LFile::Load

Summary

Loads an image file into the class object's associated bitmap. The file can be in any supported image file format and bits per pixel, whether compressed or uncompressed.

Syntax

#include "ltwrappr.h"

virtual L_INT LFile::Load(nBitsPerPixel, nOrder, nPage, pFileInfo=NULL)

virtual L_INT LFile::Load(nBitsPerPixel=0, nOrder=ORDER_BGRORGRAY, pLoadFileOption=NULL, pFileInfo=NULL)

Parameters

L_INT nBitsPerPixel

Resulting bitmap pixel depth. Possible values are:

Value Meaning
0 Keep the original file's pixel depth (Do not convert). A special note about loading 12 and 16-bit grayscale images.
1 to 8 The specified bits per pixel in the resultant bitmap
12 12 bits per pixel in the resultant bitmap.
16 16 bits per pixel in the resultant bitmap
24 24 bits per pixel in the resultant bitmap
32 32 bits per pixel in the resultant bitmap
48 48 bits per pixel in the resultant bitmap
64 64 bits per pixel in the resultant bitmap

L_INT nOrder

Color order for 16-, 24-, 32-, 48-, and 64-bit bitmaps. If the resultant bitmap is less than 16 bits per pixel, this will have no effect since palletized images have no order. Possible values are:

Value Meaning
ORDER_RGB [0] Red, green, and blue color order in memory
ORDER_BGR [1] Blue, green, and red color order in memory
ORDER_GRAY [2] 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are only supported in the Document/Medical toolkits.
ORDER_RGBORGRAY [3] Load the image as red, green, blue OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical toolkits only.
ORDER_BGRORGRAY [4] Load the image as blue, green, red OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical toolkits only.

L_INT nPage

The number of the page to load.

pLOADFILEOPTION pLoadFileOption

Pointer to optional extended load options. Pass NULL to use the default load options.

pFILEINFO pFileInfo

Pointer to a FILEINFO structure. This structure may contain file information used in loading an image, or it may be updated with information about the file being loaded.

If nothing is known about the file, pass NULL for this parameter, or declare a variable of type FILEINFO and set the FILEINFO.Flags to 0, then pass the address of the FILEINFO structure in this parameter. In this case, if the address of a FILEINFO structure is passed, the FILEINFO structure will be updated with the results of LFile::GetInfo.

If only the file type is known, set pFileInfo.Format to the file type and set pFileInfo.Flags to FILEINFO_FORMATVALID. This can also be done if LFile::GetInfo has been called previously, but values that affect the size of the image loaded have been changed (for example, by calling LFileSettings::SetPCDResolution or LFileSettings::SetWMFResolution). In this case the FILEINFO structure pointed to by pFileInfo will be updated with the results of LFile::GetInfo.

If LFile::GetInfo has been called prior to calling this function, and no changes have been made to the contents of the structure filled by LFile::GetInfo, then the address of the filled FILEINFO structure can be passed for this parameter. In this case, the FILEINFO.Flags member should be set to FILEINFO_INFOVALID. The LFile::GetInfo function will set the FILEINFO.Flags to FILEINFO_INFOVALID. In this case the load will be faster since this function does not have to query the file filters for the file type.

Returns

Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.

Comments

Note: More options are available in the LOADFILEOPTION structure.

Support for 12 and 16-bit grayscale images is only available in the Document/Medical toolkits.

For supported formats, refer to Summary of All Supported Image File Formats.

Before calling this function, you may need to get or set file information, such as the page number of a multipage file or the resolution of a PCD file. Refer to Getting and Setting File Information.

The function will initialize the associated bitmap handle and allocate the storage necessary to hold the image. If the bits per pixel of the file is larger than 8 bits, the image data will be loaded in the same color order as the one passed to the function in nOrder.

Since the function allocates storage to hold the image, it is up to you to free this storage by calling LBitmapBase::Free.

Warning: The function will return ERROR_INV_PARAMETER if nOrder was set to ORDER_GRAY and the image file was not 12 or 16 bits per pixel.

NOTES:

Required DLLs and Libraries

Platforms

Win32, x64.

See Also

Functions

Topics

Example

L_INT LFile__LoadExample() 
{ 
   L_INT nRet; 
   LFile LeadFile ; 
   LBitmapBase LeadBitmap; 
 
   LeadFile.SetBitmap(&LeadBitmap); 
   LeadFile.SetFileName(MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP"))); 
 
   L_INT nBitsPerPixel = 48;  /* resulting bitmap pixel depth */ 
 
   nRet = LeadFile.Load(nBitsPerPixel, ORDER_RGB, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   LeadFile.SetFileName(TEXT("TestBMP.bmp")) ; 
   nRet = LeadFile.Save(FILE_BMP, 8, 0); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   nRet = LeadFile.FileConvert(TEXT("TestBMP2.bmp"), MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP")), FILE_BMP, LeadBitmap.GetWidth(), LeadBitmap.GetHeight(), 24, 0, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
} 
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LEADTOOLS Raster Imaging C++ Class Library Help

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.