Use cvresize of opencv to scale all the images in the folder to a uniform size.

Before training a classifier, one step is to create a sample. Before creating a classifier, you must scale the positive sample and the secondary sample to a uniform size. How can you batch scale the images in the entire folder? The procedure is as follows:

Run in vc6.0 + opencv2.1,

The following error occurs in vs2010:

Error c2440: 'initializing': cannot convert from 'wchar [260] 'to 'std: basic_string <_ ELEM, _ traits, _ ax>'

Solution: This is caused by the character encoding used by the project. When Unicode is used, lpstr P = Str. getbuffer (LEN + 1) returns this error. The solution is to recompile configureation Properties> General> Character Set = not set in project properties.

 

# Include <iostream>
# Include <windows. h>
# Include <string>
# Include <cv. h>

# Include

Using namespace STD;
Long cc = 0; // The Name Of The stored image 1.jpg 2.jpg ....
Void findfile (string filename, const string filter );

Void setsize (string filename) // scale the image using the cvresize function of opencv
{
Iplimage * src = 0; // source image pointer
Iplimage * DST = 0; // target image pointer
Float scale = 0.618; // The scaling factor is 0.618 times.
Cvsize dst_cvsize; // target image size

CC ++;
Char temp [64];
String str1;
String str2;
Sprintf (temp, "% d", CC );
Str1 = temp;
 

Src = cvloadimage (filename. c_str ());//
Dst_cvsize.width = 32; // The width of the target image is fixed to 32 pixels.
Dst_cvsize.height = 24; // Src-> height * (float) dst_cvsize.width/src-> width); // zoom in at a high ratio
DST = cvcreateimage (dst_cvsize, Src-> depth, Src-> nchannels); // construct the Target Image
 
Cvresize (SRC, DST, cv_inter_linear); // scales the source image to the target image.
Sprintf (temp, "E: // PIC // neg ");
Str2 = temp;
Filename = str2 + "//" + str1 + ". jpg"; // str2 = "E: // PIC //... "
Cvsaveimage (filename. c_str (), DST); // The saved location after scaling
 
/*
Cvnamedwindow ("src", cv_window_autosize); // create a window for displaying the source Image
Cvnamedwindow ("DST", cv_window_autosize); // create a window for displaying the Target Image
Cvshowimage ("src", Src); // display the source Image
Cvshowimage ("DST", DST); // display the Target Image
Cvreleaseimage (& SRC); // release the memory occupied by the source Image
Cvreleaseimage (& DST); // release the memory occupied by the target image
Cvdestroyallwindows ();
*/
Cvwaitkey (-1); // wait for user response
 
}

Void findfile (string filename, string filter) // traverses all JPG files in the folder.
{
Win32_find_data findfiledate; // data buffer
Handle hfind = invalid_handle_value;
If (filename [filename. Length ()-1]! = '//')
Filename + = '//';
String lpfilename = filename + "//" + filter; // if the function fails, the return value is invalid_handle_value
Hfind = findfirstfile (lpfilename. c_str (), & findfiledate );
If (hfind = invalid_handle_value) return;
While (true)
{// Determine whether it is a file or a folder
If (findfiledate. dwfileattributes> = 32)
{
Cout <"file:" <findfiledate. cfilename;
Cout <'/t' <"&" <FILENAME <"77" <lpfilename <Endl;
Lpfilename = filename + "//" + findfiledate. cfilename;
Setsize (lpfilename); // scale the image
}
// For folders
Else
{
// If it is not a parent directory
String fname = findfiledate. cfilename;
If (fname! = "." & Fname! = "..")
{
Lpfilename = filename + fname;
Findfile (lpfilename, filter );

}
}
// If the next query succeeds, a value other than 0 is returned; otherwise, 0 is returned.
Int result = findnextfile (hfind, & findfiledate );
If (result = 0) break;
}
Findclose (hfind );
// Release the handle
Return;
}

Int main (INT argc, char * argv [])
{
String directory = "E: // original (1) // original // neg // ch00_20110121092157"; // directory of the file to be found
String filter = "*. jpg"; // file with the suffix. jpg
Findfile (directory, filter );
Return 0;
}