Skip To Content ArcGIS for Developers Sign In Dashboard

Web Map Specification


The image service uses a mosaic rule to mosaick multiple rasters on the fly. The mosaic rule parameter is used by many image service operations, for example, export image and identify operations.


Property Details
ascending Indicate whether to use ascending or descending order.
fids A list that defines a subset of rasters used in the mosaic, be aware that the rasters may not be visible at all scales.
itemRenderingRule The rendering rule applies on items before mosaicking.
lockRasterIds Lock a few rasters in the image service. Used together with esriMosaicLockRaster.
mosaicMethod A string value that determines how the selected rasters are ordered.
Must be one of the following values:
  • esriMosaicNone
  • esriMosaicCenter
  • esriMosaicNadir
  • esriMosaicViewpoint
  • esriMosaicAttribute
  • esriMosaicLockRaster
  • esriMosaicNorthwest
  • esriMosaicSeamline
mosaicOperation Use the mosaic operation to resolve overlap pixel values: from first or last raster, use the min, max or mean of the pixel values, or blend them.
If property is present, must be one of the following values:
  • MT_MIN
  • MT_MAX
  • MT_SUM
multidimensionalDefinition Definition of multidimentional variables.
sortField The field name used together with esriMosaicAttribute method.
sortValue The base sort value used together with esriMosaicAttribute method and sortField parameter.
viewpoint Use a view point along with esriMosaicViewpoint.
where Deprecated. Use layerDefinition.definitionExpression instead.


  "operationalLayers": [
      "id": "Terrain_2295",
      "layerType": "ArcGISImageServiceLayer",
      "url": "",
      "visibility": true,
      "bandIds": [],
      "format": "jpgpng",
      "compressionQuality": 75,
      "opacity": 1,
      "title": "Terrain",
      "itemId": "58a541efc59545e6b7137f961d7de883",
      "renderingRule": {
        "rasterFunction": "Aspect"
      "mosaicRule": {
        "mosaicMethod": "esriMosaicSeamline",
        "mosaicOperation": "MT_FIRST"

Feedback on this topic?