geotrellis.raster.render.JpgRenderMethods.scala Maven / Gradle / Ivy

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package geotrellis.raster.render

import geotrellis.raster._
import geotrellis.raster.render.jpg._
import geotrellis.raster.histogram.Histogram
import geotrellis.raster.summary._
import geotrellis.util.MethodExtensions


trait JpgRenderMethods extends MethodExtensions[Tile] {

  def renderJpg(): Jpg =
    renderJpg(Settings.DEFAULT)

  /** Generate a JPG from a raster of RGBA integer values.
    *
    * Use this operation when you have created a raster whose values are already
    * RGBA color values that you wish to render into a JPG. If you have a raster
    * with data that you wish to render, you should use RenderJpg instead.
    *
    * An RGBA value is a 32 bit integer with 8 bits used for each component:
    * the first 8 bits are the red value (between 0 and 255), then green, blue,
    * and alpha (with 0 being transparent and 255 being opaque).
    *
    */
  def renderJpg(settings: Settings): Jpg =
    new JpgEncoder(settings).writeByteArray(self)

  def renderJpg(colorRamp: ColorRamp): Jpg =
    renderJpg(colorRamp, Settings.DEFAULT)

  def renderJpg(colorRamp: ColorRamp, settings: Settings): Jpg = {
    if(self.cellType.isFloatingPoint) {
      val histogram = self.histogram
      val quantileBreaks = histogram.quantileBreaks(colorRamp.numStops)
      renderJpg(new IntColorMap(quantileBreaks.zip(colorRamp.colors).toMap).cache(histogram), settings)
    } else {
      val histogram = self.histogramDouble
      renderJpg(ColorMap.fromQuantileBreaks(histogram, colorRamp), settings)
    }
  }

  def renderJpg(colorMap: ColorMap): Jpg =
    renderJpg(colorMap, Settings.DEFAULT)

  /**
    * Generate a JPG image from a raster.
    *
    * Use this operation when you have a raster of data that you want to visualize
    * with an image.
    *
    * To render a data raster into an image, the operation needs to know which
    * values should be painted with which colors.  To that end, you'll need to
    * generate a ColorBreaks object which represents the value ranges and the
    * assigned color.  One way to create these color breaks is to use the
    * [[geotrellis.raster.stats.op.stat.GetClassBreaks]] operation to generate
    * quantile class breaks.
    */
  def renderJpg(colorMap: ColorMap, settings: Settings): Jpg = {
    val encoder = new JpgEncoder(new Settings(1.0, false))
    encoder.writeByteArray(colorMap.render(self).map(_.toARGB))
  }
}