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Physics 4.3A
Term | Definition |
---|---|
Image Processor Parts | Preprocessor, post-processor, scan converter, analog to digital converter |
Image Processor Functions | converts scan line data into images, processes the images before storing them into the image memory |
Image Processor | processes them as they come out of the memory, coverts from digital to analog form, sends them out to display |
Preprocessing | Image processing done before storing in memory. Edge enhancement Persistence Write zoom Pixel interpolation Three Dimensional Acquisition |
Edge Enhancement | sharpens boundaries to make them more detectable and measurements more precise |
Persistence | Reduces noise and smooths the image by frame averaging Higher levels are appropriate for slow moving structures |
Pixel Interpolation | Fills in missing pixels Assigns brightness based on average brightness of adjacent pixels |
Three Dimensional Acquisition | Acquiring several two dimensional scans for three dimensional volume of information in the image memory |
Write Magnification | Smaller anatomic fields of view written into memory, Image can be enlarged without enlarging pixel size |
Scan Converters | to store and create each frame of information Analog Digital |
Analog | used vacuum tubes with a wire element |
Analog Scan Converters | advatages: continuous disadvantages: burned out, must warm up, drifted |
Digital Scan Converters | used in todays equipment, uses a computer |
Digital means... | "finger" or "toe", no drift, stable, lasts a long time, they are discrete |
ADC review | All components of the equipment use analog signal processing EXCEPT the memory Information stored in the memory MUST be in a digital signal |
The ADC is located, | Between the receiver and the memory converts the analog signal to a digital signal |
The ADC is located between the receiver and the memory | |
Image frames are stored in the memory | |
post processing occurs after images are stored in memory | |
Information from the memory goes on to the display for everyone to see |