Chapter 7

Question 1

What does BLOB stand for?

Answer 1

Binary large object.

Question 2

What is connectivity

Answer 2

Relates to whether to objects are connected or not.

Question 3

Two types of connectivity:

Answer 3

4- and 8-connectivity.

Question 4

Grass-fire:

Answer 4

Pretend you light one place on fire (top left) and that the fire can only travel via 4-or 8-connectivity.

Question 5

What are BLOB-features?

Answer 5

Different attributes of BLOBs -this could be circularity. Often held up against known object.

Question 6

BLOB area:

Answer 6

Number of pixels in a blob

Question 7

BLOB bounding box:

Answer 7

The quadrate around the blob with sides lowest x and highest x and top and bottom lowest y and highest y.

Question 8

Bounding box ratio:

Answer 8

Height of box divided by width.

Question 9

Bounding circle:

Answer 9

same as BB but a circle.Found by finding center then looking in all directions.

Question 10

Feature vector:

Answer 10

All BLOB features collected in a vector.

Question 11

Convex hull:

Answer 11

minimum novex ploygon.

Question 12

BLOB compactness:

Answer 12

Area/BB_area

Question 13

Center of mass:

Answer 13

(average_x_coordinate, average_y_coordinate)

Question 14

Perimeter:

Answer 14

Like f(x,y) - erosion f(x,y)

Question 15

Circularity:

Answer 15

Perimeter_measured/perimeter_estimated

Question 16

BLOB classification

Answer 16

BLOBs can be classified on the basis of their features being within certain values.

Question 17

Feature space:

Answer 17

For Blob features a feature space can be made -basicallye every axis is a feature and you must stay within certain values of each feature to be in the feature space.

Question 18

What is a confusion matrix?

Answer 18

matrix listing

TN FP
FN TP

Question 19

Accuracy:

Answer 19

(TP+TN)/N

Question 20

Misclassification rate:

Answer 20

(FN+FP)/N

Question 21

True positive rate / sensitivity:

Answer 21

TP / (TP + FN)

Question 22

False positive rate

Answer 22

FP / (TN + FP)

Question 23

Specificity

Answer 23

TN / (TN + FP)

Question 24

Precision

Answer 24

TP / (FP + TP)