L_LTIMGEFX_API L_INT L_DirectionEdgeStatisticalBitmap(pBitmap, uDim, nThreshold, nAngle, crEdgeColor, crBkColor, uFlags)
Detects the variation of colors in the specified direction using statistical indices. It is similar to L_EdgeDetectStatisticalBitmap, but this function allows you to specify the direction angle.
Pointer to the bitmap handle that references the bitmap to which the edge detector is applied.
The dimension or the number of pixels used to calculate the edge in the specified direction.
Threshold value used to determine which pixels are edge pixels. If the difference in the intensity value between the pixel being tested and the average intensity of the pixels in the
uDim around it is greater than this value, the pixel is an edge pixel. The threshold range for the 16, 48, and 64-bit bitmaps is from 0 to 65535 and for 12-bit bitmaps from 0 to 4095. Otherwise, it is from 0 to 255. The threshold is applied on channels separately.
Angular amount that specifies edge detector direction, in hundredths of degrees. Valid values range from 18000 through 18000. Positive valued angles are produced by counterclockwise rotation above the horizon and negative valued angles are produced by clockwise rotation below the horizon. This value is divided internally by 100.
The COLORREF value that specifies the edge color. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.
The COLORREF value that specifies the non edge color. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.
Reserved for future use. Must be 0.
|SUCCESS||The function was successful.|
|< 1||An error occurred. Refer to Return Codes.|
The edges are detected by applying a statistical filter that analyzes the variations of colors in a specified direction around each pixel.
To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.
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 in the Document and Medical Imaging toolkits.
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.
The threshold range for 16, 48 and 64-bit images is from 0 to 65535 for unsigned images, and from –32768 to +32767 for signed images. For 12-bit images, the threshold range is from 0 to 4095 for unsigned images, and from –2048 to +2047 for signed images. Otherwise, it is from 0 to 255. The threshold is applied to channels separately.
Required DLLs and Libraries
Win32, x64, Linux.
This example loads a bitmap and find its edges using a 45 degree angle, a 128 threshold, and a size equal to 15
BITMAPHANDLE LeadBitmap; /* Bitmap handle to hold the loaded image. */
/* Load the bitmap, keeping the bits per pixel of the file */
nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\NaturalFruits.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
/* Find the edges in the bitmap*/
nRet = L_DirectionEdgeStatisticalBitmap (&LeadBitmap, 15, 128, 4500, RGB(255, 255, 255), RGB(0, 0, 0), 0);
nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL);
Medical Web Viewer .NET
.NET, Java, Android, and iOS/macOS Assemblies
C API/C++ Class Libraries