Log Transformation in IDL

;####################################################
;              Log Transformation
;                  Author : S.Ganesh Babu
;####################################################

PRO EX10

file = DIALOG_PICKFILE(PATH='E:\Image')
im = READ_IMAGE(file)
sz=SIZE(im,/DIMENSIONS)
nv=SIZE(sz,/DIMENSIONS)
PRINT, sz
nim=ALOG(1+im)
IF nv EQ 2 THEN BEGIN
WINDOW,0,XSIZE=sz[0],YSIZE=sz[1],TITLE='INPUT IMAGE'
TV,im
WINDOW,1,XSIZE=sz[0],YSIZE=sz[1],TITLE='LOG IMAGE'
TV,nim
ENDIF ELSE BEGIN
WINDOW,0,XSIZE=sz[1],YSIZE=sz[2],TITLE='INPUT IMAGE'
TV,im,TRUE=1
WINDOW,1,XSIZE=sz[1],YSIZE=sz[2],TITLE='LOG IMAGE'
TV,nim,TRUE=1
ENDELSE
END