FlatCV Haskell Bindings

Haskell bindings for the FlatCV image processing library.

Usage

import FlatCV
import qualified Data.Vector.Storable as V

main :: IO ()
main = do
  -- Assuming you have RGBA image data as a Vector Word8
  let
    width = 640
    height = 480
    -- imageData :: V.Vector Word8

  -- Convert to grayscale
  grayData <- grayscale width height imageData

  -- Apply Gaussian blur
  blurredData <- gaussianBlur width height 2.0 imageData

  -- Detect edges
  edges <- sobelEdgeDetection width height 4 imageData

  -- Extract a document from a photo
  (outW, outH, docData) <- extractDocumentAuto width height imageData

Available Functions

Color Conversion

• grayscale - Convert RGBA to grayscale (4-channel output)
• grayscaleStretch - Grayscale with contrast stretching
• rgbaToGrayscale - Convert to single-channel grayscale
• singleToMultichannel - Convert grayscale to RGBA

Filtering

• gaussianBlur - Apply Gaussian blur

Thresholding

• otsuThreshold - Otsu's automatic thresholding
• bwSmart - Smart black & white conversion
• applyGlobalThreshold - Apply fixed threshold

Edge Detection

• sobelEdgeDetection - Sobel edge detection
• foerstnerCorner - Foerstner corner detection

Morphological Operations

• binaryDilationDisk - Binary dilation
• binaryErosionDisk - Binary erosion
• binaryClosingDisk - Binary closing
• binaryOpeningDisk - Binary opening

Geometric Transforms

• flipX, flipY - Flip horizontally/vertically
• transpose, transverse - Transpose operations
• rotate90CW, rotate180, rotate270CW - Rotations
• resize - Resize with bilinear interpolation

Cropping & Trimming

• crop - Crop rectangular region
• trim - Auto-trim borders
• trimThreshold - Trim with threshold tolerance

Perspective Transform

• calculatePerspectiveTransform - Calculate transform matrix
• applyMatrix3x3 - Apply 3x3 transformation
• detectCorners - Detect document corners

Document Extraction

• extractDocument - Extract with fixed output size
• extractDocumentAuto - Extract with automatic sizing

Drawing

• drawCircle - Draw circle outline
• drawDisk - Draw filled circle
• addBorder - Add border around image

Analysis

• generateHistogram - Generate histogram visualization

Segmentation

• watershedSegmentation - Watershed segmentation
• floodFill - Flood fill with multiple seeds and 4- or 8-connectivity

Utility

• getExifOrientation - Read JPEG EXIF orientation
• parseHexColor - Parse hex color string
• convertToBinary - Convert to binary with custom colors