MiniPatch.cc
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00001 // Copyright 2008 Isis Innovation Limited
00002 #include "ptam/MiniPatch.h"
00003 using namespace CVD;
00004 using namespace std;
00005 
00006 // Scoring function
00007 inline int MiniPatch::SSDAtPoint(CVD::BasicImage<CVD::byte> &im, const CVD::ImageRef &ir)
00008 {
00009   if(!im.in_image_with_border(ir, mnHalfPatchSize))
00010     return mnMaxSSD + 1;
00011   ImageRef irImgBase = ir - ImageRef(mnHalfPatchSize, mnHalfPatchSize);
00012   int nRows = mimOrigPatch.size().y;
00013   int nCols = mimOrigPatch.size().x;
00014   byte *imagepointer;
00015   byte *templatepointer;
00016   int nDiff;
00017   int nSumSqDiff = 0;
00018   for(int nRow = 0; nRow < nRows; nRow++)
00019   {
00020     imagepointer = &im[irImgBase + ImageRef(0,nRow)];
00021     templatepointer = &mimOrigPatch[ImageRef(0,nRow)];
00022     for(int nCol = 0; nCol < nCols; nCol++)
00023     {
00024       nDiff = imagepointer[nCol] - templatepointer[nCol];
00025       nSumSqDiff += nDiff * nDiff;
00026     };
00027   };
00028   return nSumSqDiff;
00029 }
00030 
00031 // Find a patch by searching at FAST corners in an input image
00032 // If available, a row-corner LUT is used to speed up search through the
00033 // FAST corners
00034 bool MiniPatch::FindPatch(CVD::ImageRef &irPos, 
00035                           CVD::BasicImage<CVD::byte> &im,
00036                           int nRange,
00037                           vector<ImageRef> &vCorners,
00038                           std::vector<int> *pvRowLUT)
00039 {
00040   ImageRef irCenter = irPos;
00041   ImageRef irBest;
00042   int nBestSSD = mnMaxSSD + 1;
00043   ImageRef irBBoxTL = irPos - ImageRef(nRange, nRange);
00044   ImageRef irBBoxBR = irPos + ImageRef(nRange, nRange);
00045   vector<ImageRef>::iterator i;
00046   if(!pvRowLUT)
00047   {
00048     for(i = vCorners.begin(); i!=vCorners.end(); i++)
00049       if(i->y >= irBBoxTL.y) break;
00050   }
00051   else
00052   {
00053     int nTopRow = irBBoxTL.y;
00054     if(nTopRow < 0)
00055       nTopRow = 0;
00056     if(nTopRow >= (int) pvRowLUT->size())
00057       nTopRow = (int) pvRowLUT->size() - 1;
00058     i = vCorners.begin() + (*pvRowLUT)[nTopRow];
00059   }
00060 
00061   for(; i!=vCorners.end(); i++)
00062   {
00063     if(i->x < irBBoxTL.x  || i->x > irBBoxBR.x)
00064       continue;
00065     if(i->y > irBBoxBR.y)
00066       break;
00067     int nSSD = SSDAtPoint(im, *i);
00068 
00069     if(nSSD < nBestSSD)
00070     {
00071       irBest = *i;
00072       nBestSSD = nSSD;
00073     }
00074   }
00075   if(nBestSSD < mnMaxSSD)
00076   {
00077     irPos = irBest;
00078     return true;
00079   }
00080   else
00081     return false;
00082 }
00083 
00084 // Define the patch from an input image
00085 void MiniPatch::SampleFromImage(ImageRef irPos, BasicImage<byte> &im)
00086 {
00087   assert(im.in_image_with_border(irPos, mnHalfPatchSize));
00088   CVD::ImageRef irPatchSize( 2 * mnHalfPatchSize + 1 , 2 * mnHalfPatchSize + 1);
00089   mimOrigPatch.resize(irPatchSize);
00090   copy(im, mimOrigPatch, mimOrigPatch.size(), irPos - mimOrigPatch.size() / 2);
00091 }
00092 
00093 // Static members
00094 int MiniPatch::mnHalfPatchSize = 4;
00095 int MiniPatch::mnRange = 10;
00096 int MiniPatch::mnMaxSSD = 9999;
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ptam
Author(s): Markus Achtelik , Stephan Weiss , Simon Lynen
autogenerated on Sun Oct 5 2014 23:52:33