FULL PRODUCT VERSION :
Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
Java HotSpot(TM) Server VM (build 23.21-b01, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux xxxx 2.6.31-23-generic-pae #75-Ubuntu SMP Fri Mar 18 19:14:10 UTC 2011 i686 GNU/Linux

EXTRA RELEVANT SYSTEM CONFIGURATION :
I've seen this same problem on Windows 7 as well. Also, the artifacts can be triggered with Java 1.6 if the background image has just the right band ordering, and maybe sample model.

A DESCRIPTION OF THE PROBLEM :
Text drawn on translucent backgrounds with Java 7 with anti-aliasing turned on get artifacts in the anti-aliased pixels. These pixels are brighter than they should be.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a buffered image with transparency, fill it with a color that's translucent, turn on text anti aliasing, then draw text with an opaque color.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
All sample values in the resulting image should have values in the range between the background color and the text color, inclusive.
ACTUAL -
The anti-aliased pixels around the edges of the text are brighter than they should be. For example, with a background color RGB (153, 153, 153) and a text color (255, 136, 0), the defective pixels have values like (255, 255, 239). Orange text on a gray background shouldn't have white edges!

Depending on the colors used for background and text, the problem can be hard to detect.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package bugtester;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class AwtAntiAliasingBugRunner {

public static void main(String[] args) throws IOException {

BufferedImage bufferedImage = new BufferedImage(200, 100, BufferedImage.TYPE_4BYTE_ABGR);

Graphics2D graphics = (Graphics2D) bufferedImage.getGraphics();

graphics.setColor(new Color(153, 153, 153, 127));
graphics.fillRect(0, 0, 100, 100);

graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

Font font = new Font( " Verdana " , Font.PLAIN, 55);

graphics.setFont(font);

graphics.setColor(new Color(255, 136, 0));
graphics.drawString( " Save " , 20, 60);

graphics.dispose();

ImageIO.write(bufferedImage, " png " , new File( " artifacts.png " ));
}
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
No known workaround. Although the impact of this bug is not severe right now, this may prevent us from migrating our software from Java 6 to Java 7.