From ad57750d254aad5173fe2c2b2e826eeec94f111c Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@intel.com>
Date: Fri, 25 May 2018 15:09:36 +0300
Subject: [PATCH] calib3d: chess board - properly detect/handle iCntMaxima=0
case
---
modules/calib3d/src/calibinit.cpp | 36 ++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 8 deletions(-)
diff --git a/modules/calib3d/src/calibinit.cpp b/modules/calib3d/src/calibinit.cpp
index 283a9217a9..8f66b3a871 100644
--- a/modules/calib3d/src/calibinit.cpp
+++ b/modules/calib3d/src/calibinit.cpp
@@ -293,7 +293,7 @@ static bool icvBinarizationHistogramBased( Mat & img )
std::vector<int> piHistSmooth(iNumBins, 0);
std::vector<int> piHistGrad(iNumBins, 0);
std::vector<int> piAccumSum(iNumBins, 0);
- std::vector<int> piMaxPos(20, 0);
+ std::vector<int> piMaxPos; piMaxPos.reserve(20);
int iThresh = 0;
int iIdx;
int iWidth = 1;
@@ -319,7 +319,7 @@ static bool icvBinarizationHistogramBased( Mat & img )
{
if ( (piHistGrad[i-1] < 0) && (piHistGrad[i] > 0) )
{
- piMaxPos[iCntMaxima] = i;
+ piMaxPos.push_back(i);
iCntMaxima++;
}
}
@@ -332,15 +332,35 @@ static bool icvBinarizationHistogramBased( Mat & img )
iSumAroundMax = piHistSmooth[iIdx-1] + piHistSmooth[iIdx] + piHistSmooth[iIdx+1];
if ( iSumAroundMax < iMaxPix1 && iIdx < 64 )
{
- for ( int j=i; j<iCntMaxima-1; j++ )
- {
- piMaxPos[j] = piMaxPos[j+1];
- }
+ piMaxPos.erase(piMaxPos.begin() + i);
iCntMaxima--;
i--;
}
}
- if ( iCntMaxima == 1)
+
+ CV_Assert((size_t)iCntMaxima == piMaxPos.size());
+
+ PRINTF("HIST: MAXIMA COUNT: %d (%d, %d, %d, ...)\n", iCntMaxima,
+ iCntMaxima > 0 ? piMaxPos[0] : -1,
+ iCntMaxima > 1 ? piMaxPos[1] : -1,
+ iCntMaxima > 2 ? piMaxPos[2] : -1);
+
+ if (iCntMaxima == 0)
+ {
+ // no any maxima inside (except 0 and 255 which are not handled above)
+ // Does image black-write already?
+ const int iMaxPix2 = iMaxPix / 2;
+ for (int sum = 0, i = 0; i < 256; ++i) // select mean intensity
+ {
+ sum += piHistIntensity[i];
+ if (sum > iMaxPix2)
+ {
+ iThresh = i;
+ break;
+ }
+ }
+ }
+ else if (iCntMaxima == 1)
{
iThresh = piMaxPos[0]/2;
}
@@ -380,7 +400,7 @@ static bool icvBinarizationHistogramBased( Mat & img )
int iMaxVal = piHistIntensity[piMaxPos[iIdxBGMax]];
//IF TOO CLOSE TO 255, jump to next maximum
- if ( piMaxPos[iIdxBGMax] >= 250 && iIdxBGMax < iCntMaxima )
+ if ( piMaxPos[iIdxBGMax] >= 250 && iIdxBGMax + 1 < iCntMaxima )
{
iIdxBGMax++;
iMaxVal = piHistIntensity[piMaxPos[iIdxBGMax]];
--
2.18.0