Gm : GraphicsMagick For Node.js - GitHub Pages

manipulation

• adjoin gm("img.png").adjoin()
• affine gm("img.png").affine(matrix)
• antialias

  By default all imgs are anti-aliased by GraphicsMagick. To disable it pass false.

  gm("img.png").antialias(false)
• append

  Append a set of images

  img the path to another img ltr (optional) Boolean - specifies append direction true for left-to-right false for top-to-bottom (default) gm("img.png").append(img [, img, ltr]) // appends another.jpg to img.png from left-to-right gm("img.png").append("another.jpg").append(true) // appends another.jpg to img.png from left-to-right gm("img.png").append("another.jpg", true) // appends another.jpg to img.png from top-to-bottom gm("img.png").append("another.jpg") // appends third.gif below another.jpg below img.png gm("img.png").append("another.jpg").append("third.gif") // appends third.gif below another.jpg below img.png gm("img.png").append("another.jpg", "third.gif") // appends third.gif to the right of another.jpg to the right to img.png gm("img.png").append("another.jpg", "third.gif", true)
• authenticate gm("img.png").authenticate(password)
• autoOrient

  Auto-orients the image according to its EXIF data.

  GraphicsMagick doesn't actually have the -auto-orient option but we emulate this by first reading the EXIF data and rotate/flip from there.

  gm("img.jpg").autoOrient()
• average gm("img.png").average()
• backdrop gm("img.png").backdrop()
• bitdepth

  Specifies the number of bits of color to preserve in the image. See the docs for more detail.

  gm("img.png").bitdepth(bits)
• blackThreshold

  pixels below `threshold` become black.

  gm("img.png").blackThreshold(red [,green] [,blue] [,opacity])
• bluePrimary gm("img.png").bluePrimary(x, x)
• blur

  Accepts a radius and optional sigma (standard deviation).

  gm("img.png").blur(radius [, sigma])
• border gm("img.png").border(width, height)
• borderColor gm("img.png").borderColor(color)
• box gm("img.png").box(color)
• channel type Red, Green, Blue, Opacity, Matte, Cyan, Magenta, Yellow, Black, or Gray gm("img.png").channel(type)
• charcoal

  Simulates a charcoal drawing. Accepts a factor.

  gm("img.png").charcoal(factor)
• chop

  Removes pixels from the interior of an image.

  gm("img.png").chop(width, height, x, y)
• clip gm("img.png").clip()
• coalesce gm("img.png").coalesce()
• colorize

  Colorize the image with optionally separate red, green, and blue values.

  gm("img.png").colorize(red [, green [, blue]])
• colorMap type shared or private gm("img.png").colorMap(type)
• colors

  Sets the preferred number of colors for the image (color reduction).

  gm("img.png").colors(int)
• colorspace

  Specifies the type of colorspace. See the GraphicsMagick docs for val details.

  gm("img.png").colorspace(val)
• compose gm("img.png").compose(operator)
• compress type None, BZip, Fax, Group4, JPEG, Lossless, LZW, RLE, Zip, or LZMA gm("img.png").compress(type)
• comment

  Annotates an image. See the docs for more info.

  gm("img.png").comment(text|format)
• contrast

  Increases or reduces the image contrast. Accepts a multiplier.

  gm("img.png").contrast([+-]multiplier)
• convolve gm("img.png").convolve(kernel)
• createDirectories gm("img.png").createDirectories()
• crop

  Crops the image to the given width and height at the given x and y position.

  gm("img.png").crop(width, height, x, y)
• cycle

  Displace the image colormap by amount. amount is the number of positions each colormap entry is shifted.

  gm("img.png").cycle(amount)
• deconstruct gm("img.png").deconstruct()
• define gm("img.png").define()
• delay

  `amount` is in hundreths of a second.

  gm("img.png").delay(amout)
• density

  This option specifies the image resolution to store while encoding a raster image or the canvas resolution while rendering (reading) vector formats into an image.

  gm("img.png").density(width, height)
• despeckle

  Reduces the speckles within the image.

  gm("img.png").despeckle()
• displace

  Shift image pixels as defined by a displacement map.

  gm("img.png").displace(horizontal, vertical)
• display gm("img.png").display(value)
• dispose gm("img.png").dispose(method)
• dissolve gm("img.png").dissolve(method)
• dither

  Applies Floyd/Steinberg error diffusion to the image. Pass false to disable dithering.Note: either .colors() or .monochrome() must be used for this to take effect.

  gm("img.png").dither([bool])
• edge

  Emphasizes edges in an image. Takes an optional radius of the emphasis to apply.

  gm("img.png").edge([radius])
• emboss

  Embosses the image. Takes an optional radius.

  gm("img.png").emboss([radius])
• encoding type AdobeCustom, AdobeExpert, AdobeStandard, AppleRoman, BIG5, GB2312, Latin 2, None, SJIScode, Symbol, Unicode, Wansung gm("img.png").encoding(type)
• endian type MSB, LSB, or Native gm("img.png").endian(type)
• enhance

  Enhances the image.

  gm("img.png").enhance()
• equalize

  Performs histogram equalization to the image.

  gm("img.png").equalize()
• extent

  composite image on background color canvas image.

  gm("img.png").extent([width, height, options])
• file gm("img.png").file(filename)
• filter

  Specifies the filter to use when resizing. see link for available types.

  gm("img.png").filter(type)
• flatten gm("img.png").flatten()
• flip

  Creates a mirror image (vertically).

  gm("img.png").flip()
• flop

  Creates a mirror image (horizontally).

  gm("img.png").flop()
• foreground gm("img.png").foreground(color)
• frame gm("img.png").frame(width, height, outerBevelWidth, innerBevelWidth)
• fuzz gm("img.png").fuzz(distance [,percent])
• gamma

  Adjusts the level of gamma correction.

  gm("img.png").gamma(r, g, b)
• gaussian gm("img.png").gaussian(radius [,sigma])
• geometry gm("img.png").geometry(width, height [,arg])
• greenPrimary gm("img.png").greenPrimary(x, y)
• gravity

  The direction the primitive gravitates to when annotating the image. Defaults to NorthWest.

  direction NorthWest|North|NorthEast|West|Center|East|SouthWest|South|SouthEast gm("img.png").gravity(direction)
• highlightColor gm("img.png").highlightColor(color)
• highlightStyle gm("img.png").highlightStyle(color)
• iconGeometry gm("img.png").iconGeometry(geometry)
• implode

  Implodes the image pixels around the center. Takes an optional factor.

  gm("img.png").implode([factor])
• intent type Absolute, Perceptual, Relative, or Saturation gm("img.png").intent(type)
• interlace

  Specifies the type of interlacing scheme. Defaults to None.

  type None|Line|Plane|Partition gm("img.png").interlace(type)
• label

  Assigns a label to an image.

  gm("img.png").label(name)
• lat gm("img.png").lat(width, height, offset [,percent])
• level gm("img.png").level(blackPoint, gamma, whitePoint [,percent])
• limit

  Sets resource limits.

  type disk|file|map|memory|pixels|threads val follows the same rules as specified in the GraphicsMagick docs gm("img.png").limit(type, val)
• list type Color, Delegate, Format, Magic, Module, Resource, or Type gm("img.png").list(type)
• log

  Specify format for debug log. See the docs for detail.

  gm("img.png").log(format)
• loop

  See the docs for detail.

  gm("img.png").loop(iterations)
• lower

  Creates a pseudo 3D lowering effect of the images edges.

  gm("img.png").lower(width, height)
• magnify

  Magnifies the image factor times.

  gm("img.png").magnify(factor)
• map

  See the docs for detail.

  gm("img.png").map(filename)
• mask

  See the docs for detail.

  gm("img.png").mask(filename)
• matte

  See the docs for detail.

  gm("img.png").matte()
• matteColor

  See the docs for detail.

  gm("img.png").matteColor(color)
• maximumError

  See the docs for detail.

  gm("img.png").maximumError(limit)
• median

  Applies a median filter to the image. The optional param radius adjusts the weight of the effect.

  gm("img.png").median([radius])
• minify

  Minifies the image factor times.

  gm("img.png").minify(factor)
• mode

  See the docs for detail.

  gm("img.png").mode(value)
• modulate

  Varies the brightness, saturation, and hue of the image.

  gm("img.png").modulate(b [, s [, h]])
• monitor

  See the docs for detail.

  gm("img.png").monitor()
• monochrome

  Transforms the image to black and white.

  gm("img.png").monochrome()
• morph

  Morphs two images together.

  otherImg the path to another img outName the path where the image will be saved callback A function to be executed when morphing is complete. callback will be passed the standard args that .write() receives. gm("img.png").morph(otherImg, outName, callback)
• mosaic

  See the docs for detail.

  gm("img.png").mosaic()
• motionBlur

  See the docs for detail.

  gm("img.png").motionBlur(radius [, sigma, angle])
• name

  See the docs for detail.

  gm("img.png").name()
• negative

  Replaces every pixel with its complementary color.

  gm("img.png").negative()
• noise

  Add or reduce noise in the image.

  radius|type To add noise pass one of the following:
  • uniform
  • gaussian
  • multiplicative
  • impulse
  • laplacian
  • poisson
  Otherwise the argument will be interpreted as a radius which adjusts the weight of the effect. gm("img.png").noise(radius|type)
• noop

  See the docs for detail.

  gm("img.png").noop()
• normalize

  See the docs for detail.

  gm("img.png").normalize()
• opaque

  See the docs for detail.

  gm("img.png").opaque(color)
• operator

  See the docs for detail.

  gm("img.png").operator(channel, operator, rvalue [,percent])
• orderedDither

  See the docs for detail.

  gm("img.png").orderedDither(channelType, NxN)
• outputDirectory

  See the docs for detail.

  gm("img.png").outputDirectory(channelType, NxN)
• page

  See the docs for detail.

  gm("img.png").page(width, height [,arg])
• pause

  See the docs for detail.

  gm("img.png").pause(seconds)
• pen

  See the docs for detail.

  gm("img.png").pen(color)
• ping

  See the docs for detail.

  gm("img.png").ping()
• pointSize

  See the docs for detail.

  gm("img.png").pointSize(value)
• noProfile

  Removes EXIF, ICM, etc profile data.

  gm("img.png").noProfile()
• preview type

  See the docs for valid types.

  gm("img.png").preview(type)
• paint

  Simulates an oil painting.

  gm("img.png").paint(radius)
• process

  See the docs for detail.

  gm("img.png").process(command)
• profile

  See the docs for detail.

  gm("img.png").profile(filename)
• progress

  See the docs for detail.

  gm("img.png").progress()
• randomThreshold

  See the docs for detail.

  gm("img.png").randomThreshold(channelType, LOWxHIGH)
• quality

  Adjusts the jpeg|miff|png|tiff compression level. val ranges from 0 to 100 (best).

  gm("img.png").quality(val)
• raise

  Creates a pseudo 3D raising effect of the images edges.

  gm("img.png").raise(width, height)
• recolor

  See the docs for detail.

  gm("img.png").recolor(matrix)
• redPrimary

  See the docs for detail.

  gm("img.png").redPrimary(x, y)
• region

  Specifies that all following methods only apply to the area specified by width, height, x, y.

  gm("img.png").region(width, height, x, y).sepia()

  In this case, the sepia effect would only be applied within the area specified by width, height, x, y.

• remote

  See the docs for detail.

  gm("img.png").remote()
• render

  See the docs for detail.

  gm("img.png").render()
• repage

  See the docs for detail.

  gm("img.png").repage(width, height, xoff, yoff, arg)
• sample

  See the docs for detail.

  gm("img.png").sample(geometry)
• samplingFactor

  See the docs for detail.

  gm("img.png").samplingFactor(horizontalFactor, verticalFactor)
• rawSize

  See the docs for detail.

  gm("img.png").rawSize(width, height, offset)
• resample

  Resamples the image to specified horizontal and vertical resolution.

  gm("img.png").resample(horizontal, vertical)
• resize

  Resize the image.

  options %, @, !, < or > see the GraphicsMagick docs for details gm("img.png").resize(width [, height [, options]])

  To resize an image to a width of 40px while maintaining aspect ratio: gm("img.png").resize(40)

  To resize an image to a height of 50px while maintaining aspect ratio: gm("img.png").resize(null, 50)

  To resize an image to a fit a 40x50 rectangle while maintaining aspect ratio: gm("img.png").resize(40, 50)

  To override the image's proportions and force a resize to 40x50: gm("img.png").resize(40, 50, "!")

• roll

  Rolls an image vertically or horizontally.

  gm("img.png").roll(horizontalInt, verticalInt)
• rotate

  Rotates the image by degrees and fills the background with color.

  gm("img.png").rotate(color, degrees)
• scene

  See the docs for detail.

  gm("img.png").scene(value)
• scenes

  See the docs for detail.

  gm("img.png").scenes(start, end)
• scale

  Scales the image.

  gm("img.png").scale(width, height)
• screen

  See the docs for detail.

  gm("img.png").screen()
• segment

  See the docs for detail.

  gm("img.png").segment(clusterThreshold, smoothingThreshold)
• selectFrame

  Helpful if we process a large .gif so we don't load in memory each frame.

  gm("img.png").selectFrame(0)
• sepia

  A convenience method to apply a sepia effect to the image.

  gm("img.png").sepia()
• set

  See the docs for detail.

  gm("img.png").set(attribute, value)
• setFormat

  Overriddes the output image format.

  Helpful if we are outputting an image with no extention but need to change formats.

  gm("img.png").setFormat(format)
• shade

  See the docs for detail.

  gm("img.png").shade(azimuth, elevation)
• shadow

  See the docs for detail.

  gm("img.png").shadow(radius, sigma)
• sharedMemory

  See the docs for detail.

  gm("img.png").sharedMemory()
• shave

  See the docs for detail.

  gm("img.png").shave(width, height, percent)
• sharpen

  Sharpens the image.

  gm("img.png").sharpen(radius [, sigma])
• shear

  See the docs for detail.

  gm("img.png").shear(xDegrees, yDegrees)
• silent

  See the docs for detail.

  gm("img.png").silent()
• snaps

  See the docs for detail.

  gm("img.png").snaps(value)
• solarize

  Negates all pixels above threshold percent.

  gm("img.png").solarize(threshold)
• spread

  Desplaces pixels by a random amount.

  gm("img.png").spread(amount)
• stegano

  See the docs for detail.

  gm("img.png").stegano(offset)
• stereo

  See the docs for detail.

  gm("img.png").stereo()
• strip

  Strips the image of any profiles or comments.

  Similar to noProfile() but removes both profile and comment data. only works with imageMagick.

  gm("img.png").strip()
• swirl

  Swirls pixels arount the center of the image. degrees specifies the tightness of the swirl.

  gm("img.png").swirl(degrees)
• textFont

  See the docs for detail.

  gm("img.png").textFont(font)
• texture

  See the docs for detail.

  gm("img.png").texture(font)
• threshold

  See the docs for detail.

  gm("img.png").threshold(value [, percent])
• thumb

  Creates a thumbnail based on minimum sizes.

  width the minimum width of the thumbnail height the minimum height of the thumbnail outName the path where the image will be saved quality Adjusts the image compression level. Ranges from 0 to 100 (best). callback called after the thumbnail is written. receives the same args that .write(err, stdout, stderr, command) receives. gm("img.png").thumb(width, height, outName, quality, callback)
• tile

  See the docs for detail.

  gm("img.png").tile(filename)
• title

  See the docs for detail.

  gm("img.png").title(string)
• transform

  See the docs for detail.

  gm("img.png").transform(color)
• transparent

  See the docs for detail.

  gm("img.png").transparent(color)
• treeDepth

  See the docs for detail.

  gm("img.png").treeDepth(color)
• trim

  Trim an image by removing any edges that are exactly the same color as the corner pixels.

  gm("img.png").trim()
• type

  Specifies the image type.

  type Can be one of the following:
  • Bilevel
  • Grayscale
  • Palette
  • PaletteMatte
  • TrueColor
  • TrueColorMatte
  • ColorSeparation
  • ColorSeparationMatte
  • Optimize
  gm("img.png").type(type)
• update

  See the docs for detail.

  gm("img.png").update(seconds)
• units

  See the docs for detail.

  gm("img.png").units(type)
• unsharp

  See the docs for detail.

  gm("img.png").unsharp(radius [, sigma, amount, threshold])
• usePixmap

  See the docs for detail.

  gm("img.png").usePixmap()
• view

  See the docs for detail.

  gm("img.png").view()
• virtualPixel

  See the docs for detail.

  gm("img.png").virtualPixel(method)
• visual

  See the docs for detail.

  gm("img.png").visual(type)
• watermark

  See the docs for detail.

  gm("img.png").watermark(brightness, saturation)
• wave

  See the docs for detail.

  gm("img.png").wave(amplitude, wavelength)
• whitePoint

  See the docs for detail.

  gm("img.png").whitePoint(x, y)
• whiteThreshold

  See the docs for detail.

  gm("img.png").whiteThreshold(red, green, blue, opacity)
• window

  See the docs for detail.

  gm("img.png").window(id)
• windowGroup

  See the docs for detail.

  gm("img.png").windowGroup()

getters

All getters have the same signature: gm("image.png").size(function(err, value){ // note : value may be undefined })

• size - returns the size (WxH) of the image
• format - returns the image format (gif, jpeg, png, etc)
• depth - returns the image color depth
• color - returns the number of colors
• res - returns the image resolution
• filesize - returns image filesize
• identify - returns all image data available
• orientation - returns the EXIF orientation of the image

Drawing Primitives

Take a look at drawing.js for examples.

• draw

  Annotate an image with one or more graphic primitives (shapes, text, transformations, pixel operations). Used internally for all drawing methods.

  gm("img.png").draw(args)
• drawArc

  Inscribe an elliptical arc within a rectangle. Requires a start and end point as well as the degrees of rotation.

  gm("img.png").drawArc(x0, y0, x1, y1, r0, r1)
• drawBezier

  Draw a Bezier curve.

  gm("img.png").drawBezier([x0, y0], ... [xn, yn])
• drawCircle

  Draws a Circle.

  gm("img.png").drawCircle(x0, y0, x1, y1)
• drawEllipse

  Draws an Ellipse.

  gm("img.png").drawEllipse(x0, y0, r0, ry, r0, r1)
• drawLine

  Draws a Line.

  gm("img.png").drawLine(x0, y0, x1, y1)
• drawPoint

  Draws a Point.

  gm("img.png").drawPoint(x, y)
• drawPolygon

  Draws a Polygon.

  gm("img.png").drawPolygon([x0, y0] ... [xn, yn])
• drawPolyline

  Draws a Polyline.

  gm("img.png").drawPolyline([x0, y0] ... [xn, yn])
• drawRectangle

  Draws a Rectangle. wc and hc are optional and add roundness to the corners.

  gm("img.png").drawRectangle(x0, y0, x1, y1 [, wc, hc])
• drawText

  Draws text on an image at x/y coordinates.

  gm("img.png").drawText(x, y, text [, gravity])
• fill

  Specifies the color to use when filling a drawn shape.

  gm("img.png").fill(color)
• font

  Specifies the font to use when you drawText.

  gm("img.png").font(name)
• fontSize

  Specifies the font size to use when you drawText.

  gm("img.png").fontSize(size)
• stroke

  Specifies the color to use when stroking a drawn shape.

  gm("img.png").stroke(color [, width])
• strokeWidth

  Specifies the stroke width to use when stroking a drawn shape.

  gm("img.png").strokeWidth(width)
• setDraw

  Sets drawing properties. property can be either "color" or "matte".

  gm("img.png").setDraw(property, x, y, method)

Image comparisons

Both GraphicsMagick and ImageMagick support image comparisons which are exposed through gm.compare().

Currently both path1 and path2 must be strings (no Buffers or Streams). Optionally pass a custom tolerance level if 0.4 (the default) is too lax for your use case.

Your callback will be passed four arguments:

You can also output a diff image of the two images by passing a configuration object in place of the tolerance:

Using ImageMagick

We have compatibility with ImageMagick too. Just subclass the gm constructor passing the imageMagick option.

Then use imageMagick the same way you'd normally use gm.

ImageMagick Options

Unlike GraphicsMagick, ImageMagick supports the WebP format. However, you must compile ImageMagick with the WebP option. To do so on OS X, install ImageMagick with the following command using Homebrew:

If you have already installed ImageMagick, you would have to uninstall it then reinstall it.