Lecture 6 Flashcards
5 parts of image processor
Preprocessor Scan converter Image memory Postprocessor Digital to analog converter
Scan line information is built into _____ of info
Frames
The scan line info being changed into frames is called
Pre-processed
Where are frames stored
Image memory
Frames are pulled out of memory and
Post processed
Where is the frames sent after post processing
Sent to display as an analog signal
What does the scan conversion
Scan converter
What is scan conversion
Building a frame
What happens during scan conversion
Digital echo information of scan line changed to digital image form of frames
Scan conversion is responsible for
Properly locating each echo on the image frame
Scan conversion happens in
Real time
96-256 scan lines in a frame
Each frame is made up of a matrix of tiny blocks called
Pixel
___pixels = better resolution
More
Pixels in 3 D are called
Voxels
Frames require _______
Processing
When is pre processing done
Done while echo data is being stored in the memory
The frame is still being built during this time
When is post processing done
Done on image retrieved from image memory
Other functions of preprocessing (5)
Persistence, panoramic, 3D and 4D, spatial compounding, Write magnification
Functions of post processing (5)
B colour Freeze frame Black/ white image inversion Read magnification Contrast variation
What is edge enhancement of preprocessing
Sharpens boundaries to make them more detectable and make measurements more precise
What is pixel interpolation in the pre-processing ?
Filling in missed pixels
aka fill-in interpolation
Where are pixels missing
At the deeper portions of the echoes where the rays spread out more on curved probe
How is pixel interpolation done
Average the brightness of the adjacent pixels and fill in the missing pixel accordingly
What is panoramic imaging in the pre processing
Compilation of frames as transducer is moved
Results in an image with a wider field of view
What is panaramic imaging limited by
Sonographer skill
