Lesson 6 (Part 2) Flashcards
What type of processing is write magnification?
Preprocessing
Write magnification
Uses a small field of view so the pixels fill up the entire frame to get a better resolution
When is post processing done?
Done on the image after the data has been stored and in the image memory
- can be done on a frozen image
What are 5 examples of post processing?
- B colour
- Freeze frame
- Black/white image inversion
- Read magnification
- Contrast variation
B colour
Similar to tint
- displays different colour
How many shades of gray can the human eye detect?
100 shades
How many shades of colour can the human eye detect?
256 shades
Freeze frame
Can adjust the frame after the image is frozen
Black/white image inversion
Highest intensities will appear white in a black picture and vis versa for a white picture
- most of the echoes are bouncing back
Read magnification
Pulls out specific pixels from the frame and memory and displays them using the entire display
What does read magnification act as?
Zoom
Where is pixel interpolation most common?
When using a sector scan
- as the beams go out they get farther apart
What does speckle reduction (persistence) improve? (2)
- Dynamic range
2. Contrast resolution
Why does persistence decrease frame rate?
Because the averaged frames are no longer independent
What are lower levels of persistence appropriate for following?
Rapidly moving structures
