StereoSGBM
import { StereoSGBM } from '@banou/opencv-wasm'Use after await initOpenCV(). See the initialization and named imports guide.
Native object: release it with using or delete(). Factories can return null; check before calling methods. Inherits StereoMatcher.
The class implements the modified H. Hirschmuller algorithm [HH08] that differs from the original one as follows:
- By default, the algorithm is single-pass, which means that you consider only 5 directions instead of 8. Set mode=StereoSGBM::MODE_HH in createStereoSGBM to run the full variant of the algorithm but beware that it may consume a lot of memory.
- The algorithm matches blocks, not individual pixels. Though, setting blockSize=1 reduces the blocks to single pixels.
- Mutual information cost function is not implemented. Instead, a simpler Birchfield-Tomasi sub-pixel metric from [BT98] is used. Though, the color images are supported as well.
- Some pre- and post- processing steps from K. Konolige algorithm StereoBM are included, for example: pre-filtering (StereoBM::PREFILTER_XSOBEL type) and post-filtering (uniqueness check, quadratic interpolation and speckle filtering).
Note: - (Python) An example illustrating the use of the StereoSGBM matching algorithm can be found at opencv_source_code/samples/python/stereo_match.py
Constructors and members
static create
Creates StereoSGBM object
create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number, uniquenessRatio: number, speckleWindowSize: number, speckleRange: number, mode: number): StereoSGBM | null;12 available overloads
create(): StereoSGBM | null;create(minDisparity: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number, uniquenessRatio: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number, uniquenessRatio: number, speckleWindowSize: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number, uniquenessRatio: number, speckleWindowSize: number, speckleRange: number): StereoSGBM | null;create(minDisparity: number, numDisparities: number, blockSize: number, P1: number, P2: number, disp12MaxDiff: number, preFilterCap: number, uniquenessRatio: number, speckleWindowSize: number, speckleRange: number, mode: number): StereoSGBM | null;minDisparityMinimum possible disparity value. Normally, it is zero but sometimes rectification algorithms can shift images, so this parameter needs to be adjusted accordingly.
numDisparitiesMaximum disparity minus minimum disparity. The value is always greater than zero. In the current implementation, this parameter must be divisible by 16.
blockSizeMatched block size. It must be an odd number >=1 . Normally, it should be somewhere in the 3..11 range.
P1The first parameter controlling the disparity smoothness. See below.
P2The second parameter controlling the disparity smoothness. The larger the values are, the smoother the disparity is. P1 is the penalty on the disparity change by plus or minus 1 between neighbor pixels. P2 is the penalty on the disparity change by more than 1 between neighbor pixels. The algorithm requires P2 > P1 . See stereo_match.cpp sample where some reasonably good P1 and P2 values are shown (like 8*number_of_image_channels*blockSize*blockSize and 32*number_of_image_channels*blockSize*blockSize , respectively).
disp12MaxDiffMaximum allowed difference (in integer pixel units) in the left-right disparity check. Set it to a non-positive value to disable the check.
preFilterCapTruncation value for the prefiltered image pixels. The algorithm first computes x-derivative at each pixel and clips its value by [-preFilterCap, preFilterCap] interval. The result values are passed to the Birchfield-Tomasi pixel cost function.
uniquenessRatioMargin in percentage by which the best (minimum) computed cost function value should "win" the second best value to consider the found match correct. Normally, a value within the 5-15 range is good enough.
speckleWindowSizeMaximum size of smooth disparity regions to consider their noise speckles and invalidate. Set it to 0 to disable speckle filtering. Otherwise, set it somewhere in the 50-200 range.
speckleRangeMaximum disparity variation within each connected component. If you do speckle filtering, set the parameter to a positive value, it will be implicitly multiplied by 16. Normally, 1 or 2 is good enough.
modeSet it to StereoSGBM::MODE_HH to run the full-scale two-pass dynamic programming algorithm. It will consume O(W*H*numDisparities) bytes, which is large for 640x480 stereo and huge for HD-size pictures. By default, it is set to false .
The first constructor initializes StereoSGBM with all the default parameters. So, you only have to set StereoSGBM::numDisparities at minimum. The second constructor enables you to set each parameter to a custom value.
The StereoSGBM | null result.
clone
Create another handle to the same native object. This retains the object without copying its pixels or algorithm state; dispose both handles separately.
clone(): this;The this result.
getPreFilterCap
Return the pre filter cap configured on this StereoSGBM object.
getPreFilterCap(): number;The number result.
setPreFilterCap
Set the pre filter cap used by this StereoSGBM object.
setPreFilterCap(preFilterCap: number): void;preFilterCappre filter cap argument (number).
getUniquenessRatio
Return the uniqueness ratio configured on this StereoSGBM object.
getUniquenessRatio(): number;The number result.
setUniquenessRatio
Set the uniqueness ratio used by this StereoSGBM object.
setUniquenessRatio(uniquenessRatio: number): void;uniquenessRatiouniqueness ratio argument (number).
getP1
Return the p1 configured on this StereoSGBM object.
getP1(): number;The number result.
setP1
Set the p1 used by this StereoSGBM object.
setP1(P1: number): void;P1p1 argument (number).
getP2
Return the p2 configured on this StereoSGBM object.
getP2(): number;The number result.
setP2
Set the p2 used by this StereoSGBM object.
setP2(P2: number): void;P2p2 argument (number).
getMode
Return the mode configured on this StereoSGBM object.
getMode(): number;The number result.
setMode
Set the mode used by this StereoSGBM object.
setMode(mode: number): void;modemode argument (number).
These signatures describe this package. Upstream documentation can mention optional backends that are absent from this build. Check runtime compatibility before choosing a backend or file format.