CVP Basic Certified Vision Professional (CVP) Basic Certification , A3
- Certified Vision Professional - Basic 11/4, CVP Test 1, Reflection
and Machine Vision System Design Skills, CVP Basic Exam FINAL,
Certified Vision Professional - Basic Additional Terms, Test bank
Exam
What are the limitations imposed by using a circular bright
field ring light geometry?
-limited only to intensity needed on part
-not good on reflective parts or objects
What are the limitations imposed by using a circular dark
field ring light geometry?
-light must be very close to part
-large footprint
-limited spot size
-ambient light may interfere
,Histogram Equalization (imaging processing)
-example of a look-up table
-alters gray scale values of pixels so that they become
evenly distributed across the full grayscale range
-associates an equal number of pixels per a constant
grayscale interval
-essentially changing the contrast of the image without
altering the spatial arrangement of pixels, meaning the
overall structure of the image (like edges and shapes)
remains the same, but the intensity values of each pixel
are adjusted to create a more even distribution across the
intensity range, making details more visible in low-
contrast areas
FOV calculation with fixed magnification:
FOV = sensor size/PMAG
,A lenses ability to reproduce contrast for a given
resolution is controlled by what?
theoretical limitations associated with laws of physics, the
actual design of the lens, and the the actual
manufacturing of the lens
Gain
-amplifies analog signal from pixel before conversion
--Pro: higher grayscale level (brighter)
--Con: introduces noise (6db gain = 2x noise)
-increases visibility of both signal and noise
-should only be used as a last resort to increase
brightness
, Exposure Time
-length of time that the sensor is open for collecting light.
Also, known as shutter speed and integration time.
-considerations:
--frame rate may be reduced with increase
--motion blur is greater with increase
--SNR is greatly increased with more exposure
Quantization Noise
-errors coming from the A/D conversion process
-use better ADC (anolog-to-digital converter) = less noise
Signal to Noise Ratio (SNR)
-ratio of good signal caused by light to unwanted noise.
The most important measurement of image quality for
digital cameras.
- Certified Vision Professional - Basic 11/4, CVP Test 1, Reflection
and Machine Vision System Design Skills, CVP Basic Exam FINAL,
Certified Vision Professional - Basic Additional Terms, Test bank
Exam
What are the limitations imposed by using a circular bright
field ring light geometry?
-limited only to intensity needed on part
-not good on reflective parts or objects
What are the limitations imposed by using a circular dark
field ring light geometry?
-light must be very close to part
-large footprint
-limited spot size
-ambient light may interfere
,Histogram Equalization (imaging processing)
-example of a look-up table
-alters gray scale values of pixels so that they become
evenly distributed across the full grayscale range
-associates an equal number of pixels per a constant
grayscale interval
-essentially changing the contrast of the image without
altering the spatial arrangement of pixels, meaning the
overall structure of the image (like edges and shapes)
remains the same, but the intensity values of each pixel
are adjusted to create a more even distribution across the
intensity range, making details more visible in low-
contrast areas
FOV calculation with fixed magnification:
FOV = sensor size/PMAG
,A lenses ability to reproduce contrast for a given
resolution is controlled by what?
theoretical limitations associated with laws of physics, the
actual design of the lens, and the the actual
manufacturing of the lens
Gain
-amplifies analog signal from pixel before conversion
--Pro: higher grayscale level (brighter)
--Con: introduces noise (6db gain = 2x noise)
-increases visibility of both signal and noise
-should only be used as a last resort to increase
brightness
, Exposure Time
-length of time that the sensor is open for collecting light.
Also, known as shutter speed and integration time.
-considerations:
--frame rate may be reduced with increase
--motion blur is greater with increase
--SNR is greatly increased with more exposure
Quantization Noise
-errors coming from the A/D conversion process
-use better ADC (anolog-to-digital converter) = less noise
Signal to Noise Ratio (SNR)
-ratio of good signal caused by light to unwanted noise.
The most important measurement of image quality for
digital cameras.
