Most people are familiar with the concept of filters, in fact unconsciously used them many times. Everytime you sharpen an image or apply a gaussian blur, every single pixel gets processed by a certain mathematical rule.
This post demonstrates a few well known filters and reveals the magic of what goes on under the hood.
Task 1+2: Filter types
There a lot of filter masks. This applet demonstrates a few of them (accessible by the keys 1-5):
- High-pass
- Low-pass
- Laplace
- Prewitt
- Sobel (horizontal)
This is what the matrices look like for the respective filters:
Task 3: Image Sharpening
This is a practical usage of the filter types shown in task 1 and 2. First, we “clean up” the noise in the original picture and sharpen it. In the applet, you can use the keys 1-7 to apply the different steps BETA.
