deskew-ocr-1.scala

def imageDeSkew(skewThreshold:Double = 0.05) = Flow[BufferedImage].map(bi => {
  val deSkew = new ImageDeskew(bi)
  val imageSkewAngle = deSkew.getSkewAngle

  if (imageSkewAngle > skewThreshold || imageSkewAngle < -skewThreshold) {
    ImageUtil.rotate(bi, -imageSkewAngle, bi.getWidth() / 2, bi.getHeight() / 2)
  } else {
    bi
  }
})

def imageWriter(format:String = "png") = Flow[BufferedImage].map(bi => {
  val ri = bi.asInstanceOf[RenderedImage]
  val outPutStream = new ByteArrayOutputStream
  val writer = ImageIO.getImageWritersByFormatName(format).next()
  val imageOutputStream = ImageIO.createImageOutputStream(outPutStream)
  
  writer.setOutput(imageOutputStream)
  writer.write(ri)

  val bytes = outPutStream.toByteArray
  outPutStream.close()
  ByteString(bytes)
})