cache - Methods to Get or Set Image Pixels
status: Method AcquireImagePixels( )returns a pointer to the pixels if they are transferred, otherwise a NULL is returned.;
pixels: Method AcquireOnePixel( )returns a pixel at the specified( x, y );
void DestroyImagePixels( Image *image );
status: Method GetImagePixels( )returns a pointer to the pixels if they are transferred, otherwise a NULL is returned.;
indexes: Method GetIndexes( )returns the indexes associated with the last call to SetImagePixels( )or GetImagePixels( ).;
pixels: Method GetOnePixel( )returns a pixel at the specified( x, y );
pixels: Method GetPixels( )returns the pixels associated with the last call to SetImagePixels( )or GetImagePixels( ).;
unsigned int ModifyCache( Image *image );
Cache ReferenceCache( Cache cache_info );
PixelPacket * SetImagePixels( Image *image, const long x, const long y, const unsigned long columns, const unsigned long rows );
status: Method SyncImagePixels( )returns True if the image pixels are transferred to the in-memory or disk cache otherwise False.;
Method AcquireImagePixels ( ) acquires pixels from the in-memory or disk pixelcache as defined by the geometry parameters. A pointer to the pixels isreturned if the pixels are transferred, otherwise a NULL is returned.;
The format of the AcquireImagePixels ( ) method is:;
const PixelPacket *AcquireImagePixels ( const Image *image, const long x, const long y, const unsigned long columns, const unsigned long rows, ExceptionInfo *exception );
A description of each parameter follows:
status: Method AcquireImagePixels ( ) returns a pointer to the pixels if they are transferred, otherwise a NULL is returned.;
Method AcquireOnePixel ( ) returns a single pixel at the specified ( x, y );
location. The image background color is returned if an error occurs.
The format of the AcquireOnePixel ( ) method is:;
PixelPacket AcquireOnePixel ( const Image image, const long x, const long y, ExceptionInfo exception );
A description of each parameter follows:
pixels: Method AcquireOnePixel ( ) returns a pixel at the specified ( x, y );
location. =over 4
Method DestroyImagePixels ( ) deallocates memory associated with the pixelcache.;
The format of the DestroyImagePixels ( ) method is:;
void DestroyImagePixels ( Image *image );
A description of each parameter follows:
Method GetImagePixels ( ) gets pixels from the in-memory or disk pixel cacheas defined by the geometry parameters. A pointer to the pixels is returnedif the pixels are transferred, otherwise a NULL is returned.;
The format of the GetImagePixels ( ) method is:;
PixelPacket *GetImagePixels ( Image *image, const long x, const long y, const unsigned long columns, const unsigned long rows );
A description of each parameter follows:
status: Method GetImagePixels ( ) returns a pointer to the pixels if they are transferred, otherwise a NULL is returned.;
Method GetIndexes ( ) returns the indexes associated with the last call toSetImagePixels ( ) or GetImagePixels ( ) .;
The format of the GetIndexes ( ) method is:;
IndexPacket *GetIndexes ( const Image *image );
A description of each parameter follows:
indexes: Method GetIndexes ( ) returns the indexes associated with the last call to SetImagePixels ( ) or GetImagePixels ( ) .;
Method GetOnePixel ( ) returns a single pixel at the specified ( x, y ) location.The image background color is returned if an error occurs.;
The format of the GetOnePixel ( ) method is:;
PixelPacket *GetOnePixel ( const Image image, const long x, const long y );
A description of each parameter follows:
pixels: Method GetOnePixel ( ) returns a pixel at the specified ( x, y );
location. =over 4
Method GetPixels ( ) returns the pixels associated with the last call toSetImagePixels ( ) or GetImagePixels ( ) .;
The format of the GetPixels ( ) method is:;
PixelPacket *GetPixels ( const Image image );
A description of each parameter follows:
pixels: Method GetPixels ( ) returns the pixels associated with the last call to SetImagePixels ( ) or GetImagePixels ( ) .;
ModifyCache ( ) ensures that there is only a single reference to the pixelcache to be modified, updating the provided cache pointer to point toa clone of the original pixel cache if necessary.;
The format of the ModifyCache method is:
unsigned int ModifyCache ( Image *image );
A description of each parameter follows:
ReferenceCache ( ) increments the reference count associated with the pixelcache returning a pointer to the cache.;
The format of the ReferenceCache method is:
Cache ReferenceCache ( Cache cache_info );
A description of each parameter follows:
Method SetImagePixels ( ) allocates an area to store image pixels as definedby the region rectangle and returns a pointer to the area. This area issubsequently transferred from the pixel cache with SyncImagePixels ( ) . Apointer to the pixels is returned if the pixels are transferred, otherwisea NULL is returned.;
The format of the SetImagePixels ( ) method is:;
PixelPacket *SetImagePixels ( Image *image, const long x, const long y, const unsigned long columns, const unsigned long rows );
A description of each parameter follows:
Method SyncImagePixels ( ) saves the image pixels to the in-memory or diskcache. The method returns True if the pixel region is synced, otherwiseFalse.;
The format of the SyncImagePixels ( ) method is:;
unsigned int SyncImagePixels ( Image *image );
A description of each parameter follows:
status: Method SyncImagePixels ( ) returns True if the image pixels are transferred to the in-memory or disk cache otherwise False.;