Update image_processing_fourier.qmd

Adding calls to reference the figure

Author: vksvinicius

image_processing_fourier.qmd

@@ -1016,8 +1016,8 @@ analysis of linear filters.
 
 ### Example 1: Removing the Columns from the MIT Building
 
-fig-filteringFT (a) shows a picture of the main MIT building. The columns
-produce a quasiperiodic pattern. fig-filteringFT (b) shows the magnitude
+@fig-filteringFT (a) shows a picture of the main MIT building. The columns
+produce a quasiperiodic pattern. @fig-filteringFT (b) shows the magnitude
 of the DFT of the MIT picture. One can see picks in the horizontal
 frequency axis, those picks are due to the columns.