کشیدن دایره و خط روی تصویر با opencv
ShahBaz | يكشنبه, ۲۴ مرداد ۱۳۹۵، ۰۷:۲۷ ب.ظ
Basic drawing examples
Drawing a line
void line(Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int lineType=8, int shift=0)Parameters:
- img – Image.
- pt1 – First point of the line segment.
- pt2 – Second point of the line segment.
- color – Line color.
- thickness – Line thickness.
-
lineType – Type of the line:
- 8 (or omitted) - 8-connected line.
- 4 - 4-connected line.
- CV_AA - antialiased line.
- shift – Number of fractional bits in the point coordinates.
Example 1: Drawing a line
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); // Draw a line line( image, Point( 15, 20 ), Point( 70, 50), Scalar( 110, 220, 0 ), 2, 8 ); imshow("Image",image); waitKey( 0 ); return(0); }-------------
Drawing a Circle
void circle(Mat& img, Point center, int radius, const Scalar& color, int thickness=1, int lineType=8, int shift=0)Parameters:
- img – Image where the circle is drawn.
- center – Center of the circle.
- radius – Radius of the circle.
- color – Circle color.
- thickness – Thickness of the circle outline, if positive. Negative thickness means that a filled circle is to be drawn.
- lineType – Type of the circle boundary. See the line() description.
- shift – Number of fractional bits in the coordinates of the center and in the radius value.
Example 2: Drawing a Circle
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); // Draw a circle circle( image, Point( 200, 200 ), 32.0, Scalar( 0, 0, 255 ), 1, 8 ); imshow("Image",image); waitKey( 0 ); return(0); }-------------
Drawing an Ellipse
void ellipse(Mat& img, Point center, Size axes, double angle, double startAngle, double endAngle, const Scalar& color, int thickness=1, int lineType=8, int shift=0)Parameters:
- img – Image.
- center – Center of the ellipse.
- axes – Length of the ellipse axes.
- angle – Ellipse rotation angle in degrees.
- startAngle – Starting angle of the elliptic arc in degrees.
- endAngle – Ending angle of the elliptic arc in degrees.
- box – Alternative ellipse representation via RotatedRect or CvBox2D. This means that the function draws an ellipse inscribed in the rotated rectangle.
- color – Ellipse color.
- thickness – Thickness of the ellipse arc outline, if positive. Otherwise, this indicates that a filled ellipse sector is to be drawn.
- lineType – Type of the ellipse boundary. See the line() description.
- shift – Number of fractional bits in the coordinates of the center and values of axes.
If you use the first variant of the function and want to draw the whole ellipse, not an arc, pass startAngle=0 and endAngle=360.
Example 3: Drawing an Ellipse
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); // Draw a ellipse ellipse( image, Point( 200, 200 ), Size( 100.0, 160.0 ), 45, 0, 360, Scalar( 255, 0, 0 ), 1, 8 ); ellipse( image, Point( 200, 200 ), Size( 100.0, 160.0 ), 135, 0, 360, Scalar( 255, 0, 0 ), 10, 8 ); ellipse( image, Point( 200, 200 ), Size( 150.0, 50.0 ), 135, 0, 360, Scalar( 0, 255, 0 ), 1, 8 ); imshow("Image",image); waitKey( 0 ); return(0); }-------------
Drawing a Rectangle
void rectangle(Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int lineType=8, int shift=0)Parameters:
- img – Image.
- pt1 – Vertex of the rectangle.
- pt2 – Vertex of the rectangle opposite to pt1 .
- rec – Alternative specification of the drawn rectangle.
- color – Rectangle color or brightness (grayscale image).
- thickness – Thickness of lines that make up the rectangle. Negative values, like CV_FILLED , mean that the function has to draw a filled rectangle.
- lineType – Type of the line. See the line() description.
- shift – Number of fractional bits in the point coordinates.
Example 4: Drawing a Rectangle
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); // Draw a rectangle ( 5th argument is not -ve) rectangle( image, Point( 15, 20 ), Point( 70, 50), Scalar( 0, 55, 255 ), +1, 4 ); imshow("Image1",image); // Draw a filled rectangle ( 5th argument is -ve) rectangle( image, Point( 115, 120 ), Point( 170, 150), Scalar( 100, 155, 25 ), -1, 8 ); imshow("Image2",image); waitKey( 0 ); return(0); }-------------
Drawing a Filled Polygon
void fillPoly(Mat& img, const Point** pts, const int* npts, int ncontours, const Scalar& color, int lineType=8, int shift=0, Point offset=Point() )Parameters:
- img – Image.
- pts – Array of polygons where each polygon is represented as an array of points.
- npts – Array of polygon vertex counters.
- ncontours – Number of contours that bind the filled region.
- color – Polygon color.
- lineType – Type of the polygon boundaries. See the line() description.
- shift – Number of fractional bits in the vertex coordinates.
- offset – Optional offset of all points of the contours.
Example 4: Drawing a Filled Polygon
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); int w=400; // Draw a circle /** Create some points */ Point rook_points[1][20]; rook_points[0][0] = Point( w/4.0, 7*w/8.0 ); rook_points[0][1] = Point( 3*w/4.0, 7*w/8.0 ); rook_points[0][2] = Point( 3*w/4.0, 13*w/16.0 ); rook_points[0][3] = Point( 11*w/16.0, 13*w/16.0 ); rook_points[0][4] = Point( 19*w/32.0, 3*w/8.0 ); rook_points[0][5] = Point( 3*w/4.0, 3*w/8.0 ); rook_points[0][6] = Point( 3*w/4.0, w/8.0 ); rook_points[0][7] = Point( 26*w/40.0, w/8.0 ); rook_points[0][8] = Point( 26*w/40.0, w/4.0 ); rook_points[0][9] = Point( 22*w/40.0, w/4.0 ); rook_points[0][10] = Point( 22*w/40.0, w/8.0 ); rook_points[0][11] = Point( 18*w/40.0, w/8.0 ); rook_points[0][12] = Point( 18*w/40.0, w/4.0 ); rook_points[0][13] = Point( 14*w/40.0, w/4.0 ); rook_points[0][14] = Point( 14*w/40.0, w/8.0 ); rook_points[0][15] = Point( w/4.0, w/8.0 ); rook_points[0][16] = Point( w/4.0, 3*w/8.0 ); rook_points[0][17] = Point( 13*w/32.0, 3*w/8.0 ); rook_points[0][18] = Point( 5*w/16.0, 13*w/16.0 ); rook_points[0][19] = Point( w/4.0, 13*w/16.0) ; const Point* ppt[1] = { rook_points[0] }; int npt[] = { 20 }; fillPoly( image, ppt, npt, 1, Scalar( 255, 255, 255 ), 8 ); imshow("Image",image); waitKey( 0 ); return(0); }-------------
Putting Text in image
putText renders the specified text string in the image.void putText(Mat& img, const string& text, Point org, int fontFace, double fontScale, Scalar color, int thickness=1, int lineType=8, bool bottomLeftOrigin=false )
Parameters:
- img – Image.
- text – Text string to be drawn.
- org – Bottom-left corner of the text string in the image.
- fontFace – Font type. One of FONT_HERSHEY_SIMPLEX, FONT_HERSHEY_PLAIN, FONT_HERSHEY_DUPLEX, FONT_HERSHEY_COMPLEX, FONT_HERSHEY_TRIPLEX, FONT_HERSHEY_COMPLEX_SMALL, FONT_HERSHEY_SCRIPT_SIMPLEX, or FONT_HERSHEY_SCRIPT_COMPLEX, where each of the font ID’s can be combined with FONT_HERSHEY_ITALIC to get the slanted letters.
- fontScale – Font scale factor that is multiplied by the font-specific base size.
- color – Text color.
- thickness – Thickness of the lines used to draw a text.
- lineType – Line type. See the line for details.
- bottomLeftOrigin – When true, the image data origin is at the bottom-left corner. Otherwise, it is at the top-left corner.
Example 5: Putting Text in image
-------------#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main( ) { // Create black empty images Mat image = Mat::zeros( 400, 400, CV_8UC3 ); putText(image, "Hi all...", Point(50,100), FONT_HERSHEY_SIMPLEX, 1, Scalar(0,200,200), 4); imshow("Image",image); waitKey( 0 ); return(0); }-------------
Source:
http://docs.opencv.org/modules/core/doc/drawing_functions.html?highlight=rectangle#void%20line%28Mat&%20img,%20Point%20pt1,%20Point%20pt2,%20const%20Scalar&%20color,%20int%20thickness,%20int%20lineType,%20int%20shift%29
- ۰ نظر
- ۲۴ مرداد ۹۵ ، ۱۹:۲۷