+\subsection{BoxBlur}%
+\label{sub:boxblur}
+Based on ffmpeg’s boxblur, this is a very fast algorithm which can be used to blur horizontal,
+vertical, and at a power level. Simplest usage is to just blur the entire image but with
+the following parameters, you can create a specific rectangular section to blur instead.
+
+\begin{description}
+ \item[X/Y:] point coordinates of a rectangular box to be blurred. X and Y of 0 are in the
+upper left hand corner. Default to be blurred is the entire image.
+ \item[Drag:] is used when you want to create just a rectangular area to be blurred rather
+than the enire image. If you used keyframes to cover a moving area and had left the Drag box
+enabled, you can remove the drag box with \textit{Allow keyframe spanning} whose use is
+described in \nameref{sec:allow_keyframes_spanning}.
+ \item[W/H] the values in these 2 boxes specify the width and height of the drag area box
+measured in pixels as shown in the compositor window. You can set these manually and if you
+can not see the location of your box, set them to zero because $0$ sets it to the same as the
+width/height of the project.
+ \item[Horiz:] slider goes from $0\, to\, 100$. Increasing this \textit{horizontal} number,
+increases the blurriness in the horizontal direction. The default value is 2. You can also use
+the mouse wheel to scroll the slider. There is a clear button on the right to set the value to 0.
+ \item[Vert:] slider goes from $0\, to\, 100$. Increasing this \textit{vertical} number,
+increases the blurriness in the vertical direction. The default value is 2. You can also use
+the mouse wheel to scroll the slider. There is a clear button on the right to set the value to 0.
+ \item[Power:] the way \textit{Power} works is like stacking up the blur multiple times.
+For example, a power of 3 would be like blurring once, then blurring that again, and finally
+blurring that a third time. The slider varies from 1 to 10 with 2 being the default value. There
+is a clear button on the right to set the value to 1.
+ \item[Reset:] button to revert to the default values and turn off Drag if it is on.
+\end{description}
+