HowTo_Definitions

How to Prepare a Definitions File

Definition files contain descriptions of landmarks and derived geometric objects like line segments of finite length and straight lines. The items listed in a definitions file build a To-Do-List for measuring the individual images.

File Structure

A definitions file is a basic CSV file (currently using ; as field separator). A line in this file is considered to be usable data if it starts with one of the following key words:

• point: a distinct landmark on the image, coordinates will be exported
• segment: a finite line segment between two points, length will be exported
• line: a straight line through two points, auxiliary object, no data will be exported

All other lines are not used by FacePalm and can be freely used to provide comments or history of modifications.

The example files provided with FacePalm use this to provide "column headings" for the three sections:

TYPE;NAME OF LINE;NAME OF FIRST POINT;NAME OF SECOND POINT;DESCRIPTION
line;A;2;7;middle line (ML)
...
;;;;
TYPE;NAME OF SEGMENT;NAME OF FIRST POINT;NAME OF SECOND POINT;DESCRIPTION
segment;d1;23;24;outside eye corners
...
;;;;
TYPE;GROUP;NAME OF POINT;DESCRIPTION;
point;eyes;23;outside eye corner, left;
...

The "names" within each section must be unique to be useful. The items are used in the same order as they are listed in the definitions, both on screen and during data export. This gives the research organizer the maximum amount of control.

Defining Points

Points require the following fields in exactly this sequence:

1. field TYPE: the keyword point
2. field GROUP: group name: this is currently not used by FacePalm, but intended to help manage large lists of points
3. field NAME OF POINT: name of the point: must be unique to identify points for lines and segments
4. field DESCRIPTION: informative description of the location

Points use their number as part of coordinate labels during export: The coordinates for point 23 are written to columns X23 and Y23.

Defining Line Segments

Line segments require the following fields in exactly this sequence:

1. field TYPE: the keyword segment
2. field NAME OF SEGMENT: name of the segment: a text label
3. field NAME OF FIRST POINT: name of the first point defining the segment
4. field NAME OF SECOND POINT: name of the second point defining the segment
5. field DESCRIPTION: description of the line segment

Line segments use their name as column header during export: The length of line d1 shows up in column d1. The segment name is displayed below the midpoint of the line segment drawn on the image.

Defining Lines

Lines require the following fields in exactly this sequence:

1. field TYPE: the keyword line
2. field NAME OF LINE: name of the line: a text label
3. field NAME OF FIRST POINT: name of the first point defining the line
4. field NAME OF SECOND POINT: name of the second point defining the line
5. field DESCRIPTION: description of the line segment

Lines are currently not exported. The line name is displayed near the first point outside of the segment defined by the two points.