buildpyramid.m

论文Beyond Bags of Features源代码

function [ pyramid_all ] = BuildPyramid( imageFileList, imageBaseDir, dataBaseDir, maxImageSize, dictionarySize, numTextonImages, pyramidLevels, canSkip )
%function [ pyramid_all ] = BuildPyramid( imageFileList, imageBaseDir, dataBaseDir, dictionarySize, numTextonImages, pyramidLevels )
%
%Complete all steps necessary to build a spatial pyramid based
% on sift features.
%
% To build the pyramid this function first extracts the sift descriptors
%  for each image. It then calculates the centers of the bins for the
%  dictionary. Each sift descriptor is given a texton label corresponding
%  to the appropriate dictionary bin. Finally the spatial pyramid
%  is generated from these label lists.
%
%
% imageFileList: cell of file paths
% imageBaseDir: the base directory for the image files
% dataBaseDir: the base directory for the data files that are generated
%  by the algorithm. If this dir is the same as imageBaseDir the files
%  will be generated in the same location as the image files
% maxImageSize: the max image size. If the image is larger it will be
%  resampeled.
% dictionarySize: size of descriptor dictionary (200 has been found to be a
%  good size)
% numTextonImages: number of images to be used to create the histogram bins
% pyramidLevels: number of levels of the pyramid to build
% canSkip: if true the calculation will be skipped if the appropriate data 
%  file is found in dataBaseDir. This is very useful if you just want to
%  update some of the data or if you've added new images.
%
% Example:
% BuildPyramid(file_list, image_dir, data_dir);
%  Builds the spacial pyramid descriptor for all files in the file_list and
%  stores the data generated in data_dir. Dictionary size is set to 200,
%  50 texton images are used to build the historgram bins, 4 pyramid
%  levels are generated, and the image size has a maximum of 1000 pixels in
%  either the x or y direction.

%% parameters for feature extraction (see GenerateSiftDescriptors)
if(nargin<4)
    maxImageSize = 1000
end

gridSpacing = 8
patchSize = 16


%% parameters for obtaining texton dictionary (see CalculateDictionary)
if(nargin<5)
    dictionarySize = 200
end

if(nargin<6)
    numTextonImages = 50
end


%% parameters for pyramid computation (see CompilePyramid)
if(nargin<7)
    pyramidLevels = 4
end

%% parameters for all functions
if(nargin<8)
    canSkip = 1
end

%% build the pyramid
GenerateSiftDescriptors( imageFileList,imageBaseDir,dataBaseDir,maxImageSize,gridSpacing,patchSize,canSkip);
CalculateDictionary(imageFileList,dataBaseDir,'_sift.mat',dictionarySize,numTextonImages,canSkip);
BuildHistograms(imageFileList,dataBaseDir,'_sift.mat',dictionarySize,canSkip);
pyramid_all = CompilePyramid(imageFileList,dataBaseDir,sprintf('_texton_ind_%d.mat',dictionarySize),dictionarySize,pyramidLevels,canSkip);
end