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<TITLE>Engauge Digitizer - Automatic Point Graph Tutorial</TITLE>
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  Engauge Digitizer - Automatic Point Graph Tutorial</H2>
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Warning: Not all point graphs work well when automatically matching points
in Engauge. Before going any further, you may want to read about 
<A HREF="pointmatchrequirements.html">point match requirements</A>.
</TD></TR></TABLE>
<H3>Automatically Digitizing A Point Graph Image</H3>
<P>The following steps automatically digitize a linear cartesian graph with 
one curve.</P>
<UL>
<LI>Import the pointplot.bmp case from the Samples directory, using 
File/Import as shown. Not shown are the other methods of importing:
using the <A HREF="commandlineoptions.html">"-import" command line option</A>, 
by copying and pasting, and by dragging and dropping</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph1.png" ALT=""></P>
<UL>
<LI>Click on the Axes Point button before entering axes points. These will 
define the coordinate system</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph2.png" ALT=""></P>
<UL>
<LI>Click on one of the axes to add the first axes point, then enter its 
graph coordinates</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph3.png" ALT=""></P>
<UL>
<LI>Click on one of the axes to add the second axes point, then enter its 
graph coordinates</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph4.png" ALT=""></P>
<UL>
<LI>Click on one of the axes to add the third axes point, then enter its 
graph coordinates</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph5.png" ALT=""></P>
<UL>
<LI>View the processed image by selecting the View/Background/Filtered Image
menu option.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph6.png" ALT=""></P>
<UL>
<LI>Tune the discretize settings using the Settings/Discretize 
menu option, so unwanted information in the image is removed. 
The dialog that appears is explained at
<A HREF="dlgdiscretize.html">Discretize Dialog</A>. For the PointPlot
sample image shown here, the discretize settings are Intensity,
from 90 to 99.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph7.png" ALT=""></P>
<UL>
<LI>Click on the <A NAME="pointmatch">Point Match</A> button.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph9.png" ALT=""></P>
<UL>
<LI>Click on the point in the filtered image that 
is the best example of the type of
point you want. A blue box will appear around the candidate point that
best matches the sample point you picked. In the example below, the
leftmost point was chosen as the sample.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph10.png" ALT=""></P>
<UL>
<LI>Mark the candidate image point as either Accepted or Rejected
by pressing the Right Arrow or Space Bar, respectively. If you
accept the candidate point then it will turn green, otherwise it will
turn red. A new candidate point will then be displayed. To unmark the
previously marked point, press the Left Arrow.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph11.png" ALT=""></P>
<UL>
<LI>Leave Point Match mode to assign all accepted points to the
current curve, by clicking on the Select button, or any Digitize
toolbar button other than Point Match. If no points are acceptable, 
reject and/or unmark all points before leaving Point Match mode.</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph12.png" ALT=""></P>
<UL>
<LI>Export the curve points into a tabular text file using the 
File/Export As menu option as shown. Not shown are the other methods of
exporting the curve points from the
<A HREF="dlgcurvegeometry.html">curve geometry window</A>: copying and pasting,
and dragging and dropping</LI>
</UL>
<P ALIGN="center"><IMG SRC="tutorautopointgraph13.png" ALT=""></P>
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