ArcGIS AllSource displays raster data with the most appropriate renderer according to the raster properties (such as number of bands, source type, pixel type, and statistics) and metadata that is available. You can control the default rendering in the Options window by changing the settings on Raster and Imagery > Appearance.
You can interactively choose different rendering methods based on your display and analysis needs once the raster data is added to the display. You can change these methods in the Symbology pane or on the Raster Layer, Mosaic Layer, or Image Service Layer tab. To preserve the rendering properties you've set, you can save a layer file (*.lyrx).
All raster datasets and mosaic datasets include a Source Type property, such as elevation or thematic, that describes the data. This property affects how the data is rendered. For example, for elevation, the default resampling method is bilinear and the default stretch is minimum-maximum. For thematic, nearest neighbor resampling is used with a standard deviation stretch. If the value is Processed, no stretch is applied.
Render raster products
Raster products are designed to make adding imagery from specific sensors or data providers to your map simpler because each raster product has a unique set of enhancements and band combinations to provide an optimal view of your data. The stretch, band combinations, and necessary functions are added to enhance the layer to modify the display. However, as with any other layer, you can modify these functions once they are added to the map.
Each raster product has a default template. This is typically Multispectral. Therefore, if you don't expand the raster product to choose a different template, this default is used.
Render single-band datasets
When a single-band raster dataset is drawn, the rules for determining the default renderer are as follows:
- If your data includes an attribute table with red, green, and blue values, those colors will be used to display as with the Unique Values renderer, and takes priority over any color map file that may exist.
- If your dataset includes a color map, it is displayed with the Colormap renderer using the colors stored in the color map.
- If your dataset contains 1-bit data and the dataset does not include pyramids, the Unique Values renderer is used with 0 set to white and 1 set to black. When 1-bit data includes pyramids, the Stretched renderer is used. Pyramid files for 1-bit data are created as 8-bit grayscale to achieve improved display when viewing the raster at its full extent.
- If your dataset contains 25 or fewer unique values, the Unique Values renderer is used with random colors assigned to the values.
- If your dataset includes an internally stored custom stretch, the Stretched renderer is used with a black to white color scheme.
- If your dataset includes statistics, the Stretched renderer is used with a black to white color scheme, using the most appropriate stretch type for the data. If there are no statistics stored with your dataset, they are sampled from the dataset and the Stretched renderer is applied; however, these statistics are only used for the display and are not stored with the dataset.
- If your dataset has standard time values within the metadata, the Stretched render is used with a custom green to purple color scheme. The labels automatically display the oldest and most recent dates, using a year, month, day, and time format.
Render multiband datasets
If your data has a Source Type value of Vector-UV, Vector-MagDir, Vector-Magnitude, or Vector-Direction, the Vector Field renderer is used to display your data with vector arrows.
When a multiband raster dataset is drawn, the default uses the RGB composite renderer. If the data includes wavelength information, it is displayed with the red, green, and blue bands; otherwise, it uses the default band combination set within the Options window. If your dataset does not include statistics, they are sampled from the dataset and the RGB composite renderer is applied; however, these statistics are only used for the display and are not stored with the dataset.
Render mosaic datasets
A mosaic dataset is a data model in the geodatabase used to manage a collection of raster datasets (images) stored as a catalog and viewed as a mosaicked image. When you add a mosaic dataset to ArcGIS AllSource, it is added as a mosaic layer that appears in the Contents pane as a special group layer with a minimum of three layers: Boundary, Footprint, and Image.
The Image layer is used to control the rendering of the mosaicked image of the mosaic dataset. You can edit the symbology in the Symbology pane or on the Raster Layer, Mosaic Layer, or Image Service Layer tab. Modifications you make to the Image layer properties do not affect the mosaic dataset—only how the Mosaic layer is rendered at the time you are viewing it.
Render alpha bands
An alpha band acts as a transparency mask, providing a transparency value for each pixel. You can specify an alpha band for multiple-band raster datasets rendered with the RGB renderer.
By default, the alpha band is set to None.