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Apply a colormap renderer to a raster.

Image of colormap renderer

Use case

A colormap renderer transforms pixel values in a raster to display raster data based on specific colors, aiding in visual analysis of the data. For example, a forestry commission may want to quickly visualize areas above and below the tree-line line occurring at a known elevation on a raster containing elevation values. They could overlay a transparent colormap set to color those areas below the tree-line elevation green, and those above white.

How to use the sample

Pan and zoom to explore the effect of the colormap applied to the raster.

How it works

  1. Create a Raster from a raster file.
  2. Create a RasterLayer from the raster.
  3. Create a List<Color> representing colors. Colors at the beginning of the list replace the darkest values in the raster and colors at the end of the list replaced the brightest values of the raster.
  4. Create a ColormapRenderer with the color list: ColormapRenderer(colors), and apply it to the raster layer with rasterLayer.setRasterRenderer(colormapRenderer).

Relevant API

  • ColormapRenderer
  • Raster
  • RasterLayer

About the data

The raster used in this sample shows an area in the south of the Shasta-Trinity National Forest, California.

Tags

colormap, data, raster, renderer, visualization

Sample Code

module-info.java module-info.java ColormapRendererSample.java
/*
* Copyright 2022 Esri.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
module com.esri.samples.colormap_renderer {
// require ArcGIS Maps SDK for Java module
requires com.esri.arcgisruntime;
// handle SLF4J http://www.slf4j.org/codes.html#StaticLoggerBinder
requires org.slf4j.nop;
// require JavaFX modules that the application uses
requires javafx.graphics;
exports com.esri.samples.colormap_renderer;
}