Image Scaling Function

Image scaling using CImage.

 

 

[Cpp]
// Used for image scaling
Bool CDIGTLSView: myScale (float keyX, float keyY) // when defining keyx and keyy as int, an error occurs.
{
// Programming: Li lizong lilizong@gmail.com
// 2012-8-6
KeyX = keyX;
KeyY = keyY;
// Srand (unsigned) time (NULL ));
// Float keyX, keyY; // magnification
// KeyX = (rand () % 20 + 1)/10.0 );
// KeyY = (rand () % 20 + 1)/10.0 );
// For a long time, there was always a problem during debugging. Later I found that the key value may be 0 at the beginning, so there was a problem. Remember !!!
// 2012-8-6
// CString str;
// Str. Format (TEXT ("% f"), key );
// MessageBox (str );
If (! MyImage2.IsNull ())
MyImage2.Destroy ();
If (! MyImage1.IsNull ())
MyImage1.Destroy ();
If (myImage1.IsNull ())
// OnOpenResourceFile ();
MyImage1.LoadFromResource (AfxGetInstanceHandle (), MAKEINTRESOURCE (IDB_BITMAP3 ));
// OnOpenCustomeFile ();
// MyImage2.Destroy ();
If (myImage2.IsNull ())
MyImage2.Create (int) (myImage1.GetWidth () * keyX), (int) (myImage1.GetHeight () * keyY), 24, 0 );
COLORREF pixel;
Int maxY = myImage2.GetHeight ();
Int maxX = myImage2.GetWidth ();
// Int maxX1 = myImage1.GetWidth ();
// Int maxY1 = myImage1.GetHeight ();
// CString str;
// Str. Format (TEXT ("% d"), maxX );
// MessageBox (str );
// Str. Format (TEXT ("% d"), maxX1 );
// MessageBox (str );
// Str. Format (TEXT ("% d"), maxY );
// MessageBox (str );
// Str. Format (TEXT ("% d"), maxY1 );
// MessageBox (str );
Int r, g, B, avg;
Double c;
Byte * pRealData;
Byte * pRealData2;
PRealData = (byte *) myImage1.GetBits ();
PRealData2 = (byte *) myImage2.GetBits ();
Int pit = myImage1.GetPitch ();
Int pit2 = myImage2.GetPitch ();
// Note that the values of pit and pit2 are not the same, so if you use a value, different results will appear.
// CString str;
// Str. Format (TEXT ("% d"), pit2 );
// MessageBox (str );
// Str. Format (TEXT ("% d"), pit2 );
// MessageBox (str );
Int bitCount = myImage1.GetBPP ()/8;
Int bitCount2 = myImage2.GetBPP ()/8;
// CString str;
// Str. Format (TEXT ("% d"), bitCount );
// MessageBox (str );
// Str. Format (TEXT ("% d"), bitCount2 );
// MessageBox (str );
Int newValue;
Int tempR, tempG, tempB;
Int newX, newY;
For (int y = 0; y <maxY; y ++ ){
For (int x = 0; x <maxX; x ++ ){
NewX = (int) (x/keyX );
NewY = (int) (y/keyY );
TempR = (int) (* (pRealData + pit * newY + newX * bitCount ));
If (bitCount = 1)
{
TempG = tempR;
TempB = tempR;
}
Else
{
TempG = (int) (* (pRealData + pit * newY + newX * bitCount + 1 ));
TempB = (int) (* (pRealData + pit * newY + newX * bitCount + 2 ));
}
* (PRealData2 + pit2 * y + x * bitCount2) = tempR;
* (PRealData2 + pit2 * y + x * bitCount2 + 1) = tempG;
* (PRealData2 + pit2 * y + x * bitCount2 + 2) = tempB;
}
}
Invalidate ();
Return false;
}

Author; superdont