The Cached Raster function creates a preprocessed cache at the point in the function chain where it's added. It is typically inserted in a function chain, on top of the functions that can impede performance due to more computationally intensive processing. These functions can include the Convolution, Band Arithmetic, Pan-sharpening, multiple Arithmetic functions, and the Geometric function when it's used to perform orthorectification.
You can insert this function when accessing the function chain for each raster in a mosaic dataset, using the Batch Functions Editor Wizard, or using the Define Mosaic Dataset Item Cache tool. You can generate the cache for each item when adding the function using the Define Mosaic Dataset Item Cache tool, or generate or update the cache using the Synchronize Mosaic Dataset tool (check the Build Cache option).
The inputs to this function are the following:
- Input Raster—Location in the function chain representing the last function output used in this function. This will be populated automatically.
- Cache Path—The location where the cached dataset will be stored. By default, the cache is generated and stored in a folder next to where the mosaic dataset resides. This folder has the same name as the geodatabase, with a .cache extension. However, if the mosaic dataset is created in an ArcSDE geodatabase, the cache will be created within that geodatabase.
- Cache File name—System-generated name used to identify the cached dataset. This will appear once the function has been added to the function chain. It cannot be edited.
- Compression—Type of compression, if any, that will be used when generating the cache.
- Lossless—Lossless compression retains the values of each pixel when generating the cache dataset.
- Lossy—Lossy compression does not retain the exact values of each pixel when generating the cached dataset. When using this method, a compression quality can also be set between 1 and 100 percent.
- None—No compression will be used when generating the cached dataset.
- Cache Generation Criteria—Limits the size of the cache dataset by number of pixels, in rows and columns. If the extent of the data cannot fit within this constraint, it will not be generated.
- Resampling—Allows you to resample the resolution of the cached raster. Resampling your cached raster can make very intensive processes and complicated function chains perform faster.
- Pixel Size Factor—Allows you to choose a scaling factor to resample the cached raster. The default factor is 1, so that no scaling takes place.
- Pixel Size—Allows you to specify the pixel size at which to create the cached raster.