Refinement of digital image using Fourier transformation method

Abstract EN

The method is used here to process a digital satellite images, further a photography digital image and many morphology shapes in grayscale mode with horizontal lines which is formed noises to reduce or delete it.

We analyze the images here with the frequency domain using the Fourier transformation, the result can be displayed as image, once the manipulation has been in completion, an inversed Fourier transformation is conducted in order to obtain the image information again.

In order to remove noises, matrix (h) is first made, with ones values for each it’s elements using the following command: h = ones (256); whose dimension equals to that of the matrix to save the Fourier transformation result, which is 256 x 256.

Once certain part of the matrix has been given the value zero, while the other remain to have the value one, each of the elements of the matrix is multiplied with its respective elements of the image Fourier spectrum with the following command: g = img_fs.* h; the multiplication will result in a new Fourier spectrum where the noise area has been removed because it has been multiplied by zero.

The removed area is displayed in black color in the visualization of the Fourier spectrum