extract.clj

(defn ExtractRenderListener
  "A RenderListener implementation that extracts images from a PDF and
writes them to disk."
  [^String path]
  (reify RenderListener
    (renderImage [_ renderInfo]
      (let [image (.getImage renderInfo)
            refNumber (.getNumber (.getRef renderInfo))
            fileType (.getFileType image)]
        (if image 
          (let [filename (str path refNumber "." fileType)]
            (with-open [os (clojure.java.io/output-stream filename)]
              (.write os (.getImageAsBytes image))
              (.flush os))))))
    (beginTextBlock [_] nil)
    (endTextBlock [_] nil)
    (renderText [_ renderInfo] nil)))

(defn MatrixRenderListener
  "A RenderListener implementation that updates shared mutable state with
nested vectors of image coordinate data."
  [^Integer page]
  (reify RenderListener
    (renderImage [_ renderInfo]
      (let [matrix (. renderInfo getImageCTM)
            x (.get matrix 6)
            y (.get matrix 7)
            w (.get matrix 0)
            h (.get matrix 4)
            pagekey (keyword (str page))]
        (dosync (alter coords update-in [pagekey] #(conj % [x y w h]))))
      nil)
    (beginTextBlock [_] nil)
    (endTextBlock [_] nil)
    (renderText [_ renderInfo] nil)))