plot.matrix
(Package: rtiff) :
Overload the plot function for matrices
This is a simple S3 method for the plot function which takes a matrix, converts it to an RGB pixmap (by replicating it 3 times, once for each channel), and then plotting the resulting image.
This package will read TIFF format images and return them as a pixmap object. Because the resulting object can be very large for even modestly sized TIFF images, images can be reduced as they are read for improved performance. This package is a wrapper around libtiff (www.libtiff.org), on which it depends. By using libtiff's highlevel TIFFReadRGBAImage function, this package inherently support a wide range of image formats and compression schemes. This package also provides an implementation of the Ridler Autothresholding algorithm for easy generation of binary masks.
autoThreshold
(Package: rtiff) :
Suggests threshold levels to use in binarizing an image channel.
This is an implementation of the Ridler method for binarization (see references). NOTE: The order of the values returned did not match what is described in the "value" section below. This is fixed in this version.
providing 
.