OpenCV.ImgProc.Drawing

Documentation

data LineType

Constructors

LineType_8

8-connected line.

LineType_4

4-connected line.

LineType_AA

Antialiased line.

Instances

Bounded LineType

Methods

minBound :: LineType

maxBound :: LineType

Enum LineType

Methods

succ :: LineType -> LineType

pred :: LineType -> LineType

toEnum :: Int -> LineType

fromEnum :: LineType -> Int

enumFrom :: LineType -> [LineType]

enumFromThen :: LineType -> LineType -> [LineType]

enumFromTo :: LineType -> LineType -> [LineType]

enumFromThenTo :: LineType -> LineType -> LineType -> [LineType]

Show LineType

Methods

showsPrec :: Int -> LineType -> ShowS

show :: LineType -> String

showList :: [LineType] -> ShowS

data Font

Constructors

Font

Fields

• _fontFace :: !FontFace
• _fontSlant :: !FontSlant
• _fontScale :: !Double

Instances

Show Font

Methods

showsPrec :: Int -> Font -> ShowS

show :: Font -> String

showList :: [Font] -> ShowS

data FontFace

Constructors

FontHersheySimplex

Normal size sans-serif font. Does not have a Slanted variant.

FontHersheyPlain

Small size sans-serif font.

FontHersheyDuplex

Normal size sans-serif font (more complex than FontHersheySimplex). Does not have a Slanted variant.

FontHersheyComplex

Normal size serif font.

FontHersheyTriplex

Normal size serif font (more complex than FontHersheyComplex).

FontHersheyComplexSmall

Smaller version of FontHersheyComplex.

FontHersheyScriptSimplex

Hand-writing style font. Does not have a Slanted variant.

FontHersheyScriptComplex

More complex variant of FontHersheyScriptSimplex. Does not have a Slanted variant.

Instances

Bounded FontFace

Methods

minBound :: FontFace

maxBound :: FontFace

Enum FontFace

Methods

succ :: FontFace -> FontFace

pred :: FontFace -> FontFace

toEnum :: Int -> FontFace

fromEnum :: FontFace -> Int

enumFrom :: FontFace -> [FontFace]

enumFromThen :: FontFace -> FontFace -> [FontFace]

enumFromTo :: FontFace -> FontFace -> [FontFace]

enumFromThenTo :: FontFace -> FontFace -> FontFace -> [FontFace]

Show FontFace

Methods

showsPrec :: Int -> FontFace -> ShowS

show :: FontFace -> String

showList :: [FontFace] -> ShowS

data FontSlant

Constructors

NotSlanted

Slanted

Instances

Show FontSlant

Methods

showsPrec :: Int -> FontSlant -> ShowS

show :: FontSlant -> String

showList :: [FontSlant] -> ShowS

data ContourDrawMode

Constructors

OutlineContour LineType Int32

Thickness of lines the contours are drawn with.

FillContours

Draw the contour, filling in the area.

arrowedLine

Arguments

:: (IsPoint2 fromPoint2 Int32, IsPoint2 toPoint2 Int32, ToScalar color, PrimMonad m)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> fromPoint2 Int32

The point the arrow starts from.

-> toPoint2 Int32

The point the arrow points to.

-> color

Line color.

-> Int32

Line thickness.

-> LineType

-> Int32

Number of fractional bits in the point coordinates.

-> Double

The length of the arrow tip in relation to the arrow length.

-> m ()

Draws a arrow segment pointing from the first point to the second one

Example:

arrowedLineImg :: Mat (ShapeT [200, 300]) ('S 4) ('S Word8)
arrowedLineImg = exceptError $
    withMatM
      (Proxy :: Proxy [200, 300])
      (Proxy :: Proxy 4)
      (Proxy :: Proxy Word8)
      transparent $ \imgM -> do
        arrowedLine imgM (V2  10 130 :: V2 Int32) (V2 190  40 :: V2 Int32) blue 5 LineType_AA 0 0.15
        arrowedLine imgM (V2 210  50 :: V2 Int32) (V2 250 180 :: V2 Int32) red  8 LineType_AA 0 0.4

OpenCV Doxygen doc OpenCV Sphinx doc

circle

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image where the circle is drawn.

-> point2 Int32

Center of the circle.

-> Int32

Radius of the circle.

-> color

Circle color.

-> Int32

Thickness of the circle outline, if positive. Negative thickness means that a filled circle is to be drawn.

-> LineType

Type of the circle boundary.

-> Int32

Number of fractional bits in the coordinates of the center and in the radius value.

-> m ()

Draws a circle.

Example:

circleImg :: Mat (ShapeT [200, 400]) ('S 4) ('S Word8)
circleImg = exceptError $
    withMatM
      (Proxy :: Proxy [200, 400])
      (Proxy :: Proxy 4)
      (Proxy :: Proxy Word8)
      transparent $ \imgM -> do
        lift $ circle imgM (V2 100 100 :: V2 Int32) 90 blue  5  LineType_AA 0
        lift $ circle imgM (V2 300 100 :: V2 Int32) 45 red (-1) LineType_AA 0

OpenCV Sphinx doc

ellipse

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, IsSize size Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> point2 Int32

Center of the ellipse.

-> size Int32

Half of the size of the ellipse main axes.

-> Double

Ellipse rotation angle in degrees.

-> Double

Starting angle of the elliptic arc in degrees.

-> Double

Ending angle of the elliptic arc in degrees.

-> color

Ellipse color.

-> Int32

Thickness of the ellipse arc outline, if positive. Otherwise, this indicates that a filled ellipse sector is to be drawn.

-> LineType

Type of the ellipse boundary.

-> Int32

Number of fractional bits in the coordinates of the center and values of axes.

-> m ()

Draws a simple or thick elliptic arc or fills an ellipse sector

Example:

ellipseImg :: Mat (ShapeT [200, 400]) ('S 4) ('S Word8)
ellipseImg = exceptError $
    withMatM
      (Proxy :: Proxy [200, 400])
      (Proxy :: Proxy 4)
      (Proxy :: Proxy Word8)
      transparent $ \imgM -> do
        lift $ ellipse imgM (V2 100 100 :: V2 Int32) (V2 90 60 :: V2 Int32)  30  0 360 blue  5  LineType_AA 0
        lift $ ellipse imgM (V2 300 100 :: V2 Int32) (V2 80 40 :: V2 Int32) 160 40 290 red (-1) LineType_AA 0

OpenCV Sphinx doc

fillConvexPoly

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> Vector (point2 Int32)

Polygon vertices.

-> color

Polygon color.

-> LineType

-> Int32

Number of fractional bits in the vertex coordinates.

-> m ()

Fills a convex polygon.

The function fillConvexPoly draws a filled convex polygon. This function is much faster than the function fillPoly . It can fill not only convex polygons but any monotonic polygon without self-intersections, that is, a polygon whose contour intersects every horizontal line (scan line) twice at the most (though, its top-most and/or the bottom edge could be horizontal).

Example:

fillConvexPolyImg
    :: forall (h :: Nat) (w :: Nat)
     . (h ~ 300, w ~ 300)
    => Mat (ShapeT [h, w]) ('S 4) ('S Word8)
fillConvexPolyImg = exceptError $
    withMatM (Proxy :: Proxy [h, w])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ fillConvexPoly imgM pentagon blue LineType_AA 0
  where
    pentagon :: V.Vector (V2 Int32)
    pentagon = V.fromList
               [ V2 150   0
               , V2   7 104
               , V2  62 271
               , V2 238 271
               , V2 293 104
               ]

OpenCV Sphinx doc

fillPoly

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> Vector (Vector (point2 Int32))

Polygons.

-> color

Polygon color.

-> LineType

-> Int32

Number of fractional bits in the vertex coordinates.

-> m ()

Fills the area bounded by one or more polygons.

Example:

rookPts :: Int32 -> Int32 -> V.Vector (V.Vector (V2 Int32))
rookPts w h = V.singleton $ V.fromList
          [ V2 (    w `div`  4) ( 7*h `div`  8)
          , V2 (  3*w `div`  4) ( 7*h `div`  8)
          , V2 (  3*w `div`  4) (13*h `div` 16)
          , V2 ( 11*w `div` 16) (13*h `div` 16)
          , V2 ( 19*w `div` 32) ( 3*h `div`  8)
          , V2 (  3*w `div`  4) ( 3*h `div`  8)
          , V2 (  3*w `div`  4) (   h `div`  8)
          , V2 ( 26*w `div` 40) (   h `div`  8)
          , V2 ( 26*w `div` 40) (   h `div`  4)
          , V2 ( 22*w `div` 40) (   h `div`  4)
          , V2 ( 22*w `div` 40) (   h `div`  8)
          , V2 ( 18*w `div` 40) (   h `div`  8)
          , V2 ( 18*w `div` 40) (   h `div`  4)
          , V2 ( 14*w `div` 40) (   h `div`  4)
          , V2 ( 14*w `div` 40) (   h `div`  8)
          , V2 (    w `div`  4) (   h `div`  8)
          , V2 (    w `div`  4) ( 3*h `div`  8)
          , V2 ( 13*w `div` 32) ( 3*h `div`  8)
          , V2 (  5*w `div` 16) (13*h `div` 16)
          , V2 (    w `div`  4) (13*h `div` 16)
          ]

fillPolyImg
    :: forall (h :: Nat) (w :: Nat)
     . (h ~ 300, w ~ 300)
    => Mat (ShapeT [h, w]) ('S 4) ('S Word8)
fillPolyImg = exceptError $
    withMatM (Proxy :: Proxy [h, w])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ fillPoly imgM (rookPts w h) blue LineType_AA 0
  where
    h = fromInteger $ natVal (Proxy :: Proxy h)
    w = fromInteger $ natVal (Proxy :: Proxy w)

OpenCV Sphinx doc

polylines

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> Vector (Vector (point2 Int32))

Vertices.

-> Bool

Flag indicating whether the drawn polylines are closed or not. If they are closed, the function draws a line from the last vertex of each curve to its first vertex.

-> color

-> Int32

Thickness of the polyline edges.

-> LineType

-> Int32

Number of fractional bits in the vertex coordinates.

-> m ()

Draws several polygonal curves

Example:

polylinesImg
    :: forall (h :: Nat) (w :: Nat)
     . (h ~ 300, w ~ 300)
    => Mat (ShapeT [h, w]) ('S 4) ('S Word8)
polylinesImg = exceptError $
    withMatM (Proxy :: Proxy [h, w])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ polylines imgM (rookPts w h) True blue 2 LineType_AA 0
  where
    h = fromInteger $ natVal (Proxy :: Proxy h)
    w = fromInteger $ natVal (Proxy :: Proxy w)

OpenCV Sphinx doc

line

Arguments

:: (PrimMonad m, IsPoint2 fromPoint2 Int32, IsPoint2 toPoint2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> fromPoint2 Int32

First point of the line segment.

-> toPoint2 Int32

Scond point of the line segment.

-> color

Line color.

-> Int32

Line thickness.

-> LineType

-> Int32

Number of fractional bits in the point coordinates.

-> m ()

Draws a line segment connecting two points.

Example:

lineImg :: Mat (ShapeT [200, 300]) ('S 4) ('S Word8)
lineImg = exceptError $
    withMatM (Proxy :: Proxy [200, 300])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ line imgM (V2  10 130 :: V2 Int32) (V2 190  40 :: V2 Int32) blue 5 LineType_AA 0
      lift $ line imgM (V2 210  50 :: V2 Int32) (V2 250 180 :: V2 Int32) red  8 LineType_AA 0

OpenCV Sphinx doc

getTextSize

Arguments

:: Text

-> Font

-> Int32

Thickness of lines used to render the text.

-> (Size2i, Int32)

(size, baseLine) = (The size of a box that contains the specified text. , y-coordinate of the baseline relative to the bottom-most text point)

Calculates the size of a box that contains the specified text

OpenCV Sphinx doc

putText

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> Text

Text string to be drawn.

-> point2 Int32

Bottom-left corner of the text string in the image.

-> Font

-> color

Text color.

-> Int32

Thickness of the lines used to draw a text.

-> LineType

-> Bool

When True, the image data origin is at the bottom-left corner. Otherwise, it is at the top-left corner.

-> m ()

Draws a text string.

The function putText renders the specified text string in the image. Symbols that cannot be rendered using the specified font are replaced by question marks.

Example:

putTextImg :: Mat ('S ['D, 'S 400]) ('S 4) ('S Word8)
putTextImg = exceptError $
    withMatM (height ::: (Proxy :: Proxy 400) ::: Z)
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      forM_ (zip [0..] [minBound .. maxBound]) $ \(n, fontFace) ->
        lift $ putText imgM
                       (T.pack $ show fontFace)
                       (V2 10 (35 + n * 30) :: V2 Int32)
                       (Font fontFace NotSlanted 1.0)
                       black
                       1
                       LineType_AA
                       False
  where
    height :: Int32
    height = 50 + fromIntegral (30 * fromEnum (maxBound :: FontFace))

OpenCV Sphinx doc

rectangle

Arguments

:: (PrimMonad m, ToScalar color, IsRect rect Int32)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

Image.

-> rect Int32

-> color

Rectangle color or brightness (grayscale image).

-> Int32

Line thickness.

-> LineType

-> Int32

Number of fractional bits in the point coordinates.

-> m ()

Draws a simple, thick, or filled up-right rectangle

Example:

rectangleImg :: Mat (ShapeT [200, 400]) ('S 4) ('S Word8)
rectangleImg = exceptError $
    withMatM (Proxy :: Proxy [200, 400])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ rectangle imgM (toRect $ HRect (V2  10 10) (V2 180 180)) blue  5  LineType_8 0
      lift $ rectangle imgM (toRect $ HRect (V2 260 30) (V2  80 140)) red (-1) LineType_8 0

OpenCV Sphinx doc

drawContours

Arguments

:: (ToScalar color, PrimMonad m)

=> Vector (Vector Point2i)

-> color

Color of the contours.

-> ContourDrawMode

-> Mut (Mat (S '[h, w]) channels depth) (PrimState m)

Image.

-> m ()

Draw contours onto a black image.

Example:

flowerContours :: Mat ('S ['S 512, 'S 768]) ('S 3) ('S Word8)
flowerContours = exceptError $
  withMatM (Proxy :: Proxy [512,768])
           (Proxy :: Proxy 3)
           (Proxy :: Proxy Word8)
           black $ \imgM -> do
    edges <- thaw $ exceptError $
             cvtColor bgr gray flower_768x512 >>=
             canny 30 20 Nothing CannyNormL1
    contours <- findContours ContourRetrievalList
                             ContourApproximationSimple edges
    lift $ drawContours (V.map contourPoints contours)
                        red
                        (OutlineContour LineType_AA 1)
                        imgM

marker

Arguments

:: (PrimMonad m, IsPoint2 point2 Int32, ToScalar color)

=> Mut (Mat (S '[height, width]) channels depth) (PrimState m)

The image to draw the marker on.

-> point2 Int32

The point where the crosshair is positioned.

-> color

Line color.

-> m ()

Draws a marker on a predefined position in an image.

The marker will be drawn as as a 20-pixel cross.

Example:

markerImg :: Mat (ShapeT [100, 100]) ('S 4) ('S Word8)
markerImg = exceptError $
    withMatM (Proxy :: Proxy [100, 100])
             (Proxy :: Proxy 4)
             (Proxy :: Proxy Word8)
             transparent $ \imgM -> do
      lift $ marker imgM (50 :: V2 Int32) blue