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based on an earlier version of the Wolfram Language.
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ImageKeypoints

ImageKeypoints[image]
finds key features in image and returns their coordinates.
ImageKeypoints
gives the specified property prop for each keypoint.
  • ImageKeypoints[image] finds keypoints in image and returns their image coordinates as a list of the form .
  • The following properties can be specified:
"Position"image coordinates in the range ,
"PixelPosition"pixel coordinates in the range ,
"Descriptor"SURF keypoint descriptor, given as a unit vector of length 64
"OrientedDescriptor"oriented descriptor
"Orientation"orientation angle, given in radians
"Scale"keypoint scale
"ContrastSign"1 if the keypoint is lighter than its surrounding, -1 otherwise
  • The feature descriptors returned by ImageKeypoints are numerically robust against translation, rotation, and scale changes.
Count the number of interest points in an image:
Count the number of interest points in an image:
In[1]:=
Click for copyable input
Out[1]=
Find keypoints in an image:
Scales, orientations, and contrast signs:
Visualize the positions of keypoints:
Extract local patches of fixed size around detected keypoints:
Extract patches of size proportional to the scale of keypoints:
Use keypoints to crop an image to keep the main features:
Create thumbnails of uniform size:
Cluster the keypoints based on their descriptors:
Visualize the keypoints using their scale, orientation, and contrast:
New in 8