Activity 4. Enhancement by Histogram Manipulation

This activity focused on the enhancement of a low resolution image using histogram manipulation. The activity was started by selecting and downloading a low contrast image from the internet. The image is shown below.

(static.photo.net)

The image was then resized and converted into grayscale using the im2gray command in Scilab. The histogram of the gray levels was then generated using the same program. The generated histogram is shown below.

The CDF of the image was then generated using Scilab. The CDF is presented in the figure below.The image was then enhanced using a linear function. The enhanced image is shown below.

The CDF and the PDF of the enhanced image was generated using Scilab. The CDF and the PDF of the enhanced image above is shown below, respectively.

The primary axis of the two plots above represent grayscale values. The image was then enhanced using a nonlinear (x^3) function. The image enhanced using the nonlinear function is shown below.

The CDF and the PDF was then computed and generated using Scilab. The CDF and PDF of the enhanced image enhanced using the nonlinear function is shown below. The first image is the CDF and the second image is the PDF.

From the images enhanced using linear and nonlinear function, it can be observed that the image generated or enhanced using the nonlinear function has a higher level of contrast than the image generated after enhancing the original image by the linear function.


I will give myself 8/10 for this activity.

**Neil and Gilbert helped me in debugging the Scilab code.