YAZAPA - yet another zooming and panning application: CRESIDUE Class Reference


Static Public Member Functions
static __forceinline void	split_RGB_move (uchar_t data, imgdata_t img)
	RGB -> YCbCr colorspace transform (JPEG 2000 standard -> component transform).
static void	merge_RGB (float img_dataR, float img_dataG, float img_dataB, imgdata_t img)
	Reconstruct an RGB image from 3 separate channels.
static void	fwd_transform_channel (float img_data, int pitch, int dwt_levels, int ezw_passes, int ch_num, uchar_t ext_compr_data_dom, uchar_t *ext_compr_data_sub)
	Do forward wavelet transform.
static __forceinline void	inv_transform_channel (float img_data, int pitch, int dwt_levels, int ezw_passes, int ch_num, uchar_t ext_compr_data_dom, uchar_t *ext_compr_data_sub)
	Do inverse wavelet transform.
static int	load_ezw_files (char *nameRGB, ezw3_t data_from_3_channels, int *file_lenRGB)
	Load EZW-compressed files.
static int	build_startaddr_idx_struct (ezw3_t meta3ch, int file_lenRGB)
	Build index-structure for accessing each compressed tile.
static __forceinline void	decompress_tile_at (int tile_addr, ezw3_t pyr, imgdata_t dst_decompr_tile_RGB)
	Perform random access decompression.

Detailed Description

Calculates and compresses the residual signal. Once the successively downsampled images are precalculated the higher detail images are predicted from the coarsest resolution and the difference-image to the previously computed downsampled image is EZW-compressed

Member Function Documentation

static int CRESIDUE::build_startaddr_idx_struct	(	ezw3_t *	meta3ch,
		int *	file_lenRGB
	)			`[inline, static]`

Build index-structure for accessing each compressed tile.

Parameters:

	meta3ch	Datastructure that describes the data for which the index-struct is to be built.
	file_lenRGB	Total length of each compressed channel.

Returns:: Returns -1 upon any error, else 0.

static __forceinline void CRESIDUE::decompress_tile_at	(	int	tile_addr,
		ezw3_t *	pyr,
		imgdata_t *	dst_decompr_tile_RGB
	)			`[inline, static]`

Perform random access decompression.

Parameters:

	tile_addr	The tile which is to be decompressed.
	pyr	Datastructure that describes all tiles in the current image-pyramid level.
	dst_decompr_tile_RGB	Decompressed data in RGB-format.

static void CRESIDUE::fwd_transform_channel	(	float *	img_data,
		int	pitch,
		int	dwt_levels,
		int	ezw_passes,
		int	ch_num,
		uchar_t *	ext_compr_data_dom,
		uchar_t *	ext_compr_data_sub
	)			`[inline, static]`

Do forward wavelet transform.

Parameters:

	img_data	Data to transform.
	pitch	Pitch of img_data.
	dwt_levels	Determines, how many stages/levels the wavelet-filter has.
	ezw_passes	Determines, how often the EZW algorithm is to be applied.
	ch_num	Identifier for the current channel (R, G or B).
	ext_compr_data_dom	Destination for the symbols of the EZW dominant pass.
	ext_compr_data_sub	Destination for the symbols of the EZW subordinate pass.

static __forceinline void CRESIDUE::inv_transform_channel	(	float *	img_data,
		int	pitch,
		int	dwt_levels,
		int	ezw_passes,
		int	ch_num,
		uchar_t *	ext_compr_data_dom,
		uchar_t *	ext_compr_data_sub
	)			`[inline, static]`

Do inverse wavelet transform.

Parameters:

	img_data	Destination for inverse-transformed data.
	pitch	Pitch of img_data.
	dwt_levels	Determines, how many stages/levels the wavelet-filter has.
	ezw_passes	Determines, how often the EZW algorithm is to be applied.
	ch_num	Identifier for the current channel (R, G or B).
	ext_compr_data_dom	Source of the symbols for the EZW dominant pass.
	ext_compr_data_sub	Source of the symbols for the EZW subordinate pass.

static int CRESIDUE::load_ezw_files	(	char **	nameRGB,
		ezw3_t *	data_from_3_channels,
		int *	file_lenRGB
	)			`[inline, static]`

Load EZW-compressed files.

Parameters:

	nameRGB	Stores 3 pointers to the compressed datafiles for the R-, G- and B-channel.
	data_from_3_channels	Destination for the read data.
	file_lenRGB	Stores the 3 file lengths.

Returns:: Returns -1 if any of the 3 EZW-compressed files couldn't be loaded, else 0.

static void CRESIDUE::merge_RGB	(	float *	img_dataR,
		float *	img_dataG,
		float *	img_dataB,
		imgdata_t *	img
	)			`[inline, static]`

Reconstruct an RGB image from 3 separate channels.

Parameters:

	img_dataR	Data for the red channel.
	img_dataG	Data for the green channel.
	img_dataB	Data for the blue channel.
	img	Destination for the reconstructed image.

static __forceinline void CRESIDUE::split_RGB_move	(	uchar_t *	data,
		imgdata_t *	img
	)			`[inline, static]`

RGB -> YCbCr colorspace transform (JPEG 2000 standard -> component transform).

Move channels to diff_tile[R|G|B]. This is necessary, because the wavelet-transform is carried out individually on each channel. Use "imgdata_t"-struct only for addressing issues. The colorspace transform compacts the energy of the image in (mainly) one channel, so that the overall compressionrate is improved.

Parameters:

	data	Pointer to RGB data.
	img	Information about the image (width, height, pitch, bytes per pixel, ...).

CRESIDUE Class Reference

Static Public Member Functions

Detailed Description

Member Function Documentation