DIGIT

Name

digit

Purpose (one Line)

Digitize from a displayed gif file.

Description

Calling Sequence

digit, image, outfile

Inputs

image : Image to be displayed. May be a string scalar containing the
name of an image file to be loaded and displayed, or an image
array to be displayed. File is read with READ_IMAGE.
outfile : File into which collected points are saved.

Optional Input Parameters

Keyword Input Parameters

NATURAL = If set, the natural screen coordinates are used. No
control points are solicited and no coordinate
transformations are computed.
NOSCALE = If set, the image is displayed without being scaled.
ROTATE = Rotation angle (in degrees) for the gif image. Allowed
values are 90, 180, and 270 counterclockwise.

Outputs

Keyword Output Parameters

XVEC, YVEC = If both of these keywords are present, the collected
coordinates are returned as vectors to the variables
specified in the keywords. The collected coordinates are
always written to the output file.

Common Blocks

Side Effects

Restrictions

Procedure

Unless the 'NATURAL' keyword is specified, four control points and four
associated values are requested in order to define the x and y axes and
scale factors.
The first two points are the x-axis control points (and their values) and
the second two are the y-axis control points (and their values).
Control vectors are computed from the requested control points and
coordinate transformations are computed using simple vector algebra.

Modification History

Written by Doug Loucks, Lowell Observatory, April, 1993.
94/10/04 - MWB - moved cr to front of print statement (v3.6 bug workaround)
2000/01/31, MWB, fixed bug that was introduced by some IDL version that
changed the way CURSOR worked.
2009/01/13, MWB, changed to use READ_IMAGE to read external file.