3-D Image Printing: A Crash Course

Transcription

3-D Image Printing: A Crash Course
3-D Image Printing:
A Crash Course
Recent years have seen incredible advances in technology, specifically in how we
communicate with one another. Naturally, even in the face of myriad online offerings
that can be accessed through more portable, intuitive devices, printers and graphic
communicators continue to defend their position as a viable information source.
Many are purchasing equipment and software and training personnel in added-value
services such as mailing, fulfillment, and database management. Others are bolstering their production and finishing capabilities to offer either a greater variety of
products or to better specialize in producing a niche offering.
In and of themselves, those additions can be extremely effective means of enticing
potential and current clients to make use of your services. Unfortunately, they all require some form of expenditure—usually significant—-before they can fit seamlessly
into your existing catalog.
The 3-D Re-Revolution
Doubtless you’ve seen the numerous advertisements for three-dimensional (3-D)
films and other 3-D enabled technologies such as televisions, hand-held gaming
consoles, etc. Who knows, maybe you’ve printed some of those advertisements in
your own plant. Many of us remember 3-D fads of the past as just that—fads. But,
like it or not, that fad is rapidly returning to the forefront of all media consumers’
minds, and whether this “fad” passes once again or is here to stay, there’s absolutely no reason that you can’t take advantage of it while it enjoys its return to popularity.
“If the purpose of using novel imaging technology is simply because it is new, or it is
The most important thing to
used for trivial reasons, it is doomed to fail,”
consider is whether the subject
said Manfred Breede, retired graphic commatter is appropriate for the 3-D
munications professor at Ryerson University
treatment.
and author of the books Adding Value to Print,
Handbook of Graphic Arts Equations, and The
Brave New World of Publishing. “3-D imaging
techniques serve their purpose best if the message one wants to convey or the information one wants to extract is enhanced by three-dimensionality.”
Selling 3-D Printing
Consider a brochure for a local retailer. You could use 3-D image printing to add
depth to the products therein. But, how much more does that really entice the reader
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The trick to success with 3-D image printing is not so much in the production of the
image and distribution of the proper materials with which to view them—though, naturally, these are important elements. Rather, the most important thing to consider
is whether the subject matter is appropriate for the 3-D treatment. Be careful not to
use this technique “just because you can.”
3-D Image Printing: A Crash Course
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to buy any of those products? Now consider the 3-D television that the same retailer
might offer in its electronics section. If you can use 3-D image printing to show
that product’s potential on the page, the advertisement becomes that much more
compelling to someone considering such a purchase. Maybe you can work with the
retailer on a special mini-catalog highlighting the 3-D technology they offer.
The same can be applied to location-based promotions. How much easier will it be
to sell a sunny resort destination vacation package if you can put the reader right
on the beach? What about a collegiate athletic program? Put the viewer right in the
stands or, better yet, on the field.
Once you’ve sold the value proposition of a 3-D piece, now all you have
to do is come up with the images.
3-D Theory
The 3-D Image Engine
Let’s face it, without the proper viewer, all of your 3-D efforts
aren’t worth the paper on which they’re printed. Proper 3-D
viewers are the engine that drives your project and enables
it to reach its full potential. When it comes time to map out
your 3-D image printing job, make sure you have a plan for
getting viewers into the hands of those who will be looking at
the final piece.
You can purchase bulk orders of standard anaglyph viewers
at the following websites:
• www.3dstereo.com
• www.berezin.com/3D/
• Or, if you have the means, you can always construct them
in house.
Consider how you want the reader to interact with the viewer.
Will they be tipped in, glued, clipped, etc.? Do you need to
plan perforations and a guide for the readers to “construct”
the viewers themselves?
Unlike most other special effects
printing techniques, anaglyph images do not in any way depend on special inks or substrates, but they are created
by a non-standard color separation technique, where certain color channels of each
of the two images are omitted and subsequently merged into one flattened image.
The perception of depth in anaglyph images is created by the left and right eyes receiving slightly different images and distinctively different color information. The two
images are being offset in the horizontal direction. The red filter of the spectacles
transmits red image content to the left eye, while the cyan filter transmits blue and
green image content to the right eye.
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The illusion of depth by stereoscopy can be created by a number
of different methods, but the presentation of a slightly different
image to each eye is the underlying principle that produces them
all. Most of these techniques also
require some kind of viewer, such
as parallel sighting or crossed-eye
stereoscopes, head-mounted displays, LCD shutter glasses, polarized glasses, interference technology glasses, or complementary color
filter glasses. The latter method is
used for viewing anaglyph images
through spectacles with a red filter
for the left eye and a cyan filter for
the right eye. Because of the low
cost of these spectacles, which can
be manufactured from cardboard
and plastic filter foils, anaglyph images are a relatively low-cost method for print-based 3-D images.
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The combinatory effects of the red and cyan filters transmitting blue, green, and red
colors provide theoretically enough color information to reproduce chromatic images.
This despite the fact that the filtered light originated from two different sources, because the human visual system merges the light transmitted from both filters into
one cohesive image. In practice however, some colors (red hues in particular) will
suffer some loss of color fidelity.
Creating
the Image
What follows are the photographic setup and color separation procedures to produce
an anaglyph image.
Overview
1. U
sing a digital camera, photograph a scene; then move the camera horizontally
for the second shot of the same scene (Figure 1A and Figure 1B).
2. In the RGB color mode of an image editing software program, remove the red
component of the right image. Then remove the green and blue components of
the left image.
3. Merge both images.
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Figure 1
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Step-by-Step Photoshop CS4 Procedure (using two images)
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1. Open both images in Photoshop.
2. Select the RGB color mode (Image > Mode > RGB Color).
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3-D Image Printing: A Crash Course
Figure 2
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3. T o compensate for a loss of saturation when the image is viewed through anaglyph glasses,
J increase the saturation of both images. The amount of saturation
increase can only be determined by trial and error, as it depends on the predominant colors of an image (Image > Adjustments > Hue > Saturation).
4. S
elect the right image and remove the red component (Image > Adjustments >
Levels > Channels).
5. S
elect R from the Channel drop-down menu, then change the second Output level
to 0 (click OK). The right image is now cyan (Figure 2A).
6. S
elect the left image and remove the Green and the Blue components (Image >
Adjustments > Levels > Channel).
8. S
elect B from the Channel drop-down menu; then change the second Output level
to 0 (click OK). The left image is now red (Figure 2B).
9. Select the right image and copy it to the clipboard (Select > All; Edit > Copy).
10. C
reate a bigger window to allow for space around the 3-D image (File > New). Add
200 pixels to the Width and Height dimensions.
11. Place the right image in the center of the new window (Paste).
12. Select the left image and copy it to the clipboard (Select > All; Edit > Copy).
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7. S
elect G from the Channels drop-down menu, then change the second Output
level to 0.
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13. P
lace the left image in perfect registration with the right image with respect to
their edges (Paste).
14. C
hange the way the top layer reacts with the bottom layer (click on the top layer in
the Layers palette). Select (Screen) from the drop-down menu. The red and cyan
layers appear misregistered.
15. V iew the image in 3-D through anaglyph glasses.
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djust the misregistration, but do not eliminate it, so as to minimize ghosting
and maximize depth.
17. If necessary crop the image to eliminate color offsets at the right or left margins.
18. Save the 3-D image with a new name (File > Save As).
When the red image is to
the right of the cyan image,
one speaks of a negative
parallax. The opposite is
called a positive parallax.
If both the red and cyan images register perfectly, a
zero parallax condition exists. A negative parallax results in the image or parts
of the image to be levitating
in space above the picture
plane (Figure 3A). Positive
parallax causes the image
to penetrate into the depth
behind the picture plane
(Figure 3B) and in a zero
parallax condition the image
is even with the picture plane.
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Converting 2-D Images into 3-D Images
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It is also possible to create anaglyphs
from a single image by applying the
above step-by-step procedures to the
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original image and an exact copy
the original (Figure 4). One image is
arbitrarily selected as the right and the
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other as the left image. This produces
a simple 3-D effect that is relative to
the picture plane but not relative to elements of the image itself.
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Figure 4
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3-D Image Printing: A Crash Course
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To produce multiple depth levels of elements within the image itself (Figure 5A)
a depth map is created in Photoshop to
determine relative depth levels (Figure
5B) and Photoshop’s Displace filter function is used to offset the left and the right
images.
Step-by-Step Photoshop CS4
Procedure to Convert a 2-D
Image to a 3-D image
1. Select a 2-D image.
2. R
ename the image “left” and open it
(File > Open).
3. C
reate a new layer (Layer > New >
Layer).
4. W
ith the new layer still selected, create
a gradient fill with the Gradient Tool. If
the nearest image element is at the
bottom of the image and the farthest
image element is at the top of the image, create a gradient fill that is white
at the bottom and black at the top.
5. In the Layers palette, move the Opacity
slider so that the image underneath
becomes visible.
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Figure 5
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6. In the Tool panel, set the fore and background to black and white respectively.
7. W
ith the Eyedropper Tool, sample a given image
H area and trace, as well as fill
it in, with the Brush Tool. This will create varying levels of gray image areas, as
near and far image areas are located beneath a different gradient fill gray level,
effectively generating near image areas thatI are lighter than far image areas.
8. Save the image map layer as a separate file named “depth map” (File > Save As).
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10. T he Displace menu appears. Set the Horizontal Scale to a positive value. The
greater the Horizontal Scale value, the larger the stereoscopic parallax will be.
For example, the Horizontal Scale for the seagull image was set to 5. The Vertical Scale is always set to 0. If the Stretch To Fit and Repeat Edge Pixels radio
buttons are not already selected, select them now.
11. C
lick “OK” and select the previously created depth map named “depth map” and
open it.
12. T he image named “left” will now have the required stereoscopic parallax. Save
the first of two images and name it “right” (File > Save As).
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9. O
pen the file named “left” to generate the first image with a stereoscopic parallax by way of the Displace function (Filter > Distort > Displace).
3-D Image Printing: A Crash Course
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13. O
pen the file named “left” to generate the second image with a stereoscopic
parallax by way of the Displace function (Filter > Distort > Displace).
14. T he Displace menu appears. Set the Horizontal Scale to the same setting as the
image saved under the name “right,” but assign a negative value. The Vertical
Scale is always set to 0. If the Stretch To Fit and Repeat Edge Pixels radio buttons
are not already selected, select them now.
15. C
lick “OK.” Select the previously created depth map named “depth map” and open it.
16. S
ave the second of two images—File > Save (it will have been saved with the
name “left”). From this point on apply the earlier step-by-step Photoshop CS4
procedure (using two images).
Phantograms
Phantograms display a deceptively realistic three-dimensional illusion of objects that
are observed from a higher vantage point (Figure 6). While three-dimensionality is
still achieved by the anaglyph method, the photographic setup for phantograms has
to follow some prescribed rules, and the left and the right images must be edited
before the anaglyph method is applied to them. The object to be photographed must
be placed on a rectangular base, such as a piece of cardboard. The two shots are
taken from above the object at an angle of about 45 degrees, in such a way that the
entire base is seen in the frame.
Because of the angle at which the camera was aimed at the object, the rectangular
outline of the base will have a perspective distortion that will have to be corrected
in image editing software. In Photoshop select: Filter > Distort > Lens Correction and
move the Vertical Perspective slider until the trapezoid-shaped base on which the
object rests is once again rectangular.
From this point on the anaglyph method is applied to the two images as outlined in
the earlier procedures. Additionally, the red and cyan layers in Figure 6B were rotated 3º in opposite directions in order to create a negative parallax at the top of the
food can and zero parallax at the bottom.
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Figure 6
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3-D Image Printing: A Crash Course
Tips
for
8
Shooting Effective 3-D Photographs
Images with long depths of field should have a distinct image element in the foreground and one or more distinct image elements at some distance away. Examples
include a lamppost in the foreground and a building in the distance, or a building in
the foreground and a mountain range in the distance. All elements must be static.
Anaglyphs with elements in motion can only be produced with dual lens arrangements. Choose objects with near-neutral white or light gray hues—such as concrete
architectural details or marble statues—to be in the foreground.
Conclusion
Compared to many options you might consider for adding value to your finished
products, the creation and placement of 3-D images is relatively inexpensive, and
chances are great that you already have everything you need to jump right in.
Additional Value-Add Options
In addition to exploring 3-D image printing, Manfred H. Breede’s new book, Adding
Value to Print: A Survey of Novel Products, Finishing Techniques, and Materials Options offers insights into additional avenues printers can explore to enhance their
existing product offerings as well as producing valuable complements to the newest
media channels that are challenging print’s position in the communications arena.
Seven-Minute Solutions
Contact Member Central at [email protected], 1-800-910-4283 ext. 770,
412-259-1770 or visit www.printing.org/store for more information on the book.
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