; Albert Cardona 20080427 at MPI-CBG Dresden FIJI hackathon.

(import '(ij.process ByteProcessor)
	'(ij ImagePlus)
	'(java.awt.image IndexColorModel)
	'(java.util Random))

; A closure over a new instance of Random,
; used in an inner function that generates random bytes
(let [rand (new Random)]
  (defn rand-byte []
	(byte (- (.nextInt rand 256) 128))))

; Create a new image and set each pixel to a random byte
(let [bp (new ByteProcessor 512 512)
      pix (. bp (getPixels))]
  (dotimes [i (count pix)]
    (aset pix i (rand-byte)))
  (.show (ImagePlus. "random" bp)))

; Returns a new grayscale LUT
(defn make-grayscale-lut []
      (defn make-channel []
	    (let [channel (make-array Byte/TYPE 256)]
	      (dotimes [i 256]
		(aset channel i (byte i)))
	      channel))
      (IndexColorModel. 8 256 (make-channel) (make-channel) (make-channel)))

; Create a second image directly from a byte array
(let [pix (make-array Byte/TYPE (* 512 512))]
  (dotimes [i (count pix)]
    (aset pix i (rand-byte)))
  (.show (ImagePlus. "random 2" (ByteProcessor. 512 512 pix (make-grayscale-lut)))))