2012

Cal
Calibrates the digitizer with a paper drawing or photograph, creating the tablet
transformation, which is the mapping of points from the tablet to the
coordinate drawing system. Calibration is digitizing points on the drawing
and mapping them to their real coordinates.
Calibration can be performed in model space or paper space. The Cal option
turns on Tablet mode in the space in which the tablet is calibrated. When the
space is changed, the Cal option turns off Tablet mode.
The paper should be flat (with no bumps or wrinkles) and securely fastened
to the digitizing tablet. The paper can be oriented at any angle.
The points you enter cannot be duplicates. The points need not be the origin
on either axis, and you can enter as many points as you like. The more points
you enter, the more accurate the drawing will be.
If you enter only two points, the program automatically computes an
orthogonal transformation.
If you enter three or more points, the program computes the transformation
in each of the three transformation types (Orthogonal, Affine, and Projective)
to determine which best fits the calibration points. If you enter more than
four points, computing the best-fitting projective transformation can take a
long time. You can cancel the process by pressing Esc.
When the computations are complete, the program displays a table with the
number of calibration points and a column for each transformation type.
If there have been no failures of projection transformation, the program
prompts you to choose a transformation type.
Only transformation types for which the outcome was Success, Exact, or
Canceled are included in this prompt. A projective transformation can be
specified even if it was canceled. The program uses the result computed at the
time you canceled.
Orthogonal Specifies translation, uniform scaling, and rotation with two
calibration points.
Use Orthogonal for dimensionally accurate paper drawings and paper drawings
in which the portion to be digitized is long and narrow, with most points
confined to single lines.
NOTE You must specify the lower-left point location before specifying the
upper-right point location.
TABLET | 1913