image.m still opens ImageMagick

[Stephan Paukner]

I'm using octave2.9 (2.9.9-8etch1) and octave2.9-forge (2006.07.09+dfsg1-8) from Debian Etch and installed octplot from source (because Debian's own octplot package depends on the octave2.1 branch). The `toggle_octplot' command seems to work, but calls to image.m still open images in the ImageMagick viewer 'display'. However, an OctPlot-window does open a placeholder, but the actual image isn't added there. What could I have missed?

[Stephan Paukner]

I found out that I should call pcolor instead of imagesc while using OctPlot. Maybe I'll redefine imagesc for me to be an alias for pcolor.

[Shai Ayal]

image is not implemented in octplot (yet) so you have done nothing wrong.

using pcolor instead is a geed idea. If you have any experience with images can you please write to this list what are the differences between pcolor and image?

Shai

[Stephan Paukner]

Hi,

I saw that I still owe you an answer.

imagesc ("image scale") is intended for scaling the values of a matrix between 0 and 1 to match the current colormap (e.g. for colormap gray: 0=black and 1=white). The second parameter is optional for giving the scaling borders, e.g. imagesc(img,[0.2,0.5]) fits the values between 0.2 and 0.5 into the whole range of the colormap. The image is opened in an image viewer and not in an octplot window.

pcolor ("pseudo color") works similar to plot.m, one can give vectors x and y to have a correct labelling. The image opens in an octplot window.
However, one can hand the return value of imagesc over to pcolor to output the image with octplot, like:

pcolor( imagesc(img, [0.2 0.5]) )

Regards
Stephan