Scaling Binary JPEG images

Question

Sorry if this is in the wrong forum.
I am extracting JPEG images stored in a blob field in a DB. I can obtain the bytes of the JPEG in a couple different ways but I have had no luck in scaling the images.
I need to simple scale the image, and then return the new image preferably in a byte[] or something that I can convert to a byte[].
I have come accross several past post, and at times seems to work. None of them actually return an image or errors so I am not sure where it fails.
I tried a modified version of the following which was an example on making thumbnails out of a larger image.
Here's the url to that example
http://developer.java.sun.com/developer/TechTips/1999/tt1021.html
After modifying the code, when I went to test I recieved a weird error in a log file that basically said something could not use :0 which is refering to my monitor.
This is and will be used in a Linux env, but does not or should not invlove X in anyway. I have come accross other example that talk about a frame.addnotify() method that is supposed to resolve this issue when not outputing to a monitor.
After adding that, the error is not there, but neither is my scaled image.(which wasn't there before either)
If this sound strange, that's beacuse I am creating a custom Generator object. Generator being a Servlet created by Macromedia to generate Flash movies and etc. on the fly.
For some reason in the API it lacks the ability to scale a JPEG image. Yet to be able to put the image into Flash, I must get the image's byte[].
Please help, I have played around with this one for some time now, and have tried more things than I could document here.
Any assistance is greatly appreciated!
Sincerely,
William L. Thomson Jr.
Support Group
Obsidian-Studios Inc.
439 Amber Way
Petaluma, Ca. 94952
Phone/Fax [phone]

Answer 1

HI,
The code is not very well organized, but should be clear enough for your reference.
import java.awt.image.*;
import java.awt.Image;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import javax.swing.ImageIcon;
byte[] b; /* your binary image */
Image inImage = new ImageIcon(b).getImage();
int iH=inImage.getHeight(null);
int iW=inImage.getWidth(null);
BufferedImage outBImage = new BufferedImage(iW,iH,BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = outBImage.createGraphics();
g2d.drawImage(inImage,null,null);
g2d.dispose();
double scale=0.5; /* rescale the image to 50% of its original size*/
int scaledW=(int)iW*scale;
int scaledH=(int)iH*scale;
BufferedImage dstbimg = new BufferedImage(scaledW, scaledH,BufferedImage.TYPE_INT_RGB);
AffineTransform tx = new AffineTransform();
tx.scale(scale, scale);
Graphics2D g2d = dstbimg.createGraphics();
RenderingHints qualityHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
qualityHints.put(RenderingHints.KEY_RENDERING,RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHints(qualityHints);
g2d.drawImage(outBImage, tx, null);
g2d.dispose();
/* dstbimg is the scaled BufferedImage */