JPEG encoding-decoding of intensities

Question

Hi,
I used the following code to create jpeg image from intensity values and to retrieve the intensity values by decoding the jpeg image. Everything works fine except that I got some intensity values which are negative. I don't know from where this negative intensities are coming from. Here is my code:
import java.awt.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
public class JpegEnDecoder{
public static void main(String[] args) throws Throwable {
int w = 200, h = 1;
          short[] OneDimImage = new short[w*h];
for (int i=0;i<w*h;i++)
               OneDimImage=(short)(32500+i);
          DataBuffer dbuf = new DataBufferUShort(OneDimImage, OneDimImage.length);
          int[] masks = {0xf800, 0x07e0, 0x001f};
WritableRaster raster = Raster.createPackedRaster(dbuf, w, h, w, masks, null);
          ColorModel colorModel = new DirectColorModel(16, masks[0], masks[1], masks[2]);
BufferedImage bi1 = new BufferedImage(colorModel, raster, false, null);
File file = new File("test.jpeg");
ImageIO.write(bi1, "jpeg", file);
          int type = bi1.getType();
          BufferedImage bi2 = convert(ImageIO.read(file), BufferedImage.TYPE_USHORT_565_RGB);
WritableRaster raster1 = bi2.getRaster();
DataBuffer db = raster1.getDataBuffer();
          DataBufferUShort dbi = (DataBufferUShort) db;
short[] data = dbi.getData();
for (int j=0;j<data.length;j++)
System.out.println(data[j]);
public static BufferedImage convert(BufferedImage source, int targetType) {
int sourceType = source.getType();
if (sourceType == targetType)
return source;
BufferedImage result = new BufferedImage(source.getWidth(), source.getHeight(), targetType);
Graphics2D g = result.createGraphics();
g.drawRenderedImage(source, null);
g.dispose();
return result;
I will be pleased if anybody can explain how to solve this problem. Thanks in advance.

Answer 1

{noformat}_Anti{noformat}, don't double post. If you want a thread moved to a more appropriate forum, make a request in the [_current RA thread_|http://forums.sun.com/thread.jspa?threadID=5414121] in the News and Updates forum.
I've removed your other thread on the same topic.
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