Ogre::Image Class Reference

Class representing an image file. More...

#include <OgreImage.h>

Inheritance diagram for Ogre::Image:

Public Types
typedef Ogre::Box	Box
enum	Filter {   FILTER_NEAREST , FILTER_LINEAR , FILTER_BILINEAR , FILTER_BOX ,   FILTER_TRIANGLE , FILTER_BICUBIC , FILTER_GAUSSIAN , FILTER_GAUSSIAN_HIGH }
typedef Ogre::Rect	Rect

Public Member Functions
	Image ()
	Standard constructor.
	Image (const Image &img)
	Copy-constructor - copies all the data from the target image.
virtual	~Image ()
	Standard destructor.
Image &	combineTwoImagesAsRGBA (const Image &rgb, const Image &alpha, PixelFormat format=PF_BYTE_RGBA)
	Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).
DataStreamPtr	encode (const String &formatextension)
	Encode the image and return a stream to the data.
Image &	flipAroundX ()
	Flips (mirrors) the image around the X-axis.
Image &	flipAroundY ()
	Flips (mirrors) the image around the Y-axis.
void	freeMemory ()
	Delete all the memory held by this image, if owned by this image (not dynamic)
bool	generateMipmaps (bool gammaCorrected, Filter filter=FILTER_BILINEAR)
	Generates the mipmaps for this image.
uchar	getBPP () const
	Returns the number of bits per pixel.
ColourValue	getColourAt (size_t x, size_t y, size_t z) const
	Get colour value from a certain location in the image.
const uchar *	getData () const
	Returns a const pointer to the internal image buffer.
uchar *	getData (void)
	Returns a pointer to the internal image buffer.
uint32	getDepth (void) const
	Gets the depth of the image.
PixelFormat	getFormat () const
	Returns the image format.
bool	getHasAlpha () const
	Returns true if the image has an alpha component.
uint32	getHeight (void) const
	Gets the height of the image in pixels.
size_t	getNumFaces (void) const
	Get the number of faces of the image.
uint8	getNumMipmaps () const
	Returns the number of mipmaps contained in the image.
PixelBox	getPixelBox (size_t face=0, size_t mipmap=0) const
	Get a PixelBox encapsulating the image data of a mipmap.
size_t	getRowSpan (void) const
	Gets the physical width in bytes of each row of pixels.
size_t	getSize () const
	Returns the size of the data buffer.
uint32	getWidth (void) const
	Gets the width of the image in pixels.
bool	hasFlag (const ImageFlags imgFlag) const
	Returns true if the image has the appropriate flag set.
Image &	load (const String &filename, const String &groupName)
	Loads an image file.
Image &	load (DataStreamPtr &stream, const String &type=BLANKSTRING)
	Loads an image file from a stream.
Image &	loadDynamicImage (uchar *data, uint32 width, uint32 height, PixelFormat format)
	Stores a pointer to raw data in memory.
Image &	loadDynamicImage (uchar *data, uint32 width, uint32 height, uint32 depth, PixelFormat format, bool autoDelete=false, size_t numFaces=1, uint8 numMipMaps=0)
	Stores a pointer to raw data in memory.
Image &	loadRawData (DataStreamPtr &stream, uint32 width, uint32 height, PixelFormat format)
	Loads raw data from a stream.
Image &	loadRawData (DataStreamPtr &stream, uint32 width, uint32 height, uint32 depth, PixelFormat format, size_t numFaces=1, size_t numMipMaps=0)
	Loads raw data from a stream.
Image &	loadTwoImagesAsRGBA (const String &rgbFilename, const String &alphaFilename, const String &groupName, PixelFormat format=PF_BYTE_RGBA)
	Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).
Image &	loadTwoImagesAsRGBA (DataStreamPtr &rgbStream, DataStreamPtr &alphaStream, PixelFormat format=PF_BYTE_RGBA, const String &rgbType=BLANKSTRING, const String &alphaType=BLANKSTRING)
	Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).
void	operator delete (void *ptr)
void	operator delete (void *ptr, const char *, int, const char *)
void	operator delete (void *ptr, void *)
void	operator delete[] (void *ptr)
void	operator delete[] (void *ptr, const char *, int, const char *)
void *	operator new (size_t sz)
void *	operator new (size_t sz, const char *file, int line, const char *func)
	operator new, with debug line info
void *	operator new (size_t sz, void *ptr)
	placement operator new
void *	operator new[] (size_t sz)
void *	operator new[] (size_t sz, const char *file, int line, const char *func)
	array operator new, with debug line info
Image &	operator= (const Image &img)
	Assignment operator - copies all the data from the target image.
void	resize (ushort width, ushort height, Filter filter=FILTER_BILINEAR)
	Resize a 2D image, applying the appropriate filter.
void	save (const String &filename)
	Save the image as a file.
void	setColourAt (ColourValue const &cv, size_t x, size_t y, size_t z)
	Set colour value at a certain location in the image.

Static Public Member Functions
static void	applyGamma (uchar *buffer, Real gamma, size_t size, uchar bpp)
	Does gamma adjustment.
static size_t	calculateSize (size_t mipmaps, size_t faces, uint32 width, uint32 height, uint32 depth, PixelFormat format)
	Static function to calculate size in bytes from the number of mipmaps, faces and the dimensions.
static String	getFileExtFromMagic (DataStreamPtr stream)
	Static function to get an image type string from a stream via magic numbers.
static void	scale (const PixelBox &src, const PixelBox &dst, Filter filter=FILTER_BILINEAR)
	Scale a 1D, 2D or 3D image volume.

Detailed Description

Class representing an image file.

Remarks

The Image class usually holds uncompressed image data and is the only object that can be loaded in a texture. Image objects handle image data decoding themselves by the means of locating the correct Codec object for each data type.

Typically, you would want to use an Image object to load a texture when extra processing needs to be done on an image before it is loaded or when you want to blit to an existing texture.

Member Typedef Documentation

Box

typedef Ogre::Box Ogre::Image::Box

Rect

typedef Ogre::Rect Ogre::Image::Rect

Member Enumeration Documentation

Filter

enum Ogre::Image::Filter

Enumerator
FILTER_NEAREST
FILTER_LINEAR
FILTER_BILINEAR
FILTER_BOX
FILTER_TRIANGLE
FILTER_BICUBIC
FILTER_GAUSSIAN	Applies gaussian filter over the image, then a point sampling reduction This is done at the same time (i.e. we don't blur pixels we ignore).
FILTER_GAUSSIAN_HIGH	Applies gaussian filter over the image, then bilinear downsamples. This prevents certain artifacts for some images when using FILTER_GAUSSIAN, like biasing towards certain direction. Not supported by cubemaps.

Constructor & Destructor Documentation

Image() [1/2]

Ogre::Image::Image

(

)

Standard constructor.

Image() [2/2]

Ogre::Image::Image

(

const Image &

img

)

Copy-constructor - copies all the data from the target image.

~Image()

virtual Ogre::Image::~Image ( )

virtual

Standard destructor.

Member Function Documentation

applyGamma()

static void Ogre::Image::applyGamma ( uchar *  buffer, Real  gamma, size_t  size, uchar  bpp  )

static

Does gamma adjustment.

Note

Basic algo taken from Titan Engine, copyright (c) 2000 Ignacio Castano Iguado

calculateSize()

static size_t Ogre::Image::calculateSize ( size_t  mipmaps, size_t  faces, uint32  width, uint32  height, uint32  depth, PixelFormat  format  )

static

Static function to calculate size in bytes from the number of mipmaps, faces and the dimensions.

combineTwoImagesAsRGBA()

Image & Ogre::Image::combineTwoImagesAsRGBA	(	const Image &	rgb,
		const Image &	alpha,
		PixelFormat	format = PF_BYTE_RGBA
	)

Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).

Parameters

rgb	Image supplying the RGB channels (any alpha is ignored)
alpha	Image supplying the alpha channel. If a luminance image the single channel is used directly, if an RGB image then the values are converted to greyscale.
format	The destination format

encode()

DataStreamPtr Ogre::Image::encode

(

const String &

formatextension

)

Encode the image and return a stream to the data.

Parameters

formatextension

An extension to identify the image format to encode into, e.g. "jpg" or "png"

flipAroundX()

Image & Ogre::Image::flipAroundX

(

)

Flips (mirrors) the image around the X-axis.

Remarks

An example of an original and flipped image:

            flip axis
                |
    originalimg|gmilanigiro
    00000000000|00000000000
    00000000000|00000000000
    00000000000|00000000000
    00000000000|00000000000
    00000000000|00000000000
    

flipAroundY()

Image & Ogre::Image::flipAroundY

(

)

Flips (mirrors) the image around the Y-axis.

Remarks

An example of an original and flipped image:

                
    originalimg
    00000000000
    00000000000
    00000000000
    00000000000
    00000000000
    ------------> flip axis
    00000000000
    00000000000
    00000000000
    00000000000
    00000000000
    originalimg
    

freeMemory()

void Ogre::Image::freeMemory

(

)

Delete all the memory held by this image, if owned by this image (not dynamic)

generateMipmaps()

bool Ogre::Image::generateMipmaps	(	bool	gammaCorrected,
		Filter	filter = FILTER_BILINEAR
	)

Generates the mipmaps for this image.

For Cubemaps, the filtering is seamless; and a gaussian filter is recommended although it's slow.

Remarks

Cannot handle compressed formats. Gaussian filter is implemented with a generic 1-pass convolution matrix, which in turn means it is O( N^N ) instead of a 2-pass filter which is O( 2^N ); where N is the number of taps. The Gaussian filter is 5x5

Parameters

gammaCorrected	True if the filter should be applied in linear space.
filter	The type of filter to use.

Returns

False if failed to generate and mipmaps properties won't be changed. True on success.

getBPP()

uchar Ogre::Image::getBPP

(

)

const

Returns the number of bits per pixel.

getColourAt()

ColourValue Ogre::Image::getColourAt	(	size_t	x,
		size_t	y,
		size_t	z
	)		const

Get colour value from a certain location in the image.

The z coordinate is only valid for cubemaps and volume textures. This uses the first (largest) mipmap.

getData() [1/2]

const uchar * Ogre::Image::getData

(

)

const

Returns a const pointer to the internal image buffer.

Remarks

Be careful with this method. You will almost certainly prefer to use getPixelBox, especially with complex images which include many faces or custom mipmaps.

getData() [2/2]

uchar * Ogre::Image::getData

(

void

)

Returns a pointer to the internal image buffer.

Remarks

Be careful with this method. You will almost certainly prefer to use getPixelBox, especially with complex images which include many faces or custom mipmaps.

getDepth()

uint32 Ogre::Image::getDepth

(

void

)

const

Gets the depth of the image.

getFileExtFromMagic()

static String Ogre::Image::getFileExtFromMagic ( DataStreamPtr  stream )

static

Static function to get an image type string from a stream via magic numbers.

getFormat()

PixelFormat Ogre::Image::getFormat

(

)

const

Returns the image format.

getHasAlpha()

bool Ogre::Image::getHasAlpha

(

)

const

Returns true if the image has an alpha component.

getHeight()

uint32 Ogre::Image::getHeight

(

void

)

const

Gets the height of the image in pixels.

getNumFaces()

size_t Ogre::Image::getNumFaces

(

void

)

const

Get the number of faces of the image.

This is usually 6 for a cubemap, and 1 for a normal image.

getNumMipmaps()

uint8 Ogre::Image::getNumMipmaps

(

)

const

Returns the number of mipmaps contained in the image.

getPixelBox()

PixelBox Ogre::Image::getPixelBox	(	size_t	face = 0,
		size_t	mipmap = 0
	)		const

Get a PixelBox encapsulating the image data of a mipmap.

getRowSpan()

size_t Ogre::Image::getRowSpan

(

void

)

const

Gets the physical width in bytes of each row of pixels.

getSize()

size_t Ogre::Image::getSize

(

)

const

Returns the size of the data buffer.

getWidth()

uint32 Ogre::Image::getWidth

(

void

)

const

Gets the width of the image in pixels.

hasFlag()

bool Ogre::Image::hasFlag

(

const ImageFlags

imgFlag

)

const

Returns true if the image has the appropriate flag set.

load() [1/2]

Image & Ogre::Image::load	(	const String &	filename,
		const String &	groupName
	)

Loads an image file.

Remarks

This method loads an image into memory. Any format for which an associated ImageCodec is registered can be loaded. This can include complex formats like DDS with embedded custom mipmaps, cube faces and volume textures. The type can be determined by calling getFormat().

Parameters

filename	Name of an image file to load.
groupName	Name of the resource group to search for the image

Note

The memory associated with this buffer is destroyed with the Image object.

load() [2/2]

Image & Ogre::Image::load	(	DataStreamPtr &	stream,
		const String &	type = BLANKSTRING
	)

Loads an image file from a stream.

Remarks

This method works in the same way as the filename-based load method except it loads the image from a DataStream object. This DataStream is expected to contain the encoded data as it would be held in a file. Any format for which an associated ImageCodec is registered can be loaded. This can include complex formats like DDS with embedded custom mipmaps, cube faces and volume textures. The type can be determined by calling getFormat().

Parameters

stream	The source data.
type	The type of the image. Used to decide what decompression codec to use. Can be left blank if the stream data includes a header to identify the data.

See also

Image::load( const String& filename )

loadDynamicImage() [1/2]

Image & Ogre::Image::loadDynamicImage ( uchar *  data, uint32  width, uint32  height, PixelFormat  format  )

inline

Stores a pointer to raw data in memory.

The pixel format has to be specified.

Remarks

This method loads an image into memory held in the object. The pixel format will be either greyscale or RGB with an optional Alpha component. The type can be determined by calling getFormat().

Note

Whilst typically your image is likely to be a simple 2D image, you can define complex images including cube maps and images including custom mip levels. The layout of the internal memory should be:

• face 0, mip 0 (top), width x height
• face 0, mip 1, width/2 x height/2
• face 0, mip 2, width/4 x height/4
• .. remaining mips for face 0 ..
• face 1, mip 0 (top), width x height (x depth)</li
• .. and so on.

Of course, you will never have multiple faces (cube map) and depth too.

Parameters

data	The data pointer
width	Width of image
height	Height of image
format	Pixel Format

Note

The memory associated with this buffer is NOT destroyed with the Image object.

Remarks

This function is deprecated; one should really use the Image::loadDynamicImage(data, width, height, depth, format, ...) to be compatible with future Ogre versions.

loadDynamicImage() [2/2]

Image & Ogre::Image::loadDynamicImage	(	uchar *	data,
		uint32	width,
		uint32	height,
		uint32	depth,
		PixelFormat	format,
		bool	autoDelete = false,
		size_t	numFaces = 1,
		uint8	numMipMaps = 0
	)

Stores a pointer to raw data in memory.

The pixel format has to be specified.

Remarks

This method loads an image into memory held in the object. The pixel format will be either greyscale or RGB with an optional Alpha component. The type can be determined by calling getFormat().

Note

Whilst typically your image is likely to be a simple 2D image, you can define complex images including cube maps, volume maps, and images including custom mip levels. The layout of the internal memory should be:

• face 0, mip 0 (top), width x height (x depth)
• face 0, mip 1, width/2 x height/2 (x depth/2)
• face 0, mip 2, width/4 x height/4 (x depth/4)
• .. remaining mips for face 0 ..
• face 1, mip 0 (top), width x height (x depth)</li
• .. and so on.

Of course, you will never have multiple faces (cube map) and depth too.

Parameters

data	The data pointer
width	Width of image
height	Height of image
depth	Image Depth (in 3d images, numbers of layers, otherwise 1)
format	Pixel Format
autoDelete	If memory associated with this buffer is to be destroyed with the Image object. Note: it's important that if you set this option to true, that you allocated the memory using OGRE_ALLOC_T with a category of MEMCATEGORY_GENERAL to ensure the freeing of memory matches up.
numFaces	The number of faces the image data has inside (6 for cubemaps, 1 otherwise)
numMipMaps	The number of mipmaps the image data has inside

Note

The memory associated with this buffer is NOT destroyed with the Image object, unless autoDelete is set to true.

Remarks

The size of the buffer must be numFaces*PixelUtil::getMemorySize(width, height, depth, format)

loadRawData() [1/2]

Image & Ogre::Image::loadRawData ( DataStreamPtr &  stream, uint32  width, uint32  height, PixelFormat  format  )

inline

Loads raw data from a stream.

The pixel format has to be specified.

Remarks

This function is deprecated; one should really use the Image::loadRawData(stream, width, height, depth, format, ...) to be compatible with future Ogre versions.

Note

Whilst typically your image is likely to be a simple 2D image, you can define complex images including cube maps and images including custom mip levels. The layout of the internal memory should be:

• face 0, mip 0 (top), width x height
• face 0, mip 1, width/2 x height/2
• face 0, mip 2, width/4 x height/4
• .. remaining mips for face 0 ..
• face 1, mip 0 (top), width x height (x depth)</li
• .. and so on.

Of course, you will never have multiple faces (cube map) and depth too.

loadRawData() [2/2]

Image & Ogre::Image::loadRawData	(	DataStreamPtr &	stream,
		uint32	width,
		uint32	height,
		uint32	depth,
		PixelFormat	format,
		size_t	numFaces = 1,
		size_t	numMipMaps = 0
	)

Loads raw data from a stream.

See the function loadDynamicImage for a description of the parameters.

Remarks

The size of the buffer must be numFaces*PixelUtil::getMemorySize(width, height, depth, format)

Note

Whilst typically your image is likely to be a simple 2D image, you can define complex images including cube maps and images including custom mip levels. The layout of the internal memory should be:

• face 0, mip 0 (top), width x height (x depth)
• face 0, mip 1, width/2 x height/2 (x depth/2)
• face 0, mip 2, width/4 x height/4 (x depth/4)
• .. remaining mips for face 0 ..
• face 1, mip 0 (top), width x height (x depth)</li
• .. and so on.

Of course, you will never have multiple faces (cube map) and depth too.

loadTwoImagesAsRGBA() [1/2]

Image & Ogre::Image::loadTwoImagesAsRGBA	(	const String &	rgbFilename,
		const String &	alphaFilename,
		const String &	groupName,
		PixelFormat	format = PF_BYTE_RGBA
	)

Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).

Parameters

rgbFilename	Filename of image supplying the RGB channels (any alpha is ignored)
alphaFilename	Filename of image supplying the alpha channel. If a luminance image the single channel is used directly, if an RGB image then the values are converted to greyscale.
groupName	The resource group from which to load the images
format	The destination format

loadTwoImagesAsRGBA() [2/2]

Image & Ogre::Image::loadTwoImagesAsRGBA	(	DataStreamPtr &	rgbStream,
		DataStreamPtr &	alphaStream,
		PixelFormat	format = PF_BYTE_RGBA,
		const String &	rgbType = BLANKSTRING,
		const String &	alphaType = BLANKSTRING
	)

Utility method to combine 2 separate images into this one, with the first image source supplying the RGB channels, and the second image supplying the alpha channel (as luminance or separate alpha).

Parameters

rgbStream	Stream of image supplying the RGB channels (any alpha is ignored)
alphaStream	Stream of image supplying the alpha channel. If a luminance image the single channel is used directly, if an RGB image then the values are converted to greyscale.
format	The destination format
rgbType	The type of the RGB image. Used to decide what decompression codec to use. Can be left blank if the stream data includes a header to identify the data.
alphaType	The type of the alpha image. Used to decide what decompression codec to use. Can be left blank if the stream data includes a header to identify the data.

operator delete() [1/3]

template<class Alloc >

void Ogre::AllocatedObject< Alloc >::operator delete ( void *  ptr )

inlineinherited

operator delete() [2/3]

template<class Alloc >

void Ogre::AllocatedObject< Alloc >::operator delete ( void *  ptr, const char *  , int  , const char *    )

inlineinherited

operator delete() [3/3]

template<class Alloc >

void Ogre::AllocatedObject< Alloc >::operator delete ( void *  ptr, void *    )

inlineinherited

operator delete[]() [1/2]

template<class Alloc >

void Ogre::AllocatedObject< Alloc >::operator delete[] ( void *  ptr )

inlineinherited

operator delete[]() [2/2]

template<class Alloc >

void Ogre::AllocatedObject< Alloc >::operator delete[] ( void *  ptr, const char *  , int  , const char *    )

inlineinherited

operator new() [1/3]

template<class Alloc >

void * Ogre::AllocatedObject< Alloc >::operator new ( size_t  sz )

inlineinherited

operator new() [2/3]

template<class Alloc >

void * Ogre::AllocatedObject< Alloc >::operator new ( size_t  sz, const char *  file, int  line, const char *  func  )

inlineinherited

operator new, with debug line info

operator new() [3/3]

template<class Alloc >

void * Ogre::AllocatedObject< Alloc >::operator new ( size_t  sz, void *  ptr  )

inlineinherited

placement operator new

operator new[]() [1/2]

template<class Alloc >

void * Ogre::AllocatedObject< Alloc >::operator new[] ( size_t  sz )

inlineinherited

operator new[]() [2/2]

template<class Alloc >

void * Ogre::AllocatedObject< Alloc >::operator new[] ( size_t  sz, const char *  file, int  line, const char *  func  )

inlineinherited

array operator new, with debug line info

operator=()

Image & Ogre::Image::operator=

(

const Image &

img

)

Assignment operator - copies all the data from the target image.

resize()

void Ogre::Image::resize	(	ushort	width,
		ushort	height,
		Filter	filter = FILTER_BILINEAR
	)

Resize a 2D image, applying the appropriate filter.

save()

void Ogre::Image::save

(

const String &

filename

)

Save the image as a file.

Remarks

Saving and loading are implemented by back end (sometimes third party) codecs. Implemented saving functionality is more limited than loading in some cases. Particularly DDS file format support is currently limited to true colour or single channel float32, square, power of two textures with no mipmaps. Volumetric support is currently limited to DDS files.

scale()

static void Ogre::Image::scale ( const PixelBox &  src, const PixelBox &  dst, Filter  filter = FILTER_BILINEAR  )

static

Scale a 1D, 2D or 3D image volume.

Parameters

src	PixelBox containing the source pointer, dimensions and format
dst	PixelBox containing the destination pointer, dimensions and format
filter	Which filter to use

Remarks

This function can do pixel format conversion in the process.

Note

dst and src can point to the same PixelBox object without any problem

setColourAt()

void Ogre::Image::setColourAt	(	ColourValue const &	cv,
		size_t	x,
		size_t	y,
		size_t	z
	)

Set colour value at a certain location in the image.

The z coordinate is only valid for cubemaps and volume textures. This uses the first (largest) mipmap.

---

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

• OgreImage.h