JDK-6381195 : ImageIO creates images of type CUSTOM for some common formats
  • Type: Bug
  • Component: client-libs
  • Sub-Component: javax.imageio
  • Affected Version: 6
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • OS: windows_xp
  • CPU: x86
  • Submitted: 2006-02-03
  • Updated: 2015-11-03
Related Reports
Relates :  
JDK-4883787 - REG: Rendering a TYPE_CUSTOM buffered image (read using ImageIO) takes long time
Description
When ImageIO reads in PNG files (and perhaps other formats?) it creates BufferedImages of type CUSTOM.  We probably do not have optimized rendering for copying from this image type, so there may be performance implications here (although managed images probably mitigates this in most situations).

These images are of known types; we should create something that makes sense in the PNG context (like ARGB, for example).
Comments
Please re-open if - if fix is in progress or on the plan to fix soon - if this is a P3 (file as P3, not P4)
18-03-2014
EVALUATION According to one of the ImageIO developers: -------- It's most noticeable with the IIO PNGImageReader, but it may affect some other IIO plugins as well. The basic issue is that the PNGImageReader by default creates 3ByteRgb images, for which we don't have optimized rendering loops (I still haven't figured out the exact reason why). At least if it created 3ByteBgr images, we'd have decent rendering loops and it wouldn't be as much of an issue. -------- Note that I created this as a P4; if we didn't have managed images (which will end up caching a more optimal format), I'd put this as a higher priority because it has pretty steep performance implications for the copies from a CUSTOM image to any other destination. As it is, it's only going to be the first copy (plus the copy to the managed image) that's slow.
03-02-2006