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nodename/test.clj

Created December 20, 2011 07:25
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Revisions

  1. nodename revised this gist Dec 21, 2011. 1 changed file with 7 additions and 3 deletions.
    10 changes: 7 additions & 3 deletions test.clj
    View file
    Original file line number Diff line number Diff line change
    @@ -82,9 +82,13 @@
    (let [dataArrayList (.unknownChunkData png-metadata)
    typeArrayList (.unknownChunkType png-metadata)]
    (loop [i 0]
    (if (= (.get typeArrayList i) generator-chunk-name)
    (String. (.get dataArrayList i))
    (recur (+ i 1))))))
    (cond
    (>= i (.size dataArrayList))
    ""
    (= (.get typeArrayList i) generator-chunk-name)
    (String. (.get dataArrayList i))
    :else
    (recur (+ i 1))))))


    (def input-generator (get-generator-string input-metadata))
  2. nodename created this gist Dec 20, 2011.
    91 changes: 91 additions & 0 deletions test.clj
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,91 @@
    (import '(java.awt.image BufferedImage))
    (import '(javax.imageio ImageIO IIOImage))
    (import '(javax.imageio.stream FileImageOutputStream))
    (import '(com.sun.imageio.plugins.png PNGMetadata PNGImageReader))
    (import '(java.io ByteArrayOutputStream File))

    ;; See the following document for requirements
    ;; for upper- and lower-case letters in the four-letter chunk name:
    ;; http://en.wikipedia.org/wiki/Portable_Network_Graphics#.22Chunks.22_within_the_file
    (def generator-chunk-name "gnTr")

    (def image-file-name "test.png")

    (defn get-png-imagewriter
    "Return an ImageWriter for PNG images"
    []
    (let [iterator (ImageIO/getImageWritersBySuffix "png")]
    (if-not (.hasNext iterator)
    (throw (Exception. "No image writer for PNG")))
    (.next iterator)))

    (def imagewriter (get-png-imagewriter))


    (def bi (BufferedImage. 16 16 BufferedImage/TYPE_INT_ARGB))
    (def g (.createGraphics bi))

    ;; use g
    (.drawLine g 0 0 10 10)
    (.drawLine g 0 15 15 0)

    ;; (def output-bytes (ByteArrayOutputStream. ))
    ;; (.setOutput imagewriter (ImageIO/createImageOutputStream output-bytes))
    (def output (FileImageOutputStream. (File. image-file-name)))
    (.setOutput imagewriter output)

    (defn make-generator-metadata
    "Create a PNGMetadata containing generator-string in its generator header chunk"
    [generator-string]
    (let [png-metadata (PNGMetadata.)]
    (.add (.unknownChunkType png-metadata) generator-chunk-name)
    (.add (.unknownChunkData png-metadata) (.getBytes generator-string))
    png-metadata))

    (def metadata (make-generator-metadata "This is the generator"))

    (defn write-image
    [writer image metadata]
    (let [iio-image (IIOImage. image nil nil)]
    (.setMetadata iio-image metadata)
    (.write writer nil iio-image nil)))

    (write-image imagewriter bi metadata)

    (.flush output)
    (.close output)
    (.dispose imagewriter)


    ;; now reopen the file and read the header

    (def input-stream (ImageIO/createImageInputStream (File. image-file-name)))


    (defn get-imagereader
    [inputstream]
    (let [iterator (ImageIO/getImageReaders inputstream)]
    (if-not (.hasNext iterator)
    (throw (Exception. "No image reader found for stream")))
    (.next iterator)))


    (def imagereader (get-imagereader input-stream))
    (.setInput imagereader input-stream true)

    (def image-index 0)
    (def input-metadata (.getImageMetadata imagereader image-index))

    (defn get-generator-string
    "Get the generator string from a PNGMetadata"
    [png-metadata]
    (let [dataArrayList (.unknownChunkData png-metadata)
    typeArrayList (.unknownChunkType png-metadata)]
    (loop [i 0]
    (if (= (.get typeArrayList i) generator-chunk-name)
    (String. (.get dataArrayList i))
    (recur (+ i 1))))))


    (def input-generator (get-generator-string input-metadata))
    (println input-generator)