Keep SURF features from many images

Hello everybody,

Currently I wanted to extract SURF feature, let say from bunch of images stored in one folder. I run the following code, I managed to get the feature from the last image only. How can we keep the features for all images we extracted?

Thanks.

 srcFiles = dir('D:\Phd Study\Matlab Food\fooddemo\try\*.jpg');  % the folder in which ur images exists
for i = 1 : length(srcFiles)
    filename = strcat('D:\Phd Study\Matlab Food\fooddemo\try\',srcFiles(i).name);
    I = imread(filename);
    a=rgb2gray(I);

        points = detectSURFFeatures(a);
        [features, valid_points] = extractFeatures(a, points);

     end 

    figure; imshow(I); hold on;
    plot(valid_points.selectStrongest(10),'showOrientation',true);

Answer 1

[Thorsten]

The most general form is

[features{i}, valid_points{i}] = extractFeatures(a, points);

if features is just a single number, you can use

[features(i), ...

if features is always a column vector of the same length, you can use

[features(:,i), ...

if features is always a row vector of the same length, you can use

 [features(i,:), ...

if features is always a matrix of same size, you can use

[features(:,:,i)

and so on, same for valid_points, of course.

In this case it is efficient to pre-allocate the feature, like

feature = zeros(1, length(srcFiles))

or using

features(1, length(srcFiles)) = 0;

[Erysham]

Thank you..its works beautifully.