Median Filtering using JAI

Question

Hi, I am not so familiar with JAI API but I do use some of it sometimes in my coding. I am trying to figure out why I keep receiving the same error message when applying MedianFiltering to my image as in the following code snippet:
public BufferedImage medianFilter (Image image){
ParameterBlock pb = new ParameterBlock();
pb.add(image);
PlanarImage input = (PlanarImage)JAI.create("awtImage",pb);
pb.addSource(input);
pb.add(MedianFilterDescriptor.MEDIAN_MASK_SQUARE);
pb.add(3);
input = JAI.create("medianfilter", pb, null);
BufferedImage nImage = input.getAsBufferedImage();
BufferedImage filteredImage = new BufferedImage(nImage.getWidth(null), nImage.getHeight(null), BufferedImage.TYPE_INT_RGB);
Graphics g = filteredImage.getGraphics();
g.drawImage(nImage, 0, 0, null);
return filteredImage;
ERROR MESSAGE
java.lang.IllegalArgumentException: MedianFilter - Parameter value`s class (sun.awt.windows.WImage) is not an instance of the parameter class (javax.media.jai.operator.MedianFilterShape) for parameter "maskShape".
at javax.media.jai.JAI.createNS(JAI.java:1091)
at javax.media.jai.JAI.create(JAI.java:977)
at imagesegmentationrgb.ImageSegmentationRGB.medianFilter(ImageSegmentationRGB.java:210)
I have tried to amend it for so long and I don't know what else to do. Could anyone help me? Cheers and thanks.

Answer 1

My solution would be to work with the image in its raw format. Extract the image into a 2 dimensional array, loop throught the rows and columns and compare to your zero crossing window detector. after you have aquired the new image array, you set pixels that are next to an edge 0 and the rest #ffff. this will create a binary image (black and white) with the edges black and rest white. Be careful of your conventions used to determine what are edges. This may seem primitive, but thats just the way i think :P
-fastrike