_y += 2;
                f += ddF_y;
            }
            x++;
            ddF_x += 2;
            f += ddF_x;

            g.drawLine(cx+x,cy+y,cx+x,cy+y);
            g.drawLine(cx-x,cy+y,cx-x,cy+y);
            g.drawLine(cx+x,cy-y,cx+x,cy-y);
            g.drawLine(cx-x,cy-y,cx-x,cy-y);
            g.drawLine(cx+y,cy+x,cx+y,cy+x);
            g.drawLine(cx-y,cy+x,cx-y,cy+x);
            g.drawLine(cx+y,cy-x,cx+y,cy-x);
            g.drawLine(cx-y,cy-x,cx-y,cy-x);
        }
    
}

    static void findCircle(int r,BufferedImage img, int w, int h) {

    	//getting all the pixels from an image
    	int[][] pixels = new int[w][h];

    	for( int i = 0; i < w; i++ ){
      	 	 for( int j = 0; j < h; j++ ){
         		   pixels[i][j] = img.getRGB( i, j );
      	 	 }
    	}
    	
    	 // graphical output
        Graphics2D g2 = img.createGraphics();
        // use red
        g2.setColor(Color.RED);
    	
    	
    	for (int i1=0; i1<pixels.length; i1++) {
    	     for (int j1=0; j1<pixels[i1].length; j1++) {
    	         
    	    	 if(pixels[i1][j1] != pixels[i1+r][j1]
    	     			|| pixels[i1][j1] != pixels[i1-r][j1]
    	     			|| pixels[i1][j1] != pixels[i1][j1+r]
    	     			|| pixels[i1][j1] != pixels[i1][j1-r]){
    	     		drawCircle(i1,j1,r,img,g2);   //EXCEPTION HERE
    	     	}
    	     }
    	  
    	 }
    }
}