;Given a bounding box, return the x and y coordinates, and
;the latitude and longitude, of each pixel in the box
;Input
;  bbox - array of integers [left,bottom,right,top] defining the bounding box
;Output
;  x,y                  Each is a 2D array of long integers, giving the
;                       x and y coordinate of the center pixel of each tile.
;  lat,lon              Each is a 2D array of doubles, with the latitude
;                       in degrees, and the longitude in degrees ranging from
;                       -180 to 180.
;
pro map_lat_lon,bbox,x=x,y=y,lat=lat,lon=lon,tile_size=tile_size,_extra=extra
  if n_elements(tile_size) eq 0 then tile_size=1
  s=intarr(2)
  x_size=bbox[2]-bbox[0]+1
  y_size=bbox[3]-bbox[1]+1
  s=[x_size,y_size]
  x=rebin(indgen(x_size),x_size,y_size)
  y=rebin(transpose(indgen(y_size)),x_size,y_size)
  x=x*tile_size+bbox[0]
  y=y*tile_size+bbox[1]
  project_lambert,x=x,y=y,lat=lat,lon=lon,/inverse,_extra=extra
end