@Namespace(value="cv") @Properties(inherit=opencv_features2d.class) public class SimpleBlobDetector extends Feature2D
The class implements a simple algorithm for extracting blobs from an image:
1. Convert the source image to binary images by applying thresholding with several thresholds from minThreshold (inclusive) to maxThreshold (exclusive) with distance thresholdStep between neighboring thresholds. 2. Extract connected components from every binary image by findContours and calculate their centers. 3. Group centers from several binary images by their coordinates. Close centers form one group that corresponds to one blob, which is controlled by the minDistBetweenBlobs parameter. 4. From the groups, estimate final centers of blobs and their radiuses and return as locations and sizes of keypoints.
This class performs several filtrations of returned blobs. You should set filterBy\* to true/false to turn on/off corresponding filtration. Available filtrations:
- **By color**. This filter compares the intensity of a binary image at the center of a blob to
blobColor. If they differ, the blob is filtered out. Use blobColor = 0 to extract dark blobs
and blobColor = 255 to extract light blobs.
- **By area**. Extracted blobs have an area between minArea (inclusive) and maxArea (exclusive).
- **By circularity**. Extracted blobs have circularity
(\frac{4*\pi*Area}{perimeter * perimeter}) between minCircularity (inclusive) and
maxCircularity (exclusive).
- **By ratio of the minimum inertia to maximum inertia**. Extracted blobs have this ratio
between minInertiaRatio (inclusive) and maxInertiaRatio (exclusive).
- **By convexity**. Extracted blobs have convexity (area / area of blob convex hull) between
minConvexity (inclusive) and maxConvexity (exclusive).
Default values of parameters are tuned to extract dark circular blobs.
| Modifier and Type | Class and Description |
|---|---|
static class |
SimpleBlobDetector.Params |
Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter| Constructor and Description |
|---|
SimpleBlobDetector()
Default native constructor.
|
SimpleBlobDetector(long size)
Native array allocator.
|
SimpleBlobDetector(Pointer p)
Pointer cast constructor.
|
| Modifier and Type | Method and Description |
|---|---|
static SimpleBlobDetector |
create() |
static SimpleBlobDetector |
create(SimpleBlobDetector.Params parameters) |
BytePointer |
getDefaultName()
Returns the algorithm string identifier.
|
SimpleBlobDetector |
position(long position) |
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public SimpleBlobDetector(long size)
Pointer.position(long).public SimpleBlobDetector(Pointer p)
Pointer.Pointer(Pointer).public SimpleBlobDetector position(long position)
@opencv_core.Ptr public static SimpleBlobDetector create(@Const @ByRef(nullValue="cv::SimpleBlobDetector::Params()") SimpleBlobDetector.Params parameters)
@opencv_core.Ptr public static SimpleBlobDetector create()
@opencv_core.Str public BytePointer getDefaultName()
AlgorithmgetDefaultName in class Feature2DCopyright © 2020. All rights reserved.