generic-library/opencv
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fixed bug #1571

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This commit is contained in:
Marina Kolpakova 2012-03-20 09:44:40 +00:00
parent f1cf411ffe
commit 577dabb8bc
1 changed files with 55 additions and 46 deletions
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101
samples/cpp/tutorial_code/core/how_to_scan_images/how_to_scan_images.cpp
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@ -3,7 +3,7 @@
#include <iostream>
#include <sstream>
using namespace std;
using namespace std;
using namespace cv;
void help()
@ -16,7 +16,7 @@ void help()
<< "Usage:" << endl
<< "./howToScanImages imageNameToUse divideWith [G]" << endl
<< "if you add a G parameter the image is processed in gray scale" << endl
<< "--------------------------------------------------------------------------" << endl
<< "--------------------------------------------------------------------------" << endl
<< endl;
}
@ -26,11 +26,11 @@ Mat& ScanImageAndReduceRandomAccess(Mat& I, const uchar * table);
int main( int argc, char* argv[])
{
help();
help();
if (argc < 3)
{
cout << "Not enough parameters" << endl;
return -1;
return -1;
}
Mat I, J;
@ -51,115 +51,124 @@ int main( int argc, char* argv[])
s >> divideWith;
if (!s)
{
cout << "Invalid number entered for dividing. " << endl;
cout << "Invalid number entered for dividing. " << endl;
return -1;
}
uchar table[256];
uchar table[256];
for (int i = 0; i < 256; ++i)
table[i] = divideWith* (i/divideWith);
const int times = 100;
const int times = 100;
double t;
t = (double)getTickCount();
t = (double)getTickCount();
for (int i = 0; i < times; ++i)
J = ScanImageAndReduceC(I.clone(), table);
{
cv::Mat clone_i = I.clone();
J = ScanImageAndReduceC(clone_i, table);
}
t = 1000*((double)getTickCount() - t)/getTickFrequency();
t /= times;
cout << "Time of reducing with the C operator [] (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
cout << "Time of reducing with the C operator [] (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
t = (double)getTickCount();
t = (double)getTickCount();
for (int i = 0; i < times; ++i)
J = ScanImageAndReduceIterator(I.clone(), table);
{
cv::Mat clone_i = I.clone();
J = ScanImageAndReduceIterator(clone_i, table);
}
t = 1000*((double)getTickCount() - t)/getTickFrequency();
t /= times;
cout << "Time of reducing with the iterator (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
cout << "Time of reducing with the iterator (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
t = (double)getTickCount();
t = (double)getTickCount();
for (int i = 0; i < times; ++i)
ScanImageAndReduceRandomAccess(I.clone(), table);
{
cv::Mat clone_i = I.clone();
ScanImageAndReduceRandomAccess(clone_i, table);
}
t = 1000*((double)getTickCount() - t)/getTickFrequency();
t /= times;
cout << "Time of reducing with the on-the-fly address generation - at function (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
cout << "Time of reducing with the on-the-fly address generation - at function (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
Mat lookUpTable(1, 256, CV_8U);
uchar* p = lookUpTable.data;
uchar* p = lookUpTable.data;
for( int i = 0; i < 256; ++i)
p[i] = table[i];
t = (double)getTickCount();
t = (double)getTickCount();
for (int i = 0; i < times; ++i)
LUT(I, lookUpTable, J);
t = 1000*((double)getTickCount() - t)/getTickFrequency();
t /= times;
cout << "Time of reducing with the LUT function (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
return 0;
cout << "Time of reducing with the LUT function (averaged for "
<< times << " runs): " << t << " milliseconds."<< endl;
return 0;
}
Mat& ScanImageAndReduceC(Mat& I, const uchar* const table)
{
// accept only char type matrices
CV_Assert(I.depth() != sizeof(uchar));
CV_Assert(I.depth() != sizeof(uchar));
int channels = I.channels();
int nRows = I.rows * channels;
int nRows = I.rows * channels;
int nCols = I.cols;
if (I.isContinuous())
{
nCols *= nRows;
nRows = 1;
nRows = 1;
}
int i,j;
uchar* p;
uchar* p;
for( i = 0; i < nRows; ++i)
{
p = I.ptr<uchar>(i);
for ( j = 0; j < nCols; ++j)
{
p[j] = table[p[j]];
p[j] = table[p[j]];
}
}
return I;
return I;
}
Mat& ScanImageAndReduceIterator(Mat& I, const uchar* const table)
{
// accept only char type matrices
CV_Assert(I.depth() != sizeof(uchar));
CV_Assert(I.depth() != sizeof(uchar));
const int channels = I.channels();
switch(channels)
{
case 1:
case 1:
{
MatIterator_<uchar> it, end;
MatIterator_<uchar> it, end;
for( it = I.begin<uchar>(), end = I.end<uchar>(); it != end; ++it)
*it = table[*it];
break;
}
case 3:
case 3:
{
MatIterator_<Vec3b> it, end;
MatIterator_<Vec3b> it, end;
for( it = I.begin<Vec3b>(), end = I.end<Vec3b>(); it != end; ++it)
{
(*it)[0] = table[(*it)[0]];
@ -168,29 +177,29 @@ Mat& ScanImageAndReduceIterator(Mat& I, const uchar* const table)
}
}
}
return I;
return I;
}
Mat& ScanImageAndReduceRandomAccess(Mat& I, const uchar* const table)
{
// accept only char type matrices
CV_Assert(I.depth() != sizeof(uchar));
CV_Assert(I.depth() != sizeof(uchar));
const int channels = I.channels();
switch(channels)
{
case 1:
case 1:
{
for( int i = 0; i < I.rows; ++i)
for( int j = 0; j < I.cols; ++j )
I.at<uchar>(i,j) = table[I.at<uchar>(i,j)];
break;
}
case 3:
case 3:
{
Mat_<Vec3b> _I = I;
for( int i = 0; i < I.rows; ++i)
for( int j = 0; j < I.cols; ++j )
{
@ -202,6 +211,6 @@ Mat& ScanImageAndReduceRandomAccess(Mat& I, const uchar* const table)
break;
}
}
return I;
}