14-08-2012, 03:44 PM
Spatial Domain Methods – Basic Gray Level Transformations
02Basic Gray Level Transformations.ppt (Size: 1.24 MB / Downloads: 39)
Objectives:
To study the basic gray level transformations for enhancing the Images.
To know the effect of various types of transformations while enhancing the images.
Three basic types of functions used frequently for image enhancement: linear (negative and identity transformations), logarithmic (log and inverse log transformations) and power law ( nth power and nth root transformations).
Image Negatives:
The negative of an image with gray levels in the range
[0, L-1] is obtained by using the negative transformation, which is given by
s = L – 1 – r
This type of processing is suited for enhancing the white or gray detail embedded in dark regions of an image, especially when the black areas are dominant in size.
Power Law Transformations:
A variety of devices are used for image capture, printing and display respond according to the power law.
The exponent in the power – law equation is referred as gamma.
The process used to correct this power – law response phenomena is called gamma correction.
Summary:
The basic gray level transformations for enhancing the Images are studied.
The effect of various types of transformations while enhancing the images are explained.