Workspace To Mosaic (Samples)
Summary
Mosaics all the raster datasets in a workspace, or geodatabase, to an output raster dataset. The output raster dataset must already exist.
Legacy:Usage
Mosaic is useful when two or more adjacent raster datasets need to be merged into one entity. Some mosaic techniques can help minimize the abrupt changes along the boundaries of the overlapping rasters.
For mosaicking of discrete data, First, Minimum, or Maximum Mosaic Operator options will provide the most meaningful results. The Blend and Mean Mosaic Operator options are best suited for continuous data.
For floating-point input raster datasets of different resolutions or when cells are not aligned, it is recommended to resample all the data using bilinear interpolation or cubic convolution before running Mosaic; otherwise, Mosaic will automatically resample the raster datasets using nearest neighbor resampling, which is not appropriate for continuous data types.
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The output raster dataset must already exist since the input raster datasets will all be mosaicked into it. This raster dataset cell size determines the cell size for the entire mosaic.
If an output raster dataset does not already exist, you can use the Mosaic to New Raster tool, or create an empty raster dataset prior to running this tool.
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This sample tool was created using Python. The code can be viewed and edited, to help you write your own scripts.
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The Raster Analysis Environment Settings are not valid for this tool.
Syntax
| Parameter | Explanation | Data Type |
input_workspace |
The input workspace can be a directory, a personal geodatabase, file geodatabase, or an ArcSDE geodatabase. | Folder | Workspace |
output_raster |
The output raster dataset into which the other input raster datasets are mosaicked. The output raster dataset must already exist. | Raster Dataset |
mosaic_method (Optional) |
The method used to mosaic overlapping areas.
| String |
mosaic_colormap_mode |
The method used to choose which colormap from the input rasters will be applied to the mosaic output.
| String |
ignore_background_value (Optional) |
Use this option to remove the unwanted values created around the raster data. The value specified will be distinguished from other valuable data in the raster dataset. For example, a value of zero along the raster dataset's borders will be distinguished from zero values within the raster dataset. The pixel value specified will be set to NoData in the output raster dataset. For file-based rasters and personal geodatabase rasters, the Ignore Background Value must be set to the same value as NoData in order for the background value to be ignored. ArcSDE and file geodatabase rasters will work without this extra step. | Double |
nodata_value (Optional) |
All the pixels with the specified value will be set to NoData in the output raster dataset. | Double |
convert_1_bit_data_to_8_bit (Optional) |
Choose whether the input 1-bit raster dataset will be converted to an 8-bit raster dataset. In this conversion the value 1 in the input raster dataset will be changed to 255 in the output raster dataset. This is useful when importing a 1-bit raster dataset to ArcSDE. One-bit raster dataset have 8-bit pyramid layers when stored in a file system, but in ArcSDE, 1-bit raster datasets can only have 1-bit pyramid layers, which makes the display unpleasant. By converting the data to 8-bit in ArcSDE, the pyramid layers are built as 8-bit instead of 1-bit, resulting in a proper raster dataset in the display.
| Boolean |
mosaic_tolerance (Optional) |
When mosaicking takes place, the target and the source pixels do not always line up exactly. When there is a misalignment of pixels, a decision needs to be made whether resampling takes place, or whether the data should be shifted. The mosaicking tolerance controls whether resampling of the pixels take place, or if the pixels should be shifted. If the difference in pixel alignment (of the incoming dataset and the target dataset) is greater than the tolerance, resampling will take place. If the difference in pixel alignment (of the incoming dataset and the target dataset) is less than the tolerance, resampling will not take place (instead, a shift is performed). The unit of tolerance is a pixel; the valid value range is 0 to 0.9999. The maximum a pixel can be shifted is 0.5, so anything you set that is greater than 0.5 will guarentee a shift takes place. A tolerance of zero guantees resampling, if there is a misalignment in pixels. For example, the source and target pixels have a misalignment of 0.25. If the mosaicking tolerance is set to 0.2, then resampling will take place since the pixel misalignment is greater than the tolerance. If the mosaicking tolerance is set to 0.3, then the pixels will be shifted. | Double |
Code Sample
import arcgisscripting
gp = arcgisscripting.create()
gp.WorkspaceToMosaic_samples("D:\\temp\\tempws", "Database Connections\\raster.sde\\RASTER.WRKSPTOMOSAIC", "LAST", "FIRST", "#", "#", "#", "0")