Raster type properties
There are properties for each raster type that you can modify before adding your raster data to a mosaic dataset. These include choosing a product type, specifying a particular band combination and a stretch, identifying the DEM for orthorectification, and modifying the parameters for pan sharpening. The properties that are available depend on what is supported by a particular raster type. Raster types are stored with .art extensions. Any time you make an edit to the raster type, you can save it to a new .art file so you can load additional data at another time using the same modifications.
You can access the properties of a raster type by picking the raster type in the Add Rasters To Mosaic Dataset tool dialog box, then clicking the Properties button 
. For most raster types you will see three tabs: General, Properties, and Functions. There will be additional tabs for specific raster types depending on their needs. For example, when using the LAS raster type, the Properties tab does not apply to this data, therefore, a specific LAS tab is present.
General tab
For each raster dataset, there are a number of product types and templates that help determine how the data is added and what functions may be applied by default. For example, if you choose the Landsat 7 ETM+ raster type and choose its Level 1 product, you could choose the Pansharpen template, which will create a product using bands 1–4 that is pan sharpened using band 8. But if you choose Thermal, only the thermal bands, 6a and 6b, will be added.
The product type is specified by the vendor, which also determines the format of files that will be available, such as any metadata files and the raster file format, such as TIFF (one multiband TIFF or many one-band TIFFs). The processing templates are used to define different products that can be created from the input data and the function chains required to create them. For example, you may want to add all the bands as just raw bands or create a pan-sharpened output from your input data. For the first example, you would choose All Bands, and for the second example, you would choose Pansharpen.
The Filter text box allows you to specify the file extension to be used when using this particular raster type.
The Save As options allows you to save the edits you made to this raster type (on any tab) to a new raster type file (.art).
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The Merge Items check box is activated for specific raster types that contain multiple rasters that can be treated as a single item.
Properties tab
The product types and processing templates from the General tab affect the properties on the Properties tab; which you can modify. For example, if you didn't want a multispectral product using all six Landsat 7 ETM+ bands, you could specify the bands you wanted in the output. If using a pan-sharpening template you can modify the method and the weights for the inputs. You can also specify the type of stretch you want applied to the histogram. If orthorectifying, you can specify the DEM.
Only the properties that apply to the product types and processing template are active on the Properties tab.
Stretch
Stretching improves the appearance of the data by spreading the pixel values along a histogram from the minimum and maximum values defined by their bit depth. The dialog box will change according to the options picked.
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Type—Defines the histogram stretch used to enhance the appearance of the raster data. The options are the same as those used when rendering any raster data in ArcGIS:
- None—No stretch is applied.
- Standard Deviation—Applies a linear stretch between the values defined by the standard deviation (n) value.
- When picked, enter a value in the n text box.
- Optionally enter an Output Min and Output Max value. The values can limit the stretch to a range within the supported bit depth.
- Minimum-Maximum—Applies a linear stretch based on the output minimum and output maximum pixel values, which are used as the endpoints for the histogram.
- When picked, enter the minimum and maximum values in the Output Min and Output Max text boxes.
- Percent Clip—Applies a linear stretch between the percent clip minimum and percent clip maximum pixel values.
- When picked, enter a percentage value in the Minimum and Maximum text boxes. This value can be different and often depends on the shape of the histogram in determining how to clip the tails.
- Optionally enter an Output Min and Output Max value. The values can limit the stretch to a range within the supported bit depth.
Estimate statistics—If statistics don't exist for the raster dataset, the statistics will be estimated from a sampling within the dataset. However, for more accurate results, it is recommended that you calculate statistics, which can be done on the Add Rasters To Mosaic Dataset tool. Either way, calculating or estimating statistics will increase the time it takes to add the data to the mosaic dataset.
Gamma—Allows you to specify a gamma stretch that will be applied to each band. There are two types of stretches:
- Auto-Per Band—The system will examine the histograms and determine a gamma value for each band in the dataset.
- User Defined—You can enter a single number in the Value text box to be applied to each band in the dataset.
Band combination
This set of parameters may be disabled depending on if the mosaic dataset was created using a product definition or the raster type.
The Band combination parameters allows you to control the order in which you want the bands added to the mosaic dataset. You can define this order using one of three methods:
- Band IDs—Identifies that you will specify the band order using the band ID numbers associated with your input bands. For example, bands 3 2 1 4 5 6 will be added in this order. Band 3 will be mapped to the first band in the mosaic dataset, Band 2 will be mapped to the second band, and so on.
- Band Names—Identifies that you will specify the band order using the names associated with your input bands. You can choose the names from the drop-down list or enter them manually. This uses a space-delimited list. The names generally appear on the Key Metadata tab of the dataset's properties dialog box.
- Band Wavelengths—Identifies that you will specify the band order using the mid-wavelength value for each input band. For example, if adding three bands where the wavelengths you require from your inputs are 400–500, 550–680, and 840–1200, you would enter a space-delimited list using the mean of each wavelength range—450 615 1020. The input band with its mean wavelength closest to the specified value will be added.
Pan-sharpening
Pan-sharpening fuses a higher-resolution panchromatic image with a lower-resolution, multiband raster dataset. When the Processing Template on the General tab is Pansharpen and the data contains the mix of bands to support pan-sharpening, this option is active.
Type—Defines the method of pan-sharpening.
- Esri—Uses the Esri algorithm based on spectral modeling for data fusion
- Brovey—Uses the Brovey algorithm based on spectral modeling for data fusion
- Gram-Schmidt—Uses the Gram-Schmidt orthogonalization algorithm for for data fusion
- IHS—Uses Intensity, Hue, and Saturation color space for data fusion
- Mean—Uses the averaged value between the red, green, and blue values and the panchromatic pixel value
Sharpen image—Allows you to apply a sharpening filter to the panchromatic band.
- None—No sharpening
- Sharpen—Uses a simple 3 by 3 sharpening kernel
- Sharpen More—Uses a simple 3 by 3 sharpening kernel but with a stronger effect than the Sharpen kernel
Band weights—Contains a space-delimited list of weights that will be applied depending on the type of pan sharpening. This list can be edited. The first value in the list corresponds to the first band in the dataset. The sum of all the band weights should equal 1.
4th-band as infrared image—Specifies that the fourth band is an infrared band and that it should be used by the algorithm depending on the type of pan sharpening.
Orthorectification using elevation
Orthorectification is the process of stretching the image to match the spatial accuracy of a map by considering location, elevation, and sensor information. This option is available when the data contains the appropriate information, such as the rational polynomial coefficients (RPCs).
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There are three options to define the elevation component:
- Average elevation—Uses the average z-value that is defined within the sensor definition.
- Constant elevation—Uses the value entered in the text box.
- DEM—Uses the DEM specified. Optionally, you can define a scale or offset or a geoid correction for the DEM.
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Elevation adjustment parameter |
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Z offset |
The base value to be added to the elevation value in the DEM. This could be used to offset elevation values that do not start at sea level. |
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Z factor |
The scaling factor used to convert the elevation values. The scaling factor is used for two purposes: first, to convert the elevation units (such as meters or feet) to the horizontal coordinate units of the dataset, which may be feet, meters, or degrees, and second, to add vertical exaggeration for visual effect. To convert from feet to meters or vice versa, see the table below. For example, if your DEM's elevation units are feet and your mosaic dataset's units are meters, you would use a value of 0.3048 to convert your elevation units from feet to meters (1 foot = 0.3048 meters). This is also useful when you have geographic data (such as DTED in GCS_WGS 84 using latitude and longitude coordinates) where the elevation units are in meters. In this case, you need to convert from meters to degrees. The value for degree conversions are approximations, and depend on the latitude of your area of interest. Conversion factor between feet and meters
To apply vertical exaggeration, you must multiply the conversion factor by the exaggeration factor. For example, if both elevation and dataset coordinates are meters and you want to exaggerate by a multiple of 10, the scaling factor would be unit conversion factor (1.0 from the table) multiplied by the vertical exaggeration factor (10.0), or 10. As another example, if the elevations are meters and the dataset is geographic (degrees), you would multiply the units conversion factor (0.00001) by 10 to get 0.0001. |
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Geoid |
If checked, a geoid correction will be made using a spherical model. |
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Function tab
Functions can be applied to each raster in a mosaic dataset or on the entire mosaic dataset. These functions are dynamically applied to the raster data as the mosaicked image is accessed and viewed.
The Functions tab lists functions that will be applied and how or what order they will be applied. There may be a single function, such as the Stretch function, or they may be chained together to create a more advanced product.
The functions are organized by processing templates. Therefore, if you choose the Pansharpen template, you can view the function chain that will be applied to create this product. You can also modify the chain by adding or removing functions or the parameters of the functions by right-clicking within the window and selecting the appropriate command. You can also add new templates whose function chains you edit by right-clicking Processing Templates and clicking Add. The new templates will appear in the Processing Templates list on the General tab.