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SiftJS

An HTML canvas filter library

This library still has a lot of unfinished components and is not stable.

Filters

Filters are ways to alter existing canvas image data by altering individual pixel values. This is achieved by either a simple filter (such as blackAndWhite) or via a convolution filter (such as sobel).

var results = SIFT.Filter.filterName(canvasImageDataObject);

These functions return a filtered canvas image data object.

Available filters are:

  • SIFT.Filter.blackAndWhite();
  • SIFT.Filter.saturation();
  • SIFT.Filter.brighten();
  • SIFT.Filter.contrast();
  • SIFT.Filter.invert();
  • SIFT.Filter.gamma();
  • SIFT.Filter.threshold();
  • SIFT.Filter.otsuThreshold();
  • SIFT.Filter.detectShadows();
  • SIFT.Filter.sharpen();
  • SIFT.Filter.gaussianBlur();
  • SIFT.Filter.median();
  • SIFT.Filter.sobel();
  • SIFT.Filter.depthChannels();
  • SIFT.Filter.depthEdges();
  • SIFT.Filter.depthIntensity();

Blenders

Blenders are ways to blend and combine different canvas element data objects.

var results = SIFT.Blender.blenderName(arrayOfCanvasImageDataObjects);

Blenders will return a canvas image object.

Available blenders are:

  • SIFT.Blender.combine();

Kernels

These are the pre-stored kernel matrices for static convolution filters. The available kernels are:

  • Sobel 3x3 Horizontal and Vertical
  • Sobel 5x5 Horizontal and Vertical
  • Kirsch 3x3 North, NorthEast, East, SouthEast, South, SouthWest, West, NorthWest
  • Laplacian Of Gaussian 9x9
  • Prewitt 3x3 Horizontal and Vertical
  • Prewitt 5x5 Horizontal and Vertical
  • Blur (Box Blur) 3x3
  • Blur (Box Blur) 5x5
  • Motion Blur 3x3 (statically NorthWest -> SouthEast direction only)
  • Motion Blur 5x5 (statically NorthWest -> SouthEast direction only)
  • Gaussian Blur 3x3
  • Gaussian Blur 5x5
  • Sharpen 3x3

Kernels can be accessed via SIFT.Kernel.kernelName.kernelSize.kernelDirection

You can run Kernels over an image by passing the preferred kernel with the canvas ImageData object into one of the convolution functions: var results = SIFT.baseAlgorithms.convolveKernel(canvasImageDataObject, kernelArray, opaqueBool); var results = SIFT.baseAlgorithms.convolveKernelFloat32(canvasImageDataObject, kernelArray, opaqueBool);

If you want more control over your convolution filters, you can run your canvas image data through the vertical and horizontal convolve functions with your custom weight arrays:

SIFT.baseAlgorithms.convolveVertical(canvasImageDataObject, weightsArray, opacityBool) SIFT.baseAlgorithms.convolveHorizontal(canvasImageDataObject, weightsArray, opacityBool)