"image.plot" <-
function (..., add=F, nlevel = 32, legend.shrink = 0.9, legend.width = 
0.04,  graphics.reset = F, horizontal = F, offset = 2 * legend.width, 
    bigplot = NULL, smallplot = NULL, legend.only = F, col = topo.colors(64)) 
{
    old.par <- par(no.readonly = T)
    info <- image.plot.info(...)
#
if( add) big.plot<- old.par$plt
#
# reset graphics if just drawing the legend. 
#
if( legend.only) graphics.reset<- T
#
#
temp<-image.plot.plt( add=add,  legend.shrink = legend.shrink, 
legend.width =legend.width, horizontal = horizontal, offset = offset,
    bigplot = bigplot, smallplot = smallplot)    
#
#plotting regions for image and legend
#
smallplot<- temp$smallplot
bigplot<- temp$bigplot
#
#
    if (!legend.only) {
 if(!add) { par(plt = bigplot) }   
        image(..., add=add,col = col)
        big.par <- par(no.readonly = T)
    }
    if ((smallplot[2] < smallplot[1]) | (smallplot[4] < smallplot[3])) {
        par(old.par)
        stop("plot region too small to add legend\n")
    }
    temp <- list(...)
    iy <- seq(info$zlim[1], info$zlim[2], , nlevel)
    iz <- matrix(iy, nrow = 1, ncol = length(iy))
    ix <- 1
    if (!horizontal) {
        par(new = T, pty = "m", plt = smallplot, err = -1)
        image(ix, iy, iz, xaxt = "n", yaxt = "n", xlab = "", 
            ylab = "", col = col)
        axis(4, mgp = c(3, 0, 0))
    }
    else {
        par(new = T, pty = "m", plt = smallplot, err = -1)
        image(iy, ix, t(iz), yaxt = "n", xlab = "", ylab = "", 
            col = col)
    }
    if (graphics.reset|add) {
        par( old.par)
        invisible()
    }
    else {
        par(big.par)
        invisible()
    }
}