L_GetAutoTrimRect

#include "l_bitmap.h"

L_INT EXT_FUNCTION L_GetAutoTrimRect(pBitmap, uThreshold, pRect)

pBITMAPHANDLE pBitmap;

/* pointer to the bitmap handle */

L_UINT uThreshold;

/* delta value for detecting blank space */

RECT L_FAR * pRect;

/* address of the variable to be updated */

Gets the rectangle that that would be used to trim the bitmap if L_AutoTrimBitmap were used.

Parameter

Description

pBitmap

Pointer to the bitmap handle that references the bitmap to be trimmed.

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.

pRect

Address of the RECT variable to be updated.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

Use this function in conjunction with L_TrimBitmap instead of L_AutoTrimBitmap 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.

Required DLLs and Libraries

LTIMG

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Windows 95 / 98 / Me, Windows 2000 / XP, Windows CE.

See Also

Functions:

L_AutoTrimBitmap, L_TrimBitmap, L_CopyBitmapRect, L_WindowLevel

Topics:

Raster Image Functions: Doing Geometric Transformations

Example

/* This example loads an image, gets the AutoTrim RECT, modifies it, */
/* and then trims the bitmap */
BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */
RECT rc;
/* Load the bitmap, keeping the bits per pixel of the file */
L_LoadBitmap
 (TEXT("IMAGE1.TIF"), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
/* Get the RECT for AutoTrim with 0 tolerance */
L_GetAutoTrimRect
 ( &LeadBitmap, 0, &rc );
/* Trim the bitmap with modified RECT */
L_TrimBitmap
 ( &LeadBitmap, rc.left - 10, rc.top - 10, rc.right - rc.left + 20, rc.bottom - rc.top + 20 );