digital imaging and image manipulation

Question 1

-older tech
-require an additional power via adjunct box to convert photon energy to electronic digital signl

Answer 1

CCD

Question 2

each pixel has to be sent to the ADC to be read, then transferred to voltage. what is this

[photon-to-electron conversion]
then
[electron-to-voltage conversion]

Answer 2

CCD

Question 3

each pixel can be read in voltages directly in sensory

[ so photon to electron to voltage]

Answer 3

CMOS

Question 4

compare/contrast CCD and CMOS

Answer 4

CMOS
-less power consumption (40 mW)
-low sens to xrays [CCD high]
-medium cost [CCD is high]
-voltage pixel signal [CCD is electrons]
-chip output: bit (digital) [CCD is voltage (analog)]
high sensor complex [CCD low sensor complexity]
[CCD system complexity high]

Question 5

what is newer, require less power, superior?? image quality

Answer 5

CMOS

Question 6

the number of colors (or gray shades) that a pixel is able to show

Answer 6

bit depth

Question 7

what is the average bit depth nowadays

Answer 7

8 bits (2^8)=256 shades but we are around 8-16 bit depths now

Question 8

increasing bit depth does what to shades of gray

Answer 8

increases shades of gray

Question 9

___ and ____ plates have been applied in panoramic and plain skull images

Answer 9

CCD and PSP

Question 10

why digital imaging is appealing?

Answer 10

-significantly less radiation
-better image(?)
-lower costs
(reduced pt chair time, no variable cost like darkroom)
-environmentally friendly- less toxic chemicals are disposed into the sewage systems

Question 11

why digital imaging should be appealing

Answer 11

-electronic communication improves efficiency
-rapid acquisition and storage
-image portability (storage, transmission, duplication)

Question 12

digital image processing/modifications-> mathematical manipulation of image data:

Answer 12

-compression
-imaging manipulations (qualitative)
-automated image analysis

Question 13

mathematical manipulation of image data:

Answer 13

-compression
-imaging manipulation (qualitative)
-automated image analysis (quantitative)
-image reconstruction

Question 14

what is image processing?

Answer 14

mathematical manipulation of image data

Question 15

-uses mathematical operations called matrix transformers
-maginfy, adjust contrast, brightness, gray scale, colors, swap black and white

Answer 15

qualitative

Question 16

-measures length(# of pixels for length, area, circumference)
-measures pixel values (bone, enamel, dentin, pulp, soft tissue densities)

Answer 16

quantitative

Question 17

affects image file size in memory storage
-useful for storage issues (zipping) files
-actual file size is larger than stored file size
-algorithm that can shrink the file size for storage and recreate the data when retrieving the data

Answer 17

compression

Question 18

file memory can come quite large because of

Answer 18

-size of grid(sensor size)
-number of images
-bit depth

Question 19

affects image storage

Answer 19

compression

Question 20

to be able to do this, the computer will change density values to predetermine numbers which then changes the image’s presentation (light or darker)
-are post-displayed mathematical algorithms that manipulate the digita signal

Answer 20

image manipulation
(sharpening/density/contrast/brightness)

Question 21

does image manipulation increase the diagnostic accuracy?

Answer 21

NO

Question 22

-removes low-frequency noise; increases image contrast
-exaggerate the contrast difference between adjacent pixels; to increase contrast, all pixel values are stretched; dark shades become darker and light shades become lighter
-enhances local contrast and makes edges sharper to diagnose caries, restoration fit and fractures

Answer 22

sharpening filter edge enhancement

Question 23

applies a three dimensional effect to the image
-could be useful in presentation situations

Answer 23

emboss function (inactive)

Question 24

-length
-angles
-bone density
-area
-circumference
-measurement calibration

Answer 24

automated image analysis (quanititative)

Question 25

data is utilized by other software programs and produces different image presentations

Answer 25

image reconstruction