On the General tab, under Raster Information is the NoData Value.In the ArcCatalog or the Catalog window, right-click the raster dataset and click Properties.This tool allows you to specify more than one NoData value. NoData values can also be assigned for a mosaic dataset using the Define Mosaic Dataset NoData tool. You can also remove a value from being NoData using the raster dataset's Properties dialog box. Assign the NoData value for an input image. There are two ways to assign the cell value in a raster dataset to be NoData-using the Set Null tool or through the raster dataset's Properties dialog box. Rules for data type promotion Defining NoData The following table lists the rules for data type promotion: Original file-based raster data type

For example, a hillshade grid with cell values of 0 to 255, which then has NoData added to it, will be represented as unsigned 16 bit in order to store a value that is not being used to represent a valid value, such as 256. Alternatively, you can clear the value entered to remove the NoData value. You can specify a different value for each band. Only one value can be entered for each band. You must enter a value contained within the dataset. When NoData is added to a file-based raster that already has a full-bit range (meaning that all the values in the bit range, for example, 0 to 255, are all represented by at least one cell), it will be promoted to the next higher bit depth. Click the column next to the band name to edit the NoData Value. The bit mask will be read, and NoData areas will be extracted at the time of retrieval. In ArcSDE and file geodatabases, if the original raster data contains NoData cells, a bit mask will be generated when loading the raster, and it will be stored in the database. For example, -9999 is a common value for storing NoData. 1 Answer Sorted by: 5 You were on the right track with cellsFromExtent. NoData is stored as a mask that is part of the raster dataset, or using a pixel value in the dataset that is not used as a valid value elsewhere in the dataset. A value must be estimated, and NoData cannot be returned.NoData is ignored, and a value is computed using any available values.NoData can be returned for the location no matter what.When performing operations on raster data containing NoData values, there are typically three ways that NoData is treated for each cell: When calculating the statistics for a raster dataset, you can choose to ignore any cells with NoData. Learn about symbolizing values of NoData in raster datasets The image on the left shows a NoData area with a black background, and the image on the right shows that same area using no color. When displaying rasters with NoData values, all renderers allow you to set the NoData value to a color or no color however, the Stretched renderer allows you to identify a specific background value and display color or no color. Sometimes these are expressed as NoData values, although other times they may have real values. These can include borders, backgrounds, or other data considered to not have valid values.

Sometimes there are homogeneous areas in a raster dataset that the you do not want to display. Cells can also have a NoData value to represent the absence of data. Cell values can be either positive or negative, integer, or floating point.

Change nodata values for raster in r