features
f = iblobs(im, options) is a vector of RegionFeature objects that describe each connected region in the image im.
| 'aspect', A | set pixel aspect ratio, default 1.0 |
| 'connect', C | set connectivity, 4 (default) or 8 |
| 'greyscale' | compute greyscale moments 0 (default) or 1 |
| 'boundary' | compute boundary (default off) |
| 'area', [A1,A2] | accept only blobs with area in the interval A1 to A2 |
| 'shape', [S1,S2] | accept only blobs with shape in the interval S1 to S2 |
| 'touch', T | accept only blobs that touch (1) or do not touch (0) the edge (default accept all) |
| 'class', C | accept only blobs of pixel value C (default all) |
The RegionFeature object has many properties including:
| uc | centroid, horizontal coordinate |
| vc | centroid, vertical coordinate |
| p | centroid (uc, vc) |
| umin | bounding box, minimum horizontal coordinate |
| umax | bounding box, maximum horizontal coordinate |
| vmin | bounding box, minimum vertical coordinate |
| vmax | bounding box, maximum vertical coordinate |
| area | the number of pixels |
| class | the value of the pixels forming this region |
| label | the label assigned to this region |
| children | a list of indices of features that are children of this feature |
| edgepoint | coordinate of a point on the perimeter |
| edge | a list of edge points 2xN matrix |
| perimeter | edge length (pixels) |
| touch | true if region touches edge of the image |
| a | major axis length of equivalent ellipse |
| b | minor axis length of equivalent ellipse |
| theta | angle of major ellipse axis to horizontal axis |
| shape | aspect ratio b/a (always <= 1.0) |
| circularity | 1 for a circle, less for other shapes |
| moments | a structure containing moments of order 0 to 2 |
RegionFeature, ilabel, idisplabel, imoments
Machine Vision Toolbox for MATLAB © 1990-2014 Peter Corke.