#include "ltimgcor.h"
L_LTIMGCOR_API L_INT L_ManualPerspectiveDeskew(pBitmap, InPoints, ppOutBitmap)
Corrects the view perspective.
Pointer to the bitmap handle referencing the bitmap to be transformed.
Pointer to ManualPerspectiveDeskewPoints structure that contains a list of points that will be transformed to match the location of the mapped points list
Pointer of pointer to bitmap handle that contains the deskewed image.
Value | Meaning |
---|---|
SUCCESS | The function was successful. |
< 1 | An error occurred. Refer to Return Codes. |
The L_ManualPerspectiveDeskew can change the specified image. To keep the original image unchanged, use this function on a copy.
Typically, this function is used as a step when preprocessing images from digital cameras. It changes the image based on a view perspective equation, taking the depth of the objects into account as well as their relative dimensions.
It is best to choose input points that are far away from each other.
Use the L_ManualPerspectiveDeskew, L_Keystone, or L_PerspectiveDeskew function if there is a planar deformation along all three axes. Use the L_UnWarp function if there is a cylindrical deformation. Use the L_DeskewBitmap function if there is deformation along both the x- and y- axes.
This function can only process entire images. It does not support regions.
This function supports 24- and 36-bit color images and 8- and 16-bit grayscale images.
This command supports signed/unsigned images.
Required DLLs and Libraries
Win32, x64, Linux.
This example loads a bitmap and applies manual perspective deskew filter.
L_INT ManualPerspectiveDeskewFilterBitmapExample(L_VOID)
{
L_INT nRet;
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("cannon.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
if(nRet !=SUCCESS)
return nRet;
int Width = LeadBitmap.Width ;
int Height = LeadBitmap.Height ;
/* Apply manual perspective deskew filter to move down the top right corner by half of the image height*/
MANUALPERSPECTIVEDESKEWPOINTS manual3ddeskewpoints ;
manual3ddeskewpoints.InputPoints[0].x = 0 ; manual3ddeskewpoints.InputPoints[0].y = 0 ;
manual3ddeskewpoints.InputPoints[1].x = Width-1 ; manual3ddeskewpoints.InputPoints[1].y = 0 ;
manual3ddeskewpoints.InputPoints[2].x = 0 ; manual3ddeskewpoints.InputPoints[2].y = Height-1 ;
manual3ddeskewpoints.InputPoints[3].x = Width-1 ; manual3ddeskewpoints.InputPoints[3].y = Height-1 ;
manual3ddeskewpoints.MappingPoints[0].x = 0 ; manual3ddeskewpoints.MappingPoints[0].y = 0 ;
manual3ddeskewpoints.MappingPoints[1].x = Width-1 ; manual3ddeskewpoints.MappingPoints[1].y = Height/2 ;
manual3ddeskewpoints.MappingPoints[2].x = 0 ; manual3ddeskewpoints.MappingPoints[2].y = Height-1 ;
manual3ddeskewpoints.MappingPoints[3].x = Width-1 ; manual3ddeskewpoints.MappingPoints[3].y = Height-1 ;
pBITMAPHANDLE pOutBitmap = NULL;
nRet = L_ManualPerspectiveDeskew(&LeadBitmap, &manual3ddeskewpoints, &pOutBitmap);
if(nRet !=SUCCESS)
{
//free bitmap
if(LeadBitmap.Flags.Allocated)
L_FreeBitmap(&LeadBitmap);
return nRet;
}
nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), pOutBitmap, FILE_BMP, 24, 0, NULL);
L_FreeManualPerspectiveDeskewBitmap(pOutBitmap);
//free bitmap
if(LeadBitmap.Flags.Allocated)
L_FreeBitmap(&LeadBitmap);
return nRet;
}
Help Collections
Raster .NET | C API | C++ Class Library | HTML5 JavaScript
Document .NET | C API | C++ Class Library | HTML5 JavaScript
Medical .NET | C API | C++ Class Library | HTML5 JavaScript
Medical Web Viewer .NET
Multimedia
Direct Show .NET | C API | Filters
Media Foundation .NET | C API | Transforms
Supported Platforms
.NET, Java, Android, and iOS/macOS Assemblies
Imaging, Medical, and Document
C API/C++ Class Libraries
Imaging, Medical, and Document
HTML5 JavaScript Libraries
Imaging, Medical, and Document