Image pre-processing I & II

Question 1

Image processing is also called

Answer 1

Image restoration

Question 2

Image pre-processing is ….

Answer 2

a preparatory phase to improve image quality as a basis for further analysis

Question 3

Unprocessed images can be very

Answer 3

noisy, incomplete and inconsistent

Question 4

Errors in image classification can be divided into two. What are they?

Answer 4

System and non-system errors

Question 5

Internal errors due to the sensor itself is

Answer 5

System errors

Question 6

External errors are ?

Answer 6

non-system errors

Question 7

A system error caused by failure of one of the detectors is

Answer 7

line drop-outs

Question 8

A system error caused by incorrect calibration of one of the n detectors is

Answer 8

N-line striping

Question 9

An error caused by variations of neighboring forward and backward scans of the landsat thematic mapper is ….

Answer 9

Banding

Question 10

Failure of one or more detectors to start collecting data along a line is

Answer 10

line-start

Question 11

An error that is created due to atmospheric haze which scatters short wavelengths bands is called

Answer 11

Uniformly elevated values

Question 12

An error due to unpredictable or unsystematic performance of the sensor is

Answer 12

random noise

Question 13

When does striping occur?

Answer 13

when a detector goes out of adjustment

Question 14

Banding is most evident in ?

Answer 14

water bodies or areas with low variability

Question 15

Line drop out can be removed by …

Answer 15

Principal component analysis (PCA)

Question 16

A common device error caused by either a failed detector or a completely saturated is called

Answer 16

Line drop out

Question 17

If an image is already geo referenced, will destriping work?

Answer 17

No

Question 18

What are the two sources of u systematic errors?

Answer 18

Topography and atmosphere attenuation

Question 19

Error when the ground swath is skewed is called

Answer 19

Scan skew

Question 20

Error due to change in speed of the platform is called

Answer 20

platform velocity

Question 21

Error due to rotation of the earth during scan period is

Answer 21

earth’s rotation

Question 22

Error when the rate of scanning is not constant is

Answer 22

mirror scan velocity

Question 23

Error when sensors produce images whose pixels are not square is

Answer 23

aspect ratio

Question 24

Pixel values in commercially available satellite 📡 imagery represent radiance in the form of ….

Answer 24

Digital numbers (DN)

Question 25

Assigning coordinates to known locations is

Answer 25

rectification

Question 26

Resetting the pixels to match the ground control point is

Answer 26

Resampling

Question 27

The process of making an image conform to another image is

Answer 27

Registration

Question 28

A specific pixel on an image or location on a map whose geographic coordinates are known is called

Answer 28

ground control point

Question 29

……are needed for geo referencing.

Answer 29

GCP’s

Question 30

…… are used to correct image distortions by matching image coordinates to the map.

Answer 30

GCP’s

Question 31

The process of transforming the data from one grid system into another an nth order polynomial is called

Answer 31

rectification

Question 32

The two types of transformation available for rectification are

Answer 32

linear and non-linear transformation

Question 33

Raw remote sensing data contain distortions, preventing overlay with map layers, comparison between image scenes, and with new geographic coordinates. Which geometric correction can be used?

Answer 33

Rectification

Question 34

Since pixels of new grid systems do not align with old grid systems, the former must be ?

Answer 34

resampled

Question 35

Resampling is also known as

Answer 35

pixel value or intensity interpolation

Question 36

Example of radiometric correction is ?

Answer 36

Mosaicking, FLAASH, Quac

Question 37

Geo referencing is an example of what type of pre processing?

Answer 37

Geometric correction

Question 38

……. helps convert data to real world coordinates

Answer 38

geometric correction

Question 39

The resampling method that assigns output pixel values by interpolating brightness values into two orthogonal directions in the input image is called

Answer 39

Bilinear interpolation

Question 40

What resampling method is the slowest ?

Answer 40

Cubic convolution

Question 41

The most computationally intensive resampling method is ?

Answer 41

cubic convolution

Question 42

Which geometric correction method is known to cause the problem of duplicating pixel values and loss of some pixel values ?

Answer 42

nearest neighbor

Question 43

…… is done to remove effects of atmosphere from the data.

Answer 43

atmosphere correction or modeling

Question 44

What is used to create output images by combining the DN’s of different bands mathematically?

Answer 44

Indices

Question 45

……. is used as a method of data compression.

Answer 45

principal component analysis

Question 46

……uses a more complicated mathematical combination of many bands to define vegetation.

Answer 46

Tasseled Cap Transformation (T-Cap)