CImageReadFormat Class Reference

Inheritance diagram for CImageReadFormat:

Public Member Functions
virtual bool16	Open (IPMStream *)
virtual bool16	GetImageAttributes (IImageAttributes *)
virtual bool16	GetGraphicLayerInfo (IGraphicLayerInfo *)
virtual bool16	Close ()
virtual bool16	CanRead (IPMStream *)
virtual bool16	SetFormatOption (uint32, uint32 &)
virtual bool16	ReadData (ImageStreamRecord &)

Additional Inherited Members
Public Types inherited from IImageReadFormat
enum	{ kOptionSetImage = 1, kOptionSetLayer = 2 }
enum	{ kOptionUseFullRes = kMaxInt32, kOptionUseSmallestRes = 0 }

Member Function Documentation

virtual bool16 CImageReadFormat::CanRead ( IPMStream *  iPMStream )

inlinevirtual

Called to determine if this reader can process the data in the given stream.

This can be the first call to the image format reader. It does not take place after the Open call. CanRead is the filter's oppurtunity to determine if it in fact can read the stream of data.

Parameters

iPMStream

IN The stream of data

Returns

kTrue if the reader can process the data in the stream, else kFalse

See Also

IPMStream

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::Close ( )

inlinevirtual

Closes this reader.

Returns

kTrue if the method succeeds, else kFalse

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::GetGraphicLayerInfo ( IGraphicLayerInfo *  iLayerInfo )

inlinevirtual

Retrieves the graphic layer information for the current image.

GetGraphicLayerInfo will return kFalse if Open has not been called.

Note: May return kTrue even if layers do not exist.

Parameters

iLayerInfo

OUT The IGraphicLayerInfo object to which the layer information is written

Returns

kTrue if the method succeeds, else kFalse

See Also

IGraphicLayerInfo

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::GetImageAttributes ( IImageAttributes *  iImageAttributes )

inlinevirtual

Retrieves the image attributes for the current image (there may be only one; see note below about multiple images).

GetImageAttributes will return kFalse if Open has not been called.

GetAttributes is a separate method so that IImageReadFormat users can cache the information.

IMPORTANT: If the format supports more than one image per file and there is another image, then the attributes returned are those for the currently set image (via the SetFormatOption call).

Parameters

iImageAttributes

OUT The IImageAttributes object to which the attributes are written

Returns

kTrue if the method succeeds, else kFalse

See Also

IImageAttributes

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::Open ( IPMStream *  iPMStream )

inlinevirtual

Open is the initial call made to the image format reader (after the optional CanRead call, however). The image format reader should do any initialization and check the stream to make sure it really understands the data.

Parameters

iPMStream

IN The stream to read

Returns

kTrue if the reader can process the data in the given stream, else kFalse

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::ReadData ( ImageStreamRecord &  outRecord )

inlinevirtual

Reads data from the image. The data copied into outRecord.buffer is expected to be in the format described by the image attributes.

Note: For 1-bit data each row is bit-padded to a byte boundary.

Parameters

outRecord

IN/OUT Describes the data to be read and holds pointer to the caller-provided buffer to which data is copied

See Also

IImageStream

Implements IImageReadFormat.

virtual bool16 CImageReadFormat::SetFormatOption ( uint32  formatOption, uint32 &  formatData  )

inlinevirtual

Sets an additional format option. It allows the caller to request a particular resolution of image or a specific layer in a multi-layer image, if the IImageReadFormat instance supports the options. Returns kTrue if the reader supports the option and the image contains sufficient data to satisify the request, otherwise kFalse.

Inputs are as follows:

formatOption = kOptionSetImage, formatData = kOptionUseFullRes. The resolution of the main image will be returned in formatData.

formatOption = kOptionSetImage, formatData = kOptionUseSmallestRes. If there are multiple images then the resolution of the smallest subsampled version of the main image will be returned in formatData.

formatOption = kOptionSetImage, formatData = desired resolution. If there are multiple images then the closest resolution which is greater than or equal to the desired resolution will be returned in formatData.

formatOption = kOptionSetLayer, formatData = zero based index of desired layer. Sets the index of the layer to use. No return value will be placed in formatData.

Note: This call must be made after the call to Open().

Parameters

formatOption	IN The selector for the format to use
formatData	IN/OUT The data to use with the specified selector on input; various on output

Returns

kTrue if the method succeeds, else kFalse

Implements IImageReadFormat.