A tile file is a file that contains coordinates which define a geographical extent\s on the ground of a terrain model or ortho-mosaic as well as the name of the GeoTiff file for each tile.
A tile is commonly referred to as a “sheet” and this name may appear in various locations throughout the software.
OenButton™ Standard and OneButton™ Professional generate GeoTiff files which are limited in their size to 2 GB. In some larger projects, because of this limitation a tile file can help split the area into several GeoTiff files keeping each file size under the 2 GB limit.
The OneButton™ and OneButton Professional™ applications create this file automatically but there may be occasions where you would want to create this file manually or modify an existing the extents.
For example, in some projects, the extent of each tile is pre-defined and is a hard requirement so you will need to enter the extents before creating your output.
In order to create a tile file manually, we recommend that you have the necessary geographic extent of your project area. The coordinates for this extent will have to be in the same projection as the projection defined when creating the project.
How to Create a Tile File
- In the DTM or Stitch parameter window, select the “Tile File Path” option:
- Press the “Create” button to open the Tile File creation window (also referred to as “sheet division”):
- In the “output tile file” text box, press the “…” button and navigate to the folder in which you would like to save your tile file. Give the file a name and press the “Save” button.
- In the “Block parameters” section, review the upper left and lower right coordinates of your project area and modify them if necessary. You can also change the extent box definition to lower left and upper right by pressing the upper right or lower left of the extent box:
- Select the number of tiles or define the dimension of each tile. You can also change the overlap between the tiles if needed:
- Press the “Estimate tile size” button and review the value calculated in the “estimated sheet size:” text box
This value is the estimated file size that will be created for each tile. Currently, Tiff format limits the file size to 2GB so we recommend that you verify that the size does not exceed 1.5 GB. If the size is estimated to be larger we recommend creating more tiles or changing the area of the project in the “Block parameters” section.
- Press the “Create Tile File” button to create your tile file according to the parameters defined in the window.
How to Modify an Existing Tile File
An existing tile file can be modified using either the Seamline Editor application or the GeoClipboard.
Via Seamline Editor
- In the OneButton Professional main window, go to the “Processing” tab and press the “Seamline Editor” button.
- Go to the “Sheets Editing” tab and press the “Import Sheets” button to load the existing tile file.
- An additional layer named “Sheets” will appear in the Table of Contents and the tile polygon will load in the main window.
- In the toolbar press the “Select and Edit Sheets” tool .
- Press the CTRL key and drag the with left mouse button over any area inside the tile to select it.
- The tile polygon will change to a yellow dashed line with handles at the edges and centers of each polygon line:
- Hover with your mouse over any of these handles and move them to adjust the tile extents.
- When you are finished simply left click on any part of the window.
- Go to the “Sheets Editing” tab and press the “Save Sheets to Tile File” button to implement thee changes.
- You can now re-run the stitch process to re-create your mosaic with the updated tile size.