class MImage

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public members:

enum	MImageFilterFormat kNoFormat kHeightFieldBumpFormat kNormalMapBumpFormat kUnknownFormat
enum	MPixelType kUnknown kByte kFloat
	MImage ()
	~MImage ()
MStatus	create (unsigned int width, unsigned int height, unsigned int channels = 4, MPixelType type = kByte )
MStatus	readFromFile ( MString pathname, MPixelType type = kByte )
MStatus	readFromTextureNode (const MObject & fileTextureObject, MPixelType type = kByte )
MStatus	getSize (unsigned int &width, unsigned int &height) const
MPixelType	pixelType () const
unsigned char*	pixels () const
float*	floatPixels () const
void	setPixels (unsigned char* pixels , unsigned int width, unsigned int height)
void	setFloatPixels (float* pixels , unsigned int width, unsigned int height, unsigned int channels = 4)
unsigned int	depth ()
MStatus	getDepthMapSize ( unsigned int &width, unsigned int &height ) const
MStatus	setDepthMap (float * depth , unsigned width, unsigned height )
MStatus	setDepthMap (const MFloatArray & depth , unsigned width, unsigned height )
float *	depthMap ( MStatus *ReturnStatus = NULL ) const
MStatus	readDepthMap ( MString pathname)
MStatus	resize (int width, int height, bool preserveAspectRatio = true)
static bool	filterExists ( MImageFilterFormat sourceFormat, MImageFilterFormat targetFormat)
MStatus	filter ( MImageFilterFormat sourceFormat, MImageFilterFormat targetFormat, double scale = 1.0, double offset = 0.0)
MStatus	writeToFile ( MString pathname, MString outputFormat = kIffStringDefault )
MStatus	writeToFileWithDepth ( MString pathname, MString outputFormat = kIffStringDefault, bool writeDepth = false )
MStatus	release ()
void	verticalFlip ()
void	setRGBA (bool rgbaFormat)
bool	isRGBA () const
bool	haveDepth () const
MStatus	convertPixelFormat ( MPixelType type, double scale = 1.0, double offset = 0.0)

Documentation

Description

MImage is a class which provides access to some of Maya's image manipulation functionality. It has methods for loading and resizing image files in any Maya-supported raster format, including IFF, SGI, Softimage (pic), TIFF (tif), Alias PIX (als), GIF, RLA, JPEG (jpg). The image is stored as an uncompressed array of pixels, that can be read and manipulated directly. For simplicity, the pixels are stored in a RGBA format (4 bytes per pixel).

Functions

MImage:: MImage ()

Description

The default class constructor. Initialize the image.

MImage:: ~MImage ()

Description

Class destructor. Automatically releases the associated image array.

MStatus MImage:: create (unsigned int width, unsigned int height, unsigned int channels, MPixelType type)

Description

Create a new MImage object. Allocates memory for an RGBA array of pixels of the given size. If an object was already in memory, it is released first.

Arguments

• width the desired image's width in pixels.
• height the desired image's height in pixels.
• channels the desired number of channels per pixel. For byte typed images, 4 channels is the only value currently supported.
• type the desired pixel format.

Return Value

• MS::kFailure if there is not enough memory to allocate the array.
• MS::kSuccess otherwise.

MStatus MImage:: readFromFile ( MString pathname, MPixelType type)

Description

Attempt to identify and open the specified image file. Please note that IFF and SGI are the fastest image file formats for reading.

Arguments

• pathname the full path of the image file that should be opened.
• type the desired pixel format. kUnknown attempts to load the native pixel type.

Return Value

• MS::kSuccess if the image file was succesfully identified and opened.
• MS::kFailure otherwise.

MStatus MImage:: readFromTextureNode (const MObject & fileTextureObject, MPixelType type)

Description

Attempt to read the content of the given file texture node. Please note that IFF and SGI are the fastest image file formats for reading.

Arguments

• fileTextureObject an object that refers to the file texture node that should be read.
• type the desired pixel format. kUnknown attempts to load the native image pixel type.

Return Value

• MS::kSuccess if the content of the file texture was read succesfully.
• MS::kFailure otherwise.

MStatus MImage:: release ()

Description

Release the current image. If there is no current image, the call is ignored. An image is always released automatically during destruction, so generally there is no need to call this function manually.

Arguments

• Nil

Return Value

• MS::kSuccess always.

MStatus MImage:: getSize (unsigned int &width, unsigned int &height) const

Description

Get the width and height of the currently opened image.

Arguments

• width the variable that will be set to the image's width in pixels.
• height the variable that will be set to the image's height in pixels.

Return Value

• MS::kFailure if there is no currently opened image.
• MS::kSuccess otherwise.

unsigned char* MImage:: pixels () const

Description

Returns a pointer to the first pixel of the uncompressed pixels array. This array is tightly packed, of size (width * height * depth) bytes. For the moment, pixels are always stored in a RGBA (depth=4 bytes) pixel format.

Arguments

• None

Return Value

• Pointer to the first pixel of the array.
• NULL if no image is currently opened, or the current image has a pixel type other than kByte

float* MImage:: floatPixels () const

Description

Returns a pointer to the first pixel of the uncompressed pixels array. This array is tightly packed, of size (width * height * depth * sizeof( float)) bytes.

Arguments

• None

Return Value

• Pointer to the first pixel of the array.
• NULL if no image is currently opened, or the current image has a pixel type other than kFloat

void MImage:: setPixels (unsigned char* inPixelPtr, unsigned int width, unsigned int height)

Description

Set the pointer to the first pixel of the uncompressed pixels array. This array is tightly packed, of size (width * height * depth) bytes. For the moment, pixels are always stored in a RGBA (depth=4 bytes) pixel format.

Arguments

• pixels the variable containing a block of pixels.
• width the variable that will be set to the image's width in pixels.
• height the variable that will be set to the image's height in pixels.

Return Value

• None.

void MImage:: setFloatPixels (float* inPixelPtr, unsigned int width, unsigned int height, unsigned int channels)

Description

Set the pointer to the first pixel of the uncompressed pixels array. This array is tightly packed, of size (width * height * depth) bytes. For the moment, pixels are always stored in a RGBA (depth=4 bytes) pixel format.

Arguments

• pixels the variable containing a block of pixels.
• width the variable that will be set to the image's width in pixels.
• height the variable that will be set to the image's height in pixels.
• channels the number of channels per pixel.

Return Value

• None.

unsigned int MImage:: depth ()

Description

Get the color depth (in bytes) of the currently opened image.

Arguments

• Nil

Return Value

• The number of bytes used for each pixel.
• 0 if there is no currently opened image.

MStatus MImage:: resize (int width, int height, bool preserveAspectRatio )

Description

Resize the currently opened image to the specified dimension, or to the closest width/height that is preserves the original aspect ratio.

Resizing the image doesn't affect the file it was loaded from; it only affects the pixels in memory. The pixels are automatically filtered and antialiased to avoid a pixelated look.

Arguments

• width the desired width in pixels.
• height the desired height in pixels.
• preserveAspectRatio a boolean specifying whether the aspect ratio should be preserved or not. If this flag is set, the given width and height are interpreted as the maximum dimensions allowable.

Return Value

• MS::kSuccess if the operation was succesful.
• MS::kFailure if there is no currently opened image, the image has a pixel type other than kByte, there is not enough memory to allocate the new pixels array, or in case of any other error.

bool MImage:: filterExists ( MImageFilterFormat sourceFormat, MImageFilterFormat targetFormat)

Description

Return whether or not a given source format can be directly converted to a given target format. See MImage::filter() for more information.

Arguments

• targetFormat the format of the resulting image.
• sourceFormat the format of the source image.

Return Value

• true if the filter exists.
• false otherwise.

MStatus MImage:: filter ( MImageFilterFormat sourceFormat, MImageFilterFormat targetFormat, double scale , double offset )

Description

Modify the content of the image by applying a filter. The dimension of the image remains the same; only the RGBA components get affected.

Currently, only one filter is supported:

sourceFormat = kHeightFieldBumpFormat, targetFormat = kNormalMapBumpFormat: this filter performs a conversion from the height-field bump format (generally used by Maya) to a normal map bump format suitable for interactive display. This filter is typically most useful to support bump mapping in a MPxHwShaderNode-derived hardware shader plug-in, since most high-end graphics adapter support it. For more information regarding this filter, see "A Practical and Robust Bump-mapping Technique for Today's GPUs", by Mark J. Kilgard, NVIDIA Corporation.

The scale argument for this filter can vary from -256.0 to 256.0, although typical values range from 1.0 to 10.0. The offset argument is currently ignored and should be left to the default value of 0.0.

Arguments

• sourceFormat the source format.
• targetFormat desired target format.
• scale vary depending on the source/target format.
• offset vary depending on the source/target format.

Return Value

• MS::kSuccess if the operation was succesful.
• MS::kFailure if this image is empty or uses a format other than kByte.

MStatus MImage:: writeToFile ( MString pathname, MString outputFormat )

Description Save the content of this image in a file. By default, the file is saved in IFF format. Optionally, the file can also be converted in a variety of image formats.

Arguments

• pathname a path to the desired file. This path can be absolute (eg: "C:/temp/bump.iff") or relative (eg: "temp/bump.iff").

• outputFormat the desired image format to save into. This follows the same convention found in the Render Globals window. Examples of valid formats include: als, bmp, cin, gif, jpg, rla, sgi, tga, tif. "iff" is the default, and is the fastest format to save into since it doesn't need any internal conversion.

Return Value

• MS::kFailure if an error occured. Common potential errors include: empty image, invalid output format, invalid pathname, not enough disk space or read-only file.

• MS::kSuccess otherwise.

MStatus MImage:: writeToFileWithDepth ( MString pathname, MString outputFormat , bool writeDepth )

Description

Save the content of this image in a file. By default, the file is saved in IFF format. Optionally, the file can also be converted in a variety of image formats. If write parameter is set to true then any depth information stored in MImage will be written to file. Additionally, if the writeDepth parameter is set true, then the depth map information is written with the file.

IMPORTANT: if the depth map and color map size differ in resolution then the file cannot be written. As well, depth map is only supported if the outputFormat is 'iff'

Arguments

• pathname a path to the desired file. This path can be absolute (eg: "C:/temp/bump.iff") or relative (eg: "temp/bump.iff").

• outputFormat the desired image format to save into. This follows the same convention found in the Render Globals window. Examples of valid formats include: als, bmp, cin, gif, jpg, rla, sgi, tga, tif. "iff" is the default, and is the fastest format to save into since it doesn't need any internal conversion.

• writeDepth writes the depth channel information if it stored in the class data.

Return Value

• MS::kFailure if an error occured. Common potential errors include: empty image, invalid output format, invalid pathname, not enough disk space, read-only file, or depth map resolution does not match color map resolution.

• MS::kSuccess otherwise.

MStatus MImage:: getDepthMapSize ( unsigned int &width, unsigned int &height ) const

Description

Returns the size of the depth map buffer. Note, depth maps can differ in resolution from the color map. This is mainly for oversampling support in image planes. In all other cases, you should insure that depth size matches the color buffer size. You cannot write out an image where the depth map and image map has different resolutions.

<b>Note, depth maps are not support with HDR, or floating point, images. </b>

Arguments

• width - width of the depth map
• height - height of the depth map

Return Value

• MS::kSuccess - height / width successfully returned.
• MS::kFailure - invalid depth map data.

MStatus MImage:: setDepthMap (float * depth , unsigned width, unsigned height )

Description

Specifies the depth map resolution and data. Note, it is possible for the depth map to be a different resolution from the color map. This is to support oversampling with image planes. You cannot save image data to a file if the color map and image maps are different resolutions.

Arguments

• depth - float buffer that contains depth values. The depth values should be stored as -1.0/eyeDistance, where eyeDistance == 0.0 implies no depth is at that location.
• width - the width of the depth buffer
• height - the height of the depth buffer.

Return Value

• MS::kSuccess - depth values successfully loaded.
• MS::kFailure - invalid object.
• MS::kInvalidParameter - invalid parameter values.

MStatus MImage:: setDepthMap ( const MFloatArray & depth , unsigned width, unsigned height )

Description

Specifies the depth map resolution and data. Note, it is possible for the depth map to be a different resolution from the color map. This is to support oversampling with image planes. You cannot save image data to a file if the color map and image maps are different resolutions.

Arguments

• depth - float array that contains depth values. The depth values should be stored as -1.0/eyeDistance, where eyeDistance == 0.0 implies no depth is at that location.
• width - the width of the depth buffer
• height - the height of the depth buffer.

Return Value

• MS::kSuccess - depth values successfully loaded.
• MS::kFailure - invalid object.
• MS::kInvalidParameter - invalid parameter values.

float *MImage:: depthMap ( MStatus *ReturnStatus ) const

Description

Returns a pointer to the depth data.

Arguments

• ReturnStatus - return code.

Return Value

• MS::kFailure - invalid object, or no depth data exists for this image instance.
• MS::kSuccess - depth buffer successfully returned.

MStatus MImage:: readDepthMap ( MString pathname)

Description

Reads the depth map from the specified file and place the result into the depth map array of this MImage instance.

Arguments

• pathname - the path to the depth file.

Return Value

• MS::kFailure - invalid object, or a depth buffer does not exist in the specified file.
• MS::kSuccess - depth map successfully read.

bool MImage:: haveDepth ( ) const

Description

Returns true if this instance of MImage contains a depth map.

Return Value

• true - depth map exists for this class instance.
• false - depth map does not exist for this class instance.

MImage::MPixelType MImage:: pixelType () const

Description

Get the current pixel format of the image.

Return Value

• The current pixel format of the image.
• kUnknown if there is no currently opened image.

MStatus MImage:: convertPixelFormat ( MPixelType format, double scale, double offset)

Description

Convert the pixel format used by this image using the specified parameters.

Arguments

• format the desired pixel format. If this matches the current format, this method will do nothing.
• scale if conversion is required, this specifies the scaling applied to every channel of every pixel. A scale of 0 will automatically rescale based on the minimum and maximum values in the image.
• offset if conversion is required, this specifies the offset applied to every channel of every pixel.

Return Value

• MS::kFailure if the image is empty, or not in the requested format.
• MS::kSuccess if the image is in the requested format.

void MImage:: verticalFlip ()

Description

Flips the image vertically.

void MImage:: setRGBA (bool rgbaFormat)

Description

Sets a flag to indicate that pixel information is in RGBA sequence or BGRA sequence. Pixel data must have been allocated before this call is made.

Arguments

• rgbaFormat true value indicates RGBA format

bool MImage:: isRGBA () const

Description

Query flag which indicates whether the pixel information is in RGBA sequence or BGRA sequence. If no pixel data exists, then false will be returned.

Arguments

• None

Return Value

• true if in RGBA format.
• false if in BGRA format.

This class has no child classes.