DLJPGImage Class Reference

JPEG image I/O class. More...

#include <DLJPGImage.h>

Inheritance diagram for DLJPGImage:

DLBaseImage List of all members.

Public Member Functions

int dlGetActualColors () const
DLColorCountsdlGetPalette () const
int dlGetColorSpace () const
void dlAllocatePalette (int numberOfColors)
void dlFreePalette ()
void dlLoadImage (const char *filename, DLImage &image)
DLImage dlLoadImage (const void *pMemLoc, int nSize)
DLImage dlLoadImage (const char *filename)
DLImage dlLoadImageAtPage (const char *filename, int pageNumber)
DLImage dlLoadImageAtPage (const void *pMemLoc, int nSize, int pageNumber)
void * dlSaveImageToMem (int &nSize, const DLImage &image)
void dlSaveImage (const char *filename, const DLImage &image)
bool dlSupportImageFile (const char *filename)
bool dlSupportImageBuffer (const void *pMemLoc, int size)
int dlGetTotalPages (void *pMemLoc, int nSize)
int dlGetTotalPages (const char *filename)

Static Public Member Functions

static DLJPGImagecreateImageReader ()
static void * dlSaveImageToMem (int &nSize, const DLImage &image, const int imageQuality)
static void dlSaveImage (const char *filename, const DLImage &image, const int imageQuality)

Protected Member Functions

virtual ~DLJPGImage ()

Detailed Description

JPEG image I/O class.

Implements loading and saving for the JPEG image format, and is used by DLImageFactory. See DLImage for the typical interface for loading and saving images.

Definition at line 40 of file DLJPGImage.h.


Constructor & Destructor Documentation

virtual DLJPGImage::~DLJPGImage (  )  [protected, virtual]

Default DLJPGImage Destructor


Member Function Documentation

static DLJPGImage* DLJPGImage::createImageReader (  )  [static]

Returns:
A handle to the DLJPGImage object

int DLJPGImage::dlGetActualColors (  )  const [inline]

Returns:
actual number of colors

Definition at line 124 of file DLJPGImage.h.

DLColorCounts* DLJPGImage::dlGetPalette (  )  const [inline]

Definition at line 126 of file DLJPGImage.h.

int DLJPGImage::dlGetColorSpace (  )  const [inline]

Returns:
color space

Definition at line 131 of file DLJPGImage.h.

void DLJPGImage::dlAllocatePalette ( int  numberOfColors  ) 

void DLJPGImage::dlFreePalette (  ) 

void DLJPGImage::dlLoadImage ( const char *  filename,
DLImage image 
)

Load JPG image

Parameters:
[in] filename name of file to load
[out] image DLImage object passed by reference; will be overwritten to contain image from JPG file.

DLImage DLJPGImage::dlLoadImage ( const void *  pMemLoc,
int  nSize 
) [virtual]

Load JPG image from memory

Parameters:
pMemLoc pointer to beginning of memory buffer
nSize size of the memory buffer in bytes
Returns:
DLImage of the JPG image

Implements DLBaseImage.

DLImage DLJPGImage::dlLoadImage ( const char *  filename  )  [virtual]

Load JPG Image

Parameters:
filename name of JPG image file to be opened
Returns:
DLImage of the JPG Image

Implements DLBaseImage.

DLImage DLJPGImage::dlLoadImageAtPage ( const char *  filename,
int  pageNumber 
) [virtual]

Loads a particular page from a multiple page image.

Parameters:
filename name of image file to be opened
pageNumber number of page to be opened
Returns:
DLImage of a page in a JPG file

Implements DLBaseImage.

DLImage DLJPGImage::dlLoadImageAtPage ( const void *  pMemLoc,
int  nSize,
int  pageNumber 
) [virtual]

Loads a particular page from a multiple page image in a memory buffer into a DLImage

Parameters:
pMemLoc pointer to beginning of memory image buffer to be opened
nSize size of the memory buffer in bytes
pageNumber number of page to be opened
Returns:
DLImage of a page in a JPG buffer

Implements DLBaseImage.

void* DLJPGImage::dlSaveImageToMem ( int &  nSize,
const DLImage image 
) [virtual]

Save JPG Image to memory. See documentation for DLImage code example

Parameters:
[out] nSize size of tiff file in memory
[in] image DLImage* JPG Image
Returns:
pointer to the memory buffer in which the image was saved

Implements DLBaseImage.

static void* DLJPGImage::dlSaveImageToMem ( int &  nSize,
const DLImage image,
const int  imageQuality 
) [static]

Save JPG Image to memory buffer with specific quality factor. The quality parameter must be in the range [0,100] where 0 gives the lowest image quality and highest compression, and 100 gives the best image quality but least effective compression. See below code example for use:

 DLImage img ("a.jpg");
 int size;
 void *buff = (DLJPGImage::createImageReader())->dlSaveImageToMem(size, img, 90);
size will now contain the size of the memory block stored in buff
Parameters:
[out] nSize size of jpg file in memory
[in] image DLImage* JPG Image
[in] imageQuality int qualitiy value [0,100] (see above for explanation)
Returns:
pointer to the memory buffer in which the image was saved

void DLJPGImage::dlSaveImage ( const char *  filename,
const DLImage image 
) [virtual]

Save JPG Image. Uses default quality factor of 95.

Parameters:
filename name of file to be saved
image image to be saved

Implements DLBaseImage.

static void DLJPGImage::dlSaveImage ( const char *  filename,
const DLImage image,
const int  imageQuality 
) [static]

Save JPG Image with specific quality factor. The quality parameter must be in the range [0,100] where 0 gives the lowest image quality and highest compression, and 100 gives the best image quality but least effective compression.

Parameters:
filename name of file to be saved
image image to be saved
imageQuality int image compression quality

bool DLJPGImage::dlSupportImageFile ( const char *  filename  )  [virtual]

Determines if the image file is in the JPG format and is supported for loading by DLJPGImage.

Parameters:
filename name of file to check
Returns:
boolean: true if supported

Implements DLBaseImage.

bool DLJPGImage::dlSupportImageBuffer ( const void *  pMemLoc,
int  size 
) [virtual]

Determines if the memory buffer is in the JPEG format and is supported for loading by DLJPGImage.

Returns:
boolean: true if supported

Implements DLBaseImage.

int DLJPGImage::dlGetTotalPages ( void *  pMemLoc,
int  nSize 
) [virtual]

Get the total number of pages in the image

Parameters:
pMemLoc pointer to beginning of memory buffer
nSize buffer size in bytes
Returns:
number of pages

Implements DLBaseImage.

int DLJPGImage::dlGetTotalPages ( const char *  filename  )  [virtual]

Get the total number of pages in the image

Parameters:
filename file name
Returns:
number of pages

Implements DLBaseImage.


The documentation for this class was generated from the following file:

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