FULL PRODUCT VERSION :
java version "1.5.0_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_04-b05)
Java HotSpot(TM) Client VM (build 1.5.0_04-b05, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
When the gc transform is a translation with no scaling (scale is 1.0 in x and y), a black border sometimes appears around some sides of some images if the RenderingHints.KEY_INTERPOLATION is set to RenderingHints.VALUE_INTERPOLATION_BINLEAR or BICUBIC. Some images drawn in this mode appear fine, while others have a black border on the left and top, or right and bottom if the scale factor is exactly 1.0.

Setting the value to VALUE_INTERPOLATION_NEARESTNEIGBOR works fine in all cases, but looks very bad when actually scaled.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
A component that is painted similar to the method below might cause this. (Unfortunately, I do not have a good, isolated test-case for this, and the below is copied and pasted together from several sources to illustrate the conditions.)

public void paint(Graphics gc)
{
    gc.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                          RenderingHints.VALUE_INTERPOLATION_BILINEAR);

     AffineTransform toPixelScaleAt = new AffineTransform();
     toPixelScaleAt.translate(
                             (paintExtents_.getX() - paintExtents_.getEndX()) / 2d,
                             (paintExtents_.getY() - paintExtents_.getEndY()) / 2d);

     gc.drawImage(image_, toPixelScaleAt, this);
}


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The image would be drawn.
ACTUAL -
The image is drawn, only for some images, a 1-pixel black border appears along the left and top, or along the right and bottom.


REPRODUCIBILITY :
This bug can be reproduced often.

CUSTOMER SUBMITTED WORKAROUND :
Scaling by a tiny amount, such as:

    gc.scale(1.000001, 1.000001);

Seems to avoid the problem, and also slow down drawing.
###@###.### 2005-07-01 08:19:01 GMT