Message-ID: <17138.1222.269324.360745@celebrian.ci.tuwien.ac.at>
Date: 2005-08-04T12:06:30Z
From: Friedrich Leisch
Subject: how to read individual values from a pixmap object
In-Reply-To: <200508040803.j7482uWZ096963@smtp1.uq.edu.au>
>>>>> 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,
--
-------------------------------------------------------------------
Friedrich Leisch
Institut f??r Statistik Tel: (+43 1) 58801 10715
Technische Universit??t Wien Fax: (+43 1) 58801 10798
Wiedner Hauptstra??e 8-10/1071
A-1040 Wien, Austria http://www.ci.tuwien.ac.at/~leisch