Documentation Center

  • Trial Software
  • Product Updates


Class: SURFPoints

Plot SURF points




surfPoints.plot plots SURF points in the current axis.

surfPoints.plot(AXES_HANDLE,...) plots using axes with the handle AXES_HANDLE.

surfPoints.plot(AXES_HANDLE,Name,Value) Additional control for the plot method requires specification of parameters and corresponding values. An additional option is specified by one or more Name,Value pair arguments.

Input Arguments


Handle for plot method to use for display. You can set the handle using gca.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.


Display proportional circle around feature. Set this value to true or false. When you set this value to true, the object draws a circle proportional to the scale of the detected feature, with the feature point located at its center. When you set this value to false, the object turns the display of the circle off.

The algorithm represents the scale of the feature with a circle of 6*Scale radius. The SURF algorithm uses this equivalent size of circular area to compute the orientation of the feature.

Default: true


Display a line corresponding to feature point orientation. Set this value to true or false. When you set this value to true, the object draws a line corresponding to the point's orientation. The object draws the line from the feature point location to the edge of the circle, indicating the scale.

Default: false


% Extract SURF features
  I = imread('cameraman.tif');
  points = detectSURFFeatures(I);
  [features, valid_points] = extractFeatures(I, points);

% Visualize 10 strongest SURF features, including their 
% scales and orientation which were determined during the 
% descriptor extraction process.
  imshow(I); hold on;
  strongestPoints = valid_points.selectStrongest(10);
Was this topic helpful?