| OpenCV 5.0.0alpha Open Source Computer Vision

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samples/cpp/snippets/falsecolor.cpp

An example using applyColorMap function

#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
enum MyShape{MyCIRCLE=0,MyRECTANGLE,MyELLIPSE};
struct ParamColorMap {
int iColormap;
Mat img;
};
String winName="False color";
static const String ColorMaps[] = { "Autumn", "Bone", "Jet", "Winter", "Rainbow", "Ocean", "Summer", "Spring",
"Cool", "HSV", "Pink", "Hot", "Parula", "Magma", "Inferno", "Plasma", "Viridis",
"Cividis", "Twilight", "Twilight Shifted", "Turbo", "Deep Green", "User defined (random)" };
static void TrackColorMap(int x, void *r)
{
ParamColorMap *p = (ParamColorMap*)r;
Mat dst;
p->iColormap= x;
if (x == COLORMAP_DEEPGREEN + 1)
{
Mat lutRND(256, 1, CV_8UC3);
randu(lutRND, Scalar(0, 0, 0), Scalar(255, 255, 255));
applyColorMap(p->img, dst, lutRND);
}
else
applyColorMap(p->img,dst,p->iColormap);
putText(dst, "Colormap : "+ColorMaps[p->iColormap], Point(10, 20), FONT_HERSHEY_SIMPLEX, 0.8, Scalar(255, 255, 255),2);
imshow(winName, dst);
}
static Mat DrawMyImage(int thickness,int nbShape)
{
Mat img=Mat::zeros(500,256*thickness+100,CV_8UC1);
int offsetx = 50, offsety = 25;
int lineLength = 50;
for (int i=0;i<256;i++)
line(img,Point(thickness*i+ offsetx, offsety),Point(thickness*i+ offsetx, offsety+ lineLength),Scalar(i), thickness);
RNG r;
Point center;
int radius;
int width,height;
int angle;
Rect rc;
for (int i=1;i<=nbShape;i++)
{
int typeShape = r.uniform(MyCIRCLE, MyELLIPSE+1);
switch (typeShape) {
case MyCIRCLE:
center = Point(r.uniform(offsetx,img.cols- offsetx), r.uniform(offsety + lineLength, img.rows - offsety));
radius = r.uniform(1, min(offsetx, offsety));
circle(img,center,radius,Scalar(i),-1);
break;
case MyRECTANGLE:
center = Point(r.uniform(offsetx, img.cols - offsetx), r.uniform(offsety + lineLength, img.rows - offsety));
width = r.uniform(1, min(offsetx, offsety));
height = r.uniform(1, min(offsetx, offsety));
rc = Rect(center-Point(width ,height )/2, center + Point(width , height )/2);
rectangle(img,rc, Scalar(i), -1);
break;
case MyELLIPSE:
center = Point(r.uniform(offsetx, img.cols - offsetx), r.uniform(offsety + lineLength, img.rows - offsety));
width = r.uniform(1, min(offsetx, offsety));
height = r.uniform(1, min(offsetx, offsety));
angle = r.uniform(0, 180);
ellipse(img, center,Size(width/2,height/2),angle,0,360, Scalar(i), -1);
break;
}
}
return img;
}
int main(int argc, char** argv)
{
cout << "This program demonstrates the use of applyColorMap function.\n\n";
ParamColorMap p;
Mat img;
if (argc > 1)
img = imread(samples::findFile(argv[1]), IMREAD_GRAYSCALE);
else
img = DrawMyImage(2,256);
p.img=img;
p.iColormap=0;
imshow("Gray image",img);
namedWindow(winName);
createTrackbar("colormap", winName, NULL, COLORMAP_DEEPGREEN + 1, TrackColorMap, (void*)&p);
setTrackbarMin("colormap", winName, COLORMAP_AUTUMN);
setTrackbarMax("colormap", winName, COLORMAP_DEEPGREEN + 1);
setTrackbarPos("colormap", winName, COLORMAP_AUTUMN);
TrackColorMap(0, (void*)&p);
cout << "Press a key to exit" << endl;
waitKey(0);
return 0;
}
cv::Mat
n-dimensional dense array class
Definition mat.hpp:951
cv::Mat::cols
int cols
Definition mat.hpp:2425
cv::Mat::rows
int rows
the number of rows and columns or (-1, -1) when the matrix has more than 2 dimensions
Definition mat.hpp:2425
cv::Point_< int >
cv::RNG
Random Number Generator.
Definition core.hpp:2805
cv::RNG::uniform
int uniform(int a, int b)
returns uniformly distributed integer random number from [a,b) range
cv::Rect_
Template class for 2D rectangles.
Definition types.hpp:447
cv::Scalar_< double >
cv::Size_
Template class for specifying the size of an image or rectangle.
Definition types.hpp:338
cv::randu
void randu(InputOutputArray dst, InputArray low, InputArray high)
Generates a single uniformly-distributed random number or an array of random numbers.
cv::String
std::string String
Definition cvstd.hpp:151
CV_8UC1
#define CV_8UC1
Definition interface.h:99
CV_8UC3
#define CV_8UC3
Definition interface.h:101
cv::datasets::circle
@ circle
Definition gr_skig.hpp:62
cv::imshow
void imshow(const String &winname, InputArray mat)
Displays an image in the specified window.
cv::waitKey
int waitKey(int delay=0)
Waits for a pressed key.
cv::namedWindow
void namedWindow(const String &winname, int flags=WINDOW_AUTOSIZE)
Creates a window.
cv::setTrackbarPos
void setTrackbarPos(const String &trackbarname, const String &winname, int pos)
Sets the trackbar position.
cv::setTrackbarMax
void setTrackbarMax(const String &trackbarname, const String &winname, int maxval)
Sets the trackbar maximum position.
cv::setTrackbarMin
void setTrackbarMin(const String &trackbarname, const String &winname, int minval)
Sets the trackbar minimum position.
cv::createTrackbar
int createTrackbar(const String &trackbarname, const String &winname, int *value, int count, TrackbarCallback onChange=0, void *userdata=0)
Creates a trackbar and attaches it to the specified window.
cv::imread
CV_EXPORTS_W Mat imread(const String &filename, int flags=IMREAD_COLOR_BGR)
Loads an image from a file.
cv::applyColorMap
void applyColorMap(InputArray src, OutputArray dst, int colormap)
Applies a GNU Octave/MATLAB equivalent colormap on a given image.
cv::rectangle
void rectangle(InputOutputArray img, Point pt1, Point pt2, const Scalar &color, int thickness=1, int lineType=LINE_8, int shift=0)
Draws a simple, thick, or filled up-right rectangle.
cv::ellipse
void ellipse(InputOutputArray img, Point center, Size axes, double angle, double startAngle, double endAngle, const Scalar &color, int thickness=1, int lineType=LINE_8, int shift=0)
Draws a simple or thick elliptic arc or fills an ellipse sector.
cv::putText
void putText(InputOutputArray img, const String &text, Point org, int fontFace, double fontScale, Scalar color, int thickness=1, int lineType=LINE_8, bool bottomLeftOrigin=false)
Draws a text string.
cv::line
void line(InputOutputArray img, Point pt1, Point pt2, const Scalar &color, int thickness=1, int lineType=LINE_8, int shift=0)
Draws a line segment connecting two points.
highgui.hpp
main
int main(int argc, char *argv[])
Definition highgui_qt.cpp:3
imgcodecs.hpp
imgproc.hpp
cv
Definition core.hpp:107
std
STL namespace.