filter_logoaway documentation
-------------------------------

About this filter:
  This filter removes an image in a user specified area. An image can be a logo of a TV Station, the timestamp
  of a Camcorder or some ugly artifacts.
  It's a <PRE> process filter.

Requirements:
  transcode   - just as you guessed :-)
  ImageMagick - is used to load the image with the alpha mask.


Configuration:                     (possible values)        [default]
  Options:
      'help' Short Help
              Get a short description of all the logoaway options


     'range' Frame Range           (0-oo)                   [0-end]
              The frame region were the filter is active.
              The default is the whole video.

              range=12-1550   (filter only between frame 12 and 1550)


       'pos' Position              (0-width x 0-height)     [0x0]
              Required. The upper left corner of the area that will be removed.
            0
          0 #-------------------------
            |
            |           |50
            |           v
            |      110->#------
            |           |
            |           |

              pos=50x110


      'size' Size                  (0-width x 0-height)     [0x0]
              Required. The width and height of the remove area.


      'mode' Filter Mode           (0=none, 1=solid, 2=xy)  [0]
              There are three mode you can choose of:
              0=none   - This deactivates the filter. Useful if you want to
                         keep the settings, but the filter at the moment.
              1=solid  - Flood fills the remove area with one color. You can
                         specify the color with the 'fill' option (see below).
              2=xy     - In this mode the border pixels of the remove area are
                         used to interpolate the area between them. Interpolation
                         is done horizontally and vertically at the same time, the
                         sum of them is used. With the 'xweight' option (see below)
                         you can specify how much of the horizontally
                         interpolation is used. 50% xweight (=>50% yweight) gives
                         mostly the best results.
              3=shape  - This mode is basically the same as the xy above. An
                         alpha/shape file (see below) is needed for getting the
                         information where to render and which pixels to use
                         for interpolation. This mode is slower than xy and
                         was made for logos with holes in it or other forms that
                         are badly covered by a rectangle.


    'border' Visible Border
              Works in every mode and gives you a dotted line around the remove area

      'dump' dumps the image between the given coordinates to the file dump[instance].png continously.
             That means one image file is written for each filter instance and every frame this image is
             overwritten with the current content.
             This is useful for creating exact shape or alpha images.
             (RGB only)


   'xweight' X-Y Weight            (0%-100%)                [50]
              Only in xy-mode(2). How much of the horizontally interpolation is used
               0 means  0% horizontally and 100% vertically interpolation.
              35 means 35% horizontally and  65% vertically interpolation.
              50 is mostly the best choice.


      'fill' Solid Fill Color      (RRGGBB)                 [000000]
              Only in solid-mode(1). RGB color value in hexadecimal numbers in
              the format RRGGBB.

              fill=9A01CD   (Purple)


      'file' Image with alpha/shape information             []
              A grayscale image file with the alpha mask, that tells the filter where and
              how much to render. In shape mode it also used to get the position of the
              pixels for the interpolation. The first white pixels around a render position
              are used.
              The size have to be exacly the same as given with the 'size' option
              Color index   0     (black) - video pixel fully replaced with the interpolation.
              Color index   1-254 (gray)  - calculated and original values are blended together.
              Color index 255     (white) - video pixel left unchanged.

                000000000
                000###000   0 - White (255)
                00##0##+0   # - Alpha value
                0##00+#@+   @ - example pixel
                0##000##0   + - white pixels whose position
                00##0##+0       is used to get the pixel in
                000###000       the video for interpolation
                000000000       of @


Examples:
  -J logoaway=pos=100x100:size=50x50:border
      This gives us only a border, because the default mode is 0(none).

  -J logoaway=pos=100x100:size:50x50:mode=1:fill=228B22
      A 50x50 pixel great area at the topleft position 100x100 is filled with ForestGreen.

  -J logoaway=pos=100x100:size:50x50:mode=2:xweight=25:file=alpha.png
      1/4 horizontally and 3/4 vetically interpolation with an alpha mask.


Author:
  (c)2002-2004 Thomas Wehrspann <thomas@wehrspann.de>