#include "ltwrappr.h"

virtual L_INT LPaint::ColorRgn(crRgnColor, pXForm =NULL)

Highlights a region by displaying a filled, color representation of the region.



Color value to be XORed with colors within a region to determine the new colors for displaying the region. The color corresponding to a particular part of the region is determined as follows:

Region Color Displayed = (color of pixel in region) XOR (crRgnColor).


Pointer to an RGNXFORM structure that LEADTOOLS uses to translate between display coordinates and bitmap coordinates.

If you specify NULL in this parameter, the scalar fields default to 1, the offsets default to 0, and the view perspective defaults to the bitmap's view perspective.


Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.


This function is particularly useful when displaying regions with black and white images. All black pixels in a region are displayed with color crRgnColor, and all white pixels are displayed ~(crRgnColor). For example, suppose that crRgnColor is light green (BGR 0x80FF40). All black pixels in the region are displayed as crRgnColor. All white pixels in the region are displayed as 0xFFFFFF XOR 0x80FF40 = 0x7F00BF, which is purple.

Required DLLs and Libraries


Win32, x64.

See Also




The following should be part of the WM_PAINT processing
m_Bitmap is an object of type LBitmap and it contains a valid bitmap

L_INT LPaint_ColorRgnExample(LBitmap *pBitmap, HDC hDC) 
   L_INT nRet = 0; 
   LPaint MyPaint(pBitmap, hDC); 
   nRet = MyPaint.PaintDC(); 
   if(nRet != SUCCESS) 
      return nRet; 
   if (pBitmap->HasRgn()) 
        nRet = MyPaint.ColorRgn(RGB(255,0,0), NULL); 
        if(nRet != SUCCESS) 
           return nRet; 
   return SUCCESS; 

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