Re: getframe() alternatives

[Philip Nienhuis]

<help-octave ML added, other people can benefit as well>

address@hidden wrote:
> Philip,
>
> I saw your "getframe() alternatives" post and got very excited because I've been trying 
> to do exactly the same thing.  I have a matlab function that takes pictures overlayed with 
> scatterplot data and makes it into a video.  The function uses the matlab function 
> "hardcopy" at the end to make the video like this:
> % add this frame to movie file
>      %mov = addframe(mov,gcf);
>      renderer = get(hnd,'renderer');
>      if strcmp(renderer,'painters')
>          renderer = 'opengl';
>      end
>      set(hnd, 'Units', 'pixels');
>      pixelsperinch = get(0,'screenpixelsperInch');
>
>      frame = hardcopy(hnd, ['-d' renderer], ['-r' 
> num2str(round(pixelsperinch))]);
>      addframe(mov,frame);
>
> but Octave can't understand hardcopy, so I tried to replace it with just:
> addframe(mov,gcf);
>
> but I get error: addframe: input frame should be in [0-1]
>
> I saw your post and was hoping you could help me.  I'm a super matlab and 
> Octave novice (like, yesterday) and I'm trying to make this matlab function 
> work in octave for a collegue.
> Would you help me implement your solution to this problem for octave?
> (I tried adding this via your post:)
> HH = im2double (imread (gcf));
>    aviobj = addframe (aviobj, HH);
>
> but Octave doesn't like that either.
>
> Any help you can give would be super appreciated.  Thanks for your time.

Currently I have no time; maybe tomorrow night (but I doubt it).

Just a quick answer: gcf is a figure handle, isn't it? If so, you can't 
use that by adding it to the movie. It is a mere double (actually 
disguised as a figure handle).

You'd need to prepare a color bitmap for each movie frame and add that 
to the movie.
I created the bitmaps by printing each picture to file, then reading it 
using imread into a bitmap and feed that to aviobj. All steps but the 
last one were done in an .m-file (attached).
Each frame took ~20 secs to write and read; clumsily yes, but OK it 
worked. On my current "power"box at work I think it should go much 
faster (it has an SSD).

What we actually need is a binary getframe that makes a snapshot of the 
current figure and turns it into a bitmap. I've looked into it a while 
back it but got lost in the OpenGL and fltk sources.

Anuway I'll attach my old getframe.m to this mail.

Philip

getframe.m
Description: Text Data