josh/gvsu
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

sequential version working

Browse Source 
git-svn-id: svn://anubis/gvsu@206 45c1a28c-8058-47b2-ae61-ca45b979098e
This commit is contained in:
josh 2008-10-25 21:23:17 +00:00
parent ba89e56e44
commit da35425d51
1 changed files with 42 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
cs677/pa3/edge-detect.cc
View File

@ -8,12 +8,14 @@ using namespace std;
void usage(const char * progName);
void squashAndPadData(unsigned char * raw_data, unsigned char * padded_data,
int width, int height);
void applyEdgeDetection(unsigned char * padded_data, unsigned char * edge_data,
int width, int height, int threshold);
void usage(const char * progName)
{
cout << "Usage: " << progName << " [options] <input-BMP-file>" << endl;
cout << " Options:" << endl;
cout << " -l threshold_level : set threshold level" << endl;
cout << " -l level : apply threshold at level" << endl;
exit(42);
}
@ -22,7 +24,7 @@ int main(int argc, char * argv[])
int argi;
string inputFileName;
string outputFileName;
unsigned int threshold_level = 60;
int threshold_level = -1;
for (argi = 0; argi < argc; argi++)
{
@ -57,7 +59,15 @@ int main(int argc, char * argv[])
squashAndPadData(bmp_data, padded_data, width, height);
delete[] bmp_data;
unsigned char * edge_data = new unsigned char[width * height * 3];
applyEdgeDetection(padded_data, edge_data, width, height, threshold_level);
BMP outputImage(outputFileName.c_str(),
width,
height,
edge_data);
delete[] padded_data;
delete[] edge_data;
}
void squashAndPadData(unsigned char * raw_data, unsigned char * padded_data,
@ -79,3 +89,33 @@ void squashAndPadData(unsigned char * raw_data, unsigned char * padded_data,
*padded_data++ = 0;
}
void applyEdgeDetection(unsigned char * padded_data, unsigned char * edge_data,
int width, int height, int threshold)
{
unsigned char (*in)[height+2][width+2] =
(unsigned char (*)[height+2][width+2]) padded_data;
unsigned char (*out)[height][width][3] =
(unsigned char (*)[height][width][3]) edge_data;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
/* Apply the Sobel operator on the in to
* produce an out value. */
int gradY = (*in)[y][x] + 2 * (*in)[y][x+1] + (*in)[y][x+2]
- (*in)[y+2][x] - 2 * (*in)[y+2][x+1] - (*in)[y+2][x+2];
int gradX = (*in)[y][x+2] + 2 * (*in)[y+1][x+2] + (*in)[y+2][x+2]
- (*in)[y][x] - 2 * (*in)[y+1][x] - (*in)[y+2][x];
int grad = gradX + gradY;
if (grad < 0)
grad = 0;
else if (grad > 255)
grad = 255;
if (threshold >= 0)
grad = grad < threshold ? 0 : 255;
(*out)[y][x][0] = grad;
(*out)[y][x][1] = grad;
(*out)[y][x][2] = grad;
}
}
}