L_ContourFilterBitmap
#include "l_bitmap.h"
L_INT EXT_FUNCTION L_ContourFilterBitmap(pBitmap, nThreshold, nDeltaDirection, nMaximumError, nOption)
| pBITMAPHANDLE pBitmap; | /* pointer to a bitmap handle */ | 
| L_INT16 nThreshold; | /* threshold value */ | 
| L_INT16 nDeltaDirection; | /* maximum angle */ | 
| L_INT16 nMaximumError; | /* maximum error */ | 
| L_INT nOption; | /* flag that controls the resulting image */ | 
Performs a contour segment filter on the source bitmap. This function is available in the Medical Toolkits.
| Parameter | Description | |
| pBitmap | Pointer to a bitmap handle that references the bitmap that will be affected. | |
| nThreshold | Threshold of the gradient magnitude. Values below this will be considered as background, and will be set to 0. Values can be from 1 to 254. A lower threshold provides a better quality image. Default is 15. | |
| nDeltaDirection | Maximum angle for the thinning algorithm. Values can be from 1 to 64. Default is 35. | |
| nMaximumError | Maximum error for approximation algorithm. Values can be from 0 to 255. Default is 5. This parameter is only valid if nOption is CONTOUR_APPROX_COLOR. | |
| nOption | Flag that controls the resulting image. This value tells the method what process to complete before returning. Possible values are: | |
| 
 | Value | Meaning | 
| 
 | CONTOUR_THIN | [0] return after the thinning algorithm | 
| 
 | CONTOUR_LINK_BLACKWHITE | [1] return after contour linking, using only black and white | 
| 
 | CONTOUR_LINK_GRAY | [2] return after contour linking, using 256 grayscale | 
| 
 | CONTOUR_LINK_COLOR | [3] return after contour linking, using colors | 
| 
 | CONTOUR_APPROX_COLOR | [4] return after line segment approximation, using colors | 
Returns
| SUCCESS | The function was successful. | 
| < 1 | An error occurred. Refer to Return Codes. | 
Comments
The bits per pixel of the affected bitmap will change according to the value of nOption.
| If nOption is: | Bits per pixel will be: | 
| CONTOUR_THIN | 8 bits per pixel grayscale | 
| CONTOUR_LINK_BLACKWHITE | 1 bit per pixel | 
| CONTOUR_LINK_GRAY | 8 bits per pixel grayscale | 
| CONTOUR_LINK_COLOR | 8 bits per pixel color | 
| CONTOUR_APPROX_COLOR | 8 bits per pixel color | 
This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Supportfor 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.
See Also
Example
For an example, refer to L_DlgContourFilter.