 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. ...