Georeference Preferences

Georeference Preferences contains options that can help customize the interface. Click the Preferences button to access Georeference Preferences.

prefs_georeference

Default external reference format	Lists supported reference file formats (excluding GeoTIFF). When multiple reference files are found in the same directory, the Reference File Ambiguity dialog box appears.
Open/New: use internal format if available	This option overrides the chosen default external reference format when any internal reference is detected. This option is checked by default.
Format change: use internal format if available	This option overrides the chosen Default Reference Format when any internal reference is detected. This option is checked by default.
GeoTIFF: pixel registration method	When saving a GeoTIFF, keep existing pixel reference point of current image or override by choosing: Pixel-As-Area (upper left corner) or Pixel-As-Point (center of the pixel)

Georeference > Editor

prefs_georeference_editor

Show errors greater than number of standard deviations	Lists supported reference file formats (excluding GeoTIFF). When multiple reference files are found in the same directory, the Reference File Ambiguity dialog box appears.
Point label colour	Colour of the control point label.
Selected point colour	Colour of the selected control point.
Reference point colour	Colour of existing reference control points.
User entered point colour	Colour of assigned control points.
Unassigned point colour	Colour of unassigned control points.
Coordinate Display	Set which coordinates to display when the cursor hovers over the preview image. These coordinates are displayed in the Georeference dialog box.

Error Detection Tolerance

The standard deviation is calculated from the residual errors of the control points. It is a statistic that indicates how much the control points match with the computed values (depending on the chosen transformation method). Enable the Show errors greater than number of standard deviations option to change the multiplier coefficient. Depending on the accuracy of the control points, the multiplier coefficient and the transformation method used, points that fall outside of the standard deviation range are considered as error. To set the threshold to tolerate more error, change the multiplier coefficient to a larger value. To set a threshold that will tolerate less error, change the multiplier coefficient to a smaller value. Points that do not comply with the tolerance range (standard deviation multiplied by coefficient) will be shown in red.

This method of error detection can be turned off by unchecking the Show errors greater than number of standard deviations option. This will ensure all the control points are listed in black.

information The values displayed in the Error Detection Tolerance correspond to the PXY error and the WXY error respectively. As the tolerance level is changed these values will update indicating the maximum tolerance value allowed. Values that exceed the maximum tolerance will be displayed in red in the list of GCP points.

Control Point and Label Colours

Choose colours for the control points and control point labels in the image view.

Lat/Long format and Geodetic Precision

Use the Lat/Long preference to change how world coordinates are displayed in the Control Point List. In addition, use the Geodetic Precision preference to change how many decimal places are displayed. A degree precision of one decimal place (e.g 0.1 decimal degrees) has a qualitative scale of a large city, while a precision of six decimal places (e.g. 0.000001 decimal degrees) has a qualitative scale of individual humans. An example is displayed as to how these preferences affect the display of geodetic coordinate values.

Projected Precision

Adjust the value in the Projected precision to change the number of decimals a projected coordinate displays. Each coordinate format has its own default minimum and maximum decimal precision. The default decimal precision is 6.

Coordinate Display

Enable which format of coordinates to display. This also affects which coordinates are copied to the clipboard.