- You can give full path to an image in command line
@code{.cpp}
CommandLineParser parser(argc, argv, keys);
@snippet histo3D.cpp command_line_parser
if (parser.has("help"))
{
parser.printMessage();
return 0;
}
String nomFic = parser.get<String>(0);
Mat img;
if (nomFic.length() != 0)
{
img = imread(nomFic, IMREAD_COLOR);
if (img.empty())
{
cout << "Image does not exist!";
return 0;
}
}
@endcode
or without path, a synthetic image is generated with pixel values are a gaussian distribution center(60+/-10,40+/-5,50+/-20) in first quadrant,
or without path, a synthetic image is generated with pixel values are a gaussian distribution @ref cv::RNG::fill center(60+/-10,40+/-5,50+/-20) in first quadrant,
(160+/-20,10+/-5,50+/-10) in second quadrant, (90+/-10,100+/-20,50+/-20) in third quadrant, (100+/-10,10+/-5,150+/-40) in last quadrant.
channel are 2, 1 and 0 to synchronise color with Viz axis color in objetc viz::WCoordinateSystem.
@snippet histo3D.cpp synthetic_image
Image tridimensional histogram is calculated using opencv @ref cv::calcHist and @ref cv::normalize between 0 and 100.
@snippet histo3D.cpp calchist_for_histo3d
channel are 2, 1 and 0 to synchronise color with Viz axis color in objetc cv::viz::WCoordinateSystem.
A slidebar is inserted in image window. Init slidebar value is 90, it means that only histogram cell greater than 9/100000.0 (23 pixels for an 512X512 pixels) will be display.
We are ready to open a viz window with a callback function to capture keyboard event in viz window. Using Viz::spinonce enable keyboard event to be capture in imshow window too.
The function DrawHistogram3D processes histogram Mat to display it in a Viz window. Number of plan, row and column in three dimensional Mat ca be found using this code :
To get histogram value at a specific location we use at method with three arguments k, i and j where k is plane number, i row number and j column number.
@code{.cpp}
for (int k = 0; k < plans; k++)
{
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
double x = h.histogram.at<float>(k, i, j);
if (x >= h.threshold)
{
double r=std::max(x/h.maxH,0.1);
viz::WCube s(Point3d(k - r / 2, i - r / 2, j - r / 2), Point3d(k + r / 2, i + r / 2, j + r / 2), false, viz::Color(j / double(plans) * 255, i / double(rows) * 255, k / double(cols) * 255));
We are ready to open a viz window with a callback function to capture keyboard event in viz window. Using @ref cv::viz::Viz3d::spinOnce enable keyboard event to be capture in @ref cv::imshow window too.
@snippet histo3D.cpp manage_viz_imshow_window
The function DrawHistogram3D processes histogram Mat to display it in a Viz window. Number of plan, row and column in (three dimensional Mat)[http://docs.opencv.org/master/d3/d63/classcv_1_1Mat.html#details] can be found using this code :
@snippet histo3D.cpp get_cube_size
To get histogram value at a specific location we use @ref cv::Mat::at(int i0,int i1, int i2) method with three arguments k, i and j where k is plane number, i row number and j column number.
@snippet histo3D.cpp get_cube_values
- Callback function
Principle are as mouse callback function. Key code pressed is in field code of class viz::KeyboardEvent.
