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LMemoryFile::Save

Summary

Saves the class object's associated bitmap to a file in memory. The output can be in any of the supported compressed or uncompressed file formats.

Syntax

#include "ltwrappr.h"

virtual L_INT LMemoryFile::Save(pLMemoryBuffer, nFormat, nBitsPerPixel=0, nQFactor=2, pSaveFileOption=NULL)

Parameters

LBuffer * pLMemoryBuffer

Pointer to an LBuffer object into which the bitmap in memory will be saved. After successful completion of this function, the object pointed to by pLMemoryBuffer will contain the output file.

L_INT nFormat

Output file format. For valid values, refer to Files To Be Included With Your Application.

L_INT nBitsPerPixel

Resulting file's pixel depth. Note that not all bits per pixel are available to all file formats. For valid values, refer to Files To Be Included With Your Application. If nBitsPerPixel is 0, the file will be stored using the closest BitsPerPixel value supported by that format. For example, if a file format supports 1, 4, and 24 BitsPerPixel, and the LBitmapBase::GetBitsPerPixel returns 5, the file will be stored as 24 bit. Likewise, if LBitmapBase::GetBitsPerPixel returns 2, the file will be stored as 4 bit.

L_INT nQFactor

This parameter is used when saving an image to file format that supports quality factor (QFactor). QFactor is a number that determines the degree of loss in the compression process.

For possible values, refer to Compression Quality Factors.

pSAVEFILEOPTION pSaveFileOption

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

Returns

None.

Comments

To use this function, do the following:

Declare an LBuffer object. You can then pass its address in this function, which will allocate the memory, save the bitmap, and unlock the memory.
Declare a long integer (L_UINT32) variable for the file-size. You can then pass its address in this function, which will update its value with the size of the file.
Call this function to save the bitmap in the specified LBuffer object.

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

This function cannot be used in combination LBaseFile::EnableRedirectIO.

Notes:

More options are available in the SAVEFILEOPTION structure. However, please note that the PageNumber data member of the SAVEFILEOPTION structure is not valid with this function. Therefore you cannot save a multipage file with this function.
This function does not support Kodak PhotoCD (PCD) or FlashPix (FPX) files.

This function cannot be used in combination with the Redirect input / output functions.

This function does not support signed data images, unless they are DICOM images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image that is not a DICOM image is passed to this function.

This function supports signed data images, but only DICOM and TIFF formats support signed data. This function will return an error code if you attempt to save a signed image to a format other than DICOM or TIFF.

If the bitmap has a region, the region stored in the bitmap will be saved, if the image is saved as one of the TIFF file formats.

In LEADTOOLS version 17 and up, when saving a colored image (such as a 24-bits per pixel image) to bitonal (1-bit per pixel), the toolkit will not use any dithering when converting the image data. This is done because dithering is not the recommended when converting colored images containing text for document processing such as OCR and Barcode. The result text will be fuzzy and hard for a recognition engine to process. To save a colored image as bitonal with Floyd-Stein dithering (the behavior of LEADTOOLS 16.5 and earlier) use the ESO_USEDITHERINGMETHOD along with LBitmapBase::SetDitheringMethod as illustrated below:

// 'leadBitmap' is a colored LBitmapBase 
// 'leadFile' is LFile object 
// Setup FloydStein dithering: 
leadBitmap.SetDitheringMethod(FLOYD_STEIN_DITHERING); 
SAVEFILEOPTION saveOptions = {0}; 
leadFile.GetDefaultSaveFileOption(&saveOptions, sizeof(SAVEFILEOPTION)); 
saveOptions.Flags |= ESO_USEDITHERINGMETHOD; 
leadFile.Save(FILE_CCITT_GROUP4, 1, 0, 0, &saveOptions); 
// or any other Save overloads or methods

Required DLLs and Libraries

LTFIL
File format DLLs
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.