add ignore edge function in pdiff.

files/source/CompareArgs.h

 /*
 Comapre Args
 Copyright (C) 2006 Yangli Hector Yee
 
 This program is free software; you can redistribute it and/or modify it under the terms of the
 GNU General Public License as published by the Free Software Foundation; either version 2 of the License,
 or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
@@ skipping 17 matching lines @@
         CompareArgs();
         ~CompareArgs();
         bool Parse_Args(int argc, char **argv); 
         void Print_Args();
         
         RGBAImage               *ImgA;                          // Image A
         RGBAImage               *ImgB;                          // Image B
         RGBAImage               *ImgDiff;                       // Diff image
         bool                    Verbose;                        // Print lots of text or not
         bool                    LuminanceOnly;          // Only consider luminance; ignore chroma channels in the comparison.
-        float                   EdgeDetectDegree;   // degree to eliminate edges

[vangelis, 2009/07/01 18:35:31]

I think if you added a separate bool for "ignoreEdgePixels" it would make the
code a lot cleaner than using edgeDetectDegree = 0 as a sign that you don't want
to ignore edges.  The problem with 0 is there a discontinuity between 0 and 0 +
epsilon.  At 0 you eliminate no pixels and at 0 + epsilon you eliminate a lot of
pixels and then as you go towards 1 you eliminate fewer and fewer. 

+        bool                    IgnoreEdge;             // ignore edge in comparison
+        int                     EdgeNeighborNum;        // degree to eliminate edges
         float                   FieldOfView;            // Field of view in degrees
         float                   Gamma;                          // The gamma to convert to linear color space
         float                   Luminance;                      // the display's luminance
         unsigned int    ThresholdPixels;        // How many pixels different to ignore
         std::string             ErrorStr;                       // Error string
   // How much color to use in the metric.
   // 0.0 is the same as LuminanceOnly = true,
   // 1.0 means full strength.
   float ColorFactor;
   // How much to down sample image before comparing, in powers of 2.
   int DownSample;
 };
 
 #endif