C# Class Accord.Imaging.Formats.PNMCodec

PNM image format decoder.

The PNM (an acronym derived from "Portable Any Map") format is an abstraction of the PBM, PGM and PPM formats. I.e. the name "PNM" refers collectively to PBM (binary images), PGM (grayscale images) and PPM (color image) image formats.

Image in PNM format can be found in different scientific databases and laboratories, for example Yale Face Database and AT&T Face Database.

Only PNM images of P5 (binary encoded PGM) and P6 (binary encoded PPM) formats are supported at this point.

The maximum supported pixel value is 255 at this point.

The class supports only one-frame PNM images. As it is specified in format specification, the multi-frame PNM images has appeared starting from 2000.

Inheritance: IImageDecoder

Afficher le fichier Open project: accord-net/framework Class Usage Examples

Méthodes publiques

Méthode	Description
Close ( ) : void	Close decoding of previously opened stream. The method does not close stream itself, but just closes decoding cleaning all associated data with it.
DecodeFrame ( int frameIndex, ImageInfo &imageInfo ) : Bitmap	Decode specified frame.
DecodeSingleFrame ( Stream stream ) : Bitmap	Decode first frame of PNM image.
Open ( Stream stream ) : int	Open specified stream.

Private Methods

Méthode	Description
ReadHeader ( Stream stream ) : PNMImageInfo
ReadImageFrame ( Stream stream, PNMImageInfo imageInfo ) : Bitmap
ReadIntegerValue ( Stream stream ) : int
ReadP5Image ( Stream stream, int width, int height, int maxValue ) : Bitmap
ReadP6Image ( Stream stream, int width, int height, int maxValue ) : Bitmap
ReadUntilSpace ( Stream stream, byte buffer, int start ) : int
SkipSpaces ( Stream stream ) : byte

Method Details

Close() public méthode

Close decoding of previously opened stream.

The method does not close stream itself, but just closes decoding cleaning all associated data with it.

public Close ( ) : void
Résultat	void

DecodeFrame() public méthode

Decode specified frame.

No image stream was opened previously. Stream does not contain frame with specified index. The stream contains invalid (broken) PNM image.

public DecodeFrame ( int frameIndex, ImageInfo &imageInfo ) : Bitmap
frameIndex	int	Image frame to decode.
imageInfo	ImageInfo	Receives information about decoded frame.
Résultat	System.Drawing.Bitmap

DecodeSingleFrame() public méthode

Decode first frame of PNM image.

Not a PNM image format. Format of the PNM image is not supported. The stream contains invalid (broken) PNM image.

public DecodeSingleFrame ( Stream stream ) : Bitmap
stream	Stream	Source stream, which contains encoded image.
Résultat	System.Drawing.Bitmap

Open() public méthode

Open specified stream.

Not a PNM image format. Format of the PNM image is not supported. The stream contains invalid (broken) PNM image.

public Open ( Stream stream ) : int
stream	Stream	Stream to open.
Résultat	int