| . |
. |
Multiplane image stabilization
achieves long handheld exposures
Although use of a tripod is common in photography
with longer exposure times, Sony’s
multiplane image stabilization makes handholding
possible in such situations. The multiplane
image stabilization provided by this high-speed
imaging system captures, using a shutter speed
much faster than normal, several frames that do
not have blur (for example, 8 frames) and creates
a single image synthesized from the reference
image by matching the positions. (See figure 4.)
To implement this function, the CXD4109AGG
includes both a high-precision motion vector
detection engine that calculates the amount
of blur and a multiplane synthesis engine that
combines multiple images while matching their
positions. The affine transformation model is
adopted for position matching and can perform
rotation correction, which is impossible with
optical image stabilization systems such as lens
shift and sensor shift methods. This makes it
possible to retain high resolution even after synthesis. Furthermore, it is possible to achieve
extended-period handheld photography with
exposure times up to one second by combining
multiplane image stabilization and optical
image stabilization. In combination with the
noise reduction effect due to the multiplane
synthesis, this system can perform extremely
high-precision image stabilization, and make
handheld photography possible.
Multiplane wide dynamic range:
significantly improved image quality in
backlit situations
The multiplane wide dynamic range function
makes it possible to obtain a dynamic range
correction effect while maintaining a high signal-to-noise ratio even in conditions when the
subject is dark and other parts of the image are
bright, for example when the subject is backlit.
This high-speed imaging system achieves
wide dynamic range imaging by combining
multiplane synthesis with this dynamic range
correction function.
Figure 5 shows comparison images for normal
imaging and multiplane wide dynamic range
imaging. Since the subject in figure 5A is backlit, in this
normal imaging example the main subject, the
doll, is relatively dark. Normally, to show the
main subject, one would apply an exposure compensation
of around +2EV as shown in figure
5B. Although the main subject will be correctly
exposed by this method, the background will
be overexposed to the point of saturation. If the
dynamic range correction function provided by
this system is used, it is possible to show both
the background and the main subject at the
same time under backlit conditions as shown in
figure 5C. Figure 5D shows a multiplane wide
dynamic range imaging example in which these
two functions are combined. The main subject
and the background are both faithfully rendered
by the dynamic range correction signal processing,
and furthermore, a high signal-to-noise ratio
image is created by multiplane synthesis.
It is now possible to record the whole brightness
scale as seen with no degradation of picture
quality even for subjects that have such a large
difference between their dark and bright areas
that the bright areas would be overexposed by
earlier cameras. |
|
Multiplane Synthesis: Creating New
Functions and Superb Picture Quality
Ultrahigh-Speed Imaging:
Seeing Things that Cannot be Seen
Vol.55