### Table of Contents - [rotate](#rotate) - [extract](#extract) - [flip](#flip) - [flop](#flop) - [sharpen](#sharpen) - [blur](#blur) - [extend](#extend) - [flatten](#flatten) - [trim](#trim) - [gamma](#gamma) - [negate](#negate) - [normalise](#normalise) - [normalize](#normalize) - [convolve](#convolve) - [threshold](#threshold) - [boolean](#boolean) ## rotate Rotate the output image by either an explicit angle or auto-orient based on the EXIF `Orientation` tag. If an angle is provided, it is converted to a valid 90/180/270deg rotation. For example, `-450` will produce a 270deg rotation. If no angle is provided, it is determined from the EXIF data. Mirroring is supported and may infer the use of a flip operation. The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any. Method order is important when both rotating and extracting regions, for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`. **Parameters** - `angle` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** angle of rotation, must be a multiple of 90. (optional, default `auto`) **Examples** ```javascript const pipeline = sharp() .rotate() .resize(null, 200) .toBuffer(function (err, outputBuffer, info) { // outputBuffer contains 200px high JPEG image data, // auto-rotated using EXIF Orientation tag // info.width and info.height contain the dimensions of the resized image }); readableStream.pipe(pipeline); ``` - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## extract Extract a region of the image. - Use `extract` before `resize` for pre-resize extraction. - Use `extract` after `resize` for post-resize extraction. - Use `extract` before and after for both. **Parameters** - `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** - `options.left` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** zero-indexed offset from left edge - `options.top` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** zero-indexed offset from top edge - `options.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** dimension of extracted image - `options.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** dimension of extracted image **Examples** ```javascript sharp(input) .extract({ left: left, top: top, width: width, height: height }) .toFile(output, function(err) { // Extract a region of the input image, saving in the same format. }); ``` ```javascript sharp(input) .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre }) .resize(width, height) .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost }) .toFile(output, function(err) { // Extract a region, resize, then extract from the resized image }); ``` - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## flip Flip the image about the vertical Y axis. This always occurs after rotation, if any. The use of `flip` implies the removal of the EXIF `Orientation` tag, if any. **Parameters** - `flip` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## flop Flop the image about the horizontal X axis. This always occurs after rotation, if any. The use of `flop` implies the removal of the EXIF `Orientation` tag, if any. **Parameters** - `flop` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## sharpen Sharpen the image. When used without parameters, performs a fast, mild sharpen of the output image. When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space. Separate control over the level of sharpening in "flat" and "jagged" areas is available. **Parameters** - `sigma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`. - `flat` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the level of sharpening to apply to "flat" areas. (optional, default `1.0`) - `jagged` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the level of sharpening to apply to "jagged" areas. (optional, default `2.0`) - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## blur Blur the image. When used without parameters, performs a fast, mild blur of the output image. When a `sigma` is provided, performs a slower, more accurate Gaussian blur. **Parameters** - `sigma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`. - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## extend Extends/pads the edges of the image with the colour provided to the `background` method. This operation will always occur after resizing and extraction, if any. **Parameters** - `extend` **([Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))** single pixel count to add to all edges or an Object with per-edge counts - `extend.top` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - `extend.left` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - `extend.bottom` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - `extend.right` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** **Examples** ```javascript // Resize to 140 pixels wide, then add 10 transparent pixels // to the top, left and right edges and 20 to the bottom edge sharp(input) .resize(140) .background({r: 0, g: 0, b: 0, alpha: 0}) .extend({top: 10, bottom: 20, left: 10, right: 10}) ... ``` - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## flatten Merge alpha transparency channel, if any, with `background`. **Parameters** - `flatten` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## trim Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel. **Parameters** - `tolerance` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** value between 1 and 99 representing the percentage similarity. (optional, default `10`) - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## gamma Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma` then increasing the encoding (brighten) post-resize at a factor of `gamma`. This can improve the perceived brightness of a resized image in non-linear colour spaces. JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation when applying a gamma correction. **Parameters** - `gamma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** value between 1.0 and 3.0. (optional, default `2.2`) - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## negate Produce the "negative" of the image. **Parameters** - `negate` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## normalise Enhance output image contrast by stretching its luminance to cover the full dynamic range. **Parameters** - `normalise` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## normalize Alternative spelling of normalise. **Parameters** - `normalize` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** (optional, default `true`) Returns **Sharp** ## convolve Convolve the image with the specified kernel. **Parameters** - `kernel` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** - `kernel.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** width of the kernel in pixels. - `kernel.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** width of the kernel in pixels. - `kernel.kernel` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)>** Array of length `width*height` containing the kernel values. - `kernel.scale` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the scale of the kernel in pixels. (optional, default `sum`) - `kernel.offset` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the offset of the kernel in pixels. (optional, default `0`) **Examples** ```javascript sharp(input) .convolve({ width: 3, height: 3, kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1] }) .raw() .toBuffer(function(err, data, info) { // data contains the raw pixel data representing the convolution // of the input image with the horizontal Sobel operator }); ``` - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## threshold Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0. **Parameters** - `threshold` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** a value in the range 0-255 representing the level at which the threshold will be applied. (optional, default `128`) - `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** - `options.greyscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** convert to single channel greyscale. (optional, default `true`) - `options.grayscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** alternative spelling for greyscale. (optional, default `true`) - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp** ## boolean Perform a bitwise boolean operation with operand image. This operation creates an output image where each pixel is the result of the selected bitwise boolean `operation` between the corresponding pixels of the input images. **Parameters** - `operand` **([Buffer](https://nodejs.org/api/buffer.html) \| [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** Buffer containing image data or String containing the path to an image file. - `operator` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively. - `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** - `options.raw` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes operand when using raw pixel data. - `options.raw.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - `options.raw.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - `options.raw.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** - Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters Returns **Sharp**