|Subject:||Getting past imread fault in Octave 2.1.73|
|Date:||Sun, 21 Jan 2007 09:48:32 -0500|
I do not know if this will be of use to anyone, but I thought
I should mention it anyway. It is a way to get past
a problem I emailed about recently ...
I have found that imread() in Octave 2.1.73 (running
under Windows XP w. ServicePack 2) does not work.
I have ImageMagick now but this does not eliminate
I do not know enough about the 'guts' of Octave to
fix a problem like this, and a patch seems unavailable.
I do not wish to attempt a re-install, or major re-build.
Workaround (a kludge):
Java J2SE, JAI (Java Advanced Imaging) are freely
available from Sun Microsystems. The NetBeans
IDE from Sun is also free, but the BlueJ IDE (free)
is much easier to use and takes up a lot less disk space.
Using JAI it is not hard to read in digital images in
a wide format range, and then output the image as
an integer array to a file.
The integer array form is easily read in by Octave
2.1.73 using fscanf. Of course, once the integer
array is read in then one may process it in any manner
that one sees fit. Image display function imshow()
appears to function (more-or-less), and so a processed
result is easily displayed, and subsequently saveable
as a .bmp file.
1) Converting an image to an integer array expands
file size as bytes get turned into 4-byte integers.
2) When the Octave file reader and imshow have
done their work, and the Octave session ends I have
noticed that Octave 2.1.73 loves to create very large
Octave-Core files (e.g., 8 Mbytes and up).
I do not know why this happens, but Octave-Core
can be deleted.
3) I have not tried color images yet as my application
does not need this.
4) Of course, JAI is for digital image processing and
one may attempt to do any processing of interest
using Java/JAI, and forget about Octave altogether.
However, JAI is not so easy to use, and one may not
like to spend much time learning Java/JAI. Also,
even if one is an expert in Java/JAI, algorithm
development tends to be faster in Octave than
Java/JAI. (Consistent with the notion that scripting
languages are for rapid prototype development.)
Christopher J. Zarowski, Ph. D., P. Eng. (Ontario)
IEEE Senior Member
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