Opencv adds texts to videos _ cvputtext instructions

The cvputtext () function in opencv adds the meaning of text:

Cvputtext (cvarr * IMG, const char * Text, cvpoint origin, constcvfont * font, cvscalar color );

The meanings of parameters in the function are as follows:

IMG--- Image pointer (it must be noted that cvarr * is equivalent to void *. Generally, an iplimage * is passed here *);

Text--- Apparently the content of the string to be printed to the image;

Origin--- The source of the string printed on the image (that is, the position of the lower-left corner of the string in the image)

Font--- A variable that describes the font attributes;

Color--- Font color;

 

CvfontThe initialization of type variables is implemented through the cvinitfont function. The declaration of this function is as follows:

Void cvinitfont (cvfont * font, int font_face, double h_scale, double v_scale, double shear = 0, intthickness = 1, int line_type = 8 );

The meanings of each variable in this function are as follows:

Font --- pointer to the incoming and outgoing font attribute types;

Font_face --- indicates the font type. The value can only be one of the following values:

1. cv_font_hershey_simplex

2. cv_font_hershey_plain

3. cv_font_hershey_duplex

4. cv_font_hershey_complex

5. cv_font_hershey_triplex

6. cv_font_hershey_complex_small

7. cv_font_hershey_script_simplex

8. cv_font_hershey_script_complex

H_scale --- it can only be 1 or 0.5, indicating the scaling factor of the horizontal font;

V_scale --- it can only be 1 or 0.5, indicating the zooming factor of the vertical font;

Shear --- the value ranges from 0 to 1, indicating the font skew. 0 indicates that the font is not skewed, and 1 indicates that the font is skewed to 45 degrees;

Thichness and line_type are the same as those defined in other plotting functions of opencv, indicating the width of the line and the type of the line;

 

The most common statements:

Iplimage * IMG = cvcreateimage (cvsize (width, height), ipl_depth_8u, 3 );

Char text [20] = "to print! ";

Cvpoint point = cvpoint (10, 10 );

Cvfont font;

Cvinitfont (& font, cv_font_hershey_duplex, 1.0f, 1.0f, 2, cv_aa );

Cvputtext (IMG, text, point, & font, cv_rgb (255, 0, 0 ));

Instance:

# Include "stdafx. H"

# Include "cv. H"

# Include "highgui. H"

# Include "cxcore. H"

# Include "iostream"

Using namespace STD;

Int _ tmain (INT argc, _ tchar * argv [])

{

Iplimage * pimg = cvloadimage ("C: \ lena.jpg ");

If (! Pimg)

{

Cout <"pimg load error..." <Endl;

System ("pause ");

Exit (-1 );

}

Cvfont font;

Cvinitfont (& font, cv_font_hershey_complex, 0.5, 0.5, 1, 2, 8 );

Cvputtext (pimg, "this is a picture named Lena! ", Cvpoint (50, 50), & font, cv_rgb (255, 0 ));

Cvsaveimage ("C: \ test1.jpg", pimg );

Cvnamedwindow ("IMG", 0 );

Cvshowimage ("IMG", pimg );

Cvwaitkey (0 );

System ("pause ");

Cvreleaseimage (& pimg );

Cvdestroyallwindows ();

Return 0;

}

Opcv Chinese network:

Http://www.opencv.org.cn/index.php/Cxcore%E7%BB%98%E5%9B%BE%E5%87%BD%E6%95%B0#InitFont