ImageMagick wand module for node and backendjs

Requirements

Installing dependencies on CentOS:

yum -y install libpng-devel libjpeg-turbo-devel

Installing dependencies on Mac OS X using macports:

port install libpng jpeg

Usage

- resizeImage(source, options, callback) - resize image using ImageMagick
- source can be a Buffer or file name
- options can have the following properties:
- width - output image width, if negative and the original image width is smaller than the specified, nothing happens
- height - output image height, if negative and the original image height is smaller this the specified, nothing happens
- quality - 0 - 99
- out - output file name
- ext - image extention
- outfile - a filename where to save scaled image, if not given the binary image data is passed to the callback
- frame - which frame to resize for animated GIFs, 0 is default, -1 to convert all frames
- no_animation - if set to 1 it will convert GIF animation, otherwise animated GIF is simply returned as is
- posterize - levels, 2,3,4
- dither - 1 to dither
- normalize - 1 to normalize image
- quantize - number of colors
- treedepth - 0 or 1 for quantize
- flip - 1 to flip image
- flop - 1 1 to flop image
- blur_radius - radius in pixels
- blur_sigma - std deviation in pixels
- sharpen_radius - radius in pixels
- sharpen_sigma - std deviation in pixels
- brightness - -100 - 100
- contrast - -100 - 100
- rotate - degrees
- opacity - 0 - 1.0
- crop_width - crop coordinates
- crop_height
- crop_x
- crop_y
- bgcolor - RGB for background
- filter - box, triangle, hermite, hanning, hamming, blackman, gaussian,
quadratic, cubic, catrom, mitchell, lanczos, kaiser, welsh, parzen,
bohman, barlett, lagrange, jinc, sinc, sincfast, lanczossharp, lanzos2,
lanzos2sharp, robidoux, robidouxsharp, cosine, spline, lanczosradius
- colorspace - rgb, gray, transparent, ohta, xyz, ycbcr, ycc, yiq, ypbpr, yuv,
cmylk, srgb, hls, hwb
- gravity - northwest, north, northeast, west, center, east, southwest, south, southeast

On return the callback will receive the image data if no outfile was specified or null, and the third
argument if an object with the result image information: file, ext, height, width, orientation, rotation.

The original image dimentions are returned as _width and _height.

The file where the image is sved will have the actual extention, if the outfile parameter contains invalid extention
it will be replaced with the actual resulting image type.

``javascript
require("bkjs-wand").resizeImage("a.png", { width: 120, height: 120 }, function(err, data, info) {
if (!err) fs.writeFile("b.png", data);
console.log(err, info);
})
``

Author

Vlad Seryakov