Re: image.m using gnuplot

[Joe Koski]

on 10/18/06 6:36 PM, Paul Kienzle at address@hidden wrote:

> On Oct 18, 2006, at 9:37 AM, Quentin Spencer wrote:
> 
>> Søren Hauberg wrote:
>>> xv, loadimage, or dispæay (for image.m)
>> 
>> 
>> When gnuplot 4.2 is released, it will be possible to display images in
>> gnuplot. I'm working on a patch to image.m.
> 
> A patch is already available.  Dan Sebald worked out the initial
> details, and I think Joe Koski updated it.  I don't know if I have the
> latest version.  Joe can send you his.
> 
> - Paul
> 
Quentin, Paul,

I'll attach the files to a separate e-mail forwarded directly to Quentin.
It's been a while, but I think that all I had to do to get the routines
working with octave-2.9.x was to replace the __gnuplot_raw__ calls in
__img_gp__.m with __gnuplot_set__ calls. I left the original lines in place
as comments for comparison.

I also played around with the aspect ratio settings in the same routine. It
seems to me that we need a "square pixel" option for displaying photos, but
I didn't see a variable I could easily grab for that purpose, so I did my
experiments by hardwiring the changes. You can see the area to be modified
by looking for # signs further down in __img_gp__.m,

The short but interesting Hough transform test that was contributed a while
back is what I have been using to test the routines. It's included also.

I have not tested all the routines. Let me know if I forgot something.

Joe