# How PCA can be used for face recognition?

## How PCA can be used for face recognition?

The main idea of using PCA for face recognition is to express the large 1-D vector of pixels constructed from 2-D facial image into the compact principal components of the feature space. This can be called eigenspace projection.

## Which algorithm is used for face recognition in Matlab?

Viola-Jones detection algorithm
Detect a Face The cascade object detector uses the Viola-Jones detection algorithm and a trained classification model for detection. By default, the detector is configured to detect faces, but it can be used to detect other types of objects.

How do I use face recognition in Matlab?

It is possible to achieve face recognition using MATLAB code. The built-in class and function in MATLAB can be used to detect the face, eyes, nose, and mouth. The object vision. CascadeObjectDetector System of the computer vision system toolbox recognizes objects based on the Viola-Jones face detection algorithm.

### What algorithm is used in face recognition?

The OpenCV method is a common method in face detection. It firstly extracts the feature images into a large sample set by extracting the face Haar features in the image and then uses the AdaBoost algorithm as the face detector.

### What is LDA in face recognition?

In this paper, Linear Discriminant Analysis (LDA) which is also called fisherface is an appearance-based technique used for the dimensionality reduction and recorded a great performance in face recognition. This method works on the same principle as the eigenface method (PCA).

How face is detected?

In short, the term face recognition extends beyond detecting the presence of a human face to determine whose face it is. The process uses a computer application that captures a digital image of an individual’s face — sometimes taken from a video frame — and compares it to images in a database of stored records.

#### How does Viola-Jones algorithm work?

Detection The Viola-Jones algorithm first detects the face on the grayscale image and then finds the location on the colored image. Viola-Jones outlines a box (as you can see on the right) and searches for a face within the box. It is essentially searching for these haar-like features, which will be explained later.

#### Is PCA good for images?

PCA is very useful for reducing many dimensions into a smaller set of dimensions, as humans can not visualize data on more than 3 dimensions it is usually helpful to reduce multidimensional datasets into 2 or 3 dimensions and graph them in order to get a better understanding of the data.

Can we apply PCA on images?

One of the use cases of PCA is that it can be used for image compression — a technique that minimizes the size in bytes of an image while keeping as much of the quality of the image as possible.

## How do you create a facial recognition system?

How to build facial-recognition software in 5 steps?

1. Collect training data.
2. Make a programmatic representation of faces (high level).
3. Train your model (deep learning).
4. Build a database of pictures.
5. Train the software by inserting new pictures into the database.
6. Test your software to check its accuracy.

## What is difference between face detection and face recognition?

Face detection is a broader term than face recognition. Face detection just means that a system is able to identify that there is a human face present in an image or video. Face detection has several applications, only one of which is facial recognition. Face detection can also be used to auto focus cameras.