Fix video FPS opencv? - c++

Question

How to make my video not delay, in the beginning of the code it's not delay, but if I use the GaussianBlur, morphology operation, and SimpleBlobDetector, the video gets delayed, please someone help me..
Thanks in advance
using namespace cv;
using namespace std;
int _tmain(int argc, _TCHAR* argv[]){
VideoCapture cap(0);
cap.open("file.mp4"); //read the video
if (!cap.isOpened())
{
cout << "Cannot open the video cam" << endl;
return -1;
}
double Width = cap.get(CV_CAP_PROP_FRAME_WIDTH);
double Height = cap.get(CV_CAP_PROP_FRAME_HEIGHT);
cvNamedWindow("MyVideo", CV_WINDOW_AUTOSIZE);
while (1)
{
Mat frame;
bool bSuccess = cap.read(frame);
SimpleBlobDetector::Params params;
// Change thresholds
params.minThreshold = 0;
params.maxThreshold = 255;
params.filterByColor = true;
params.blobColor = 255;
// Filter by Area.
params.filterByArea = true;
params.minArea = 5 ;
// Filter by Circularity
params.filterByCircularity = true;
params.minCircularity = 0.1;
// Filter by Convexity
params.filterByConvexity = true;
params.minConvexity = 0.87;
// Filter by Inertia
params.filterByInertia = true;
params.minInertiaRatio = 0.01;
//crop the image with the pixel i want
Mat blur, crop;
GaussianBlur(frame, blur, Size(15, 15), 0); //blur the image
Point corners[1][4];
corners[0][0] = Point(550, 30); //top left
corners[0][1] = Point(250, 700); //bottom left
corners[0][2] = Point(1100, 700); //bottom right
corners[0][3] = Point(600, 30); //top right
const Point* corner_list[1] = { corners[0] };
int num_points = 4;
int num_polygons = 1;
int line_type = 8;
Mat mask(720, 1280, CV_8UC3, cv::Scalar(0, 0, 0));
fillPoly(mask, corner_list, &num_points, num_polygons, cv::Scalar(255, 255, 255), line_type);
bitwise_and(blur, mask, crop);//combine the image
Mat gray, changeToBlack;
cvtColor(crop, gray, COLOR_BGR2GRAY); //grayscale citra
inRange(gray, Scalar(0), Scalar(0), changeToBlack);
Mat black_image(gray.size(), CV_8U, Scalar(255));
black_image.copyTo(gray, changeToBlack);
Mat thres, tes;
threshold(gray, tes, 51, 255, THRESH_BINARY_INV); //threshold citra and 51 set value
Mat erosi, dilasi, open, close, tophat;
Mat kernel = Mat(3, 3, CV_8UC1, Scalar(1));
morphologyEx(tes, erosi, MORPH_ERODE, kernel, Point(-1, -1), 3);
morphologyEx(erosi, dilasi, MORPH_DILATE, kernel, Point(-1, -1), 20);
vector<KeyPoint> keypoints;
Ptr<SimpleBlobDetector> detector = SimpleBlobDetector::create(params);
detector->detect(dilasi, keypoints);
Mat im_with_keypoints;
drawKeypoints(dilasi, keypoints, im_with_keypoints, Scalar(205, 0, 0), DrawMatchesFlags::DRAW_RICH_KEYPOINTS);
imshow("gray", frame);
imshow("MyVideo", im_with_keypoints);
if (waitKey(30) == 27)
{
cout << "esc key is pressed by user" << endl;
break;
}
}
return 0;
}
Anyone please help me

Answer 1

Oh! All actions and memory allocation inside loop. Try this:
int _tmain(int argc, _TCHAR* argv[]){
VideoCapture cap(0);
cap.open("file.mp4"); //read the video
if (!cap.isOpened())
{
cout << "Cannot open the video cam" << endl;
return -1;
}
double Width = cap.get(CV_CAP_PROP_FRAME_WIDTH);
double Height = cap.get(CV_CAP_PROP_FRAME_HEIGHT);
cvNamedWindow("MyVideo", CV_WINDOW_AUTOSIZE);
Mat frame;
Mat blur, crop;
Mat mask(720, 1280, CV_8UC3, cv::Scalar(0, 0, 0));
Mat gray, changeToBlack;
Mat black_image(gray.size(), CV_8U, Scalar(255));
Mat thres, tes;
Mat erosi, dilasi, open, close, tophat;
Mat kernel = Mat(3, 3, CV_8UC1, Scalar(1));
Mat im_with_keypoints;
SimpleBlobDetector::Params params;
// Change thresholds
params.minThreshold = 0;
params.maxThreshold = 255;
params.filterByColor = true;
params.blobColor = 255;
// Filter by Area.
params.filterByArea = true;
params.minArea = 5 ;
// Filter by Circularity
params.filterByCircularity = true;
params.minCircularity = 0.1;
// Filter by Convexity
params.filterByConvexity = true;
params.minConvexity = 0.87;
// Filter by Inertia
params.filterByInertia = true;
params.minInertiaRatio = 0.01;
vector<KeyPoint> keypoints;
Ptr<SimpleBlobDetector> detector = SimpleBlobDetector::create(params);
while (cap.read(frame))
{
//crop the image with the pixel i want
GaussianBlur(frame, blur, Size(15, 15), 0); //blur the image
Point corners[1][4];
corners[0][0] = Point(550, 30); //top left
corners[0][1] = Point(250, 700); //bottom left
corners[0][2] = Point(1100, 700); //bottom right
corners[0][3] = Point(600, 30); //top right
const Point* corner_list[1] = { corners[0] };
int num_points = 4;
int num_polygons = 1;
int line_type = 8;
fillPoly(mask, corner_list, &num_points, num_polygons, cv::Scalar(255, 255, 255), line_type);
bitwise_and(blur, mask, crop);//combine the image
cvtColor(crop, gray, COLOR_BGR2GRAY); //grayscale citra
inRange(gray, Scalar(0), Scalar(0), changeToBlack);
black_image.copyTo(gray, changeToBlack);
threshold(gray, tes, 51, 255, THRESH_BINARY_INV); //threshold citra and 51 set value
morphologyEx(tes, erosi, MORPH_ERODE, kernel, Point(-1, -1), 3);
morphologyEx(erosi, dilasi, MORPH_DILATE, kernel, Point(-1, -1), 20);
detector->detect(dilasi, keypoints);
drawKeypoints(dilasi, keypoints, im_with_keypoints, Scalar(205, 0, 0), DrawMatchesFlags::DRAW_RICH_KEYPOINTS);
imshow("gray", frame);
imshow("MyVideo", im_with_keypoints);
if (waitKey(1) == 27)
{
cout << "esc key is pressed by user" << endl;
break;
}
}
return 0;
}