Showing posts with label Class Notes: Digital Image Processing. Show all posts
Showing posts with label Class Notes: Digital Image Processing. Show all posts

Histogram:

The histogram plots the number of pixels in the image (vertical axis) with a particular brightness value (horizontal axis). Considering the following graph,

Brightness and Contrast in Digital Image Processing.

Brightness: Brightness of an image is defined by the higher grey-scale values. Such as, if an image has grey-scale values like 175,200,255 etc, it can be said that brightness of the image is high. That is, the higher the grey-scale value the higher the brightness of an image. Thus brightness of an image is the higher values of the grey-scale levels.

Describe the high pass filter. DIP

High Pass Filter: Considering the grey-scale values of a part of an image as below,
Here, we have taken 9 grey scale values. It is seen that the 5th value is very different than the other 8 values, that is a big change is occurring at that point due to the big change of the grey-scale value at that point than the other points.

Describe the median pass filter. DIP

Median Filter: Median filter, as the name implies, replaces the center value of a mask with the median of all the values of the mask. Simply taking some grey-scale values of an image and taking a 3×3 mask. Now we have 9 values and the 5th value is the median. Thus, the center value of the mask will be replaced by the median. So, the implementation of this filter is as follows,

Describe the low pass filter.

Low Pass Filter : Considering the grey-scale values of a part of an image as below,
Here, we have taken 9 grey scale values. It is seen that the 5th value is very different than the other 8 values, that is a big change is occurring at that point due to the big change of the grey-scale value at that point than the other points.

Fundamental Steps of Digital Image Processing:

There are some fundamental steps but as they are fundamental, all these steps may have sub-steps. The fundamental steps are described below with a neat diagram.

What is digital image processing?

Digital Image Processing : An image which has a two dimensional function of f(x,y), where x and y are plane co-ordinates and the amplitude of f at any (x,y) is called the grey level of the image at that point. When the values of these of an image are finite, discrete quantities then the image is called a digital image. ...