Process

The Process theme applies Processing to items before they are drawn.

Click Home > Add Theme > Operation and select Process.

Click Next to see the Processing Steps window.

Select the required process operation from the appropriate folder in the left hand pane and click the right-arrow button to show the selected process in the right-hand pane.

The parameters associated with the process are then shown in the right-hand lower pane. Enter the value(s) for the process.

Some processes do not require any inputs.

The Draw the original Item - before and after tickboxes control the drawing order in relation to the processed Item.

When this dialog is complete click Finish.

The processing operations are categorised as shown below. Click on the category title, or the individual process, to go to the page containing the process descriptions.

General

Copy	Copies an existing Item

Construction

Create box	Creates a rectangular Polygon, around a centre point
Create ellipse	Creates an elliptical Polygon
Create from WKB	Creates an Item from OGC Well-known Binary
Create from WKT	Creates an Item from OGC Well-known Text
Create line (bearing/distance)	Creates a LineString from a bearing and distance
Create point	Creates a Point Item
Create sector (bearing/angle)	Creates a sector Polygon from a bearing and angle.
Create sector (start/end)	Creates a sector Polygon from a start and end angle

Geometry

'Dig' shape	Gets the 'dig' shape (a concave hull) of an Item using Park/Ho's algorithm
Alpha shape	Gets the Alpha shape (a concave hull) of an Item, using Edelsbrunner's algorithm
Boundary	Gets the boundary of an Item.
Chi shape	Gets the Chi shape (a concave hull) of an Item, using Duckham's algorithm
Close	Closes any open geometry, joining the end to the start
Convex hull	Creates a convex hull Polygon around an Item
Ensure anti-clockwise	Reverses the geometry of polygonal Items with coordinates specified clockwise, making them anti-clockwise instead. Other Items are left alone.
Envelope	Creates an envelope Polygon around the extents of an Item
Facet	Facets curved geometry segments into a straight geometry
Fill	Fills the boundary of an Item
Move	Moves an Item in X and/or Y and/or Z
OOBB (aligned)	Creates an object orientated bounding box (OOBB) Polygon around an Item, aligned to the 'dominant' angle of the Item geometry
OOBB (minimum)	Creates the minimum (smallest area) object orientated bounding box (OOBB) Polygon around an Item
Remove interior loops	Removes interior loops (holes and islands) from Polygons, leaving only exterior loops
Reverse geometry	Reverses the geometry of an Item
Rotate	Rotates the geometry of an Item about a hook point
Scale	Scales the geometry of an Item about a hook point
Smooth (mid-points)	Smoothes the geometry of an Item, keeping segment mid-points fixed
Smooth (vertices)	Smoothes the geometry of an Item, keeping vertices fixed
Strip geometry	Strips the geometry of an Item, leaving an Empty Item

Clean/Simplify

Generalise (Douglas-Peucker N)	Generalises geometry using a variation of the Douglas-Peucker algorithm that is limited by the number of output points
Generalise (Douglas-Peucker)	Generalises geometry using the Douglas-Peucker algorithm
Generalise (Perpendicular Distance)	Generalises geometry using the Perpendicular Distance algorithm
Generalise (Radial Distance)	Generalises geometry using the Radial Distance algorithm
Generalise (Reumann-Witkam)	Generalises geometry using the Reumann-Witkam algorithm
Remove self-intersections	Removes self-intersections, e.g. a bow-tie
Remove short segments	Removes segments shorter than a tolerance
Remove spikes	Removes vertices that cause a spike
Remove straight segments	Removes vertices between straight, or near straight segments.
Simplify	Simplifies the geometry of an item, so that it matches the OGC 'simple' form

Properties

Remove all attributes	Removes all attributes from an Item
Remove attribute	Removes an attribute from an Item
Set property	Sets a property on an Item
Set styles	Sets styling information on an Item
Strip styles	Strips all styling information from an Item. Returns Brush, Pen and Symbol Items to "By Overlay"

Analysis

Buffer	Creates a buffer around an Item
Buffer (doughnut)	Creates a buffer around the boundary of a Polygon
Buffer (inside)	Creates a buffer around the boundary of a Polygon that only contains the parts that are inside the Polygon
Buffer (interior)	Creates a buffer inside a Polygon that excludes the parts of a doughnut buffer around the boundary of the Polygon
Buffer (outside)	Creates a buffer around the boundary of a Polygon that only contains the parts that are outside the Polygon
Geodetic buffer	Creates a 'geodetic' buffer around an Item
QZone buffer	Creates a QZone buffer around an Item

Rubber-sheeting

Create Displacement

Creates a Displacement Item, for use in rubber-sheeting

Raster

Compress	Compresses a bitmap
Convert to grayscale	Converts a colour bitmap to a grayscale bitmap
Convert to sepia	Converts a colour bitmap to a sepia bitmap
Crop	Crops a bitmap

Grid

Create Terrain Ruggedness Index	Creates a Terrain Ruggedness Index map
Create Topographic Position Index	Creates a Topographic Position Index map
Create aspect	Creates an Aspect map
Create hillshade	Creates a shaded relief map from a Grid
Create roughness	Creates a Roughness map
Create slope	Creates a Slope map
Getis-Ord GI* (Z score)	Finds the locations and extents of point clusters in two-dimensional space.
Getis-Ord GI* (p-value)	Finds the locations and extents of point clusters in two-dimensional space.
Grid * Number
Grid + Number
Grid - Number
Grid / Number
Max(Grid, Number)
Min(Grid, Number)
Number - Grid
Number / Grid
Set cell value	Sets the value of all Grid cells that match a comparison against the 'from' value to the 'to' value
Set grid pixel type	Sets the grid pixel type (bit depth) of an image.
Transform Grid

Geocode

MapQuest Open	Connects to the MapQuest Open Geocoding service
Microsoft Bing Maps	Connects to the Microsoft Bing Maps geocoding service
OS (GB) Code-Point Open	Searches OS (GB) Code-Point Open data, by postcode
OS (GB) National Grid Reference	Matches search strings against OS (GB) National Grid References
OS (GB) National Grid Reference (Jersey)	Matches search strings against OS (GB) National Grid References for Jersey

User-defined

Remove all attributes	Removes all attributes from an Item
Strip styles	Strips all styling information from an Item

Filter, Scale and Legend buttons

Click here for a description of the functions of these three buttons.

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