The low-pass filter exists in many different forms, but our focus here is in signal processing but it can be found in applications such as finance and image processing. You can think of a low pass filter as a smoother or averaging function removing the short-term variations or oscillations of a signal quantity. Sep 25, 2015 · Image reserve technique, each all elements of the matrix is replaced to be the top row elements to bottom row and the bottom row elements to top row. In the other words, the image rotates on the vertical axis. MATLAB Image Processing Toolbox does not have function for it. Either the script is written or flipdim function can be used . Consider the low-pass reconstruction filter (L') for the db2 wavelet. The filter coefficients can be obtained from the dbaux function. By reversing the order of the scaling filter vector and multiplying every even element (indexing from 1) by (-1), you obtain the high-pass filter. Gaussian High Pass Filter , ,3., ,Conclusion. , , The above discussion and various results obtained ,lead to the conclusion that it is easier to comprehend ,the concepts of Digital Image Processing and ,specifically various image enhancement techniques ,with the help of their simulation on MatLAB.