Having trouble with replacing color masks - c++

Question

I am selecting the color from first frame using mouse-handler.
I am trying to replace the selected color with background frame.
This is working fine for red color but this is not working for any other color like green, blue, etc. I am using following graph for color selection:
Click here!
#include "opencv2/opencv.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace std;
using namespace cv;
// structure to be used in mouseHandler function
struct userdata {
Mat im;
vector<Point2f> points;
};
void mouseHandler(int event, int x, int y, int flags, void* data_ptr)
{
if (event == EVENT_LBUTTONDOWN) {
userdata* data = ((userdata*)data_ptr);
circle(data->im, Point(x, y), 3, Scalar(0, 0, 255), 5, LINE_AA);
imshow("Image", data->im);
if (data->points.size() < 1) {
data->points.push_back(Point2f(x, y));
}
}
}
int main(int argc, char** argv) {
// Take video frame from camera to select color of material
VideoCapture capt(0);
Mat frames;
capt >> frames;
Mat hsvimg;
// Converting image from BGR to HSV
cvtColor(frames, hsvimg, COLOR_BGR2HSV);
// Set data for mouse event
Mat im_temp = frames.clone();
userdata data;
data.im = im_temp;
cout << "Select the point on image for the color you want to create cloak and than press 'Enter'" << endl;
// Show image and wait for a click.
imshow("Image", im_temp);
// Set the callback function for any mouse event
setMouseCallback("Image", mouseHandler, &data);
waitKey(0);
//defining the HSV values of the point selected
Vec3b HSV_Color = hsvimg.at<Vec3b>(data.points[0]);
int hue = HSV_Color.val[0];
int saturation = HSV_Color.val[1];
int value = HSV_Color.val[2];
// Create a VideoCapture object and open the input file for demonstrating the cloak working
// If the input is the web camera, pass 0 instead of the video file name
// In first frame only background should be there, i.e., no person present
VideoCapture cap(0);
// Check if camera opened successfully
if (!cap.isOpened()) {
cout << "Error opening video stream or file" << endl;
return -1;
}
Mat background;
for (int i = 0; i < 30; i++)
{
cap >> background;
}
//Laterally invert the image / flip the image.
flip(background, background, 1);
while (1)
{
Mat frame;
// Capture frame-by-frame
cap >> frame;
// Laterally invert the image / flip the image
flip(frame, frame, 1);
//Converting image from BGR to HSV color space.
Mat hsv;
cvtColor(frame, hsv, COLOR_BGR2HSV);
Mat mask1, mask2;
// Creating masks to detect the upper and lower red color.
// Otherwise mask1 and mask2 are same for other colors
// Making different conditions according to hue values
// Take help from this: https://stackoverflow.com/questions/10948589/choosing-the-correct-upper-and-lower-hsv-boundaries-for-color-detection-withcv
if (saturation > 100) {
if (hue <= 10 || hue>165) {
inRange(hsv, Scalar(0, 120, 20), Scalar(10, 255, 255), mask1);
inRange(hsv, Scalar(170, 120, 20), Scalar(180, 255, 255), mask2);
}
else if (10<hue<=25) {
inRange(hsv, Scalar(10, 120, 20), Scalar(25, 255, 255), mask1);
inRange(hsv, Scalar(10, 120, 20), Scalar(25, 255, 255), mask2);
}
else if (25 < hue <= 38) {
inRange(hsv, Scalar(25, 120, 20), Scalar(35, 255, 255), mask1);
inRange(hsv, Scalar(25, 120, 20), Scalar(35, 255, 255), mask2);
}
else if (38 < hue <= 71) {
inRange(hsv, Scalar(38, 100, 20), Scalar(71, 255, 255), mask1);
inRange(hsv, Scalar(38, 100, 20), Scalar(71, 255, 255), mask2);
}
else if (71 < hue <= 100) {
inRange(hsv, Scalar(71, 120, 20), Scalar(95, 255, 255), mask1);
inRange(hsv, Scalar(71, 120, 20), Scalar(95, 255, 255), mask2);
}
else if (100 < hue <= 140) {
inRange(hsv, Scalar(100, 150, 20), Scalar(130, 255, 255), mask1);
inRange(hsv, Scalar(100, 150, 20), Scalar(130, 255, 255), mask2);
}
else if (140 < hue <= 165) {
inRange(hsv, Scalar(140, 120, 20), Scalar(170, 255, 255), mask1);
inRange(hsv, Scalar(140, 120, 20), Scalar(170, 255, 255), mask2);
}
}
else {
cout << "Use colored material." << endl;
break;
}
// Generating the final mask
mask1 = mask1 + mask2;
Mat kernel = Mat::ones(3, 3, CV_32F);
morphologyEx(mask1, mask1, cv::MORPH_OPEN, kernel);
morphologyEx(mask1, mask1, cv::MORPH_DILATE, kernel);
// creating an inverted mask to segment out the cloth from the frame
bitwise_not(mask1, mask2);
Mat res1, res2, final_output;
// Segmenting the cloth out of the frame using bitwise and with the inverted mask
bitwise_and(frame, frame, res1, mask2);
// creating image showing static background frame pixels only for the masked region
bitwise_and(background, background, res2, mask1);
// Generating the final augmented output.
addWeighted(res1, 1, res2, 1, 0, final_output);
imshow("magic", final_output);
waitKey(1);
// Press ESC on keyboard to exit
char c = (char)waitKey(25);
if (c == 27)
break;
// Also relese all the mat created in the code to avoid memory leakage.
frame.release(), hsv.release(), mask1.release(), mask2.release(), res1.release(), res2.release(), final_output.release();
}
// When everything done, release the video capture object
cap.release();
// Closes all the frames
cv::destroyAllWindows();
return 0;
}
It should do the same for all major colors as it is doing for red.

Answer 1

Have you checked the output of these two points when you are selecting another color?
Vec3b HSV_Color = hsvimg.at<Vec3b>(data.points[0]);
int hue = HSV_Color.val[0];
int saturation = HSV_Color.val[1];
int value = HSV_Color.val[2];
and this one
cvtColor(frame, hsv, COLOR_BGR2HSV);