Displays Flashcards
Many shades of gray, multiple levels, low contrast, why dynamic range, and good contrast resolution are all indicative of what?
Gray scale
Two choices – black or white, on or off, high contrast, narrow dynamic range, and poor contrast resolution are all indicative of what?
Bistable image
This converts the image into numbers which are stored in memory. The numbers, digital image data, can be processed and then re-translated for display as an image.
Digital scan converter
The smallest element of a digital picture
Pixel
The more pixels per inch the more detail in the image, spatial or detail resolution.
Pixel density
The smallest amount of digital storage
Bit - BInary digiT
A group of bits
Binary number
A group of eight bits
Byte
Two bytes
Word
How many bits are needed to represent 10 shades of gray?
Four bits
What number of shades can be represented by 10 bits?
2×2×2×2×2×2×2×2×2×2 = 2^10 = 1024
Manipulating the data before storage in the scan converter
Preprocessing
Manipulating the data after it has been stored in the scan converter memory but prior to display
Postprocessing
Preprocessing or postprocessing? TGC, log compression, right magnification, fill in interpolation, persistence, spatial compounding
Preprocessing
Related to ability of humans to see the grayscale differences in anatomic structures. Lowers the high-level echoes and boosts the low-level echoes. The image data’s dynamic range is reduced. Controlled by the sonographer.
Log compression
