Re: Image interpolation and display

Posted by Jon Harman on May 04, 2007; 4:02pm
URL: http://imagej.273.s1.nabble.com/Image-interpolation-and-display-tp3699590p3699596.html

Hi,

I didn't realize that ImageJ was just using something built into Java.

I agree that it is hard to do zooming consistently at different zoom
factors.  I still think that ImageJ produces noisier images when zooming
out (i.e. small %) than other programs and the interpolation setting
makes only a small difference.  I wonder what the other programs are
doing?  Irfanview seems to have a consistent and less noisy algorithm.

Jon

  Michael Schmid wrote:
 > Hi Jon,
 >
 > the Java Documentation at Java.sun.com says, the interpolation
 > settings for displaying images are "hints" i.e., they are not
 > necessarily obeyed by the Java implementation.
 > Obviously, when downscaling, if the zoom factor is not a power
 > of two, many (all?) Java implementations do not honor the
 > settings.
 >
 > I once wrote some code for downscaling to arbitrary sizes
 > with bilinear interpolation and I found it quite difficult
 > to do it correctly - it seems the guys at Sun have not gone
 > into that business...
 >
 > Michael
 > ________________________________________________________________
 >
 > On 4 May 2007, at 00:37, Jon Harman wrote:
 >
 >> Hi,
 >> I notice that much depends on the zoom factor.  At some zooms there
is not much difference between display quality in  ImageJ compared to
other programs.  At other zooms there is a difference.  Here is an example.
 >>
 >> For this image at 33.3% the two ImageJ displays are
indistinguishable and are similar to PSP fastest quality.  PSP best
quallity is smoother as is Irfanview.
 >