Unrecognized function or variable 'detectSIFTFeatures'

Hello friends.

I'm using matlab 2021a , but when I use command below:

points = detectSIFTFeatures(I); 

It shows this error:

Unrecognized function or variable 'detectSIFTFeatures'

Answer 1

[Image Analyst]

You probably don't have the Computer Vision Toolbox.

% Check that user has the specified Toolbox installed and licensed.
% hasLicenseForToolbox = license('test', 'image_toolbox');	% Check for Image Processing Toolbox.
% hasLicenseForToolbox = license('test', 'Image_Acquisition_Toolbox');	% Check for Image Acquisition Toolbox.
% hasLicenseForToolbox = license('test', 'Statistics_Toolbox');	% Check for Statistics and Machine Learning Toolbox.
% hasLicenseForToolbox = license('test', 'Signal_Toolbox');	% Check for Signal Processing Toolbox.
hasLicenseForToolbox = license('test', 'Video_and_Image_Blockset');	% Check for Computer Vision Toolbox.
% hasLicenseForToolbox = license('test', 'Neural_Network_Toolbox');	% Check for Deep Learning Toolbox.
if ~hasLicenseForToolbox
    % User does not have the toolbox installed, or if it is, there is no available license for it.
    % For example, there is a pool of 10 licenses and all 10 have been checked out by other people already.
    ver % List what toolboxes the user has licenses available for.
    message = sprintf('Sorry, but you do not seem to have the Computer Vision Toolbox.\nDo you want to try to continue anyway?');
    reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes');
    if strcmpi(reply, 'No')
        % User said No, so exit.
        return;
    end
end

What does the above code say? Also do

>> ver

Do you see the Computer Vision Toolbox listed?

[Mary]

hello thank you for your response . when i run above code . it run without error and hasLicenseForToolbox value is 1.

surf , kaze & .... run without error but sift isnot work

[Image Analyst]

The code from the documentation works for me.

I = imread('cameraman.tif');
% Detect SIFT features in the image.
points = detectSIFTFeatures(I);
% Display the results
imshow(I);
hold on;
plot(points.selectStrongest(10))

Since it doesn't for you, and you evidently do have the Toolbox license, I suggest you call tech support or reinstall MATLAB.

[Mary]

Hello ,

i setup matlab2021b , and resolve it. But i have a problem i can't calculate RMSE for sift. could you help me plz?

[Image Analyst]

I don't know what that means. RMSE of what values? And since RMSE looks at the difference between a reference signal and a test signal, how are you defining the reference and test signals?

[Mary]

For the difference between correct matching and incorrect matching for each key point

[Mary]

[Image Analyst]

Those look like 2 or 3 completely different images.

[Mary]

Yes, my images are from the same area but with different sensors.Is there a way?

[Image Analyst]

Try to crop them and align them with imregister() so you're looking at the same field of view.

Answer 2

[yanqi liu]

sir，may be you should use vlfeat to get sift points, of course，you can use surf，such as

clc; clear all; close all;
I = imread('cameraman.tif');
points = detectSURFFeatures(I);
imshow(I); hold on;
plot(points.selectStrongest(10));