Frequency Domain Filters are used for smoothing and sharpening of image by removal of high or low frequency components. Sometimes it is possible of removal of very high and very low frequency. Frequency domain filters are different from spatial domain filters as it basically focuses on the frequency of the images. It is basically done for two basic operation i.e., Smoothing and Sharpening.
These are of 3 types:
1. Low pass filter:
Low pass filter removes the high frequency components that means it keeps low frequency components. It is used for smoothing the image. It is used to smoothen the image by attenuating high frequency components and preserving low frequency components.
Mechanism of low pass filtering in frequency domain is given by:
G(u, v) = H(u, v) . F(u, v) where F(u, v) is the Fourier Transform of original image and H(u, v) is the Fourier Transform of filtering mask
2. High pass filter:
High pass filter removes the low frequency components that means it keeps high frequency components. It is used for sharpening the image. It is used to sharpen the image by attenuating low frequency components and preserving high frequency components.
Mechanism of high pass filtering in frequency domain is given by:
H(u, v) = 1 - H'(u, v) where H(u, v) is the Fourier Transform of high pass filtering and H'(u, v) is the Fourier Transform of low pass filtering
3. Band pass filter:
Band pass filter removes the very low frequency and very high frequency components that means it keeps the moderate range band of frequencies. Band pass filtering is used to enhance edges while reducing the noise at the same time.
- Types of Restoration Filters
- Spatial Filtering and its Types
- Digital Watermarking and its Types
- Perspective Projection and its Types
- Types of Models in Object Oriented Modeling and Design
- Univariate, Bivariate and Multivariate data and its analysis
- Vector instruction types
- Types of Antialiasing Techniques
- Geographical information system (GIS) and its Components
- Equation of parabola from its focus and directrix
- Scanning and its Tools
- Screen Density and Its terminologies
- Endian order and binary files
- Look-and-Say Sequence
- How to add articles to "To Do" and "Done" lists on GeeksforGeeks?
- Finding the number of triangles amongst horizontal and vertical line segments
- Find k-th bit in a binary string created by repeated invert and append operations
- MouseListener and MouseMotionListener in Java
- Shuffle a pack of cards and answer the query
- fgets() and gets() in C language
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.