Update or add custom-created classes. The update or new class will be assigned if the expression is satisfied.

The last Expression can be true which will imply that the last expression will always be assigned if all above evaluates as false

Parameters

Classification descriptor

Choose the classification descriptor to modify.

Expression

Choose a class from the category and write the expression for it.

The operators that can be used:

  • Equals - =

  • And - &

  • Or - |

  • Less than - <

  • Less or equal - <=

  • Larger than - >

  • Larger or equal - >=

  • Different from !=

The parameters that can be used:

  • Area

  • Length

  • Width

  • Circumference

  • Regularity

  • Roundness

  • Angle

  • D1

  • D2

  • X

  • Y

  • MaxBorderDistance

  • BoundingBoxArea

Pretreatments

Apply one or more pretreatments to spectrum, see Pretreatments

Replace

✅ Replace the classification column in the table.

⬜ Do not replace the classification column in the table instead adds a new column.

Example

Spatial descriptor

Expression:

roundness < 10 & area >5

Bands

Indexing with 1 based index in band list.

Expression:

(b10 >1.5 | b15 < 2) & b20 <= 1.2

Number

Number of pixels by a implicit and explicit given class

Expression:

[class A][ number > 10] -> Number of pixels of Class A more than 10

[class B][ precentClassA <= 10] -> Number of pixels of Class A less or equal to 10

Percent

Percent of pixels the total object, by a implicit and explicit given class

Expression:

[class A][ percent > 0.5] -> percent of pixels of Class A more than 50%

[class B][ precentClassA <= 0.5] -> percent of pixels of Class A less or equal to 50%

Connected

Number of pixels of the largest connected class-object within the object.

Expression:

[class A][ connected > 10] -> Number of connected pixels of Class A more than 10

[class B][ connectedClassA <= 10] -> Number of connected pixels of Class A less or equal to 10

Class

Compare predicted class with explicit given class

Expression:

[New Class][class = classA] => Create New Class if predicted class equals to class A
[New Class][class != classB and class != classNone] => Create New Class if predicted class is not class B and not no class

No class is specified as classNone

Wire detection

Wire detection algorithm using kernel

Syntax:

iswire + kernel size, default is 3.

Expression:

iswire, iswire3, iswire5

Variables

For assigning variables values which can be updated at runtime. The default value will be restored after each
Play-run.

Syntax:

var("Variable name", Default value)

Expression:

var("Variable A", 10)

Class expressions

For comparison based on a class related value.

Syntax:
Implicit- Within the class expression
Explicit - Sets given class after name