LDicomDS::GetOverlayBitmap
#include "ltdic.h"
L_UINT16 LDicomDS::GetOverlayBitmap( uOverlayIndex, pBitmap, uStructSize, uFlags)
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L_UINT uOverlayIndex; |
/* index */ |
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pBITMAPHANDLE pBitmap; |
/* pointer to the overlay bitmap handle */ |
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L_UINT uStructSize; |
/* size of a structure */ |
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L_UINT uFlags; |
/* reserved for future use */ |
Retrieves the "Overlay Data" (60xx,3000) for the specified overlay index.
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Parameter |
Description |
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uOverlayIndex |
The index of the overlay for which to get the bitmap. This index is zero-based. |
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pBitmap |
Pointer to a bitmap handle which will be filled with the overlay data. Cannot be NULL. |
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uStructSize |
Size of the BITMAPHANDLE structure. Pass sizeof(BITMAPHANDLE). |
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uFlags |
Reserved for future use. Pass 0. |
Returns
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0 |
The function was successful. |
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> 0 |
An error occurred. Refer to Return Codes. |
Comments
This function will extract the "Overlay Data" (60xx,3000) for an overlay, initialize and allocate pBitmap based on the "Overlay Columns" (60xx,0011) and "Overlay Rows"(60xx,0010), and then fill pBitmap with the stream of bytes under the "Overlay Data" (60xx,3000) element. Please note that pBitmap is assumed to be unallocated and un-initialized. It will be filled without freeing the existing data.
If the function doesn’t find the "Overlay Data" element inside the dataset it will return DICOM_ERROR_OVERLAY_DATA_MISSING.
Before calling this function you must call LDicomDS::GetOverlayAttributes to determine if the overlay pixel data is embedded in the "Image Pixel Data" (7FE0,0010) element or is under "Overlay Data" (60xx,3000) element. If the overlay data is embedded in the "Image Pixel Data", the flag OVERLAY_USEBITPLANE will be set inside pOverlayAttributes->uFlags (pOverlayAttributes is the OVERLAYATTRIBUTES structure returned by the LDicomDS::GetOverlayAttributes function).
If the overlay pixel data is embedded in the "Image Pixel Data" (7FE0, 0010), follow these steps to get the overlay data as a bitmap handle:
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1. |
Call one of the functions which can be used to extract the "Image Pixel Data", such as LDicomDS::GetImage. This will return a bitmap handle populated with the "Image Pixel Data" which has the overlay data embedded. For this example, assume that the bitmap handle returned by this function is called pMainBitmap. |
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2. |
Call LDicomDS::GetOverlayAttributes to get the attributes of the overlay. For this example, assume that the OVERLAYATTRIBUTES structure returned by this function is called pOverlayAttributes. |
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3. |
Now we need to add our overlay as one of the overlays associated with pMainBitmap. To do that we need to call LDicomDS::SetOverlayAttributes: |
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LBitmap::SetOverlayAttributes(pMainBitmap,0,pOverlayAttributes, OVERLAYATTRIBUTES_FLAGS | OVERLAYATTRIBUTES_BITINDEX |OVERLAYATTRIBUTES_ORIGIN |OVERLAYATTRIBUTES_DICOM | OVERLAYATTRIBUTES_COLOR); |
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We are assuming that this is the first overlay in the bitmap this is why we are passing 0 as the overlay index. |
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4. |
Now we need to extract the overlay data from the main image data: |
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LBitmap::UpdateOverlayBits(pMainBitmap,0, SETOVERLAYBITS_FROMBITMAP) |
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5. |
Now call LBitmap::GetOverlay to get the overlay data itself as a bitmap handle. |
Required DLLs and Libraries
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LTDIC For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application |
See Also
Example
// This example will extract the overlays from a
// DICOM dataset and associate them with a bitmap,
// the bitmap is assumed to be extracted from the
// same DICOM dataset.
L_UINT16 LoadOverlaysIntoBitmap
(
LDicomDS &InDS ,// Input dataset
pBITMAPHANDLE pBitmap ,// Bitmap which will be associated with
// the overlays, note this should be a
// valid bitmap loaded from the same DICOM
// dataset where the overlays exist.
L_UINT uStructSize // pass sizeof(BITMAPHANDLE)
)
{
L_UINT16 uRet;
L_UINT uOverlayCount;
L_UINT uOverlayIndex;
OVERLAYATTRIBUTES OverlayAttributes = {0};
L_INT GroupNumber=0;
L_BOOL IsOverlayInDataset = FALSE;
L_INT nLEADRet;
L_UINT uLEADOverlayIndex;
BITMAPHANDLE OverlayBitmap = {0};
//(1)Sanity Check !
if(NULL == pBitmap)
{
return DICOM_ERROR_NULL_PTR;
}
DICOM_CHECK_SIZE2(pBitmap,uStructSize);
uOverlayCount =0;
//(2)Do we have any overlays at all
uRet = InDS.GetOverlayCount (&uOverlayCount);
if( (DICOM_SUCCESS !=uRet) || (0 == uOverlayCount) )
{
return DICOM_SUCCESS;
}
//(3)Go through the overlays one by one
uOverlayIndex = 0;
uLEADOverlayIndex = 0;
while(uOverlayIndex < uOverlayCount)
{
// Reset the overlay attributes structure
memset(&OverlayAttributes,0,sizeof(OverlayAttributes));
GroupNumber = 0;
IsOverlayInDataset = FALSE;
// Reset the overlay bitmap
L_InitBitmap( &OverlayBitmap,
sizeof(OverlayBitmap),
1,
1,
1);
// Get the attributes of this overlay
uRet = InDS.GetOverlayAttributes ( uOverlayIndex,
&OverlayAttributes,
sizeof(OverlayAttributes),
&GroupNumber,
&IsOverlayInDataset,0);
if(DICOM_SUCCESS !=uRet)
{
return uRet;
}
if(!IsOverlayInDataset)
{
uOverlayIndex++;
continue;
}
// Auto paint and process overlays
OverlayAttributes.uFlags |= OVERLAY_AUTOPAINT |
OVERLAY_AUTOPROCESS ;
OverlayAttributes.crColor = RGB(0xFF,0xFF,0xFF);
// Is the overlay embedded inside the image data ?
if(OverlayAttributes.uFlags & OVERLAY_USEBITPLANE)
{
// Add this overlay to the list of overlays
// in the bitmap handle
nLEADRet = L_SetOverlayAttributes( pBitmap,
uLEADOverlayIndex,
&OverlayAttributes,
OVERLAYATTRIBUTES_FLAGS |
OVERLAYATTRIBUTES_BITINDEX |
OVERLAYATTRIBUTES_ORIGIN |
OVERLAYATTRIBUTES_DICOM |
OVERLAYATTRIBUTES_COLOR);
if(SUCCESS != nLEADRet)
{
return DICOM_ERROR_MEMORY;
}
// Make sure to extract the overlay data from the image data
nLEADRet = L_UpdateBitmapOverlayBits( pBitmap,
uLEADOverlayIndex,
SETOVERLAYBITS_FROMBITMAP);
if(SUCCESS != nLEADRet)
{
return DICOM_ERROR_MEMORY;
}
}
// The overlay is inside overlay data
else
{
// Add this overlay to the list of overlays
// in the bitmap handle
nLEADRet = L_SetOverlayAttributes( pBitmap,
uLEADOverlayIndex,
&OverlayAttributes,
OVERLAYATTRIBUTES_FLAGS |
OVERLAYATTRIBUTES_ORIGIN |
OVERLAYATTRIBUTES_DICOM |
OVERLAYATTRIBUTES_COLOR);
if(SUCCESS != nLEADRet)
{
return DICOM_ERROR_MEMORY;
}
// Get the overlay bitmap from the overlay data
uRet = InDS.GetOverlayBitmap (uOverlayIndex,&OverlayBitmap,sizeof(OverlayBitmap),0);
if(DICOM_SUCCESS !=uRet)
{
return uRet;
}
// Set the bitmap for this overlay inside the
// list of overlays we have in the bitmap handle
nLEADRet = L_SetOverlayBitmap( pBitmap,
uLEADOverlayIndex,
&OverlayBitmap,
OVERLAY_MOVE);
if(SUCCESS != nLEADRet)
{
if(OverlayBitmap.Flags.Allocated)
{
L_FreeBitmap(&OverlayBitmap);
memset(&OverlayBitmap,0,sizeof(OverlayBitmap));
}
return DICOM_ERROR_MEMORY;
}
memset(&OverlayBitmap,0,sizeof(OverlayBitmap));
}
uOverlayIndex++;
uLEADOverlayIndex++;
}
return DICOM_SUCCESS;
}