| OpenCV 3.4.8 Open Source Computer Vision

samples/cpp/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", "User defined (random)" };
static void TrackColorMap(int x, void *r)
{
ParamColorMap *p = (ParamColorMap*)r;
Mat dst;
p->iColormap= x;
if (x == COLORMAP_TURBO + 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 lineLenght = 50;
for (int i=0;i<256;i++)
line(img,Point(thickness*i+ offsetx, offsety),Point(thickness*i+ offsetx, offsety+ lineLenght),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 + lineLenght, 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 + lineLenght, 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 + lineLenght, 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,&p.iColormap,1,TrackColorMap,(void*)&p);
setTrackbarMin("colormap", winName, COLORMAP_AUTUMN);
setTrackbarMax("colormap", winName, COLORMAP_TURBO+1);
setTrackbarPos("colormap", winName, -1);
TrackColorMap(0, (void*)&p);
cout << "Press a key to exit" << endl;
waitKey(0);
return 0;
}