diff --git a/CHANGELOG.md b/CHANGELOG.md --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,3 +1,8 @@ +1.5.6.0 +======= + +* Addition of Bicubic interpolation (Thanks to @kirisaki) + 1.5.5.0 ======= diff --git a/hip.cabal b/hip.cabal --- a/hip.cabal +++ b/hip.cabal @@ -1,5 +1,5 @@ Name: hip -Version: 1.5.5.0 +Version: 1.5.6.0 License: BSD3 License-File: LICENSE Author: Alexey Kuleshevich diff --git a/src/Graphics/Image/Processing/Interpolation.hs b/src/Graphics/Image/Processing/Interpolation.hs --- a/src/Graphics/Image/Processing/Interpolation.hs +++ b/src/Graphics/Image/Processing/Interpolation.hs @@ -10,7 +10,7 @@ -- Portability : non-portable -- module Graphics.Image.Processing.Interpolation ( - Interpolation(..), Nearest(..), Bilinear(..) + Interpolation(..), Nearest(..), Bilinear(..), Bicubic(..) ) where import Graphics.Image.Interface @@ -38,16 +38,21 @@ data Bilinear = Bilinear deriving Show +-- | Bicubic interpolation method. +-- The parameter is usually set from -0.5 to -1.0. +newtype Bicubic = Bicubic Double deriving Show + + instance Interpolation Nearest where - interpolate Nearest border !sz getPx !(i, j) = + interpolate Nearest border !sz getPx (i, j) = handleBorderIndex border sz getPx (round i, round j) {-# INLINE interpolate #-} instance Interpolation Bilinear where - interpolate Bilinear border !sz getPx !(i, j) = fi0 + jPx*(fi1-fi0) where + interpolate Bilinear border !sz getPx (i, j) = fi0 + jPx*(fi1-fi0) where getPx' = handleBorderIndex border sz getPx {-# INLINE getPx' #-} !(i0, j0) = (floor i, floor j) @@ -60,4 +65,86 @@ !f11 = getPx' (i1, j1) !fi0 = f00 + iPx*(f10-f00) !fi1 = f01 + iPx*(f11-f01) + {-# INLINE interpolate #-} + + +instance Interpolation Bicubic where + + interpolate (Bicubic a) border !sz getPx (i, j) = + ( f00 + f10 + f20 + f30 + + f01 + f11 + f21 + f31 + + f02 + f12 + f22 + f32 + + f03 + f13 + f23 + f33 ) * promote (fromDouble (1 / w)) + where + getPx' = handleBorderIndex border sz getPx + {-# INLINE getPx' #-} + distX x = fromIntegral x - i + {-# INLINE distX #-} + distY y = fromIntegral y - j + {-# INLINE distY #-} + weight x + | x' <= 1 = ((a + 2) * x' - (a + 3)) * x2' + 1 + | x' < 2 = a * ((x2' - 5 * x' + 8) * x' - 4) + | otherwise = 0 + where x' = abs x + x2' = x' * x' + {-# INLINE weight #-} + !(i0, j0) = (i1 - 1, j1 - 1) + !(i1, j1) = (floor i, floor j) + !(i2, j2) = (i1 + 1, j1 + 1) + !(i3, j3) = (i1 + 2, j1 + 2) + + !weightX0 = weight (distX i0) + !weightX1 = weight (distX i1) + !weightX2 = weight (distX i2) + !weightX3 = weight (distX i3) + !weightY0 = weight (distY j0) + !weightY1 = weight (distY j1) + !weightY2 = weight (distY j2) + !weightY3 = weight (distY j3) + + !weightX0Y0 = weightX0 * weightY0 + !weightX1Y0 = weightX1 * weightY0 + !weightX2Y0 = weightX2 * weightY0 + !weightX3Y0 = weightX3 * weightY0 + + !weightX0Y1 = weightX0 * weightY1 + !weightX1Y1 = weightX1 * weightY1 + !weightX2Y1 = weightX2 * weightY1 + !weightX3Y1 = weightX3 * weightY1 + + !weightX0Y2 = weightX0 * weightY2 + !weightX1Y2 = weightX1 * weightY2 + !weightX2Y2 = weightX2 * weightY2 + !weightX3Y2 = weightX3 * weightY2 + + !weightX0Y3 = weightX0 * weightY3 + !weightX1Y3 = weightX1 * weightY3 + !weightX2Y3 = weightX2 * weightY3 + !weightX3Y3 = weightX3 * weightY3 + + !f00 = getPx' (i0, j0) * promote (fromDouble weightX0Y0) + !f10 = getPx' (i1, j0) * promote (fromDouble weightX1Y0) + !f20 = getPx' (i2, j0) * promote (fromDouble weightX2Y0) + !f30 = getPx' (i3, j0) * promote (fromDouble weightX3Y0) + + !f01 = getPx' (i0, j1) * promote (fromDouble weightX0Y1) + !f11 = getPx' (i1, j1) * promote (fromDouble weightX1Y1) + !f21 = getPx' (i2, j1) * promote (fromDouble weightX2Y1) + !f31 = getPx' (i3, j1) * promote (fromDouble weightX3Y1) + + !f02 = getPx' (i0, j2) * promote (fromDouble weightX0Y2) + !f12 = getPx' (i1, j2) * promote (fromDouble weightX1Y2) + !f22 = getPx' (i2, j2) * promote (fromDouble weightX2Y2) + !f32 = getPx' (i3, j2) * promote (fromDouble weightX3Y2) + + !f03 = getPx' (i0, j3) * promote (fromDouble weightX0Y3) + !f13 = getPx' (i1, j3) * promote (fromDouble weightX1Y3) + !f23 = getPx' (i2, j3) * promote (fromDouble weightX2Y3) + !f33 = getPx' (i3, j3) * promote (fromDouble weightX3Y3) + + !w = weightX0Y0 + weightX1Y0 + weightX2Y0 + weightX3Y0 + + weightX0Y1 + weightX1Y1 + weightX2Y1 + weightX3Y1 + + weightX0Y2 + weightX1Y2 + weightX2Y2 + weightX3Y2 + + weightX0Y3 + weightX1Y3 + weightX2Y3 + weightX3Y3 {-# INLINE interpolate #-} diff --git a/tests/Graphics/Image/ProcessingSpec.hs b/tests/Graphics/Image/ProcessingSpec.hs --- a/tests/Graphics/Image/ProcessingSpec.hs +++ b/tests/Graphics/Image/ProcessingSpec.hs @@ -13,17 +13,20 @@ data Interpol = I1 Nearest | I2 Bilinear + | I3 Bicubic instance Show Interpol where show (I1 i) = "I1 " ++ show i show (I2 i) = "I2 " ++ show i + show (I3 i) = "I3 " ++ show i instance Arbitrary Interpol where arbitrary = do ix <- arbitrary - case ix `mod` (2 :: Int) of + case ix `mod` (3 :: Int) of 0 -> return $ I1 Nearest 1 -> return $ I2 Bilinear + 2 -> I3 . Bicubic <$> pure (-1) -- choose (-1, -0.5) _ -> error $ "Unknown interpolation: " ++ show ix @@ -71,21 +74,25 @@ rotate90 (leftToRight img $ rotate180 img) -prop_rotate90 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Bool -prop_rotate90 (I1 i) border img = rotate90 img == rotate i border (pi/2) img -prop_rotate90 (I2 i) border img = rotate90 img == rotate i border (pi/2) img +prop_rotate90 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Property +prop_rotate90 (I1 i) border img = rotate90 img === rotate i border (pi/2) img +prop_rotate90 (I2 i) border img = rotate90 img === rotate i border (pi/2) img +prop_rotate90 (I3 i) border img = rotate90 img === rotate i border (pi/2) img -prop_rotate180 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Bool -prop_rotate180 (I1 i) border img = rotate180 img == rotate i border pi img -prop_rotate180 (I2 i) border img = rotate180 img == rotate i border pi img +prop_rotate180 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Property +prop_rotate180 (I1 i) border img = rotate180 img === rotate i border pi img +prop_rotate180 (I2 i) border img = rotate180 img === rotate i border pi img +prop_rotate180 (I3 i) border img = rotate180 img === rotate i border pi img -prop_rotate270 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Bool -prop_rotate270 (I1 i) border img = rotate270 img == rotate i border (3*pi/2) img -prop_rotate270 (I2 i) border img = rotate270 img == rotate i border (3*pi/2) img +prop_rotate270 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Property +prop_rotate270 (I1 i) border img = rotate270 img === rotate i border (3*pi/2) img +prop_rotate270 (I2 i) border img = rotate270 img === rotate i border (3*pi/2) img +prop_rotate270 (I3 i) border img = rotate270 img === rotate i border (3*pi/2) img -prop_rotate360 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Bool -prop_rotate360 (I1 i) border img = (rotate270 . rotate90) img == rotate i border (2*pi) img -prop_rotate360 (I2 i) border img = (rotate270 . rotate90) img == rotate i border (2*pi) img +prop_rotate360 :: Interpol -> Border (Pixel RGB Double) -> Image VU RGB Double -> Property +prop_rotate360 (I1 i) border img = (rotate270 . rotate90) img === rotate i border (2*pi) img +prop_rotate360 (I2 i) border img = (rotate270 . rotate90) img === rotate i border (2*pi) img +prop_rotate360 (I3 i) border img = (rotate270 . rotate90) img === rotate i border (2*pi) img struct :: Image VS X Bit