8-bit windows

1
Eight-bit windows will not work with various kinds of Apple monitors. For
instance, when I try,

window=SCREEN(0,'OpenWindow',[],[],[8])

on my Apple Cinema Display, I get the error message,

??? pixelSize/depthMode 8 unavailable in display mode 45.

This seems to have to do with the fact that grayscale isn't an option for the
Cinema Display. I don't know whether this is due to the nature of the monitor,
the nature of the display card, or the nature of the system software.

This appears to be a widening problem for the new Macs as few of them (iMacs,
eMacs or any flat-screen monitor) appear to support gray scale. I So I have a
couple of questions:

1. Does anyone have a work-around for this problem?

2. Will the new OSX version of the toolbox address this issue in any way?

All of my experiments use gray-scale images, and I hate the idea of having to
use the extra space and extra time for 24-bit windows if I don't have to.

Thanks for any help...

Geoff Loftus

Geoffrey R. Loftus, PhD Office: (206) 543-8874
Department of Psychology Home: (206) 547-6969
Guthrie Hall, Room 131 Mobile: (206) 605-1974
University of Washington Fax: (206) 685-3157
Box 351525 Web: http://faculty.washington.edu/gloftus
Seattle, WA 98195-1525
2
>Eight-bit windows will not work with various kinds of Apple monitors. For
>instance, when I try,
>
>window=SCREEN(0,'OpenWindow',[],[],[8])
>
>on my Apple Cinema Display, I get the error message,
>
>??? pixelSize/depthMode 8 unavailable in display mode 45.
>
>This seems to have to do with the fact that grayscale isn't an option for the
>Cinema Display. I don't know whether this is due to the nature of the monitor,
>the nature of the display card, or the nature of the system software.
>
>This appears to be a widening problem for the new Macs as few of them (iMacs,
>eMacs or any flat-screen monitor) appear to support gray scale. I So I have a
>couple of questions:
>
>1. Does anyone have a work-around for this problem?
>
>2. Will the new OSX version of the toolbox address this issue in any way?
>
>All of my experiments use gray-scale images, and I hate the idea of having to
>use the extra space and extra time for 24-bit windows if I don't have to.
>
>Thanks for any help...
>
>Geoff Loftus
>
>Geoffrey R. Loftus, PhD Office: (206) 543-8874
>Department of Psychology Home: (206) 547-6969
>Guthrie Hall, Room 131 Mobile: (206) 605-1974
>University of Washington Fax: (206) 685-3157
>Box 351525 Web: http://faculty.washington.edu/gloftus
>Seattle, WA 98195-1525


dear geoff

1. i very much doubt that using grayscale vs color mode has anything
to do with it, because that is taken care of by the Mac OS, and the
driver knows nothing about it.

2. have you looked at what the Control Panel Monitors says? Does it
too refuse to offer you 8-bit depth at that resolution?

you might also compare with the list produced by running ResolutionTest.

and, you might also try the handy INIT (link is on our download page)
called SwitchRes

The intention is that OpenWindow should be able to obtain for you a
superset of what the control panel Monitors offers. (that superset
should be the same list as offered by SwitchRes.) If that's not true
then it's a bug in our code, and probably easy to fix.

If all the various ways of listing resolutions all say that 8-bit
mode is unavailable then it's a limitation of the driver and there is
no work around. the only hope is to convince the authors of the
driver to add that resolution. it's very easy for them to do, just
adding another row to a table.

however, i'm not sure you really need to worry if it's not an
immediate problem since memory cost and processor speed are both
moving in favorable directions so that a factor of 4 loss (from 8- to
32-bit pixels) will soon be overtaken by the technological progress.

best

denis