501 lines
16 KiB
JavaScript
501 lines
16 KiB
JavaScript
'use strict';
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const color = require('color');
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const is = require('./is');
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/**
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* Rotate the output image by either an explicit angle
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* or auto-orient based on the EXIF `Orientation` tag.
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*
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* If an angle is provided, it is converted to a valid positive degree rotation.
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* For example, `-450` will produce a 270deg rotation.
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*
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* When rotating by an angle other than a multiple of 90,
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* the background colour can be provided with the `background` option.
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*
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* If no angle is provided, it is determined from the EXIF data.
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* Mirroring is supported and may infer the use of a flip operation.
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*
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* The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
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*
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* Method order is important when both rotating and extracting regions,
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* for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
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*
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* @example
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* const pipeline = sharp()
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* .rotate()
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* .resize(null, 200)
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* .toBuffer(function (err, outputBuffer, info) {
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* // outputBuffer contains 200px high JPEG image data,
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* // auto-rotated using EXIF Orientation tag
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* // info.width and info.height contain the dimensions of the resized image
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* });
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* readableStream.pipe(pipeline);
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*
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* @param {number} [angle=auto] angle of rotation.
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* @param {Object} [options] - if present, is an Object with optional attributes.
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* @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.
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function rotate (angle, options) {
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if (!is.defined(angle)) {
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this.options.useExifOrientation = true;
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} else if (is.integer(angle) && !(angle % 90)) {
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this.options.angle = angle;
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} else if (is.number(angle)) {
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this.options.rotationAngle = angle;
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if (is.object(options) && options.background) {
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const backgroundColour = color(options.background);
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this.options.rotationBackground = [
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backgroundColour.red(),
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backgroundColour.green(),
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backgroundColour.blue(),
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Math.round(backgroundColour.alpha() * 255)
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];
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}
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} else {
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throw is.invalidParameterError('angle', 'numeric', angle);
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}
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return this;
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}
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/**
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* Flip the image about the vertical Y axis. This always occurs after rotation, if any.
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* The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
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* @param {Boolean} [flip=true]
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* @returns {Sharp}
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*/
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function flip (flip) {
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this.options.flip = is.bool(flip) ? flip : true;
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return this;
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}
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/**
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* Flop the image about the horizontal X axis. This always occurs after rotation, if any.
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* The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
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* @param {Boolean} [flop=true]
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* @returns {Sharp}
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*/
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function flop (flop) {
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this.options.flop = is.bool(flop) ? flop : true;
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return this;
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}
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/**
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* Sharpen the image.
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* When used without parameters, performs a fast, mild sharpen of the output image.
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* When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
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* Separate control over the level of sharpening in "flat" and "jagged" areas is available.
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*
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* @param {number} [sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
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* @param {number} [flat=1.0] - the level of sharpening to apply to "flat" areas.
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* @param {number} [jagged=2.0] - the level of sharpening to apply to "jagged" areas.
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function sharpen (sigma, flat, jagged) {
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if (!is.defined(sigma)) {
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// No arguments: default to mild sharpen
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this.options.sharpenSigma = -1;
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} else if (is.bool(sigma)) {
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// Boolean argument: apply mild sharpen?
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this.options.sharpenSigma = sigma ? -1 : 0;
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} else if (is.number(sigma) && is.inRange(sigma, 0.01, 10000)) {
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// Numeric argument: specific sigma
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this.options.sharpenSigma = sigma;
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// Control over flat areas
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if (is.defined(flat)) {
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if (is.number(flat) && is.inRange(flat, 0, 10000)) {
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this.options.sharpenFlat = flat;
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} else {
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throw is.invalidParameterError('flat', 'number between 0 and 10000', flat);
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}
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}
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// Control over jagged areas
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if (is.defined(jagged)) {
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if (is.number(jagged) && is.inRange(jagged, 0, 10000)) {
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this.options.sharpenJagged = jagged;
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} else {
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throw is.invalidParameterError('jagged', 'number between 0 and 10000', jagged);
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}
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}
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} else {
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throw is.invalidParameterError('sigma', 'number between 0.01 and 10000', sigma);
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}
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return this;
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}
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/**
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* Apply median filter.
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* When used without parameters the default window is 3x3.
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* @param {number} [size=3] square mask size: size x size
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function median (size) {
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if (!is.defined(size)) {
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// No arguments: default to 3x3
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this.options.medianSize = 3;
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} else if (is.integer(size) && is.inRange(size, 1, 1000)) {
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// Numeric argument: specific sigma
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this.options.medianSize = size;
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} else {
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throw is.invalidParameterError('size', 'integer between 1 and 1000', size);
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}
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return this;
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}
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/**
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* Blur the image.
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* When used without parameters, performs a fast, mild blur of the output image.
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* When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
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* @param {number} [sigma] a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function blur (sigma) {
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if (!is.defined(sigma)) {
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// No arguments: default to mild blur
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this.options.blurSigma = -1;
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} else if (is.bool(sigma)) {
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// Boolean argument: apply mild blur?
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this.options.blurSigma = sigma ? -1 : 0;
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} else if (is.number(sigma) && is.inRange(sigma, 0.3, 1000)) {
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// Numeric argument: specific sigma
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this.options.blurSigma = sigma;
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} else {
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throw is.invalidParameterError('sigma', 'number between 0.3 and 1000', sigma);
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}
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return this;
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}
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/**
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* Merge alpha transparency channel, if any, with a background.
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* @param {Object} [options]
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* @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.
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* @returns {Sharp}
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*/
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function flatten (options) {
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this.options.flatten = is.bool(options) ? options : true;
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if (is.object(options)) {
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this._setBackgroundColourOption('flattenBackground', options.background);
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}
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return this;
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}
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/**
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* Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
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* then increasing the encoding (brighten) post-resize at a factor of `gamma`.
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* This can improve the perceived brightness of a resized image in non-linear colour spaces.
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* JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
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* when applying a gamma correction.
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*
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* Supply a second argument to use a different output gamma value, otherwise the first value is used in both cases.
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*
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* @param {number} [gamma=2.2] value between 1.0 and 3.0.
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* @param {number} [gammaOut] value between 1.0 and 3.0. (optional, defaults to same as `gamma`)
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function gamma (gamma, gammaOut) {
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if (!is.defined(gamma)) {
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// Default gamma correction of 2.2 (sRGB)
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this.options.gamma = 2.2;
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} else if (is.number(gamma) && is.inRange(gamma, 1, 3)) {
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this.options.gamma = gamma;
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} else {
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throw is.invalidParameterError('gamma', 'number between 1.0 and 3.0', gamma);
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}
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if (!is.defined(gammaOut)) {
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// Default gamma correction for output is same as input
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this.options.gammaOut = this.options.gamma;
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} else if (is.number(gammaOut) && is.inRange(gammaOut, 1, 3)) {
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this.options.gammaOut = gammaOut;
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} else {
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throw is.invalidParameterError('gammaOut', 'number between 1.0 and 3.0', gammaOut);
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}
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return this;
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}
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/**
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* Produce the "negative" of the image.
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* @param {Boolean} [negate=true]
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* @returns {Sharp}
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*/
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function negate (negate) {
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this.options.negate = is.bool(negate) ? negate : true;
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return this;
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}
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/**
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* Enhance output image contrast by stretching its luminance to cover the full dynamic range.
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* @param {Boolean} [normalise=true]
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* @returns {Sharp}
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*/
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function normalise (normalise) {
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this.options.normalise = is.bool(normalise) ? normalise : true;
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return this;
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}
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/**
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* Alternative spelling of normalise.
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* @param {Boolean} [normalize=true]
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* @returns {Sharp}
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*/
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function normalize (normalize) {
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return this.normalise(normalize);
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}
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/**
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* Convolve the image with the specified kernel.
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*
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* @example
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* sharp(input)
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* .convolve({
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* width: 3,
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* height: 3,
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* kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
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* })
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* .raw()
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* .toBuffer(function(err, data, info) {
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* // data contains the raw pixel data representing the convolution
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* // of the input image with the horizontal Sobel operator
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* });
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*
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* @param {Object} kernel
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* @param {number} kernel.width - width of the kernel in pixels.
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* @param {number} kernel.height - width of the kernel in pixels.
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* @param {Array<number>} kernel.kernel - Array of length `width*height` containing the kernel values.
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* @param {number} [kernel.scale=sum] - the scale of the kernel in pixels.
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* @param {number} [kernel.offset=0] - the offset of the kernel in pixels.
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function convolve (kernel) {
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if (!is.object(kernel) || !Array.isArray(kernel.kernel) ||
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!is.integer(kernel.width) || !is.integer(kernel.height) ||
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!is.inRange(kernel.width, 3, 1001) || !is.inRange(kernel.height, 3, 1001) ||
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kernel.height * kernel.width !== kernel.kernel.length
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) {
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// must pass in a kernel
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throw new Error('Invalid convolution kernel');
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}
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// Default scale is sum of kernel values
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if (!is.integer(kernel.scale)) {
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kernel.scale = kernel.kernel.reduce(function (a, b) {
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return a + b;
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}, 0);
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}
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// Clip scale to a minimum value of 1
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if (kernel.scale < 1) {
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kernel.scale = 1;
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}
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if (!is.integer(kernel.offset)) {
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kernel.offset = 0;
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}
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this.options.convKernel = kernel;
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return this;
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}
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/**
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* Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
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* @param {number} [threshold=128] - a value in the range 0-255 representing the level at which the threshold will be applied.
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* @param {Object} [options]
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* @param {Boolean} [options.greyscale=true] - convert to single channel greyscale.
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* @param {Boolean} [options.grayscale=true] - alternative spelling for greyscale.
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function threshold (threshold, options) {
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if (!is.defined(threshold)) {
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this.options.threshold = 128;
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} else if (is.bool(threshold)) {
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this.options.threshold = threshold ? 128 : 0;
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} else if (is.integer(threshold) && is.inRange(threshold, 0, 255)) {
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this.options.threshold = threshold;
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} else {
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throw is.invalidParameterError('threshold', 'integer between 0 and 255', threshold);
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}
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if (!is.object(options) || options.greyscale === true || options.grayscale === true) {
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this.options.thresholdGrayscale = true;
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} else {
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this.options.thresholdGrayscale = false;
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}
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return this;
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}
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/**
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* Perform a bitwise boolean operation with operand image.
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*
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* This operation creates an output image where each pixel is the result of
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* the selected bitwise boolean `operation` between the corresponding pixels of the input images.
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*
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* @param {Buffer|string} operand - Buffer containing image data or string containing the path to an image file.
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* @param {string} operator - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
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* @param {Object} [options]
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* @param {Object} [options.raw] - describes operand when using raw pixel data.
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* @param {number} [options.raw.width]
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* @param {number} [options.raw.height]
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* @param {number} [options.raw.channels]
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function boolean (operand, operator, options) {
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this.options.boolean = this._createInputDescriptor(operand, options);
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if (is.string(operator) && is.inArray(operator, ['and', 'or', 'eor'])) {
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this.options.booleanOp = operator;
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} else {
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throw is.invalidParameterError('operator', 'one of: and, or, eor', operator);
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}
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return this;
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}
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/**
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* Apply the linear formula a * input + b to the image (levels adjustment)
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* @param {number} [a=1.0] multiplier
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* @param {number} [b=0.0] offset
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function linear (a, b) {
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if (!is.defined(a)) {
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this.options.linearA = 1.0;
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} else if (is.number(a)) {
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this.options.linearA = a;
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} else {
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throw is.invalidParameterError('a', 'numeric', a);
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}
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if (!is.defined(b)) {
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this.options.linearB = 0.0;
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} else if (is.number(b)) {
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this.options.linearB = b;
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} else {
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throw is.invalidParameterError('b', 'numeric', b);
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}
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return this;
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}
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/**
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* Recomb the image with the specified matrix.
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*
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* @since 0.21.1
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*
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* @example
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* sharp(input)
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* .recomb([
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* [0.3588, 0.7044, 0.1368],
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* [0.2990, 0.5870, 0.1140],
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* [0.2392, 0.4696, 0.0912],
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* ])
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* .raw()
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* .toBuffer(function(err, data, info) {
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* // data contains the raw pixel data after applying the recomb
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* // With this example input, a sepia filter has been applied
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* });
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*
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* @param {Array<Array<number>>} inputMatrix - 3x3 Recombination matrix
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* @returns {Sharp}
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* @throws {Error} Invalid parameters
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*/
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function recomb (inputMatrix) {
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if (!Array.isArray(inputMatrix) || inputMatrix.length !== 3 ||
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inputMatrix[0].length !== 3 ||
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inputMatrix[1].length !== 3 ||
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inputMatrix[2].length !== 3
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) {
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// must pass in a kernel
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throw new Error('Invalid recombination matrix');
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}
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this.options.recombMatrix = [
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inputMatrix[0][0], inputMatrix[0][1], inputMatrix[0][2],
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inputMatrix[1][0], inputMatrix[1][1], inputMatrix[1][2],
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inputMatrix[2][0], inputMatrix[2][1], inputMatrix[2][2]
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].map(Number);
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return this;
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}
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/**
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* Transforms the image using brightness, saturation and hue rotation.
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*
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* @since 0.22.1
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*
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* @example
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* sharp(input)
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* .modulate({
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* brightness: 2 // increase lightness by a factor of 2
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* });
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*
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* sharp(input)
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* .modulate({
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* hue: 180 // hue-rotate by 180 degrees
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* });
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*
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* // decreate brightness and saturation while also hue-rotating by 90 degrees
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* sharp(input)
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* .modulate({
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* brightness: 0.5,
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* saturation: 0.5,
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* hue: 90
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* });
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*
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* @param {Object} [options]
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* @param {number} [options.brightness] Brightness multiplier
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* @param {number} [options.saturation] Saturation multiplier
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* @param {number} [options.hue] Degrees for hue rotation
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* @returns {Sharp}
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*/
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function modulate (options) {
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if (!is.plainObject(options)) {
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throw is.invalidParameterError('options', 'plain object', options);
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}
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if ('brightness' in options) {
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if (is.number(options.brightness) && options.brightness >= 0) {
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this.options.brightness = options.brightness;
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} else {
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throw is.invalidParameterError('brightness', 'number above zero', options.brightness);
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}
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}
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if ('saturation' in options) {
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if (is.number(options.saturation) && options.saturation >= 0) {
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this.options.saturation = options.saturation;
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} else {
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throw is.invalidParameterError('saturation', 'number above zero', options.saturation);
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}
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}
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if ('hue' in options) {
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if (is.integer(options.hue)) {
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this.options.hue = options.hue % 360;
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} else {
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throw is.invalidParameterError('hue', 'number', options.hue);
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}
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}
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return this;
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}
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/**
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* Decorate the Sharp prototype with operation-related functions.
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* @private
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*/
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module.exports = function (Sharp) {
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Object.assign(Sharp.prototype, {
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rotate,
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flip,
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flop,
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sharpen,
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median,
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blur,
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flatten,
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gamma,
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negate,
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normalise,
|
|
normalize,
|
|
convolve,
|
|
threshold,
|
|
boolean,
|
|
linear,
|
|
recomb,
|
|
modulate
|
|
});
|
|
};
|