Sampling
Realities of Focal Plane Arrays
Electronic imaging: real
data or artifacts?
or
Why are pictures "blocky?"
What is the resolution limit?
COURSE DESCRIPTION:
Sampling is an inherent feature of all electronic
imaging systems. It affects data interpretation
and displayed imagery. This course covers
all aspects of sampling: aliasing, Moiré
patterns, and variations in object edge
location and width. These effects are rarely
reported when viewing natural scenery although
present. They can dominate machine vision
system performance, camera characterization,
and resolution. The severity depends upon
the relationship between the blur diameter
and detector size. This changes as the lens
f-number changes.
To satisfy the sampling theorem, the signal
must be band-limited, the digitizer must
sample the signal at an adequate rate, and
a low-pass reconstruction filter must be
present. These conditions are not present
in today's camera systems and the reconstructed
image cannot appear exactly as the original.
BENEFITS:
This course will allow you to:
- Understand the Nyquist frequency limit
- Understand the trade-off between MTF
and aliasing
- Distinguish between aliasing and incomplete
reconstruction
- Understand why we can "see"
digital data
- Be able to determine how many samples
are adequate
- Understand why test targets "enhance"
aliasing
INTENDED AUDIENCE:
The course is for managers, system designers,
test engineers, machine vision specialist
and CCD camera users who want the best performance
from their systems.
RECOMMENDED TEXT:
"Sampling, Aliasing, and Data Fidelity,"
by Gerald C. Holst, JCD Publishing, 1998.
TYPICAL COSTS:
Call 407-365-5762 for additional information
and pricing or e-mail
us.
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