[OpenJDK 2D-Dev] Review Request for JDK-8139183 : drawImage misses background's alpha channel

[Jayathirth D V]

Hi,

 

Please review the following fix in JDK9:

 

Bug : https://bugs.openjdk.java.net/browse/JDK-8139183 

 

Webrev : http://cr.openjdk.java.net/~jdv/8139183/webrev.00/ 

 

Issue : When we scale any buffered image using drawImage() API which takes 
scale coordinates we are losing alpha channel in background color.

 

Root cause : We are creating opaque temporary image when we have background 
color and scale is happening in renderImageXform() API of DrawImage.java. By 
making it opaque we are losing translucency.

 

Solution : Instead of creating opaque RGB temporary image use ARGB temporary 
image to maintain translucency of image.

 

Thanks,

Jay