/**
* All work is done in constructor.
*
* @param filePath path to image
*/
public PrewittEdgeDetector(String filePath) {
// read image and get pixels
BufferedImage originalImage;
try {
originalImage = ImageIO.read(new File(filePath));
findEdges(Grayscale.imgToGrayPixels(originalImage), false);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Example run.
*
* <p>Displays detected edges next to orignal image.
*
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// read image and get pixels
String img = args[0];
BufferedImage originalImage = ImageIO.read(new File(img));
int[][] pixels = Grayscale.imgToGrayPixels(originalImage);
// run SobelEdgeDetector
final long startTime = System.currentTimeMillis();
PrewittEdgeDetector sed = new PrewittEdgeDetector(pixels);
final long endTime = System.currentTimeMillis();
// print timing information
final double elapsed = (double) (endTime - startTime) / 1000;
System.out.println("Prewitt Edge Detector took " + elapsed + " seconds.");
System.out.println("Threshold = " + sed.threshold);
// display edges
boolean[][] edges = sed.getEdges();
BufferedImage edges_image = Threshold.applyThresholdReversed(edges);
BufferedImage[] toShow = {originalImage, edges_image};
String title = "Prewitt Edge Detector by Jason Altschuler";
ImageViewer.showImages(toShow, title);
}