Sample .mpo image (cacti)
The stereo images in this collection are all saved in the Multi Picture
Object (
.mpo) format, with each file containing two JPEG images
(the left and the right view).
- To see a full-size image, click on a thumbnail.
- To save a full-size image, ‘save link as’ or ‘save target as’ (most
browsers allow this on right click on the thumbnail); note that
stereo images should be saved with extension .mpo – your browser
may have changed that to .jpg.
Viewing with standard image viewers
Since the ‘wrapper’ for the two images is compatible with the common
.jpg format, it is possible to view the picture with a simple
image viewer (you may have to change the file extension to
.jpg
for the viewer to accept it). In this case (unless the viewer supports
multiple images):
- you will see just the left-hand view
- if you make any changes to the image then usually only the left-hand
image is altered
- if you save a changed image then only the left-hand view is saved
and the 3D information (the right-hand view) is then lost.
Viewing in 3D
There are several ways of viewing stereo images; a brief summary
is given below; for more details, a good place to start is the
Wikipedia article on Stereoscopy ».
An effective program for presenting and working with 3D images is
the free
StereoPhoto Maker », which supports
the .mpo format and allows the 3D images to be manipulated and
viewed in a variety of ways. (Its interface is a bit quirky and
often differs from its Help, however.)
Common ways of viewing 3D images include:
Sample side-by-side image (cactus)
side-by-side – the two images are presented on a monitor
or printed next to each other:
- direct view – some people can view 3D images by viewing wide-eyed
or cross-eyed
- stereoscopes – a device with two prisms and/or lenses which make
it easier to view side-by-side images.
Sample Anaglyph (Lago Ercina)
anaglyph – the images are combined into a single image to
be viewed using glasses which usually have a red filter over the
left eye and a cyan filter over the right eye:
- the images are processed (e.g., by StereoPhoto Maker) to form an
anaglyph which can be viewed immediately with the appropriate filter
glasses or saved as a .jpg image (here is an example); the colours in anaglyphs are affected by the filtering
– so anaglyphs work best for images that are monochrome or mostly
greens and greys.
3D monitor or TV – many display devices support 3D display
for viewing with special glasses; again, StereoPhoto Maker can be
used for presenting the pictures. There are two common technologies:
- passive – the left and right images are presented on alternating
rows of the screen and are viewed with polarized glasses (similar
to those used in cinemas); this loses half the vertical resolution
but the passive glasses are lightweight and inexpensive
- active – the images are presented in successive frames and active
‘shutter’ glasses are used to switch synchronously with the frames
so that each eye sees alternate frames; this requires a special graphics
card which can refresh the monitor at 120 Hz (twice the usual rate)
and battery powered glasses (which some people find heavy and others
find cause flicker).
Many sites on the web describe these (and other) viewing methods.
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This page was last
edited on 2013-12-10 by mfc.