// [ref] ${VLFEAT_HOME}/toolbox/quickshift/vl_quickshift.c
void quick_shift()
{
const vl_qs_type kernelSize = 2.0;
const vl_qs_type maxDist = 20.0;
const vl_bool medoid = false; // true to use kernelized medoid shift, false (default) uses quick shift.
const vl_qs_type ratio = 0.5; // tradeoff between spatial consistency and color consistency.
// read image data
const std::string input_filename = "./data/machine_vision/vlfeat/roofs1.jpg";
//const std::string input_filename = "./data/machine_vision/opencv/fruits.jpg";
const cv::Mat input_img = cv::imread(input_filename, CV_LOAD_IMAGE_COLOR);
//const cv::Mat input_img = cv::imread(input_filename, CV_LOAD_IMAGE_GRAYSCALE);
if (input_img.empty())
{
std::cerr << "file not found: " << input_filename << std::endl;
return;
}
double minVal = 0.0, maxVal = 0.0;
cv::minMaxLoc(input_img, &minVal, &maxVal);
//
const int img_width = input_img.cols;
const int img_height = input_img.rows;
const int img_numChannels = input_img.channels();
// channels * width * height + width * row + col
std::vector<vl_qs_type> image(img_width * img_height * img_numChannels, 0.0);
{
if (1 == img_numChannels)
{
for (int r = 0; r < img_height; ++r)
for (int c = 0; c < img_width; ++c)
{
//image[img_width * r + c] = input_img.at<unsigned char>(r, c);
//image[img_width * r + c] = ratio * (input_img.at<unsigned char>(r, c) + cv::randu<vl_qs_type>() / 2550.0); // not correctly working
image[img_width * r + c] = ratio * (input_img.at<unsigned char>(r, c) + cv::randu<vl_qs_type>() / 10.0);
}
}
else if (3 == img_numChannels)
{
for (int r = 0; r < img_height; ++r)
for (int c = 0; c < img_width; ++c)
{
const cv::Vec3b &pix = input_img.at<cv::Vec3b>(r, c);
for (int ch = 0; ch < img_numChannels; ++ch)
{
//image[ch * img_width * img_height + img_width * r + c] = pix[ch];
//image[ch * img_width * img_height + img_width * r + c] = ratio * (pix[ch] / 255.0 + cv::randu<vl_qs_type>() / 2550.0); // not correctly working
image[ch * img_width * img_height + img_width * r + c] = ratio * (pix[ch] + cv::randu<vl_qs_type>() / 10.0);
}
}
}
else
{
std::cerr << "the number of image's channels is improper ..." << std::endl;
return;
}
}
//
VlQS *qs = vl_quickshift_new(&image[0], img_width, img_height, img_numChannels);
vl_quickshift_set_kernel_size(qs, kernelSize);
vl_quickshift_set_max_dist(qs, maxDist);
vl_quickshift_set_medoid(qs, medoid);
vl_quickshift_process(qs);
//
const int *parentsi = vl_quickshift_get_parents(qs);
const vl_qs_type *dists = vl_quickshift_get_dists(qs);
const vl_qs_type *density = vl_quickshift_get_density(qs);
// flatten a tree.
std::vector<int> parentsv(parentsi, parentsi + img_width * img_height);
{
for (int i = 0; i < img_width * img_height; ++i)
while (parentsv[i] != parentsv[parentsv[i]])
parentsv[i] = parentsv[parentsv[i]];
}
/*
{
std::vector<int> indexes(parentsv.begin(), parentsv.end());
std::sort(indexes.begin(), indexes.end());
std::vector<int>::iterator itEndNew = std::unique(indexes.begin(), indexes.end());
//const std::size_t labelCount = std::distance(indexes.begin(), itEndNew);
std::map<int, int> lblMap;
int idx = 0;
for (std::vector<int>::iterator it = indexes.begin(); it != itEndNew; ++it, ++idx)
lblMap[*it] = idx;
for (std::vector<int>::iterator it = parentsv.begin(); it != parentsv.end(); ++it)
*it = lblMap[*it];
}
*/
// visualize
cv::Mat result_img(input_img.size(), input_img.type());
{
// draw boundary.
if (1 == result_img.channels())
{
vl_size idx = 0;
for (int r = 0; r < result_img.rows; ++r)
for (int c = 0; c < result_img.cols; ++c, ++idx)
{
const int lbl = parentsv[idx];
if (r - 1 >= 0 && lbl != parentsv[(r - 1) * result_img.cols + c])
result_img.at<unsigned char>(r, c) = 255;
else if (c - 1 >= 0 && lbl != parentsv[r * result_img.cols + (c - 1)])
result_img.at<unsigned char>(r, c) = 255;
/*
else if (r + 1 < result_img.rows && lbl != parentsv[(r + 1) * result_img.cols + c])
result_img.at<unsigned char>(r, c) = 255;
else if (c + 1 < result_img.cols && lbl != parentsv[r * result_img.cols + (c + 1)])
result_img.at<unsigned char>(r, c) = 255;
*/
else
result_img.at<unsigned char>(r, c) = 0;
}
}
else if (3 == result_img.channels())
{
vl_size idx = 0;
for (int r = 0; r < result_img.rows; ++r)
for (int c = 0; c < result_img.cols; ++c, ++idx)
{
const int lbl = parentsv[idx];
if (r - 1 >= 0 && lbl != parentsv[(r - 1) * result_img.cols + c])
result_img.at<cv::Vec3b>(r, c) = cv::Vec3b(255, 255, 255);
else if (c - 1 >= 0 && lbl != parentsv[r * result_img.cols + (c - 1)])
result_img.at<cv::Vec3b>(r, c) = cv::Vec3b(255, 255, 255);
/*
else if (r + 1 < result_img.rows && lbl != parentsv[(r + 1) * result_img.cols + c])
result_img.at<cv::Vec3b>(r, c) = cv::Vec3b(255, 255, 255);
else if (c + 1 < result_img.cols && lbl != parentsv[r * result_img.cols + (c + 1)])
result_img.at<cv::Vec3b>(r, c) = cv::Vec3b(255, 255, 255);
*/
else
result_img.at<cv::Vec3b>(r, c) = cv::Vec3b(0, 0, 0);
}
}
else
{
std::cerr << "the number of image's channels is improper ..." << std::endl;
return;
}
}
cv::imshow("quick shift result", result_img);
cv::waitKey(0);
cv::destroyAllWindows();
// clean-up
vl_quickshift_delete(qs);
}
void
mexFunction(int nout, mxArray *out[],
int nin, const mxArray *in[])
{
enum {
IN_I=0, /* Input image */
IN_KERNEL_SIZE, /* The bandwidth parameter for density estimation */
IN_MAX_DIST, /* The maximum distance to a neighbor which increases
the density */
IN_END
} ;
enum {
OUT_PARENTS=0, /* parents (same size as I) */
OUT_DISTS, /* dists (same size as I) */
OUT_DENSITY /* density (same size as I) */
} ;
int verb = 0 ;
int opt ;
int next = IN_END ;
mxArray const *optarg ;
double const *I ;
double *parents, *dists, *density ;
int *parentsi;
double sigma ;
double tau ;
int K,N1,N2;
int medoid = 0 ;
mwSize const *dims ;
int ndims ;
int i;
VlQS * q;
VL_USE_MATLAB_ENV ;
/* -----------------------------------------------------------------
* Check arguments
* -------------------------------------------------------------- */
if (nin < 2) {
mexErrMsgTxt("At least two arguments.") ;
}
if (nout > 3) {
mexErrMsgTxt("At most three output arguments.") ;
}
ndims = mxGetNumberOfDimensions(in[IN_I]) ;
dims = mxGetDimensions(in[IN_I]) ;
if (ndims > 3) {
mexErrMsgTxt("I must have at most 3 dimensions.") ;
}
if (mxGetClassID(in[IN_I]) != mxDOUBLE_CLASS) {
mexErrMsgTxt("I must be DOUBLE.") ;
}
N1 = dims [0] ;
N2 = dims [1] ;
K = (ndims == 3) ? dims [2] : 1 ;
I = mxGetPr (in[IN_I]) ;
sigma = *mxGetPr (in[IN_KERNEL_SIZE]) ;
tau = 3*sigma;
if (nin > 2)
tau = *mxGetPr (in[IN_MAX_DIST]) ;
while ((opt = vlmxNextOption (in, nin, options, &next, &optarg)) >= 0) {
switch (opt) {
case opt_medoid: /* Do medoid shift instead of mean shift */
medoid = 1 ;
break ;
case opt_verbose :
++ verb ;
break ;
}
} /* while opts */
/* Create outputs */
out[OUT_PARENTS] = mxCreateDoubleMatrix(N1, N2, mxREAL) ;
parents = mxGetPr (out[OUT_PARENTS]) ;
out[OUT_DISTS] = mxCreateDoubleMatrix(N1, N2, mxREAL) ;
dists = mxGetPr (out[OUT_DISTS]) ;
out[OUT_DENSITY] = mxCreateDoubleMatrix(N1, N2, mxREAL) ;
density = mxGetPr (out[OUT_DENSITY]) ;
if (verb) {
mexPrintf("quickshift: [N1,N2,K]: [%d,%d,%d]\n", N1,N2,K) ;
mexPrintf("quickshift: type: %s\n", medoid ? "medoid" : "quick");
mexPrintf("quickshift: kernel size: %g\n", sigma) ;
mexPrintf("quickshift: maximum gap: %g\n", tau) ;
}
/* Do job */
q = vl_quickshift_new(I, N1, N2, K);
vl_quickshift_set_kernel_size (q, sigma) ;
vl_quickshift_set_max_dist (q, tau) ;
vl_quickshift_set_medoid (q, medoid) ;
vl_quickshift_process(q);
parentsi = vl_quickshift_get_parents(q);
/* Copy results */
for(i = 0; i < N1*N2; i++) parents[i] = parentsi[i] + 1;
memcpy(dists, vl_quickshift_get_dists(q), sizeof(double)*N1*N2);
memcpy(density, vl_quickshift_get_density(q), sizeof(double)*N1*N2);
/* Delete quick shift object */
vl_quickshift_delete(q);
}