There’s a lot of tiled imagery out there that gets delivered to people without any coordinates stored with the files. Often the coordinate information exists but it’s stored in a table. So how do you view it in ArcGIS.
Well, if it’s just one or two images you can create a world file for each image. To learn how to do this, see World files for raster datasets.
But in many cases it’s 100 or 1000s of images and generating a world file for every file may be a bit daunting without some automation. So the best way to deal with this in ArcGIS is to create a mosaic dataset and add the images to it using the Table raster type.
Your table must have the following fields–using these field names. The order of the fields doesn’t matter.
Raster, Xmin, Xmax, Ymin, Ymax, NCols, NRows, PixelType, NBands
The Xmin, Xmax, Ymin, and Ymax fields are the coordinates of the image extents.
The Raster field is the path and name of the image. Such as c:\data\Image01.tif.
The NCols and NRows are the dimensions of the image (the number of columns and rows).
The Nbands field is the number of bands in the image. Such as, 3 for a color image and 1 for a grayscale image.
The PixelTypefield is a number identifying the bit depth of the pixel. The supported pixel types are:
- -1: Unknown
- 0: 1-bit
- 1: 2-bits
- 2: 4-bits
- 3: Unsigned 8-bit integers
- 4: Signed 8-bit integers
- 5: Unsigned 16-bit integers
- 6: Signed 16-bit integers
- 7: Unsigned 32-bit integers
- 8: Signed 32-bit integers
- 9: Single precision floating point
- 10: Double precision floating point
- 11: Single precision complex
- 12: Double precision complex
- 13: Short integer complex
- 14: Long integer complex
You can also add other fields, such as a date or other identifiers for the imagery if you want. I often add an ImageName field that contains just the name of the image.
Next, create your mosaic dataset. Then open the Add Rasters To Mosaic Dataset tool, pick Table from the Raster Type dropdown and click the Properties button.
Make sure the Raster Source is Raster (the same Raster field in your table), and if you have a field for the image name you can enter it.
Click OK to close this dialog box and in the tool dialog box, add your table as the Input Data. Click OK and your collection of tiled images will be added to the mosaic dataset.