ComputerVision101_Week1_LocalOperators

university computervision week1 theory

Local Operators

Source:

• CV101_LectureNotes1b

Idea

Local or point operators process an image pixel by pixel.

At each location, the output value depends on the input value at the same location.

General form:

$$g=\Psi f$$

and pointwise:

$$g(x)=\psi (f(x))$$

Typical examples

• negation:

$$g(x)=1-f(x)$$

• add a scalar:

$$g=f+1$$

• logarithmic transform:

$$g=\log (1+f)$$

• thresholding:

$$g=[f>\text{thresh}]$$

Important idea

These operators change values, not pixel coordinates.

So they are different from geometric operations like interpolation or warping.

Related notes

• ComputerVision101_Week1_ImageArithmetic
• ComputerVision101_Week1_AlphaBlending
• ComputerVision101_Week1_UnsharpMasking
• ComputerVision101_Week1_Thresholding