Image Noise Removal by Dual Threshold Median Filter for RVIN
Namrata Shelke, Manisha Pariyani · 2015
Removal of random valued impulse noise in digital images with edge preservation is one of the challenging tasks in digital image processing. For removal of impulse noise as well as preserve edge proposed a new filter that is Dual Threshold Median Filter (DTMF). The removal of impulse noise is done in two main stages, firstly, the detection of the impulse noise on the basis of maximum and minimum value of pixels in a 3X3 window. In the second stage, removal of impulse noise by using of median filter. In the filtering stage, the noise- free pixels remain unchanged in the low noise density, but in case of high noise density that is very difficult of identify the noisy pixel or edge of the image, this difficulty is remove by our proposed filter. The experimental outcome of our proposed filter is superior to the previous methods in terms of Peak Signal Noise Ratio and Mean Square Error of the different testing images, with different noise density level. The mathematical analysis describes that the analysis of the noisy pixels and use of noise-free pixels for the de - noising purpose provide better results and provides better visual quality of de-noised image.