Cyclopital3D Lighted Print Viewer - Manual (Page 7)

13
The Stereo Window
The stereo window is an important concept in stereoscopic viewing
experience. If you don’t already understand what the stereo window is and
why it’s important, you should take some time and look it up on the internet.
Although it’s technically possible, SPM does not have a UI mechanism to set
the stereo window position independent of the far point spacing. However, if
the far point spacing and image width are constant, then distance from the
observer to the stereo window will also be constant. When you use the
procedure described in the step-by-step process, the stereo window is set to be
about 6 feet in front the camera and is perceived to be closer if the far point is
closer than infinity. This window position also matches the “natural” stereo
window of the LPV.
Although SPM does not have a UI method to set the window position
independent of the far point spacing, it can be done when batch processing by
manipulating the parameters for “Auto alignment” and “Multi Conversion.” If
the method for setting the stereo window in the “Auto alignment Setting”
dialog is set to “Input the deviation(%) of the image width,” the percentage
value specified can be thought of as the maximum amount of deviation
allowed in the image if all the objects in the image are to remain “behind” the
stereo window. It’s OK for an image to have more deviation than this if the
parts of the image that end up in front of the stereo window do not intersect
the sides of the frame, then there is no “window violation.” However, if the
image has more total deviation than is defined by the “% deviation” parameter
AND the near objects intersect the image frame, then there will be a window
violation. Because the view is so wide in the LPV, a “window violation” may
or may not be troublesome; if it is, there are several ways to fix it, as explained
below:
1. You can crop the image to reduce the total deviation to less than 3.5%.
This probably means trimming off the foreground (bottom).
2. You can make the border “fuzzy” so there are no hard edges to make a
window frame
3. You can move the stereo window back (towards the observer) by
cropping a little off the outside vertical edges of the mounted pair.
14
The Stereo Window (cont.)
If you want to move the window back by cropping off the outside edges, open
the finished image (from the directory “Ready2Print”) in Irfanviw and select
“Image->Change canvas size...” you will see the following dialog:
Make sure “If negative values used: add canvas to inside” is checked, and that
the “Border color:” is set to Black. Negative values for “Left side:”, “Right
side:”, “Top side:” and “Bottom side:” will add borders from the outside of the
print inwards, leaving the overall canvas size unchanged. We want to increase
the size of the existing borders on the left and the right by a little bit in order to
move the window closer. The side boarders are already 350 pixels wide, so to
crop 2mm off of each side of the image in the center we would add 47 pixels,
(2mm @ 600 dpi = 47 dots) making the side boarders -397 pixels wide. We
don’t want to change the image vertically, so the “Top side:” and “Bottom
side:” parameters should be set to 0. Press “OK” and the image will be
cropped, save it and it’s ready to be printed.
Exactly how much you need to move the stereo window back of course
depends on the image. Cropping 2mm from each side as described above will
allow for a total deviation of about 5%, cropping 4mm from each side (-444
pixels) will allow for more than 7% total deviation. Any more than this and
you are probably pushing the limits of “comfortable viewing”.
If you got this far I congratulate you on your tenacity. It’s possible I've been
too explicit in my instructions for image formatting. Basically you just need to
make the stereo pair fit the front opening of the viewer. That's really about all
there is to it, for the most part everything else just falls out naturally.
Ken Ken Ken Ken