/**
* Basic nonparametric usage of canny edge detector. No thresholding is used.
*
* @param original input image
*/
public CCannyEdgeDetector(BufferedImage original) {
size = new Dimension(original.getWidth(), original.getHeight());
input = original.getData();
image =
new BufferedImage(
(int) size.getWidth(), (int) size.getHeight(), BufferedImage.TYPE_INT_RGB);
bands = original.getSampleModel().getNumBands();
}
@Override
public void paintDone(PlanarImage image, Rectangle visibleRect, boolean synchronous, long time) {
if (image == null) return;
Dimension previewDimension = getSize();
if ((previewDimension.getHeight() > 1) && (previewDimension.getWidth() > 1)) {
this.visibleRect = visibleRect;
currentImage = new SoftReference<PlanarImage>(image);
preview = null;
repaint();
}
}
@Override
protected BufferedImage doInBackground() {
int x, y, b;
int[] A = null;
int[] sum = new int[bands], sum_x = new int[bands], sum_y = new int[bands];
WritableRaster raster = image.getRaster();
for (x = 0; x < size.getWidth(); x++) {
for (y = 0; y < size.getHeight(); y++) {
if (y == 0 || y == size.getHeight() - 1 || x == 0 || x == size.getWidth() - 1) {
for (b = 0; b < bands; b++) {
sum[b] = 0;
}
} else {
for (b = 0; b < bands; b++) {
A =
input.getSamples(
x - 1, y - 1, CSobelOperator.matrix_size, CSobelOperator.matrix_size, b, A);
sum_x[b] = CSobelOperator.getGx(A);
sum_y[b] = CSobelOperator.getGy(A);
}
for (b = 0; b < bands; b++) {
sum[b] = Math.abs(sum_x[b]) + Math.abs(sum_y[b]);
}
}
raster.setPixel(x, y, sum);
setProgress(
100
* (x * ((int) size.getHeight()) + y)
/ ((int) (size.getWidth() * size.getHeight())));
}
}
image.setData(raster);
return image;
}