This function creates an object of class "im"
representing
a two-dimensional pixel image. See im.object
for details of this class. If mat
is not a matrix, it will first be converted into
a matrix with nrow(mat) = length(yrow)
and
ncol(mat) = length(xcol)
.
Note that the row index of the matrix mat
corresponds
to increasing y coordinate, while the column index of mat
corresponds to increasing x coordinate. Thus
xrow
has one entry for each row of mat
and ycol
has one entry for each column of mat
. A correct
display of the image would be obtained by transposing, e.g.
image.default(xcol, yrow, t(mat))
, if you wanted to do it by hand.