Linear regression: Univariate and Multivariate model

Here is a simple univariate linear equation:

$$y=ax+b$$

The goal here is to find the coefficients a,b to fit the linear model. For example, I applied iris data with only petal and sepal length. I want to predict petal length by using sepal length.

Let the input as sepal length, petal length as predict variable.

SIFT Scale-Invariant Feature Transform

SIFT is commonly used in feature detectors in computer vision. Today I'm gonna briefly explain the concepts of what I learned.

Here is the an image and we want to extract key points of it: