Couple comments about image_viewer and path behavior

[Daniel J Sebald]

I've comments about a couple things related to working with images.

First, the path.  I'm trying to come up with a way of locating images and files 
in a path, not just function and m-files.  Time and again I've copied files 
into a directory I'm working in and start getting duplicate copies of files.  
So I'm trying to be more organized about it from now on.  What I'd like is to 
create a database of images, say,

~/lib/image/xray
~/lib/image/areal
etc

and then do a link of all such files into some common directory, say

~/lib/image/all

In that "all" directory I will then convert all images to lossless JPEG, 
because Octave reads JPEG with imread() or jpgread().

Can't I do something similar to

addpath("~/lib/image/all");

in my .octaverc and have Octave find those files?

Second, the image_viewer function is very useful especially for this example:

image_viewer ("display -immutable %s");

if one is doing image processing and wants a 1-to-1 match between image pixels and the 
screen pixels.  This rules out software effects and just (yeah "just") the 
hardware/monitor effects.  It might be worth adding that example to the documentation, 
Søren.  I suppose gnuplot could have an immutable mode to help matters, but 
display/ImageMagick has the nice feature of being able to store in various image formats 
very quickly.  Is there supposed to be more formality about just when an image is 
displayed 1-to-1 in accordance with the screen?

The problem with "display" is that it creates multiple copies every time some code is run.  Soon 
there are a lot of images on the screen.  Is there anything that can be done about that?  Perhaps in every 
"figure" group of data could be a "private" setting including the process ID associated 
with the viewer.  If it is ImageMagick or EOG, end the previous process.

What's more, the images are confusing because of the X titles simply being random strings.  
Couldn't there be another format sequence, like %t, in addition to %s and %f that would allow the 
title of the current figure to be put in there?  If only it said "Figure 1", "Figure 
2", etc., that would be helpful.

Dan