Abstract

Often when we take a photograph of a landscape or a monument, the picture is affected by power lines. We want to suppress these lines to restore the landscape or the monument like if we donÕt have any line in.

Thus the goal of the line suppression is to find a possibility to detect the lines in the photograph, to suppress them and then to fill them using the pixels of the neighborhood of the suppressed pixels. To do this, we use first steerable filters of the second order which allow us to find ridges in an image. After this first step, the program allows the user to apply a hyteresis threshold to the image to suppress some of the features he is not interested in. After this threshold, some of the lines can be manually suppressed and then the remaining components can be grown as many times as necessary to get a width of the line as large as in the original picture. The next step gives all the components found in the image and those are put in RGB in the original picture. The user may then choose which of the components he wants to remove or keep and the program fill the lines using the heat equation or the Laplace equation. The two following pictures show an image with some lines in and the result of the process with the use of the heat equation.