dear psychtoolbox users,
i have been using this toolbox to draw my visual stimuli and now I
have 3 questions:
1 I am drawing a rotation stimuli. The strategy I am now using is
a) pre-draw each frames in a matrix and save it.
b) I load it to the offscreen window when doing the experiment.
c) Then present them continuously.
As I have a large group of frames, step a) and b) would cost a lot
of time. The only difference between frames was the phase (rotate a
little). So is it possible to have only one frame of the picture and
only change the phase when loading to different offscreen window? Or,
better, only change the phase while put the offscreen window to the
'onscreen' one? If both was impossible, is there any other way to
reduce the time?
2 I use VisualGammaDemo.m to do gammar correction. After doing that,
I got the threshhold and the gammar value. Now, would the psychtoolbox
do gammar correction automatically or I shall manually calculate it
with the two numbers?
3 I may use an audio cue in the visual experiment. In C/DOS, I can
realize it via PC speaker (at certain frequence and certain duration).
Now in Psychtoolbox l can only do with a prepared audiofile and play
it via soundcard. It would be inconvenient and the sound from
soundcard was always not loud enough. Is it possible to make audio cue
in an easier way? It can be very simple sound: diiii...or daaaa...
etc.
Thanks a lot to the ones who will help me and the developers of this toolbox.
i have been using this toolbox to draw my visual stimuli and now I
have 3 questions:
1 I am drawing a rotation stimuli. The strategy I am now using is
a) pre-draw each frames in a matrix and save it.
b) I load it to the offscreen window when doing the experiment.
c) Then present them continuously.
As I have a large group of frames, step a) and b) would cost a lot
of time. The only difference between frames was the phase (rotate a
little). So is it possible to have only one frame of the picture and
only change the phase when loading to different offscreen window? Or,
better, only change the phase while put the offscreen window to the
'onscreen' one? If both was impossible, is there any other way to
reduce the time?
2 I use VisualGammaDemo.m to do gammar correction. After doing that,
I got the threshhold and the gammar value. Now, would the psychtoolbox
do gammar correction automatically or I shall manually calculate it
with the two numbers?
3 I may use an audio cue in the visual experiment. In C/DOS, I can
realize it via PC speaker (at certain frequence and certain duration).
Now in Psychtoolbox l can only do with a prepared audiofile and play
it via soundcard. It would be inconvenient and the sound from
soundcard was always not loud enough. Is it possible to make audio cue
in an easier way? It can be very simple sound: diiii...or daaaa...
etc.
Thanks a lot to the ones who will help me and the developers of this toolbox.