Enhancement Methods in Image Processing

Enhancement of an image simply means to convert or process an original image to other desired form which is suitable for user application. Availability of enormous enhancement methods sometimes lead to ambiguity in choosing an algorithm to process an image.
In this article, I will mention in brief about the uses of different methods which can be chosen at appropriate situations for beginners who have just entered the field of image processing. There are two important methods used for enhancement. Spatial Domain (direct manipulation of pixels of the image) and Frequency Domain (modifying the Fourier Transform of an image).

Spatial domain is directly applied on the pixel and is defined by g(x,y)=T[f(x,y)].If the processing is done over a 1*1 neighborhood, it is termed as point processing. Point operation include contrast stretching, noise clipping, window slicing and histogram modeling.

Spatial operations include noise smoothing, median filtering, lp, hp & bp filtering and zooming. There are other available methods such as transform operation and pseudo-coloring too.
On learning more about contrast stretching, the idea behind contrast stretching is to increase the dynamic range of the gray levels in the image that is being processed. Sometimes the dynamic range of a processed image far exceeds the capability of the display device, in which case only the brightest parts of the images are visible on the display screen at these situations we can use compression of the dynamic range. Gray level slicing is used for highlighting a specific range of gray levels in an image often is desired. Applications include enhancing features such as masses of water in satellite imagery and enhancing flaws in x-ray images.

Histogram processing can be done in three ways:
• histogram equalization,
• histogram specification and
• local enhancement.

The use of spatial masks for image processing is called spatial filtering. Smoothing filters are used for blurring and for noise reduction. To highlight fine detail in an image or to enhance detail that has been blurred, either in error or as a natural effect of a particular method of image acquisition. Uses of image sharpening vary and include applications ranging from electronic printing and medical imaging to industrial inspection and autonomous target detection in smart weapons. here in this we use masks such as prewitt, sobel or roberts.


Enhancement in the frequency domain
We simply compute the Fourier transform of the image to be enhanced, multiply the result by a filter transfer function, and take the inverse transform to produce the enhanced image.
Spatial domain: g(x,y)=f(x,y)*h(x,y) ¬ Frequency domain: G(w1,w2)=F(w1,w2)H(w1,w2).
Image Enhancement is one of the most necessary and important techniques in image research. The aim of enhancement is to improve the visual appearance of an image, or to provide a better transform representation for future automated image processing. Many images like medical images, satellite images, aerial images and even real life photographs suffer from poor contrast and noise. It is necessary to enhance the contrast and remove the noise to increase image quality. One of the most important stages in medical images detection and analysis is Image Enhancement techniques which improves the quality (clarity) of images for human viewing, removing blurring and noise, increasing contrast, and revealing details are examples of enhancement operations. The enhancement technique differs from one field to another according to its objective.

Start a 10-day free trial at Pluralsight – Over 5,000 Courses Available

Architha Reddy is pursuing M.Tech in NITTE, Bangalore. Apart from studies she also researches on different topics in Computer Science and contributes write-ups.

Do you want to learn image processing then join :

Start a 10-day free trial at Pluralsight – Over 5,000 Courses Available

December 28, 2018

12 responses on "Enhancement Methods in Image Processing"

  1. I like reading a post that can make people think.
    Also, thanks for allowing me to comment!

  2. Hi there it’s me, I am also visiting this site daily, this website is really fastidious and the visitors are truly sharing fastidious thoughts.

  3. What you published was actually very logical. But, what about this?
    suppose you were to create a awesome title? I ain’t suggesting your content is not good.,
    but suppose you added a title to maybe grab a person’s attention?
    I mean Enhancement Methods in Image Processing –
    Extra Period is a little vanilla. You should look at Yahoo’s home page and watch how they create news titles to
    grab people to click. You might try adding a video or a
    related picture or two to grab readers interested about everything’ve written. Just my opinion,
    it could bring your website a little livelier.

  4. Fine way of telling, and pleasant piece of writing to get data about my
    presentation subject, which i am going to convey in college.

  5. Pretty nice post. I just stumbled upon your blog and wanted to say that I have really
    enjoyed browsing your blog posts. In any case I’ll be
    subscribing to your rss feed and I hope you write again very soon!

  6. It is appropriate time to make a few plans for the future and it’s time to be happy.
    I have read this submit and if I could I wish to recommend you some attention-grabbing things or tips.

    Perhaps you could write subsequent articles relating to this article.
    I want to learn even more things approximately it!

  7. I every time emailed this blog post page to all my contacts, for the reason that if
    like to read it after that my contacts will too.

  8. Hi there would you mind letting me know which hosting company you’re utilizing?

    I’ve loaded your blog in 3 completely different internet browsers and I
    must say this blog loads a lot quicker then most.
    Can you suggest a good internet hosting provider at a reasonable price?
    Many thanks, I appreciate it!

  9. Hi are using WordPress for your blog platform?
    I’m new to the blog world but I’m trying to
    get started and set up my own. Do you require any coding expertise to
    make your own blog? Any help would be really appreciated!

  10. I just like the valuable info you provide for your articles.
    I’ll bookmark your blog and take a look at once more here frequently.
    I’m somewhat sure I will be told lots of new stuff proper here!
    Good luck for the following!

  11. We are a gaggle of volunteers and opening a
    brand new scheme in our community. Your site
    offered us with valuable info to work on. You have done a formidable job and
    our entire group will probably be thankful
    to you.

  12. If you desire to get a good deal from this article then you have to apply such techniques to your won website.

Leave a Message

Your email address will not be published.

All Rights Reserved to Extra Period. Powered by