Gr Namespace Reference

Static image classes. More...

Namespaces
	Avc
	Classes for decoding H.264 parameter sets.
	ColourSpace
	Provides rgb/yuv colourspace mapping functions.
	imagebuffer
	A namespace for low-level free functions that operate on container classes that are Gr::ImageBuffer candidates.
	imp
	A private implementation namespace.
	traits
	A namespace for traits classes.

Classes
class	Colour
	A simple rgb colour structure. More...
struct	add_size
class	Glyph
	A class for mapping characters to 8x8 glyphs. More...
class	Histogram
	A class that does histogram equalisation for eight-bit samples. More...
class	Image
	A class holding shared read-only image data (Gr::ImageBuffer) and its associated image type (Gr::ImageType). More...
class	ImageConverter
	An image format converter that can convert to and from the raw and jpeg formats (only), with scaling and monochrome options. More...
class	ImageData
	A holder for image data, having eight bits per sample and one or three channels. More...
class	ImageDataWrapper
	A class that wraps a read-only image buffer with a few methods that are similar to those of Gr::ImageData. More...
class	ImageDataWriter
class	ImageDecoder
	An interface for decoding encoded images into a raw format. More...
class	ImageType
	An encapsulation of image type, including width, height and number of channels, with support for a string form that encodes the same information. More...
class	Jpeg
	A scoping class for other jpeg classes. More...
class	JpegInfo
	Provides some basic information about a jpeg image without full decoding. More...
class	JpegReader
	A read interface for libjpeg. More...
class	JpegWriter
	A write interface for libjpeg. More...
class	JpegBufferSource
	A libjpeg 'decompression source manager' that reads from Gr::ImageBuffer. More...
class	JpegBufferDestination
	A libjpeg 'decompression destination manager' that writes to Gr::ImageBuffer. More...
class	JpegReaderImp
	A private implementation class for Gr::JpegReader. More...
class	JpegWriterImp
	A private pimple class for Gr::JpegWriter. More...
class	LineDrawImp
	A low-level line-drawing class used in the implementation of Gr::LineDraw. More...
class	LineDraw
	A class template for drawing lines in terms of separate horizontal line segments. More...
class	Png
	A static class providing information about the png library. More...
class	PngInfo
	A class that reads a png header in order to provide the image dimensions. More...
class	PngReader
	A read interface for libpng. More...
class	PngWriter
	An interface for writing a raw dgb image as a png file. More...
class	PngReaderImp
	A private pimple-pattern class for Gr::PngReader. More...
class	PngWriterImp
	A private pimple-pattern class for Gr::PngWriter. More...
class	PngImp
	A private base class that manages png_struct and png_info structures, and handles error callbacks. More...
class	PngTagsImp
	A Gr::PngWriter implementation class that holds tags. More...
class	PnmInfo
	A structure holding portable-anymap metadata. More...
class	PnmReader
	A static interface for reading portable-anymap (pnm) files. More...
class	ScalerImp
	A base class for Gr::Scaler that does scaling using the Bresenham algorithm, but limited to the first quadrant. More...
class	Scaler
	A class that allows for iterating over one integer range while accessing values from another, with no requirement for one range to be a multiple of the other, eg. More...

Typedefs
typedef Vectors	ImageBuffer
	An ImageBuffer is used to hold raw image data, typically in more than one chunk. More...
typedef unsigned char	jpeg_byte
	Equivalent to libjpeg JSAMPLE. A static-assert checks the size.
typedef std::vector < std::vector< char > >	Vectors
	A candidate for Gr::ImageBuffer that uses nested std::vectors.

Functions
bool	operator== (const Colour &p, const Colour &q)
bool	operator!= (const Colour &p, const Colour &q)
void	swap (Colour &p, Colour &q)
std::ostream &	operator<< (std::ostream &stream, const Colour &colour)
int	scaled (int n, int scale)
size_t	sizet (int a)
size_t	sizet (int a, int b)
size_t	sizet (int a, int b, int c)
std::ostream &	operator<< (std::ostream &stream, const ImageType &s)

Detailed Description

Static image classes.

Key classes are:

• ImageData
• JpegReader
• PngReader
• ImageDecoder
• Image

Typedef Documentation

typedef Vectors Gr::ImageBuffer

An ImageBuffer is used to hold raw image data, typically in more than one chunk.

The (extrinsic) data format can be 'raw', jpeg, png, pnm, etc.

In the 'raw' format each chunk contains exactly one row of image pixels ('segmented'), or alternatively the first chunk contains the whole image ('contiguous'). The Gr::ImageData class is normally used to wrap image buffers that are in the raw format.

Free functions in the Gr::imagebuffer namespace are used for low-level operations on the contrete class, and a traits class in the Gr::traits namespace is used to define associated streambuf and iterator types. Standard streaming operators are also defined.

The current definition is a vector-of-vectors, but a vector of malloced buffers might be a good alternative. Classes affected by the choice of image buffer type include Gr::ImageData, GNet::SocketProtocol, G::Publisher and G::FatPipe.

Definition at line 47 of file grimagebuffer.h.