image processing

ByDeepan Raj I

Ajith Kumar V

Image processing

Manipulation and Analysis of Two Dimensional Pictures

Technique to enhance Raw images taken from normal day-to-day life for various applications

Overview of Image Processing

Analog Image processing Alteration of Image through Electrical means

Ex: Television image

Digital Image processing

Processing of Two Dimensional picture by a Digital computer

Ex: Digital computers

Image processing Methods

Advantages of Digital Image Processing :

Versatility

Repeatability

Preservation of original data precision

Various Image Processing Techniques

• Image analysis

• Image preprocessing

• Image enhancement

• Image data compression

• Image restoration

Extraction of meaningful information from an image

Provides the description of image

Done by reading the bar coded tags

Image analysis

Magnification

Reduction

Mosaic

Image preprocessing

Improve scale of display for visual understanding

Magnify image by a factor of 2, each pixel is replaced by a block 2x2 pixels

Magnification

mth row and mth column of the imagery is selected and is displayed

Another way is by taking mxm block and display the averages after proper rounding

1x0.33x

Reduction

Combining two or more image to form single large image

To get the synoptic view

Image Mosaic

Image 1Image Mosaic

Image 2

Contrast Stretching

Noise Filtering

Edge Enhancement

Image Enhancement

Images are homogeneous due to incorrect lighting of the scene

Different stretching techniques are developed to stretch the image

Contrast Stretching

Before After

Filters unnecessary information

It is interactive

Various filters are low pass, high pass, mean, median etc.,

Noise Filtering

Before After

Done by redefining the edges of the image

Before After

Edge enhancement

Lossy compressionlossy compression is a data encoding

method which discards (loses) some of the data, in order to achieve its goal

Lossless compressionLossless data compression is a class of

data compression algorithms that allows the exact original data to be reconstructed from the compressed data

Image data compression

Image restoration refers to removal or minimization of degradations in an image.

Image Restoration

Applications

Medical Field (CT,MRI) Astronomy(Telescopes)

Software(Photoshop) Printing(Color)

Security and Digital Rights Management(Water marking, biometrics)

One picture is worth more than 1000 words

THANK YOU