.TH QCCWAVBISK3DENCODE 1 "QCCPACK" "".SH NAMEQccWAVbisk3DEncode, QccWAVbisk3DDecode \-encode/decode an image cube using the 3D-BISK algorithm.SH SYNOPSIS.B #include "libQccPack.h".sp.BI "int QccWAVbisk3DEncode(const QccIMGImageCube *" image_cube ", const QccIMGImageCube *" mask ", int " transform_type ", int " temporal_num_levels ", int " spatial_num_levels ", const QccWAVWavelet *" wavelet ", QccBitBuffer *" output_buffer ", int " target_bit_cnt );.sp.BI "int QccWAVbisk3DEncode2(QccWAVSubbandPyramid3D *" image_subband_pyramid ", QccWAVSubbandPyramid3D *" mask_subband_pyramid ", double " image_mean ", QccBitBuffer *" output_buffer ", int " target_bit_cnt );.sp.BI "int QccWAVbisk3DDecodeHeader(QccBitBuffer *" input_buffer ", int *" transform_type ", int *" temporal_num_levels ", int *" spatial_num_levels ", int *" num_frames ", int *" num_rows ", int *" num_cols ", double *" image_mean ", int *" max_coefficient_bits );.sp.BI "int QccWAVbisk3DDecode(QccBitBuffer *" input_buffer ", QccIMGImageCube *" image_cube ", const QccIMGImageCube *" mask ", int " transform_type ", int " temporal_num_levels ", int " spatial_num_levels ", const QccWAVWavelet *" wavelet ", double " image_mean ", int " max_coefficient_bits ", int " target_bit_bit );.sp.BI "int QccWAVbisk3DDecode2(QccBitBuffer *" input_buffer ", QccWAVSubbandPyramid3D *" image_subband_pyramid ", QccWAVSubbandPyramid3D *" mask_subband_pyramid ", int " max_coefficient_bits ", int " target_bit_cnt );.SH DESCRIPTION.SS Encoding.LP.B QccWAVbisk3DEncode()encodes an image cube,.IR image_cube ,using a 3D generalization of the BISK algorithm.The original BISK algorithm was developed for 2D images byFowler; it was latter extended to 3D by Rucker and Fowler.In essence, the 3D-BISK algorithm involves a 3D DWT followed by a progressive "bitplane" coding of the wavelet coefficients using acube-splitting quantization structure based on.IR k -dtrees. See "ALGORITHM" below for more detail..LP.I image_cubeis the image cube to be coded and.I output_bufferis the output bitstream..I output_buffermust be of.B QCCBITBUFFER_OUTPUTtype and opened via a prior call to.BR QccBitBufferStart (3)..LP.BR QccWAVbisk3DEncode ()supports the use of both wavelet-packet and dyadic wavelet-transformdecompositions.If.IR transform_typeis.BR QCCWAVSUBBANDPYRAMID3D_DYADIC ,a dyadic DWT is used; if.IR transform_typeis.BR QCCWAVSUBBANDPYRAMID3D_PACKET ,a wavelet-packet DWT is used..IR temporal_num_levels and.IR spatial_num_levelsgive the number of levels of wavelet decomposition to performfor both transform types; for a dyadic transform,.IR temporal_num_levels should equal.IR spatial_num_levels ..I waveletis the wavelet to use for decomposition..LPThe bitstream output from the 3D-BISK encoder is embedded, meaning thatany prefix of the bitstream can be decoded to give a valid representation of the image.  The 3D-BISK encoder essentially producesoutput bits until the number of bits output reaches.IR target_bit_cnt ,the desired (target) total length of the output bitstream in bits,and then it stops.Note that this is the bitstream length in bits, not the rate of the bitstream(which would be expressed in bits per voxel)..LP.BR QccWAVbisk3DEncode()optionally supports the use of a shape-adaptive DWT (SA-DWT) rather thanthe usual DWT. That is, .BR QccWAVbisk3DEncode()can call.BR QccWAVSubbandPyramid3DShapeAdaptiveDWT (3)as the wavelet transform rather than the usual.BR QccWAVSubbandPyramid3DDWT (3).The use of a SA-DWT is indicated by a non-NULL.IR mask ;if .I maskis NULL, then the usual DWT is used.In the case of a SA-DWT,.I mask gives the transparency mask which indicates which voxels of the imageare non-transparent and thus have data that is to be transformed.Refer to .BR QccWAVSubbandPyramid3DShapeAdaptiveDWT (3)for more details on the calculation of this SA-DWT.See "ALGORITHM" below for details on how the 3D-BISKalgorithm handles shape-adaptive coding..LPThe routine.BR QccWAVbisk3DEncode2()provides an alternative interface to 3D-BISK encoding.Specifically,.BR QccWAVbisk3DEncode2()functions indentically to.BR QccWAVbisk3DEncode()described above, except that both the image cube and optional mask areassumed to have had a 3D DWT applied to them prior to calling.BR QccWAVbisk3DEncode2() .As a consequence, the image cube and mask are passed to.BR QccWAVbisk3DEncode2()in the wavelet domain as.IR image_subband_pyramidand.IR mask_subband_pyramid .We note that most applications should opt for.BR QccWAVbisk3DEncode()rather than.BR QccWAVbisk3DEncode2() ;however,.BR QccWAVbisk3DEncode()is implemented essentially as a call to an appropriate 3D DWTfollowed by a call to.BR QccWAVbisk3DEncode2() .If .BR QccWAVbisk3DEncode2()is used, it is the responsibility of the calling routineto perform the appropriate 3D DWT prior to calling.BR QccWAVbisk3DEncode2() ..SS Decoding.LP.B QccWAVbisk3DDecodeHeader()decodes the header information in a bitstream previously produced by.BR QccWAVbisk3DEncode() .The input bitstream is.I input_bufferwhich must be of.B QCCBITBUFFER_INPUTtype and opened via a prior call to.BR QccBitBufferStart (3)..LPThe header information is returned in.I transform_type(either.BR QCCWAVSUBBANDPYRAMID3D_DYADIC or.BR QCCWAVSUBBANDPYRAMID3D_PACKET to indicate a dyadic or wavelet-packet transform decomposition, respectively),.I temporal_num_levels(number of levels of wavelet decomposition in the temporal direction),.I spatial_num_levels(number of levels of wavelet decomposition in the spatial directions),.I num_frames(size of the image cube in the temporal direction),.I num_rows(vertical size of image cube),.I num_cols(horizontal size of image cube),.I image_mean(the mean value of the original image cube), and.I max_coefficient_bits(indicates the precision, in number of bits, of the wavelet coefficientwith the largest magnitude)..LP.B QccWAVbisk3DDecode()decodes the bitstream.IR input_buffer ,producing the reconstructed image cube,.IR image_cube .The bitstream must already have had its header read by a prior callto.B QccWAVbisk3DDecodeHeader()(i.e., you call.B QccWAVbisk3DDecodeHeader() first and then.BR QccWAVbisk3DDecode() ).If.I target_bit_cntis.BR QCCENT_ANYNUMBITS ,then decoding stops when the end of the input bitstream is reached;otherwise, decoding stops when.I target_num_bitsfrom the input bitstream have been decoded..LPIf a SA-DWT was used in 3D-BISK encoding, then the original transparencymask should be passed to .BR QccWAVbisk3DDecode()as.IR mask .That is,.I maskshould be the same transparency mask (untransformed) that was passed to.BR QccWAVbisk3DEncode() .Note that.BR QccWAVbisk3DDecode()will transform this.I maskvia a Lazy wavelet transform, and then pass the transformed maskto .BR QccWAVSubbandPyramid3DInverseShapeAdaptiveDWT (3).If the usual, full-volume DWT was used in encoding, then.I maskshould be a NULL pointer..LP.BR QccWAVbisk3DDecode2()provides the appropriate alternative interface to 3D-BISK decodingrequired if encoding was done via.BR QccWAVbisk3DEncode2() .Essentially, .BR QccWAVbisk3DDecode()is implemented by a call to.BR QccWAVbisk3DDecode2()followed by an appropriate inverse 3D DWT.If.BR QccWAVbisk3DDecode2()is used, it is the responsibility of the calling to routineto perform the appropriate inverse 3D DWT subsequent to the callto.BR QccWAVbisk3DDecode2() .As noted above, most applications should use.BR QccWAVbisk3DDecode()rather than.BR QccWAVbisk3DDecode2() ..SH "ALGORITHM"The 3D-BISK algorithm involves a 3D DWT followed by a progressive encodingof the bitplanes of wavelet coefficients.As is common with bitplane-based embedded coders,the encoder of the 3D-BISK algorithmcodes significance information in a significance passfollowed by refinement-bit information in a refinement pass.The significance pass determines the significance of a wavelet coefficientagainst a given threshold, while the refinement pass codes the bits ofthose coefficients previously determined to be significant..LPThe unique aspect of the 3D-BISK algorithm is in the significancepass. In many ways, the 3D-BISK algorithm can be considered to bea variant of 3D-SPECK (Tang.IR "et al" .2003)designed specifically for improved shape-adaptive coding, and it isa generalization to 3D of the original 2D BISK algorithm developedby Fowler.The 3D-BISK coder employs two tacticsto improve shape-adaptive coding---aggressivediscarding of transparent regions from sets after partitioning,and a spatial-partitioning structure more flexible than theocttrees used by 3D-SPECK.In octtree partitioning, the significance state of an entirecube of coefficients is tested and coded, the cube is subdivided intoeight subcubes of approximately equal size, and the significance-codingprocess is repeated recursively on each of the subcubes.On the other hand, when processing a given set, the 3D-BISK coderemploys a different partitioning scheme,.IR k -dtrees (Bentley 1975)rather than octtrees, to recursively code the significancemap.Like octtrees,.IR k -dtrees are a recursivespatial partitioning data structure. Unlike octtrees, which subdividea cube into eight equally sized subcubes,.IR k -dtrees effectuatea binary partitioning; that is, cubes are divided in two.Although there are several approaches for selectingthe location and orientation of the split, the 3D-BISKalgorithm uses a simple approach inwhich cubes are divided into approximately equally sized halves, andwe alternate between splitting horizontally, vertically, and temporally..LPAdditionally, to improve shape-adaptive coding, the 3D-BISKcoder "shrinks" each set to the bounding box surrounding theopaque coefficients before subdividing the set into smaller blocks..SH "SEE ALSO".BR biskencode3d (1),.BR biskdecode3d (1),.BR QccBitBuffer (3),.BR QccWAVSubbandPyramid3D (3),.BR QccWAVSubbandPyramid3DDWT (3),.BR QccWAVSubbandPyramid3DShapeAdaptiveDWT (3),.BR QccWAVbiskEncode (3),.BR QccPackWAV (3),.BR QccPackIMG (3),.BR QccPack (3)J. T. Rucker and J. E. Fowler,"Coding of Ocean-Temperature Volumes Using Binary Set Splitting with.IR k -dTrees,"in.IR "Proceedings of the International Geoscience and Remote Sensing Symposium" ,Anchorage, AK, September 2004, to appear.J. E. Fowler,"Shape-Adaptive Coding Using Binary Set Splitting with.IR k -dTrees,"in.IR "Proceedings of the International Conference on Image Processing" ,Singapore, October 2004, to appear.X. Tang, W. A. Pearlman, and J. W. Modestino,"Hyperspectral Image Compression Using Three-DimensionalWavelet Coding,"in.IR "Image and Video Communications and Processing" ,Santa Clara, CA, January 2003, Proc. SPIE 5022, pp. 1037-1047.J. L. Bentley, "Multidimensional Binary Search Trees Used forAssociative Searching,".IR "Communications of the ACM" ,vol. 18, no. 9, pp. 509-517, September 1975..SH AUTHORCopyright (C) 1997-2005  James E. Fowler.\"  The programs herein are free software; you can redistribute them and/or.\"  modify them under the terms of the GNU General Public License.\"  as published by the Free Software Foundation; either version 2.\"  of the License, or (at your option) any later version..\"  .\"  These programs are distributed in the hope that they will be useful,.\"  but WITHOUT ANY WARRANTY; without even the implied warranty of.\"  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the.\"  GNU General Public License for more details..\"  .\"  You should have received a copy of the GNU General Public License.\"  along with these programs; if not, write to the Free Software.\"  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.