Safe Haskell	None
Language	Haskell2010

OpenCV.Extra.XFeatures2d

Contents

SURF

Synopsis

SURF

data Surf Source #

Instances

WithPtr Surf Source #
Methods withPtr :: Surf -> (Ptr (C Surf) -> IO b) -> IO b
FromPtr Surf Source #
Methods fromPtr :: IO (Ptr (C Surf)) -> IO Surf
type C Surf Source #
type C Surf

data SurfParams Source #

Constructors

SurfParams

Fields

surf_hessianThreshold :: !Double
Threshold for hessian keypoint detector used in SURF
surf_nOctaves :: !Int32
Number of pyramid octaves the keypoint detector will use.
surf_nOctaveLayers :: !Int32
Number of octave layers within each octave.
surf_extended :: !Bool
Extended descriptor flag (true - use extended 128-element descriptors; false - use 64-element descriptors).
surf_upright :: !Bool
Up-right or rotated features flag (true - do not compute orientation of features; false - compute orientation).

defaultSurfParams :: SurfParams Source #

mkSurf :: SurfParams -> Surf Source #

surfDetectAndCompute Source #

Arguments

:: Surf
-> Mat (S '[height, width]) channels depth	Image.
-> Maybe (Mat (S '[height, width]) (S 1) (S Word8))	Mask.
-> CvExcept (Vector KeyPoint, Mat D D D)

Detect keypoints and compute descriptors

Example:

surfDetectAndComputeImg
    :: forall (width    :: Nat)
              (height   :: Nat)
              (channels :: Nat)
              (depth    :: *)
     . (Mat (ShapeT [height, width]) ('S channels) ('S depth) ~ Frog)
    => Mat (ShapeT [height, width]) ('S channels) ('S depth)
surfDetectAndComputeImg = exceptError $ do
    (kpts, _descs) <- surfDetectAndCompute surf frog Nothing
    withMatM (Proxy :: Proxy [height, width])
             (Proxy :: Proxy channels)
             (Proxy :: Proxy depth)
             white $ \imgM -> do
      void $ matCopyToM imgM (V2 0 0) frog Nothing
      forM_ kpts $ \kpt -> do
        let kptRec = keyPointAsRec kpt
        circle imgM (round <$> kptPoint kptRec :: V2 Int32) 5 blue 1 LineType_AA 0
  where
    surf = mkSurf defaultSurfParams

surfDetectAndComputeImg