Gets the rectangle that would be used to trim the class object's bitmap if LBitmap::AutoTrim were used.


#include "ltwrappr.h"

virtual L_INT LBitmap::GetAutoTrimRect(uThreshold, pRect, uFlags = 0)


L_UINT uThreshold

Delta value for detecting blank space. Starting at each edge of the bitmap and evaluating toward the center, any change in intensity that is less than or equal to uThreshold is considered blank space. Valid values are 0 to 255.


Address of the RECT variable to be updated.

L_UINT32 uFlags

Reserved for future use. Must be 0.


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


Use this function in conjunction with LBitmapBase::Trim instead of LBitmap::AutoTrim when you want to modify the trim rectangle. For example, you could let the user preview the rectangle, or you could add a margin.

This function uses bitmap coordinates to specify the area to be trimmed. Therefore, you must account for the view perspective of the bitmap. For information about bitmap coordinates, refer to Accounting for View Perspective.

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LBitmap__GetAutoTrimRectExample() 
   L_INT nRet; 
   LBitmap LeadBitmap; 
   RECT rcTrimRect; 
   L_TCHAR szDummyBuffer[256]; 
   nRet =LeadBitmap.Load(MAKE_IMAGE_PATH(TEXT("image1.cmp")), 0,ORDER_BGR); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =LeadBitmap.GetAutoTrimRect(100, &rcTrimRect); 
   if(nRet !=SUCCESS) 
      return nRet; 
   wsprintf(szDummyBuffer, TEXT("Left: %d\t Top: %d\nRight: %d\tBottom: %d"), rcTrimRect.left,  
  , rcTrimRect.right, rcTrimRect.bottom); 
   MessageBox(0, szDummyBuffer, TEXT("GetAutoTrimRect"), MB_OK); 
   return SUCCESS; 
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