Chapter 1

CHAPTER 1

INTRODUCTION

1.1 Skin Disease

The skin is a huge part of physical appearance. It provides protection against infection, bacteria, virus etc. and controls temperature of body. It is a complex active organ, if any of its functions fail there can be serious consequences. Skin disease is an impairment of health or condition of abnormal functioning. It is a particular kind of illness caused by bacteria, fungus, viruses. Problems can develop wherever there is skin, including the ears, around the lips, the bottom of paws and around the anus. Skin disorders vary greatly in symptoms and severity. Situations that frustrate, change texture of the skin, or damage the skin can produce symptoms like swelling, burning, redness and itching. Skin disease causes significant impact on a person having it, causing the person to feel discomfort in his/her daily routines or may cause the person to be disabled. Collectively, there are more than 3000 known skin diseases that are present today.

1.2 Types of Skin Disease

There are various types of skin diseases found in humans, plants, animals. These diseases can be classified according to their symptoms and features. They can be:

• Temporary or permanent

• Situational or genetic

• Painless or painful

• Minor or life-threatening

These are the diseases that may originate inside the body and manifest on the skin. Permanent skin disorders are those that are present from birth. Temporary skin diseases have various causes like environmental factors, inflammation. Now a day, skin diseases such as alopecia, ringworm, hot spot and yeast infection are very common to everyone. They tend to pass on from animal to animal or animal to human very easily. These

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diseases have various dangerous effects on the skin keep on spreading over time especially when it is on the part of the body that cannot be covered. Therefore it becomes important to control it at initial stage to prevent it from spreading. These diseases also have psychological effects on humans and animals. Common skin conditions include moles, hair loss, rubbing, redness, itching, rashes, circular patches, discolored and inflamed skin. Skin can also produce many types of cancers. These diseases don‟t just damage the skin. It can have a large impact on animals and humans daily life and stop their movement. The worst situation is that, it can even kill. Animal disease means a disease to which animals are liable and whereby the normal functions of any organ or the body of an animal is impaired or disturbed by any protozoon, bacterium and virus. These diseases are identified by using many technologies such as image processing, data mining, artificial neural network (ANN) etc.

1.3 Common Skin Disorders and Their Symptoms

• Skin cancer: red, pink or rough patch of skin on sun-exposed areas.

• Lupus: fatigue, headaches, fever and painful joints, disc shaped rash that does not itch.

• Alopecia or hair loss: discolored skin, how much hair loss depends upon breed, time and environmental factors.

• Ringworm: redness, itching, circular shaped rash.

• Allergies: redness, itching, small acne onto skin, burning due to sun rays.

• Acne: small red raised bumps caused by infected hair follicles.

• Rosacea: flushing, acne-like breakouts.

• Eczema: yellow or white scaly patches, affected area may be red, itchy and greasy.

1.4 Cause of Skin Disease

The skin‟s ability to act as a barrier is particularly important for occupational health. The skin has four layers namely, base layer, prickle cell layer, granular layer, horny layer. Problems occur when skin barrier is breached.

Fig 1.1: Architecture of skin layers

This can happen due to:

• A material penetrates the barrier layer or alters it so other materials or agents can penetrate it.

• A material or agent enters sweat ducts or hair follicles, by-passing the barrier layer.

1.5 Image Processing

Recently, image processing has played a major role in this area of research and has widely used for the detection of skin diseases. Techniques like filtering, segmentation, feature extraction, image pre-processing and edge detection etc. are part of image processing and are used to identify the part affected by disease, the form of affected area, its affected area color etc. Digital image processing is the manipulation of images by computers. It has many applications in areas such as telecommunication, medical

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imaging, graphic arts, remote sensing etc. It works to divide an image into pixels and work on an individual pixel. This tool gives more accurate result as compared to other techniques. One of main purpose of image processing is to manipulate pixel values for better visibility. For example, gray-level transformation and image filtering are techniques for converting an input image into a new image with better visibility. Another purpose is to extract some target objects or regions from an input image. For example, first extract all organelles of a specific kind, then count them and understand their distribution and behavior in a cell. Image pattern recognition is widely used to classify an image or region into group of similar type of objects i.e. called class.

1.6 What Does An Image Analysis System?

A typical image analysis system performs the following operations: First is image acquisition, apply filters to remove noise, segment the image to extract meaningful information, feature extraction is done on the basis of input parameters and then classify the data by using appropriate classifier. The digital cameras are specially designed to view a scene and provide a digital representation or conversion of image data from an existing medium into a digital format. A digital image is represented by two-dimensional array or matrix of numbers. After image acquisition, next step is to apply segmentation to partition whole data into meaningful parts. There are many segmentation techniques for e.g. threshold based segmentation, region based, color segmentation etc. All of these techniques are applied according to their purpose. The next step is feature extraction for extracting important discriminative information (called features) from a target image. It involves simplifying the amount of resources required to describe a large set of data accurately. When performing analysis of complex data one of the major problems stems from the number of variables involved. Analysis with a large number of variables generally requires a large amount of memory and computation power. On the basis of extracted features, appropriate classifier is used for the classification of data into different- different categories. Classification is a process that is used for portioning the data into different classes according to some constrains. It is a two step process: the first step is supervised learning for the sake of the predefined class label for training data set. Second step is classification accuracy evaluation. It is a supervised technique where each

instance belongs to a class which is indicated by the value of a special goal attribute or simply the class attributes. The goal attribute can take on categorical values,

Impressum

Verlag: BookRix GmbH & Co. KG

Tag der Veröffentlichung: 27.05.2019
ISBN: 978-3-7487-0575-8

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