message: Fix single-word typo
diff: @@ -163,7 +163,7 @@ Our program exits if the user presses **ESC**. Besides, it has two options:
  We use the function **pyrDown()** with three arguments (similarly to **pyrUp()**):
  - *src*: The current and destination image (to be shown on screen, supposedly half the input
  image)
  - - *Size( tmp.cols/2, tmp.rows/2 )* : The destination size. Since we are upsampling,
  + - *Size( tmp.cols/2, tmp.rows/2 )* : The destination size. Since we are downsampling,
  **pyrDown()** expects half the size the input image (in this case *src*).
  @add_toggle_cpp
  