Creates StereoSGBM object
bm = cv.StereoSGBM()
bm = cv.StereoSGBM('OptionName', optionValue, ...)
Options
- MinDisparity Minimum possible disparity value. Normally,
it is zero but sometimes rectification algorithms can shift
images, so this parameter needs to be adjusted accordingly.
default 0
- NumDisparities Maximum disparity minus minimum disparity.
The value is always greater than zero. In the current
implementation, this parameter must be divisible by 16.
default 16
- BlockSize Matched block size. It must be an odd number >=1.
Normally, it should be somewhere in the 3..11 range. default 3
- P1 The first parameter controlling the disparity
smoothness. See
P2
. default 0 (which uses 2).
- P2 The 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
. (Reasonably good
P1
and P2
values are like
8*number_of_image_channels*BlockSize*BlockSize
and
32*number_of_image_channels*BlockSize*BlockSize
respectively). default 0 (which uses max(5,P1+1)
).
- Disp12MaxDiff Maximum allowed difference (in integer pixel
units) in the left-right disparity check. Set it to a
non-positive value to disable the check. default 0
- PreFilterCap Truncation 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. default 0
- UniquenessRatio Margin 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. A negative value
uses 10. default 0
- SpeckleWindowSize Maximum 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. default 0
- SpeckleRange Maximum 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. default 0
- Mode Set it to '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
'SGBM'.