write-image.clj

(defn write-image!
  ([ext buffered-image output-file]
   (write-image! ext buffered-image output-file {:quality 1.0}))
  ([ext buffered-image output-file options]
   (let [writer      (.next (ImageIO/getImageWritersByFormatName ext))
         write-param (.getDefaultWriteParam writer)
         iioimage    (IIOImage. buffered-image nil nil)
         ios         (ImageIO/createImageOutputStream output-file)]
     (doto write-param
       (.setCompressionMode ImageWriteParam/MODE_EXPLICIT)
       (.setCompressionQuality (:quality options)))
     (doto writer
       (.setOutput ios)
       (.write nil iioimage write-param)
       (.dispose))
     (doto ios
       (.close)))))