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image-js

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Image processing and manipulation in JavaScript

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import { match } from 'ts-pattern'; import { divide } from './compare/divide.js'; import { add, subtract } from './compare/index.js'; import { multiply } from './compare/multiply.js'; import { histogram, mean, median, variance } from './compute/index.js'; import { correctColor } from './correctColor/index.js'; import { drawCircleOnImage, drawLineOnImage, drawMarker, drawMarkers, drawPoints, drawPolygonOnImage, drawPolylineOnImage, drawRectangle, } from './draw/index.js'; import { blur, derivativeFilter, directConvolution, flip, gaussianBlur, gradientFilter, hypotenuse, increaseContrast, invert, level, medianFilter, pixelate, rawDirectConvolution, separableConvolution, } from './filters/index.js'; import { resize, rotate, transform, transformRotate, } from './geometry/index.js'; import { bottomHat, cannyEdgeDetector, close, dilate, erode, morphologicalGradient, open, topHat, } from './morphology/index.js'; import { convertBitDepth, convertColor, copyTo, crop, cropAlpha, cropRectangle, extract, grey, paintMaskOnImage, split, threshold, } from './operations/index.js'; import { colorModels } from './utils/constants/colorModels.js'; import { getMinMax } from './utils/getMinMax.js'; import { validateChannel, validateValue, } from './utils/validators/validators.js'; export const ImageCoordinates = { CENTER: 'center', TOP_LEFT: 'top-left', TOP_RIGHT: 'top-right', BOTTOM_LEFT: 'bottom-left', BOTTOM_RIGHT: 'bottom-right', }; export class Image { /** * The number of columns of the image. */ width; /** * The number of rows of the image. */ height; /** * The total number of pixels in the image (width × height). */ size; /** * The number of bits per value in each channel. */ bitDepth; /** * The color model of the image. */ colorModel; /** * The number of color channels in the image, excluding the alpha channel. * A GREY image has 1 component. An RGB image has 3 components. */ components; /** * The total number of channels in the image, including the alpha channel. */ channels; /** * Whether the image has an alpha channel or not. */ alpha; /** * The maximum value that a pixel channel can have. */ maxValue; /** * Origin of the image relative to a the parent image. */ origin; /** * Original image resolution. */ originalResolution; meta; /** * Typed array holding the image data. */ data; /** * Construct a new Image knowing its dimensions. * @param width - Image width. * @param height - Image height. * @param options - Image options. */ constructor(width, height, options = {}) { const { bitDepth = 8, data, colorModel = 'RGB', origin = { row: 0, column: 0 }, meta, resolution, } = options; if (width < 1 || !Number.isInteger(width)) { throw new RangeError(`width must be an integer and at least 1. Received ${width}`); } if (height < 1 || !Number.isInteger(height)) { throw new RangeError(`height must be an integer and at least 1. Received ${height}`); } this.width = width; this.height = height; this.size = width * height; this.bitDepth = bitDepth; this.colorModel = colorModel; this.origin = origin; this.meta = meta; this.originalResolution = resolution; const colorModelDef = colorModels[colorModel]; this.components = colorModelDef.components; this.alpha = colorModelDef.alpha; this.channels = colorModelDef.channels; this.maxValue = 2 ** bitDepth - 1; if (data === undefined) { this.data = createPixelArray(this.size, this.channels, this.alpha, this.bitDepth, this.maxValue); } else { if (bitDepth === 8 && data instanceof Uint16Array) { throw new RangeError(`bitDepth is ${bitDepth} but data is Uint16Array`); } else if (bitDepth === 16 && data instanceof Uint8Array) { throw new RangeError(`bitDepth is ${bitDepth} but data is Uint8Array`); } const expectedLength = this.size * this.channels; if (data.length !== expectedLength) { throw new RangeError(`incorrect data size: ${data.length}. Expected ${expectedLength}`); } this.data = data; } } /** * Returns normalized resolution in pixels per centimeter. If resolution unit is unknown, return null. * @returns Object with x and y resolutions in pixel/cm. */ get normalizedResolution() { if (!this.originalResolution) { return undefined; } const centimetersPerInch = 2.54; const centimetersPerMeter = 100; switch (this.originalResolution.unit) { case 'inch': return { x: this.originalResolution.x / centimetersPerInch, y: this.originalResolution.y / centimetersPerInch, }; case 'centimeter': return { x: this.originalResolution.x, y: this.originalResolution.y, }; case 'meter': return { x: this.originalResolution.x / centimetersPerMeter, y: this.originalResolution.y / centimetersPerMeter, }; case 'unknown': return null; default: throw new Error('Unknown resolution unit.'); } } /** * Create a new Image based on the properties of an existing one. * @param other - Reference image. * @param options - Image options. * @returns New image. */ static createFrom(other, options = {}) { const { width = other.width, height = other.height } = options; let bitDepth; if (other instanceof Image) { bitDepth = other.bitDepth; } else { bitDepth = 8; } return new Image(width, height, { bitDepth, colorModel: other.colorModel, origin: other.origin, ...options, }); } /** * Get all the channels of a pixel. * @param column - Column index. * @param row - Row index. * @returns Channels of the pixel. */ getPixel(column, row) { const result = []; const start = (row * this.width + column) * this.channels; for (let i = 0; i < this.channels; i++) { result.push(this.data[start + i]); } return result; } getColumn(column) { const columnValues = []; for (let i = 0; i < this.channels; i++) { const channelValues = []; for (let j = 0; j < this.height; j++) { channelValues.push(this.getValue(column, j, i)); } columnValues.push(channelValues); } return columnValues; } getRow(row) { const rowValues = []; for (let i = 0; i < this.channels; i++) { const channelValues = []; for (let j = 0; j < this.width; j++) { channelValues.push(this.getValue(j, row, i)); } rowValues.push(channelValues); } return rowValues; } /** * Set all the channels of a pixel. * @param column - Column index. * @param row - Row index. * @param value - New color of the pixel to set. */ setPixel(column, row, value) { const start = (row * this.width + column) * this.channels; for (let i = 0; i < this.channels; i++) { this.data[start + i] = value[i]; } } /** * Set all the channels of a pixel if the coordinates are inside the image. * @param column - Column index. * @param row - Row index. * @param value - New color of the pixel to set. */ setVisiblePixel(column, row, value) { if (column >= 0 && column < this.width && row >= 0 && row < this.height) { this.setPixel(column, row, value); } } /** * Get all the channels of a pixel using its index. * @param index - Index of the pixel. * @returns Channels of the pixel. */ getPixelByIndex(index) { const result = []; const start = index * this.channels; for (let i = 0; i < this.channels; i++) { result.push(this.data[start + i]); } return result; } /** * Set all the channels of a pixel using its index. * @param index - Index of the pixel. * @param value - New channel values of the pixel to set. */ setPixelByIndex(index, value) { const start = index * this.channels; for (let i = 0; i < this.channels; i++) { this.data[start + i] = value[i]; } } /** * Get the value of a specific pixel channel. Select pixel using coordinates. * @param column - Column index. * @param row - Row index. * @param channel - Channel index. * @returns Value of the specified channel of one pixel. */ getValue(column, row, channel) { return this.data[(row * this.width + column) * this.channels + channel]; } /** * Set the value of a specific pixel channel. Select pixel using coordinates. * @param column - Column index. * @param row - Row index. * @param channel - Channel index. * @param value - Value to set. */ setValue(column, row, channel, value) { this.data[(row * this.width + column) * this.channels + channel] = value; } /** * Set the value of a specific pixel channel. Select pixel using coordinates. * If the value is out of range it is set to the closest extremety. * @param column - Column index. * @param row - Row index. * @param channel - Channel index. * @param value - Value to set. */ setClampedValue(column, row, channel, value) { if (value < 0) value = 0; else if (value > this.maxValue) value = this.maxValue; this.data[(row * this.width + column) * this.channels + channel] = value; } /** * Get the value of a specific pixel channel. Select pixel using index. * @param index - Index of the pixel. * @param channel - Channel index. * @returns Value of the channel of the pixel. */ getValueByIndex(index, channel) { return this.data[index * this.channels + channel]; } /** * Set the value of a specific pixel channel. Select pixel using index. * @param index - Index of the pixel. * @param channel - Channel index. * @param value - Value to set. */ setValueByIndex(index, channel, value) { this.data[index * this.channels + channel] = value; } /** * Set the value of a specific pixel channel. Select pixel using index. * If the value is out of range it is set to the closest extremety. * @param index - Index of the pixel. * @param channel - Channel index. * @param value - Value to set. */ setClampedValueByIndex(index, channel, value) { if (value < 0) value = 0; else if (value > this.maxValue) value = this.maxValue; this.data[index * this.channels + channel] = value; } /** * Get the value of a specific pixel channel. Select pixel using a point. * @param point - Coordinates of the desired pixel. * @param channel - Channel index. * @returns Value of the channel of the pixel. */ getValueByPoint(point, channel) { return this.getValue(point.column, point.row, channel); } /** * Set the value of a specific pixel channel. Select pixel using a point. * @param point - Coordinates of the pixel. * @param channel - Channel index. * @param value - Value to set. */ setValueByPoint(point, channel, value) { this.setValue(point.column, point.row, channel, value); } /** * Find the min and max values of each channel of the image. * @returns An object with arrays of the min and max values. */ minMax() { return getMinMax(this); } /** * Return the raw image data. * @returns The raw data. */ getRawImage() { return { width: this.width, height: this.height, data: this.data, channels: this.channels, bitDepth: this.bitDepth, }; } [Symbol.for('nodejs.util.inspect.custom')]() { let dataString; if (this.height > 20 || this.width > 20) { dataString = '[...]'; } else { dataString = printData(this); } return `Image { width: ${this.width} height: ${this.height} bitDepth: ${this.bitDepth} colorModel: ${this.colorModel} channels: ${this.channels} data: ${dataString} }`; } /** * Fill the image with a value or a color. * @param value - Value or color. * @returns The image instance. */ fill(value) { if (typeof value === 'number') { validateValue(value, this); this.data.fill(value); return this; } else { if (value.length !== this.channels) { throw new RangeError(`the size of value must match the number of channels (${this.channels}). Received ${value.length}`); } for (const val of value) validateValue(val, this); for (let i = 0; i < this.data.length; i += this.channels) { for (let j = 0; j <= this.channels; j++) { this.data[i + j] = value[j]; } } return this; } } /** * Fill one channel with a value. * @param channel - The channel to fill. * @param value - The new value. * @returns The image instance. */ fillChannel(channel, value) { validateChannel(channel, this); validateValue(value, this); for (let i = channel; i < this.data.length; i += this.channels) { this.data[i] = value; } return this; } /** * Get one channel of the image as an array. * @param channel - The channel to fill. * @returns Array with the channel values. */ getChannel(channel) { validateChannel(channel, this); const result = new Array(this.size); for (let i = 0; i < this.size; i++) { result[i] = this.data[channel + i * this.channels]; } return result; } /** * Fill the alpha channel with the specified value. * @param value - New channel value. * @returns The image instance. */ fillAlpha(value) { validateValue(value, this); if (!this.alpha) { throw new TypeError('fillAlpha can only be called if the image has an alpha channel'); } const alphaIndex = this.channels - 1; return this.fillChannel(alphaIndex, value); } /** * Create a copy of this image. * @returns The image clone. */ clone() { return Image.createFrom(this, { data: this.data.slice() }); } /** * Modify all the values of the image using the given callback. * @param cb - Callback that modifies a given value. */ changeEach(cb) { for (let i = 0; i < this.data.length; i++) { this.data[i] = cb(this.data[i]); } } /** * Get the coordinates of a point in the image. The reference is the top-left corner. * @param coordinates - The point for which you want the coordinates. * @param round - Whether the coordinates should be rounded. This is useful when you want the center of the image. * @returns Coordinates of the point in the format [column, row]. */ getCoordinates(coordinates, round = false) { return match(coordinates) .with('center', () => { const centerX = (this.width - 1) / 2; const centerY = (this.height - 1) / 2; if (round) { return { column: Math.round(centerX), row: Math.round(centerY) }; } else { return { column: centerX, row: centerY }; } }) .with('top-left', () => ({ column: 0, row: 0 })) .with('top-right', () => ({ column: this.width - 1, row: 0 })) .with('bottom-left', () => ({ column: 0, row: this.height - 1 })) .with('bottom-right', () => ({ column: this.width - 1, row: this.height - 1, })) .exhaustive(); } // COMPARE /** * Subtract other from an image. * @param other - Image to subtract. * @param options - Inversion options. * @returns The subtracted image. */ subtract(other, options = {}) { return subtract(this, other, options); } add(other) { return add(this, other); } /** * Multiply image pixels by a constant. * @param value - Value which pixels will be multiplied to. * @param options - Multiply options. * @returns Multiplied image. */ multiply(value, options = {}) { return multiply(this, value, options); } /** * Divide image pixels by a constant. * @param value - Value which pixels will be divided to. * @param options - Divide options. * @returns Divided image. */ divide(value, options = {}) { return divide(this, value, options); } // COMPUTE histogram(options) { return histogram(this, options); } /** * Compute the mean pixel of an image. * @param options - Mean options. * @returns The mean pixel. */ mean(options) { return mean(this, options); } /** * Compute the median pixel of an image. * @param options - Median options. * @returns The median pixel. */ median(options) { return median(this, options); } /** * Compute the variance of each channel of an image. * @param options - Variance options. * @returns The variance of the channels of the image. */ variance(options) { return variance(this, options); } // DRAW /** * Draw a set of points on an image. * @param points - Array of points. * @param options - Draw points on Image options. * @returns New mask. */ drawPoints(points, options = {}) { return drawPoints(this, points, options); } /** * Draw a line defined by two points onto an image. * @param from - Line starting point. * @param to - Line ending point. * @param options - Draw Line options. * @returns The mask with the line drawing. */ drawLine(from, to, options = {}) { return drawLineOnImage(this, from, to, options); } /** * Draw a rectangle defined by position of the top-left corner, width and height. * @param options - Draw rectangle options. * @returns The image with the rectangle drawing. */ drawRectangle(options = {}) { return drawRectangle(this, options); } /** * Draw a polyline defined by an array of points on an image. * @param points - Polyline array of points. * @param options - Draw polyline options. * @returns The image with the polyline drawing. */ drawPolyline(points, options = {}) { return drawPolylineOnImage(this, points, options); } /** * Draw a polygon defined by an array of points onto an image. * @param points - Polygon vertices. * @param options - Draw Line options. * @returns The image with the polygon drawing. */ drawPolygon(points, options = {}) { return drawPolygonOnImage(this, points, options); } /** * Draw a circle defined by center and radius onto an image. * @param center - Circle center. * @param radius - Circle radius. * @param options - Draw circle options. * @returns The image with the circle drawing. */ drawCircle(center, radius, options = {}) { return drawCircleOnImage(this, center, radius, options); } /** * Draw a marker on the image. * @param point - Marker center point. * @param options - Draw marker options. * @returns The image with the marker drawing. */ drawMarker(point, options = {}) { return drawMarker(this, point, options); } /** * Draw markers on the image. * @param points - Markers center points. * @param options - Draw marker options. * @returns The image with the markers drawing. */ drawMarkers(points, options = {}) { return drawMarkers(this, points, options); } // OPERATIONS split() { return split(this); } convertColor(colorModel, options) { return convertColor(this, colorModel, options); } convertBitDepth(newDepth, options) { return convertBitDepth(this, newDepth, options); } grey(options) { return grey(this, options); } copyTo(target, options = {}) { return copyTo(this, target, options); } threshold(options = {}) { return threshold(this, options); } /** * Crop the input image to a desired size. * @param [options] - Crop options. * @returns The new cropped image. */ crop(options) { return crop(this, options); } /** * Crop an oriented rectangle from the image. * If the rectangle's length or width are not an integers, its dimension is expanded in both directions such as the length and width are integers. * @param points - The points of the rectangle. Points must be circling around the rectangle (clockwise or anti-clockwise) * @param options - Crop options, see {@link CropRectangleOptions} * @returns The cropped image. The orientation of the image is the one closest to the rectangle passed as input. */ cropRectangle(points, options) { return cropRectangle(this, points, options); } /** * Crops the image based on the alpha channel * This removes lines and columns where the alpha channel is lower than a threshold value. * @param options - Crop alpha options. * @returns The cropped image. */ cropAlpha(options = {}) { return cropAlpha(this, options); } /** * Extract the pixels of an image, as specified in a mask. * @param mask - The mask defining which pixels to keep. * @param options - Extract options. * @returns The extracted image. */ extract(mask, options) { return extract(this, mask, options); } /** * Paint a mask onto an image and the given position and with the given color. * @param mask - Mask to paint on the image. * @param options - Paint mask options. * @returns The painted image. */ paintMask(mask, options) { return paintMaskOnImage(this, mask, options); } // FILTERS blur(options) { return blur(this, options); } pixelate(options) { return pixelate(this, options); } directConvolution(kernel, options) { return directConvolution(this, kernel, options); } /** * Compute direct convolution of an image and return an array with the raw values. * @param kernel - Kernel used for the convolution. * @param options - Convolution options. * @returns Array with the raw convoluted values. */ rawDirectConvolution(kernel, options) { return rawDirectConvolution(this, kernel, options); } separableConvolution(kernelX, kernelY, options) { return separableConvolution(this, kernelX, kernelY, options); } /** * Apply a gaussian filter to an image. * @param options - Gaussian blur options. * @returns The blurred image. */ gaussianBlur(options) { return gaussianBlur(this, options); } /** * Flip the image. * @param options - Flip options. * @returns The flipped image. */ flip(options) { return flip(this, options); } /** * Invert the colors of the image. * @param options - Inversion options. * @returns The inverted image. */ invert(options) { return invert(this, options); } /** * Calculate a new image that is the hypotenuse between the current image and the other. * @param other - Other image. * @param options - Hypotenuse options. * @returns Hypotenuse of the two images. */ hypotenuse(other, options) { return hypotenuse(this, other, options); } /** * Apply a gradient filter to an image. * @param options - Gradient filter options. * @returns The gradient image. */ gradientFilter(options) { return gradientFilter(this, options); } /** * Apply a derivative filter to an image. * @param options - Derivative filter options. * @returns The processed image. */ derivativeFilter(options) { return derivativeFilter(this, options); } /** * Level the image using the optional input and output value. This function allows you to enhance the image's contrast. * @param options - Level options. * @returns The levelled image. */ level(options) { return level(this, options); } /** * Increase the contrast of an image by spanning each channel on the range [0, image.maxValue]. * @param options - Increase contrast options. * @returns The enhanced image. */ increaseContrast(options = {}) { return increaseContrast(this, options); } /** * Correct the colors in an image using the reference colors. * @param measuredColors - Colors from the image, which will be compared to the reference. * @param referenceColors - Reference colors. * @returns Image with the colors corrected. */ correctColor(measuredColors, referenceColors) { return correctColor(this, measuredColors, referenceColors); } /** * Apply a median filter to the image. * @param options - Options to apply for median filter. * @returns Image after median filter. */ medianFilter(options) { return medianFilter(this, options); } // GEOMETRY resize(options) { return resize(this, options); } rotate(angle) { return rotate(this, angle); } transform(transformMatrix, options) { return transform(this, transformMatrix, options); } transformRotate(angle, options) { return transformRotate(this, angle, options); } // MORPHOLOGY /** * Erode an image. * @param options - Erode options. * @returns The eroded image. */ erode(options) { return erode(this, options); } /** * Dilate an image. * @param options - Dilate options. * @returns The dilated image. */ dilate(options) { return dilate(this, options); } /** * Open an image. * @param options - Open options. * @returns The opened image. */ open(options) { return open(this, options); } /** * Close an image. * @param options - Close options. * @returns The closed image. */ close(options) { return close(this, options); } /** * Top hat of an image. * @param options - Top hat options. * @returns The top-hatted image. */ topHat(options) { return topHat(this, options); } /** * Bottom hat of an image. * @param options - Bottom hat options. * @returns The bottom-hatted image. */ bottomHat(options) { return bottomHat(this, options); } /** * Apply morphological gradient to an image. * @param options - Morphological gradient options. * @returns The processed image. */ morphologicalGradient(options) { return morphologicalGradient(this, options); } /** * Apply Canny edge detection to an image. * @param options - Canny edge detection options. * @returns The processed image. */ cannyEdgeDetector(options) { return cannyEdgeDetector(this, options); } } /** * Create data array and set alpha channel to max value if applicable. * @param size - Number of pixels. * @param channels - Number of channels. * @param alpha - Specify if there is alpha channel. * @param bitDepth - Number of bits per channel. * @param maxValue - Maximal acceptable value for the channels. * @returns The new pixel array. */ function createPixelArray(size, channels, alpha, bitDepth, maxValue) { const length = channels * size; const arr = match(bitDepth) .with(8, () => new Uint8Array(length)) .with(16, () => new Uint16Array(length)) .otherwise(() => { throw new RangeError(`invalid bitDepth: ${bitDepth}`); }); // Alpha channel is 100% by default. if (alpha) { for (let i = channels - 1; i < length; i += channels) { arr[i] = maxValue; } } return arr; } /** * Returns the image data as a formatted string. * @param img - The image instance. * @returns Formatted string containing the image data. */ function printData(img) { const result = []; const padding = img.bitDepth === 8 ? 3 : 5; for (let row = 0; row < img.height; row++) { const currentRow = []; for (let column = 0; column < img.width; column++) { for (let channel = 0; channel < img.channels; channel++) { currentRow.push(String(img.getValue(column, row, channel)).padStart(padding, ' ')); } } result.push(`[${currentRow.join(' ')}]`); } return `{ [\n ${result.join('\n ')}\n ] }`; } //# sourceMappingURL=Image.js.map