Chapter 2 Digital Image Processing Concepts
A common example of filtering in the spatial location domain is ________?
Convolution
The viewing task of the radiologist is to what?
Detect pathology
In digital radiography a ___ _____ is a numerical representation of the patient
Digital Image
Numerical representation of computer processing of digital data?
Digital Image
Is defined by as "subjecting numerical representations of objects to a series of operations in order to obtain a desired result" (castleman 1996)
Digital Image Processing
simply means the processing of images using a computer?
Digital Image Processing
implies that all the pixels in the entire input image are used to change the value of a pixel In the output image?
Global
Processing of an image that includes spatial filtering,image subtraction, and temporal averaging
Grayscale Processing
also known as edge enhancement or sharpness, is intended to sharpen an input image in the spatial domain that appears blurred.
High-pass filtering
Narrow WW provides a ______ image contrast and a wide WW will show an image with _____ contrast?
Higher Less
Is a graph of the number of pixels in the entire image or part of the image having the same grey levels (density values) plotted as a function of the gray levels
Histogram
improvement of image quality for the purposes of viewing needs, certain characteristics such as contours and shape can be enhanced to improve the overall quality of the image.
Image Enhancement
Digital image processing in which measurements and statistics are performed, in addition to image segments, feature extraction, and classification of objects.
Image analysis
Processing is now a routine activity in digital medical imaging,and it is also an essential tool in PACS environment?
Image post processing
A digital image is made up of a 2D array of numbers called a ______?
Matrix
What would generate an output signal in which intensity varies continuously depending on the location of the light on the image?
PMT (Photomultiplier tube)
Can be located using the X-Y coordinate system?
Pixel
Is simple and the most frequently used in digital diagnostic imaging?
Point processing operation
Process whereby the brightness levels obtained from sampling are assigned an integer (zero or negative or positive number) called a grey level
Quantization
Simply involves measuring the brightness level of each of the pixels using special devices such as a PMT
Sampling
There are three steps to digitizing an image?
Scanning Sampling Quantization
Is intended to reduce noise and the displayed brightness levels of pixels?
Smoothing
Domain in which images are acquired and described according to the wavelength of the signal used to acquire the image
Spatial frequency domain
The pixels that make up the matrix are generally what?
Square
Refers to subtraction of images in time, involves averaging a set of images to reduce image noise?
Temporal averaging
the information contained in a volume of tissue that is converted into numerical values and expressed in pixels?
Voxel (volume element)
A digital image made up of numbers is the _____ and the center of the range is defined as _____?
WW (window width) WL (window level)
an example of filtering in the spatial location domain?
convolution
The result of computer processing is a _____ _______?
digital image
When imaging a patient using a digital imaging modality, the operator selects the matrix size for the examination, sometimes referred to as the ____ ____ _____
field of view
improvement in quality of image that has distortions or degradations; for example sharpening of a blurred image.
image restoration
Images obtained in radiology can be represented in two domains?
spatial resolution domain spatial frequency domain
