// Copyright 2013 Lovell Fuller and others.
// SPDX-License-Identifier: Apache-2.0
'use strict';
const color = require('color');
const is = require('./is');
/**
* How accurate an operation should be.
* @member
* @private
*/
const vipsPrecision = {
integer: 'integer',
float: 'float',
approximate: 'approximate'
};
/**
* 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 positive degree rotation.
* For example, `-450` will produce a 270 degree rotation.
*
* When rotating by an angle other than a multiple of 90,
* the background colour can be provided with the `background` option.
*
* 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` without an angle will remove the EXIF `Orientation` tag, if any.
*
* Only one rotation can occur per pipeline.
* Previous calls to `rotate` in the same pipeline will be ignored.
*
* Multi-page images can only be rotated by 180 degrees.
*
* Method order is important when rotating, resizing and/or extracting regions,
* for example `.rotate(x).extract(y)` will produce a different result to `.extract(y).rotate(x)`.
*
* @example
* 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);
*
* @example
* const rotateThenResize = await sharp(input)
* .rotate(90)
* .resize({ width: 16, height: 8, fit: 'fill' })
* .toBuffer();
* const resizeThenRotate = await sharp(input)
* .resize({ width: 16, height: 8, fit: 'fill' })
* .rotate(90)
* .toBuffer();
*
* @param {number} [angle=auto] angle of rotation.
* @param {Object} [options] - if present, is an Object with optional attributes.
* @param {string|Object} [options.background="#000000"] parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function rotate (angle, options) {
if (this.options.useExifOrientation || this.options.angle || this.options.rotationAngle) {
this.options.debuglog('ignoring previous rotate options');
}
if (!is.defined(angle)) {
this.options.useExifOrientation = true;
} else if (is.integer(angle) && !(angle % 90)) {
this.options.angle = angle;
} else if (is.number(angle)) {
this.options.rotationAngle = angle;
if (is.object(options) && options.background) {
const backgroundColour = color(options.background);
this.options.rotationBackground = [
backgroundColour.red(),
backgroundColour.green(),
backgroundColour.blue(),
Math.round(backgroundColour.alpha() * 255)
];
}
} else {
throw is.invalidParameterError('angle', 'numeric', angle);
}
return this;
}
/**
* Mirror the image vertically (up-down) about the x-axis.
* This always occurs before rotation, if any.
*
* This operation does not work correctly with multi-page images.
*
* @example
* const output = await sharp(input).flip().toBuffer();
*
* @param {Boolean} [flip=true]
* @returns {Sharp}
*/
function flip (flip) {
this.options.flip = is.bool(flip) ? flip : true;
return this;
}
/**
* Mirror the image horizontally (left-right) about the y-axis.
* This always occurs before rotation, if any.
*
* @example
* const output = await sharp(input).flop().toBuffer();
*
* @param {Boolean} [flop=true]
* @returns {Sharp}
*/
function flop (flop) {
this.options.flop = is.bool(flop) ? flop : true;
return this;
}
/**
* Perform an affine transform on an image. This operation will always occur after resizing, extraction and rotation, if any.
*
* You must provide an array of length 4 or a 2x2 affine transformation matrix.
* By default, new pixels are filled with a black background. You can provide a background color with the `background` option.
* A particular interpolator may also be specified. Set the `interpolator` option to an attribute of the `sharp.interpolators` Object e.g. `sharp.interpolators.nohalo`.
*
* In the case of a 2x2 matrix, the transform is:
* - X = `matrix[0, 0]` \* (x + `idx`) + `matrix[0, 1]` \* (y + `idy`) + `odx`
* - Y = `matrix[1, 0]` \* (x + `idx`) + `matrix[1, 1]` \* (y + `idy`) + `ody`
*
* where:
* - x and y are the coordinates in input image.
* - X and Y are the coordinates in output image.
* - (0,0) is the upper left corner.
*
* @since 0.27.0
*
* @example
* const pipeline = sharp()
* .affine([[1, 0.3], [0.1, 0.7]], {
* background: 'white',
* interpolator: sharp.interpolators.nohalo
* })
* .toBuffer((err, outputBuffer, info) => {
* // outputBuffer contains the transformed image
* // info.width and info.height contain the new dimensions
* });
*
* inputStream
* .pipe(pipeline);
*
* @param {Array<Array<number>>|Array<number>} matrix - affine transformation matrix
* @param {Object} [options] - if present, is an Object with optional attributes.
* @param {String|Object} [options.background="#000000"] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
* @param {Number} [options.idx=0] - input horizontal offset
* @param {Number} [options.idy=0] - input vertical offset
* @param {Number} [options.odx=0] - output horizontal offset
* @param {Number} [options.ody=0] - output vertical offset
* @param {String} [options.interpolator=sharp.interpolators.bicubic] - interpolator
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function affine (matrix, options) {
const flatMatrix = [].concat(...matrix);
if (flatMatrix.length === 4 && flatMatrix.every(is.number)) {
this.options.affineMatrix = flatMatrix;
} else {
throw is.invalidParameterError('matrix', '1x4 or 2x2 array', matrix);
}
if (is.defined(options)) {
if (is.object(options)) {
this._setBackgroundColourOption('affineBackground', options.background);
if (is.defined(options.idx)) {
if (is.number(options.idx)) {
this.options.affineIdx = options.idx;
} else {
throw is.invalidParameterError('options.idx', 'number', options.idx);
}
}
if (is.defined(options.idy)) {
if (is.number(options.idy)) {
this.options.affineIdy = options.idy;
} else {
throw is.invalidParameterError('options.idy', 'number', options.idy);
}
}
if (is.defined(options.odx)) {
if (is.number(options.odx)) {
this.options.affineOdx = options.odx;
} else {
throw is.invalidParameterError('options.odx', 'number', options.odx);
}
}
if (is.defined(options.ody)) {
if (is.number(options.ody)) {
this.options.affineOdy = options.ody;
} else {
throw is.invalidParameterError('options.ody', 'number', options.ody);
}
}
if (is.defined(options.interpolator)) {
if (is.inArray(options.interpolator, Object.values(this.constructor.interpolators))) {
this.options.affineInterpolator = options.interpolator;
} else {
throw is.invalidParameterError('options.interpolator', 'valid interpolator name', options.interpolator);
}
}
} else {
throw is.invalidParameterError('options', 'object', options);
}
}
return this;
}
/**
* 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.
* Fine-grained control over the level of sharpening in "flat" (m1) and "jagged" (m2) areas is available.
*
* See {@link https://www.libvips.org/API/current/libvips-convolution.html#vips-sharpen|libvips sharpen} operation.
*
* @example
* const data = await sharp(input).sharpen().toBuffer();
*
* @example
* const data = await sharp(input).sharpen({ sigma: 2 }).toBuffer();
*
* @example
* const data = await sharp(input)
* .sharpen({
* sigma: 2,
* m1: 0,
* m2: 3,
* x1: 3,
* y2: 15,
* y3: 15,
* })
* .toBuffer();
*
* @param {Object|number} [options] - if present, is an Object with attributes
* @param {number} [options.sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`, between 0.000001 and 10
* @param {number} [options.m1=1.0] - the level of sharpening to apply to "flat" areas, between 0 and 1000000
* @param {number} [options.m2=2.0] - the level of sharpening to apply to "jagged" areas, between 0 and 1000000
* @param {number} [options.x1=2.0] - threshold between "flat" and "jagged", between 0 and 1000000
* @param {number} [options.y2=10.0] - maximum amount of brightening, between 0 and 1000000
* @param {number} [options.y3=20.0] - maximum amount of darkening, between 0 and 1000000
* @param {number} [flat] - (deprecated) see `options.m1`.
* @param {number} [jagged] - (deprecated) see `options.m2`.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function sharpen (options, flat, jagged) {
if (!is.defined(options)) {
// No arguments: default to mild sharpen
this.options.sharpenSigma = -1;
} else if (is.bool(options)) {
// Deprecated boolean argument: apply mild sharpen?
this.options.sharpenSigma = options ? -1 : 0;
} else if (is.number(options) && is.inRange(options, 0.01, 10000)) {
// Deprecated numeric argument: specific sigma
this.options.sharpenSigma = options;
// Deprecated control over flat areas
if (is.defined(flat)) {
if (is.number(flat) && is.inRange(flat, 0, 10000)) {
this.options.sharpenM1 = flat;
} else {
throw is.invalidParameterError('flat', 'number between 0 and 10000', flat);
}
}
// Deprecated control over jagged areas
if (is.defined(jagged)) {
if (is.number(jagged) && is.inRange(jagged, 0, 10000)) {
this.options.sharpenM2 = jagged;
} else {
throw is.invalidParameterError('jagged', 'number between 0 and 10000', jagged);
}
}
} else if (is.plainObject(options)) {
if (is.number(options.sigma) && is.inRange(options.sigma, 0.000001, 10)) {
this.options.sharpenSigma = options.sigma;
} else {
throw is.invalidParameterError('options.sigma', 'number between 0.000001 and 10', options.sigma);
}
if (is.defined(options.m1)) {
if (is.number(options.m1) && is.inRange(options.m1, 0, 1000000)) {
this.options.sharpenM1 = options.m1;
} else {
throw is.invalidParameterError('options.m1', 'number between 0 and 1000000', options.m1);
}
}
if (is.defined(options.m2)) {
if (is.number(options.m2) && is.inRange(options.m2, 0, 1000000)) {
this.options.sharpenM2 = options.m2;
} else {
throw is.invalidParameterError('options.m2', 'number between 0 and 1000000', options.m2);
}
}
if (is.defined(options.x1)) {
if (is.number(options.x1) && is.inRange(options.x1, 0, 1000000)) {
this.options.sharpenX1 = options.x1;
} else {
throw is.invalidParameterError('options.x1', 'number between 0 and 1000000', options.x1);
}
}
if (is.defined(options.y2)) {
if (is.number(options.y2) && is.inRange(options.y2, 0, 1000000)) {
this.options.sharpenY2 = options.y2;
} else {
throw is.invalidParameterError('options.y2', 'number between 0 and 1000000', options.y2);
}
}
if (is.defined(options.y3)) {
if (is.number(options.y3) && is.inRange(options.y3, 0, 1000000)) {
this.options.sharpenY3 = options.y3;
} else {
throw is.invalidParameterError('options.y3', 'number between 0 and 1000000', options.y3);
}
}
} else {
throw is.invalidParameterError('sigma', 'number between 0.01 and 10000', options);
}
return this;
}
/**
* Apply median filter.
* When used without parameters the default window is 3x3.
*
* @example
* const output = await sharp(input).median().toBuffer();
*
* @example
* const output = await sharp(input).median(5).toBuffer();
*
* @param {number} [size=3] square mask size: size x size
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function median (size) {
if (!is.defined(size)) {
// No arguments: default to 3x3
this.options.medianSize = 3;
} else if (is.integer(size) && is.inRange(size, 1, 1000)) {
// Numeric argument: specific sigma
this.options.medianSize = size;
} else {
throw is.invalidParameterError('size', 'integer between 1 and 1000', size);
}
return this;
}
/**
* Blur the image.
*
* When used without parameters, performs a fast 3x3 box blur (equivalent to a box linear filter).
*
* When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
*
* @example
* const boxBlurred = await sharp(input)
* .blur()
* .toBuffer();
*
* @example
* const gaussianBlurred = await sharp(input)
* .blur(5)
* .toBuffer();
*
* @param {Object|number|Boolean} [options]
* @param {number} [options.sigma] a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
* @param {string} [options.precision='integer'] How accurate the operation should be, one of: integer, float, approximate.
* @param {number} [options.minAmplitude=0.2] A value between 0.001 and 1. A smaller value will generate a larger, more accurate mask.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function blur (options) {
let sigma;
if (is.number(options)) {
sigma = options;
} else if (is.plainObject(options)) {
if (!is.number(options.sigma)) {
throw is.invalidParameterError('options.sigma', 'number between 0.3 and 1000', sigma);
}
sigma = options.sigma;
if ('precision' in options) {
if (is.string(vipsPrecision[options.precision])) {
this.options.precision = vipsPrecision[options.precision];
} else {
throw is.invalidParameterError('precision', 'one of: integer, float, approximate', options.precision);
}
}
if ('minAmplitude' in options) {
if (is.number(options.minAmplitude) && is.inRange(options.minAmplitude, 0.001, 1)) {
this.options.minAmpl = options.minAmplitude;
} else {
throw is.invalidParameterError('minAmplitude', 'number between 0.001 and 1', options.minAmplitude);
}
}
}
if (!is.defined(options)) {
// No arguments: default to mild blur
this.options.blurSigma = -1;
} else if (is.bool(options)) {
// Boolean argument: apply mild blur?
this.options.blurSigma = options ? -1 : 0;
} else if (is.number(sigma) && is.inRange(sigma, 0.3, 1000)) {
// Numeric argument: specific sigma
this.options.blurSigma = sigma;
} else {
throw is.invalidParameterError('sigma', 'number between 0.3 and 1000', sigma);
}
return this;
}
/**
* Merge alpha transparency channel, if any, with a background, then remove the alpha channel.
*
* See also {@link /api-channel#removealpha|removeAlpha}.
*
* @example
* await sharp(rgbaInput)
* .flatten({ background: '#F0A703' })
* .toBuffer();
*
* @param {Object} [options]
* @param {string|Object} [options.background={r: 0, g: 0, b: 0}] - background colour, parsed by the [color](https://www.npmjs.org/package/color) module, defaults to black.
* @returns {Sharp}
*/
function flatten (options) {
this.options.flatten = is.bool(options) ? options : true;
if (is.object(options)) {
this._setBackgroundColourOption('flattenBackground', options.background);
}
return this;
}
/**
* Ensure the image has an alpha channel
* with all white pixel values made fully transparent.
*
* Existing alpha channel values for non-white pixels remain unchanged.
*
* This feature is experimental and the API may change.
*
* @since 0.32.1
*
* @example
* await sharp(rgbInput)
* .unflatten()
* .toBuffer();
*
* @example
* await sharp(rgbInput)
* .threshold(128, { grayscale: false }) // converter bright pixels to white
* .unflatten()
* .toBuffer();
*/
function unflatten () {
this.options.unflatten = true;
return this;
}
/**
* 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.
*
* Supply a second argument to use a different output gamma value, otherwise the first value is used in both cases.
*
* @param {number} [gamma=2.2] value between 1.0 and 3.0.
* @param {number} [gammaOut] value between 1.0 and 3.0. (optional, defaults to same as `gamma`)
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function gamma (gamma, gammaOut) {
if (!is.defined(gamma)) {
// Default gamma correction of 2.2 (sRGB)
this.options.gamma = 2.2;
} else if (is.number(gamma) && is.inRange(gamma, 1, 3)) {
this.options.gamma = gamma;
} else {
throw is.invalidParameterError('gamma', 'number between 1.0 and 3.0', gamma);
}
if (!is.defined(gammaOut)) {
// Default gamma correction for output is same as input
this.options.gammaOut = this.options.gamma;
} else if (is.number(gammaOut) && is.inRange(gammaOut, 1, 3)) {
this.options.gammaOut = gammaOut;
} else {
throw is.invalidParameterError('gammaOut', 'number between 1.0 and 3.0', gammaOut);
}
return this;
}
/**
* Produce the "negative" of the image.
*
* @example
* const output = await sharp(input)
* .negate()
* .toBuffer();
*
* @example
* const output = await sharp(input)
* .negate({ alpha: false })
* .toBuffer();
*
* @param {Object} [options]
* @param {Boolean} [options.alpha=true] Whether or not to negate any alpha channel
* @returns {Sharp}
*/
function negate (options) {
this.options.negate = is.bool(options) ? options : true;
if (is.plainObject(options) && 'alpha' in options) {
if (!is.bool(options.alpha)) {
throw is.invalidParameterError('alpha', 'should be boolean value', options.alpha);
} else {
this.options.negateAlpha = options.alpha;
}
}
return this;
}
/**
* Enhance output image contrast by stretching its luminance to cover a full dynamic range.
*
* Uses a histogram-based approach, taking a default range of 1% to 99% to reduce sensitivity to noise at the extremes.
*
* Luminance values below the `lower` percentile will be underexposed by clipping to zero.
* Luminance values above the `upper` percentile will be overexposed by clipping to the max pixel value.
*
* @example
* const output = await sharp(input)
* .normalise()
* .toBuffer();
*
* @example
* const output = await sharp(input)
* .normalise({ lower: 0, upper: 100 })
* .toBuffer();
*
* @param {Object} [options]
* @param {number} [options.lower=1] - Percentile below which luminance values will be underexposed.
* @param {number} [options.upper=99] - Percentile above which luminance values will be overexposed.
* @returns {Sharp}
*/
function normalise (options) {
if (is.plainObject(options)) {
if (is.defined(options.lower)) {
if (is.number(options.lower) && is.inRange(options.lower, 0, 99)) {
this.options.normaliseLower = options.lower;
} else {
throw is.invalidParameterError('lower', 'number between 0 and 99', options.lower);
}
}
if (is.defined(options.upper)) {
if (is.number(options.upper) && is.inRange(options.upper, 1, 100)) {
this.options.normaliseUpper = options.upper;
} else {
throw is.invalidParameterError('upper', 'number between 1 and 100', options.upper);
}
}
}
if (this.options.normaliseLower >= this.options.normaliseUpper) {
throw is.invalidParameterError('range', 'lower to be less than upper',
`${this.options.normaliseLower} >= ${this.options.normaliseUpper}`);
}
this.options.normalise = true;
return this;
}
/**
* Alternative spelling of normalise.
*
* @example
* const output = await sharp(input)
* .normalize()
* .toBuffer();
*
* @param {Object} [options]
* @param {number} [options.lower=1] - Percentile below which luminance values will be underexposed.
* @param {number} [options.upper=99] - Percentile above which luminance values will be overexposed.
* @returns {Sharp}
*/
function normalize (options) {
return this.normalise(options);
}
/**
* Perform contrast limiting adaptive histogram equalization
* {@link https://en.wikipedia.org/wiki/Adaptive_histogram_equalization#Contrast_Limited_AHE|CLAHE}.
*
* This will, in general, enhance the clarity of the image by bringing out darker details.
*
* @since 0.28.3
*
* @example
* const output = await sharp(input)
* .clahe({
* width: 3,
* height: 3,
* })
* .toBuffer();
*
* @param {Object} options
* @param {number} options.width - Integral width of the search window, in pixels.
* @param {number} options.height - Integral height of the search window, in pixels.
* @param {number} [options.maxSlope=3] - Integral level of brightening, between 0 and 100, where 0 disables contrast limiting.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function clahe (options) {
if (is.plainObject(options)) {
if (is.integer(options.width) && options.width > 0) {
this.options.claheWidth = options.width;
} else {
throw is.invalidParameterError('width', 'integer greater than zero', options.width);
}
if (is.integer(options.height) && options.height > 0) {
this.options.claheHeight = options.height;
} else {
throw is.invalidParameterError('height', 'integer greater than zero', options.height);
}
if (is.defined(options.maxSlope)) {
if (is.integer(options.maxSlope) && is.inRange(options.maxSlope, 0, 100)) {
this.options.claheMaxSlope = options.maxSlope;
} else {
throw is.invalidParameterError('maxSlope', 'integer between 0 and 100', options.maxSlope);
}
}
} else {
throw is.invalidParameterError('options', 'plain object', options);
}
return this;
}
/**
* Convolve the image with the specified kernel.
*
* @example
* 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
* });
*
* @param {Object} kernel
* @param {number} kernel.width - width of the kernel in pixels.
* @param {number} kernel.height - height of the kernel in pixels.
* @param {Array<number>} kernel.kernel - Array of length `width*height` containing the kernel values.
* @param {number} [kernel.scale=sum] - the scale of the kernel in pixels.
* @param {number} [kernel.offset=0] - the offset of the kernel in pixels.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function convolve (kernel) {
if (!is.object(kernel) || !Array.isArray(kernel.kernel) ||
!is.integer(kernel.width) || !is.integer(kernel.height) ||
!is.inRange(kernel.width, 3, 1001) || !is.inRange(kernel.height, 3, 1001) ||
kernel.height * kernel.width !== kernel.kernel.length
) {
// must pass in a kernel
throw new Error('Invalid convolution kernel');
}
// Default scale is sum of kernel values
if (!is.integer(kernel.scale)) {
kernel.scale = kernel.kernel.reduce(function (a, b) {
return a + b;
}, 0);
}
// Clip scale to a minimum value of 1
if (kernel.scale < 1) {
kernel.scale = 1;
}
if (!is.integer(kernel.offset)) {
kernel.offset = 0;
}
this.options.convKernel = kernel;
return this;
}
/**
* Any pixel value greater than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
* @param {number} [threshold=128] - a value in the range 0-255 representing the level at which the threshold will be applied.
* @param {Object} [options]
* @param {Boolean} [options.greyscale=true] - convert to single channel greyscale.
* @param {Boolean} [options.grayscale=true] - alternative spelling for greyscale.
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function threshold (threshold, options) {
if (!is.defined(threshold)) {
this.options.threshold = 128;
} else if (is.bool(threshold)) {
this.options.threshold = threshold ? 128 : 0;
} else if (is.integer(threshold) && is.inRange(threshold, 0, 255)) {
this.options.threshold = threshold;
} else {
throw is.invalidParameterError('threshold', 'integer between 0 and 255', threshold);
}
if (!is.object(options) || options.greyscale === true || options.grayscale === true) {
this.options.thresholdGrayscale = true;
} else {
this.options.thresholdGrayscale = false;
}
return this;
}
/**
* 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.
*
* @param {Buffer|string} operand - Buffer containing image data or string containing the path to an image file.
* @param {string} operator - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
* @param {Object} [options]
* @param {Object} [options.raw] - describes operand when using raw pixel data.
* @param {number} [options.raw.width]
* @param {number} [options.raw.height]
* @param {number} [options.raw.channels]
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function boolean (operand, operator, options) {
this.options.boolean = this._createInputDescriptor(operand, options);
if (is.string(operator) && is.inArray(operator, ['and', 'or', 'eor'])) {
this.options.booleanOp = operator;
} else {
throw is.invalidParameterError('operator', 'one of: and, or, eor', operator);
}
return this;
}
/**
* Apply the linear formula `a` * input + `b` to the image to adjust image levels.
*
* When a single number is provided, it will be used for all image channels.
* When an array of numbers is provided, the array length must match the number of channels.
*
* @example
* await sharp(input)
* .linear(0.5, 2)
* .toBuffer();
*
* @example
* await sharp(rgbInput)
* .linear(
* [0.25, 0.5, 0.75],
* [150, 100, 50]
* )
* .toBuffer();
*
* @param {(number|number[])} [a=[]] multiplier
* @param {(number|number[])} [b=[]] offset
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function linear (a, b) {
if (!is.defined(a) && is.number(b)) {
a = 1.0;
} else if (is.number(a) && !is.defined(b)) {
b = 0.0;
}
if (!is.defined(a)) {
this.options.linearA = [];
} else if (is.number(a)) {
this.options.linearA = [a];
} else if (Array.isArray(a) && a.length && a.every(is.number)) {
this.options.linearA = a;
} else {
throw is.invalidParameterError('a', 'number or array of numbers', a);
}
if (!is.defined(b)) {
this.options.linearB = [];
} else if (is.number(b)) {
this.options.linearB = [b];
} else if (Array.isArray(b) && b.length && b.every(is.number)) {
this.options.linearB = b;
} else {
throw is.invalidParameterError('b', 'number or array of numbers', b);
}
if (this.options.linearA.length !== this.options.linearB.length) {
throw new Error('Expected a and b to be arrays of the same length');
}
return this;
}
/**
* Recombine the image with the specified matrix.
*
* @since 0.21.1
*
* @example
* sharp(input)
* .recomb([
* [0.3588, 0.7044, 0.1368],
* [0.2990, 0.5870, 0.1140],
* [0.2392, 0.4696, 0.0912],
* ])
* .raw()
* .toBuffer(function(err, data, info) {
* // data contains the raw pixel data after applying the matrix
* // With this example input, a sepia filter has been applied
* });
*
* @param {Array<Array<number>>} inputMatrix - 3x3 or 4x4 Recombination matrix
* @returns {Sharp}
* @throws {Error} Invalid parameters
*/
function recomb (inputMatrix) {
if (!Array.isArray(inputMatrix)) {
throw is.invalidParameterError('inputMatrix', 'array', inputMatrix);
}
if (inputMatrix.length !== 3 && inputMatrix.length !== 4) {
throw is.invalidParameterError('inputMatrix', '3x3 or 4x4 array', inputMatrix.length);
}
const recombMatrix = inputMatrix.flat().map(Number);
if (recombMatrix.length !== 9 && recombMatrix.length !== 16) {
throw is.invalidParameterError('inputMatrix', 'cardinality of 9 or 16', recombMatrix.length);
}
this.options.recombMatrix = recombMatrix;
return this;
}
/**
* Transforms the image using brightness, saturation, hue rotation, and lightness.
* Brightness and lightness both operate on luminance, with the difference being that
* brightness is multiplicative whereas lightness is additive.
*
* @since 0.22.1
*
* @example
* // increase brightness by a factor of 2
* const output = await sharp(input)
* .modulate({
* brightness: 2
* })
* .toBuffer();
*
* @example
* // hue-rotate by 180 degrees
* const output = await sharp(input)
* .modulate({
* hue: 180
* })
* .toBuffer();
*
* @example
* // increase lightness by +50
* const output = await sharp(input)
* .modulate({
* lightness: 50
* })
* .toBuffer();
*
* @example
* // decrease brightness and saturation while also hue-rotating by 90 degrees
* const output = await sharp(input)
* .modulate({
* brightness: 0.5,
* saturation: 0.5,
* hue: 90,
* })
* .toBuffer();
*
* @param {Object} [options]
* @param {number} [options.brightness] Brightness multiplier
* @param {number} [options.saturation] Saturation multiplier
* @param {number} [options.hue] Degrees for hue rotation
* @param {number} [options.lightness] Lightness addend
* @returns {Sharp}
*/
function modulate (options) {
if (!is.plainObject(options)) {
throw is.invalidParameterError('options', 'plain object', options);
}
if ('brightness' in options) {
if (is.number(options.brightness) && options.brightness >= 0) {
this.options.brightness = options.brightness;
} else {
throw is.invalidParameterError('brightness', 'number above zero', options.brightness);
}
}
if ('saturation' in options) {
if (is.number(options.saturation) && options.saturation >= 0) {
this.options.saturation = options.saturation;
} else {
throw is.invalidParameterError('saturation', 'number above zero', options.saturation);
}
}
if ('hue' in options) {
if (is.integer(options.hue)) {
this.options.hue = options.hue % 360;
} else {
throw is.invalidParameterError('hue', 'number', options.hue);
}
}
if ('lightness' in options) {
if (is.number(options.lightness)) {
this.options.lightness = options.lightness;
} else {
throw is.invalidParameterError('lightness', 'number', options.lightness);
}
}
return this;
}
/**
* Decorate the Sharp prototype with operation-related functions.
* @private
*/
module.exports = function (Sharp) {
Object.assign(Sharp.prototype, {
rotate,
flip,
flop,
affine,
sharpen,
median,
blur,
flatten,
unflatten,
gamma,
negate,
normalise,
normalize,
clahe,
convolve,
threshold,
boolean,
linear,
recomb,
modulate
});
};
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