Face Detection

Abstract Factory

Viola Jones

Integral Image

• An integral image is an algorithm for

quickly and efficiently generating the sum

of values in a rectangular subset of a grid

• The integral image can be computed from

an image using a few operations per pixel

Integral Image

Haar Features

• Once the integral image was computed,

any one of these Harr-like features can be

computed at any scale or location in

constant time.

Haar Features

Machine Learning

• AdaBoost => XML

• Cascade of Classifiers

AspectJ

• Profiler

– 6s/thread

• Logger

Face Recognition

Biometrics

Biometric characteristics:

● physiological

● behavioral

Why is it useful?

How the biometric system works?

● verification (one-to-one)

● identification (one-to-many)

Biometrics

Diagram of a biometric system

Stages of facial

recognition

1. Image capture

2. Face identification

3. Extraction of features to

generate a model

4. Comparing models

5. Declaration of identity

Algorithms

As researcher interest in face recognition continued, many

different algorithms were developed, three of which have

been well studied in face recognition literature:

● Principal Components Analysis (PCA)

● Linear Discriminant Analysis (LDA)

● Elastic Bunch Graph Matching (EBGM)

Method PCA Eigenfaces

Database

Database

Problems

• ● background

• ● lighting conditions (performance

• degrades with light changes)

• ● scale (performance decreases quickly

• with changes to the head size)

• ● orientation (perfomance decreases but

not as fast as with scale changes)

• ● less reliable than face detection (30-70%)

Faces

Distributed system

Time issues

Face detection – 6/7 seconds for an

average size photo

We want to be able to respond to multiple

face detection requests which come at the

same time

Don’t want our users to wait too much

Solution ?

Parallel/Distributed

Computing

JPPF

JPPF

OPEN SOURCE

easy programming model

fault-tolerance and self-repair capabilities

dynamically scalable on-demand

fine-grained monitoring and administration

JPPF architecture

Server – handles all tasks, knows all

active nodes, load balancing, queues

Node – executes tasks received from the

server

Client – issues tasks to the Server, waits

for responses

Demo

(hope this works)