[R] how to read individual values from a pixmap object

[Friedrich.Leisch@tuwien.ac.at]

>>>>> On Thu, 4 Aug 2005 18:02:55 +1000,
>>>>> Tony Gill (TG) wrote:

[...]

  > Now I would like to read individual pixel values and store them in a
  > separate vector. However I have not found a straight-forward way to do this.
 
  > I thought that something like:
 
  > x <- xGrey[1,1]
 
  > would return the pixel value, but it seems to return a pixmap object with
  > dimension 1x1 (i.e. only one pixel in size)
 
  > xGrey[1,1]
  > Pixmap image
  >   Type          : pixmapGrey 
  >   Size          : 1x1 
  >   Resolution    : 1x1 
  >   Bounding box  : 1 0 2 1
 
  > Any ideas on how to get the actual pixel value from a pixmap? (Note I could
  > output to an ascii file and then read the file back in as text - but not
  > nice!)


getChannels(xGrey) will get you the matrix of pixel values.

HTH,

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