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