Quick and dirty grayscale image to incanter matrix round trip

matrix_to_image.clj

(import [javax.imageio ImageIO]
        [java.awt.image BufferedImage])

(require 'clojure.java.io)
(require 'incanter.core)

(defn read-image-matrix [imagefile]
  (let [imagefile (clojure.java.io/as-file imagefile)
        raster (.. (. ImageIO read imagefile) getData)
        left (. raster getMinX)
        width (. raster getWidth)
        right (+ left width)
        top (. raster getMinY)
        height (. raster getHeight)
        bottom (+ top height)
        xrange (range left right)
        yrange (range top bottom)]
    (incanter.core/matrix
     (for [i xrange j yrange]
       (let [pixel (. raster getPixel i j nil)]
         (aget pixel 0))) width)))

(defn write-image-matrix [imagefile M]
  (let [width (incanter.core/ncol M)
        height (incanter.core/nrow M)
        image (BufferedImage. width height  BufferedImage/TYPE_BYTE_GRAY)
        raster (. image getRaster)]
    (doseq [i (range width) j (range height)]
      (. raster setPixel i j (float-array (incanter.core/sel M i j))))
    (. ImageIO write image "png" imagefile)))