;;; images.pro: to run this script, at the idl prompt type
;;; .run images
;;;
;;; this script shows how to load in an image, display and 
;;; manipulate it
;;;
;;; requires graphics file calvin.gif

go = strarr(1)


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Read in gif file and display it'

; read in the gif file named calvin.gif and store it
; in the variable calvin1, and display it
read_gif, 'calvin.gif', calvin1, r, g, b
tvlct, r, g, b
tv, calvin1

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Erase screen'

; erase screen
erase

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Dissolve image'

; use built-in dissolve function, which displays the image
; in scattered tiles and fills it all in
dissolve, calvin1

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
print, 'Read image from screen and store to another variable'
print, 'Delete current window, open a new window
print, 'Display newly saved image'

; read the current image in and store it in the variable calvin2,
; delete current window and open a new window with a title of a 
; specific size, and display the new variable calvin2
calvin2 = tvrd()
wdelete
window, 0, xsize=512, ysize=384, title='SWIG Window'
tv, calvin2

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Zoom in interactively'

; use the built-in zoom function, which allows one to zoom
; in interactively on the image displayed
zoom

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Add the image to itself'

; add the image to itself and display the results
tv, calvin2 + calvin2

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print,'Smooth image and add it to itself'

; smooth the image, add it to itself and display the results
tvscl, calvin2 + smooth(calvin2,3)

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Inverse video by subtracting max value'

; find the max of the image calvin2 and subtract it from
; calvin2 and display the results
tv, calvin2 - max(calvin2)

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print,'Apply a median filter'

; apply a median filter using a neighborhood of 9 pixels
tvscl, median(calvin2,9)

print, 'Hit return to continue'
readf, 0, go

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

print, 'Done!'

end