Matrix size = - ANSWER Matrix size = M x N x k bits
Field of View (FOV) - ANSWER - Overall dimensions of
the matrix.
- In CR and DR the size
of the FOV is
determined by the
size of the detector
pixel size= - ANSWER FOV/matrix
What happens to pixel size as Matrix size increases (FOV stays the same) -
ANSWER As Matrix size gets bigger, pixel size gets smaller (if FOV stays the
same)
Bit Depth - ANSWER - Number of shades of gray each pixel is capable of
displaying
- M x N x k bits
- Each pixel =2k gray levels
- Increase bit depth = more shades of gray
Classes of Image Processing (5)? - ANSWER 1. Image Enhancement
Goal: to generate a more diagnostic image;
sharpening
2. Image Restoration
Goal: to improve the quality of images that have
distortions or degradations.
3.) Image synthesis
Goal: To crate a new image from other
images
4. Image Analysis
, Goal: allows measurements and statistics to be
performed; extraction of meaningful information
(ie. ROI in CT; leg length measurements)
5. Image Compression
Lossless compression (reversible
compression)
Lossy compression (irreversible
compression)
The spatial location domain - ANSWER Physical location of each pixel
relative to the entire
image
The spatial frequency domain - ANSWER The location of small structures
(details) versus
the location of large structures (contrast)
in an image
how do you Switch domains? - ANSWER The Fourier transform converts
from one domain to the other.
explain what Image Pre-Processing: Dead pixel means? - ANSWER • Pixels
that don't
respond to
radiation at all
• Appear as small
white dots prior
to preprocessing
explain what Image pre processing: Column Drop-out means? - ANSWER •
When an entire column of pixels don't work
• Appears as very straight vertical white line
explain what Image Pre-Processing: Detector seam means? - ANSWER •
Digital detectors are made of many parts stuck together
• Where 2 parts meet there will be a slight change in image
quality
Field of View (FOV) - ANSWER - Overall dimensions of
the matrix.
- In CR and DR the size
of the FOV is
determined by the
size of the detector
pixel size= - ANSWER FOV/matrix
What happens to pixel size as Matrix size increases (FOV stays the same) -
ANSWER As Matrix size gets bigger, pixel size gets smaller (if FOV stays the
same)
Bit Depth - ANSWER - Number of shades of gray each pixel is capable of
displaying
- M x N x k bits
- Each pixel =2k gray levels
- Increase bit depth = more shades of gray
Classes of Image Processing (5)? - ANSWER 1. Image Enhancement
Goal: to generate a more diagnostic image;
sharpening
2. Image Restoration
Goal: to improve the quality of images that have
distortions or degradations.
3.) Image synthesis
Goal: To crate a new image from other
images
4. Image Analysis
, Goal: allows measurements and statistics to be
performed; extraction of meaningful information
(ie. ROI in CT; leg length measurements)
5. Image Compression
Lossless compression (reversible
compression)
Lossy compression (irreversible
compression)
The spatial location domain - ANSWER Physical location of each pixel
relative to the entire
image
The spatial frequency domain - ANSWER The location of small structures
(details) versus
the location of large structures (contrast)
in an image
how do you Switch domains? - ANSWER The Fourier transform converts
from one domain to the other.
explain what Image Pre-Processing: Dead pixel means? - ANSWER • Pixels
that don't
respond to
radiation at all
• Appear as small
white dots prior
to preprocessing
explain what Image pre processing: Column Drop-out means? - ANSWER •
When an entire column of pixels don't work
• Appears as very straight vertical white line
explain what Image Pre-Processing: Detector seam means? - ANSWER •
Digital detectors are made of many parts stuck together
• Where 2 parts meet there will be a slight change in image
quality
