Display a 2-D image in a figure window
imag2d() creates a plain FreeGLUT OpenGL window and displays
the input image with 1:1 aspect ratio for pixels. The window
resize is constrained to the actual ratio of the image
dimensions. The initial display size is currently a 200x200
window to prevent things from being too small by default.
The image to display can have dimensions ($c,$M,$N) where for
$c==4 the display is in GL_RGBA, for $c==3 the display is GL_RGB,
for $c==2 the display is GL_LUMINANCE_ALPHA, and for $c==1 or for
for dimensions ($M,$N) then the display is GL_LUMINANCE.
This routine does not yet thread but multiple images may be
viewed at the same time in separate windows by multiple
calls to imag2d(). TriD graphics visualization windows and the
imag2d() windows may be created and used independently.
NOTE: If you are twiddling a TriD window, the imag2d()
windows are active as well. If you call twiddle()
the sub, only the imag2d() windows will update correctly.
$window_id = imag2d($image, $name, $zoom, $x_off, $y_off);
creates a new image figure window from the input piddle
with the given title, zoom factor, and position (if possible)
$window_id - may be used to refer to the figure window
$image - 2D image piddle with at least 2 or 3 dimensions
e.g. [M,N], [1,M,N], [2,M,N], [3,M,N], [4,M,N]
$name - the name to use for the figure window (optional)
$zoom - desired (float) pixel zoom factor (optional)
($x_off, $y_off) - desired window pixel position (optional)
with (0,0) as the top left pixel of the
use PDL::Graphics2D; # imports imag2d() and twiddle()
$a = sequence(64,48,3); # make test RGB image
$a = $a->mv(2,0); # color must be dim(0) with size [0..4]
$a /= $a->max; # pixel values in [0.0,1.0]
$a = sin(10*$a);
$w1 = imag2d($a); # with parens...
$w2 = imag2d $a->sqrt; # or without
$w3 = imag2d $a**2;
Update an existing imag2d window with new piddle data
$image = random(3,64,48)/2 + 0.25; # random pixel image
$win = imag2d($image); # create original image display
imag2d_update($win, $image->sequence/$image->nelem); # update data
imag2d_update allows one to update an imag2d display window
by replacing the associated image data with new contents. The
new image data must be the same type and shape as the previous.
Eventually, we would like to implement this via some sort of
dataflow that would be transparent to the user.