如何从 Matlab 中的数据集中提取 LBP 特征？

Question

我已经了解了如何从单个图像中提取特征，如本示例所述：https://www.mathworks.com/help/vision/ref/extractlbpfeatures.html

现在我正在为我的 matlab 项目处理 1000 张图像的数据集，以提取自行车、汽车和摩托车的特征。我的数据集中有三个独立的文件夹，包括自行车、汽车和摩托车。在执行过程中，我收到错误提示，

Error using extractLBPFeatures>parseInputs (line 148)

Expected I to be one of these types:

double, single, int16, uint16, uint8, logical

Instead its type was imageSet.

Error in extractLBPFeatures (line 129)

params = parseInputs(I,varargin{:});

Error in LBP (line 21)

bycycleLBP = extractLBPFeatures(bycycleData,'Upright',false);

我该怎么办？下面是我的示例代码 ==>

imSet = imageSet('dataset\train','recursive');

bicycleData = imSet(1);
carData = imSet(2);
motorbikeData = imSet(3);

%%Extract LBP Features
bicycleLBP = extractLBPFeatures(bicycleData,'Upright',false);
carLBP = extractLBPFeatures(carData,'Upright',false);
motorbikeLBP = extractLBPFeatures(motorbikeData,'Upright',false);

bicycle = bicycleLBP.^2;
car = carLBP.^2;
motorbike = motorbikeLBP.^2;

figure
bar([bicycle; car; motorbike]','grouped');
title('LBP Features Of bicycle, car and motorbike');
xlabel('LBP Histogram Bins');
legend('Bicycle','Car','Motorbike');

请帮助我实现示例代码。

Answer 1

在尝试提取特征之前，让我们先看一下两个变量。

>> whos imSet bicycleData
  Name             Size            Bytes  Class       Attributes            
  imSet            1x3              1494  imageSet 
  bicycleData      1x1               498  imageSet

变量 imSet 是 3 个 imageSet 对象的列表。第一个代表自行车，所以你适当地将自行车 imageSet 拉入它自己的变量 bicycleData，这是一个单数 imageSet。到目前为止一切顺利，但是当我们查看 extractLBPFeatures...

的文档时

features = extractLBPFeatures(I,Name,Value)

I — Input image

Input image, specified as an M-by-N 2-D grayscale image that is real, and non-sparse.

该函数一次只能提取一张灰度图的特征。您必须遍历 imageSet 以一次提取一个特征。

% Create a cell array to store features per image.
bicycleFeatures = cell(size(bicycleData.ImageLocation));

for i = 1:length(bicycleFeatures)
    % Read in individual image, and convert to grayscale to extract features.
    image = imread(bicycleData.ImageLocation{i});
    bicycleFeatures{i} = extractLBPFeatures(rgb2gray(image));
end

请记住，您仍有 post 处理工作要做。这会提取每个图像的特征，因此您必须确定要如何组合每个数据集中的特征数据。

如何从 Matlab 中的数据集中提取 LBP 特征？

How to extract LBP features from datasets in Matlab?

matlab

image-processing

machine-learning

feature-extraction

lbph-algorithm