## What is 5point algorithm?

The problem is to find the possible solutions for relative camera motion between two calibrated views given five corresponding points. The algorithm consists of computing the coefficients of a tenth degree polynomial and subsequently finding its roots.

**What is the meaning of essential matrix?**

In computer vision, the essential matrix is a matrix, that relates corresponding points in stereo images assuming that the cameras satisfy the pinhole camera model.

### What is the difference between Homography and fundamental matrix?

A homography is a special case of the Fundamental matrix. A homography is a special case of the Fundamental matrix. For the general case of a scene with objects at different depths, the geometry between two views is encapsulated by the Fundamental matrix. is a 33 matrix of rank 2.

**Why do we need 8 points instead of 9 for computing the fundamental matrix?**

It is because in the case of fundamental matrix, each correspondence point relates to only one constraint(i.e it maps a point to a line in other image). Hence 8 correspondence points are required.

#### What is Ransac 5points?

When the intrinsic parameters are known a priori, the five-point algorithm is a more direct way of en- forcing the calibration constraints exactly and obtaining a Euclidean reconstruction. In light of this, a RANSAC scheme that uses the five-point algorithm over three or more views is proposed.

**What is the difference between fundamental matrix and essential matrix?**

The essential matrix reveals the relation in global coordinates, while the fundamental matrix uses each camera’s intrinsics to relate them in pixel coordinates.

## What is homography in image processing?

Homography, also referred to as planar homography, is a transformation that is occurring between two planes. In other words, it is a mapping between two planar projections of an image. It is represented by a 3×3 transformation matrix in a homogenous coordinates space.

**Why is fundamental matrix important?**

The essential and fundamental matrices are 3×3 matrices that “encode” the epipolar geometry of two views. Motivation: Given a point in one image, multiplying by the essential/fundamental matrix will tell us which epipolar line to search along in the second view.

### What is the difference between essential matrix and fundamental matrix?

**How many points is a fundamental matrix?**

Being of rank two and determined only up to scale, the fundamental matrix can be estimated given at least seven point correspondences. Its seven parameters represent the only geometric information about cameras that can be obtained through point correspondences alone.

#### Why is the matrix rank 2 essential?

Geometrically, F represents a mapping from the 2-dimensional projective plane P2 of the first image to the pencil of epipolar lines through the epipole e . Thus, it represents a mapping from a 2-dimensional onto a 1-dimensional projective space, and hence must have rank 2.