function?[imgH]?=?backproj（varargin）
%BACKPROJ?Compute?inverse?Radon?transform.
%???I?=?BACKPROJ（RTHETA）?reconstructs?the?image?I?from?projection?
%???data?in?the?2-D?array?R.??The?columns?of?R?are?parallel?beam?
%???projection?data.??IRADON?assumes?that?the?center?of?rotation
%???is?the?center?point?of?the?projections?which?is?defined?as
%???ceil（size（R1）/2）.
%
%???THETA?describes?the?angles?（in?degrees）?at?which?the?projections????
%???were?taken.??It?can?be?either?a?vector?containing?the?angles?or?
%???a?scalar?specifying?D_theta?the?incremental?angle?between?
%???projections.?If?THETA?is?a?vector?it?must?contain?angles?with?
%???equal?spacing?between?them.??If?THETA?is?a?scalar?specifying???
%???D_theta?the?projections?are?taken?at?angles?THETA?=?m?*?D_theta;?
%???m?=?012...size（R2）-1.??If?the?input?is?the?empty?matrix
%???（[]）?D_theta?defaults?to?180/size（R2）.???
%
%???BACKPROJ?uses?the?filtered?or?unfiltered?backprojection?algorithm?to?perform
%???the?inverse?Radon?transform.??The?filter?is?designed?directly?
%???in?the?frequency?domain?and?then?multiplied?by?the?FFT?of?the?
%???projections.??The?projections?are?zero-padded?to?a?power?of?2?
%???before?filtering?to?prevent?spatial?domain?aliasing?and?to?
%???speed?up?the?FFT.
%
%???I?=?BACKPROJ（RTHETAINTERPFILTERDN）?specifies?parameters?
%???to?use?in?the?inverse?Radon?transform.??You?can?specify
%???any?combination?of?the?last?four?arguments.??IRADON?uses?
%???default?values?for?any?of?these?arguments?that?you?omit.
%
%???INTERP?specifies?the?type?of?interpolation?to?use?in?the???
%???backprojection.??The?available?options?are?listed?in?order
%???of?increasing?accuracy?and?computational?complexity:
%
%??????‘nearest‘?-?nearest?neighbor?interpolation?
%??????‘linear‘??-?linear?interpolation?（default）
%??????‘spline‘??-?spline?interpolation
%
%???FILTER?specifies?the?filter?to?use?for?frequency?domain?filtering.??
%???FILTER?is?a?string?that?specifies?any?of?the?following?standard?
%???filters:
%?
%???‘None‘????????No?filter:?simple?（unfiltered）?backprojection.
%???‘Ram-Lak‘?????The?cropped?Ram-Lak?or?ramp?filter?（default）.??The????
%?????????????????frequency?response?of?this?filter?is?|f|.??Because?
%?????????????????this?filter?is?sensitive?to?noise?in?the?projections?
%?????????????????one?of?the?filters?listed?below?may?be?preferable.???
%?????????????????These?filters?multiply?the?Ram-Lak?filter?by?a
%?????????????????window?that?de-emphasizes?high?frequencies.
%???‘Shepp-Logan‘???????The?Shepp-Logan?filter?multiplies?the?Ram-Lak
%?????????????????filter?by?a?sinc?function.
%???‘Cosine‘???????The?cosine?filter?multiplies?the?Ram-Lak?filter?
%?????????????????by?a?cosine?function.
%???‘Hamming‘??????The?Hamming?filter?multiplies?the?Ram-Lak?filter?
%?????????????????by?a?Hamming?window.
%???‘Hann‘????????????The?Hann?filter?multiplies?the?Ram-Lak?filter?by?
%?????????????????a?Hann?window.
%???
%???D?is?a?scalar

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\
?????文件????????1183??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\README.md
?????文件???????10891??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\backproj.m
?????文件???????12251??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\build_weight_matrix.m
?????文件????????7709??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\build_weight_matrix_area.m
?????文件????????7217??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\build_weight_matrix_simple.m
?????文件?????????781??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\combWeightProj.m
?????文件?????????127??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\comb_projmat.m
?????文件????????5457??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\demo.m
?????目錄???????????0??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\solver\
?????文件?????????430??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\solver\solver_sart.m
?????目錄???????????0??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\
?????文件????????1100??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\ART2Dreconst.m
?????文件????????1853??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build1.m
?????文件????????1542??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build2.m
?????文件????????2597??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build3.m
?????文件????????2857??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build4.m
?????文件????????1872??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build5.m
?????文件????????2620??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build6.m
?????文件????????2476??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build7.m
?????文件????????2562??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build8.m
?????文件?????????702??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build_comp.m
?????文件?????????545??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build_comp_accuracy.m
?????文件?????????335??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\build_comp_area.m
?????文件?????????588??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\demo_crop.m
?????文件????????4910??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\demo_tomo.m
?????文件?????????760??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\demo_weightmat.m
?????文件?????????130??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\test_00_imtest.m
?????文件?????????686??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\test_01_FilterCompare.m
?????文件????????1727??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\test_02_Reconstruction.m
?????文件????????1332??2017-12-23?04:52??phymhan-matlab-tomo-2d-4ee1bce\test\test_03_FBP.m
............此處省略25個文件信息