# ![@thi.ng/pixel](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/banners/thing-pixel.svg?fdc39d3a) [![npm version](https://img.shields.io/npm/v/@thi.ng/pixel.svg)](https://www.npmjs.com/package/@thi.ng/pixel) ![npm downloads](https://img.shields.io/npm/dm/@thi.ng/pixel.svg) [![Mastodon Follow](https://img.shields.io/mastodon/follow/109331703950160316?domain=https%3A%2F%2Fmastodon.thi.ng&style=social)](https://mastodon.thi.ng/@toxi) > [!NOTE] > This is one of 205 standalone projects, maintained as part > of the [@thi.ng/umbrella](https://github.com/thi-ng/umbrella/) monorepo > and anti-framework. > > 🚀 Please help me to work full-time on these projects by [sponsoring me on > GitHub](https://github.com/sponsors/postspectacular). Thank you! ❤️ - [About](#about) - [Integer pixel formats](#integer-pixel-formats) - [Indexed, palette-based pixel formats](#indexed-palette-based-pixel-formats) - [Floating point pixel formats](#floating-point-pixel-formats) - [Filtered image sampling and resizing](#filtered-image-sampling-and-resizing) - [Filters](#filters) - [Wrap mode](#wrap-mode) - [Status](#status) - [Support packages](#support-packages) - [Related packages](#related-packages) - [Installation](#installation) - [Dependencies](#dependencies) - [Usage examples](#usage-examples) - [API](#api) - [Authors](#authors) - [License](#license) ## About Typedarray integer & float pixel buffers w/ customizable formats, blitting, drawing, convolution. > [!IMPORTANT] > In July 2024 this package was restructured and split-up to extract some > features into smaller more focused packages: > > - [@thi.ng/pixel-convolve](https://thi.ng/pixel-convolve) > - [@thi.ng/pixel-dominant-colors](https://thi.ng/pixel-dominant-colors) - Buffer creation from HTML image elements or canvas w/ opt resize & format conversion (browser only) - 12 packed integer and 6 floating point preset formats (see table below) - Palette-based indexed pixel formats - Buffer-to-buffer blitting w/ automatic format conversion - Buffer-to-canvas blitting (incl. offscreen canvas support) - Buffer-to-buffer blending w/ [Porter-Duff operators](https://github.com/thi-ng/umbrella/tree/develop/packages/porter-duff) - Pre/post-multiply alpha - Region / sub-image extraction - Single-channel manipulation / extraction / replacement / conversion - Accessors for normalized channel value - Image sampling & filtered resizing - Filters: nearest neighbor, bilinear, bicubic - Wrap behaviors: clamp, wrap, repeat - Invert image - XY coordinate-based pixel & channel-only accessors (w/ optional bounds checking) - Declarative custom pixel formats with optimized code generation - HTML canvas creation & `ImageData` utilities ### Integer pixel formats All integer formats use the canvas native ABGR 32bit format as common intermediate for conversions. During conversion to ABGR, channels with sizes smaller than 8 bits will be scaled appropriately to ensure an as full-range and as linear as possible mapping. E.g. a 4 bit channel will be scaled by 255 / 15 = 17. Format specs can freely control channel layout within current limits: - Channel sizes: 1 - 32 bits. - Storage: 8, 16 or 32 bits per pixel Custom formats can be defined via [`defIntFormat()`](https://docs.thi.ng/umbrella/pixel/functions/defIntFormat.html). | Format ID | Bits per pixel | Description | |----------------|-------------------|------------------------------------------------------| | `ALPHA8` | 8 | 8 bit channel (alpha only) | | `GRAY8` | 8 | 8 bit single channel (grayscale conv) | | `GRAY_ALPHA8` | 16 | 8 bit single channel (grayscale conv), 8 bit alpha | | `GRAY16` | 16 | 16 bit single channel (grayscale conv) | | `GRAY_ALPHA16` | 32 | 16 bit single channel (grayscale conv), 16 bit alpha | | `ARGB4444` | 16 | 4 channels @ 4 bits each | | `ARGB1555` | 16 | 5 bits each for RGB, 1 bit alpha | | `RGB565` | 16 | 5 bits red, 6 bits green, 5 bits blue | | `RGB888` | 32 (24 effective) | 3 channels @ 8 bits each | | `ARGB8888` | 32 | 4 channels @ 8 bits each | | `BGR888` | 32 (24 effective) | 3 channels @ 8 bits each | | `ABGR8888` | 32 | 4 channels @ 8 bits each | - `ALPHA8` is mapped from/to ABGR alpha channel - `GRAY8/16`, `GRAY_ALPHA8/16` compute grayscale/luminance when converting from ABGR and in return produce grayscale ABGR - In all built-in formats supporting it, the alpha channel always occupies the most-significant bits (up to format size) ### Indexed, palette-based pixel formats Instead of storing colors directly for each pixel, palette-based formats are supported which only store a color index per pixel (e.g. as is done for GIF and/or indexed PNG formats). These formats can be created via the [`defIndexed()` family of functions](https://docs.thi.ng/umbrella/pixel/functions/defIndexed.html). ### Floating point pixel formats Strided floating point format presets for use with [`floatBuffer()`](https://docs.thi.ng/umbrella/pixel/functions/floatBuffer-1.html). New formats can be defined via [`defFloatFormat()`](https://docs.thi.ng/umbrella/pixel/functions/defFloatFormat.html). | Format ID | Channel count | Description | |--------------------|---------------|--------------------------------------| | `FLOAT_GRAY` | 1 | Single channel / grayscale | | `FLOAT_GRAY_ALPHA` | 2 | Grayscale and alpha channel | | `FLOAT_GRAY_RANGE` | 1 | Grayscale (user defined value range) | | `FLOAT_NORMAL` | 3 | Normal map (signed values) | | `FLOAT_RGB` | 3 | Red, Green, Blue | | `FLOAT_RGBA` | 4 | Red, Green, Blue, Alpha | - All color channels are unclamped (but can be clamped via `buf.clamp()`). For conversion to packed int formats assumed to contain normalized data (i.e. [0..1] interval, with exception of `FLOAT_NORMAL` which uses [-1..1] range) - Conversion between float formats is currently unsupported ### Filtered image sampling and resizing Available (and optimized) for both integer & floating point formats, image samplers can be created with the following filters & wrap modes: #### Filters - `"nearest"` - nearest neighbor - `"linear"` - bilinear interpolation - `"cubic"` - bicubic interpolation #### Wrap mode - `"clamp"` - outside values return 0 - `"wrap"` - infinite tiling - `"repeat"` - edge pixels are repeated ```ts import { intBuffer, defSampler, ABGR8888 } from "@thi.ng/pixel"; const src = intBuffer(4, 4, ABGR8888); // fill w/ random colors src.forEach((_,i) => 0xff000000 | Math.random() * 0xffffff); // create bilinear sampler w/ repeated edge pixels const sampler = defSampler(src, "linear", "repeat"); // sample at fractional positions (even outside image) sampler(-1.1, 0.5).toString(16) // 'ff79643a' // resize image to 1024x256 using bicubic sampling const img = src.resize(1024, 256, "cubic"); ``` | Filter | | |-------------|------------------------------------------------------------------------------------------------------------------------------------------| | `"nearest"` | ![resized image w/ nearest neighbor sampling](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/pixel/resize-nearest.png) | | `"linear"` | ![resized image w/ bilinear sampling](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/pixel/resize-bilinear.jpg) | | `"cubic"` | ![resized image w/ bicubic sampling](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/pixel/resize-bicubic.jpg) | ## Status **STABLE** - used in production [Search or submit any issues for this package](https://github.com/thi-ng/umbrella/issues?q=%5Bpixel%5D+in%3Atitle) ## Support packages - [@thi.ng/pixel-convolve](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-convolve) - Extensible bitmap image convolution, kernel presets, normal map & image pyramid generation - [@thi.ng/pixel-dither](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-dither) - Extensible image dithering w/ various algorithm presets - [@thi.ng/pixel-dominant-colors](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-dominant-colors) - k-means based dominant color extraction from images/pixel buffers - [@thi.ng/pixel-flow](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-flow) - Naive, lightweight CPU-based dense optical flow implementation - [@thi.ng/pixel-io-geotiff](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-io-geotiff) - GeoTIFF reader support for [@thi.ng/pixel](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel) - [@thi.ng/pixel-io-netpbm](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-io-netpbm) - Multi-format NetPBM reader & writer support for [@thi.ng/pixel](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel) - [@thi.ng/pixel-io-pfm](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel-io-pfm) - Portable FloatMap image format support for [@thi.ng/pixel](https://github.com/thi-ng/umbrella/tree/develop/packages/pixel) ## Related packages - [@thi.ng/color](https://github.com/thi-ng/umbrella/tree/develop/packages/color) - Array-based color types, CSS parsing, conversions, transformations, declarative theme generation, gradients, presets - [@thi.ng/porter-duff](https://github.com/thi-ng/umbrella/tree/develop/packages/porter-duff) - Porter-Duff operators for packed ints & float-array alpha compositing - [@thi.ng/rasterize](https://github.com/thi-ng/umbrella/tree/develop/packages/rasterize) - Headless 2D shape drawing, filling & rasterization for arbitrary targets/purposes (no canvas required) - [@thi.ng/shader-ast](https://github.com/thi-ng/umbrella/tree/develop/packages/shader-ast) - DSL to define shader code in TypeScript and cross-compile to GLSL, JS and other targets - [@thi.ng/webgl](https://github.com/thi-ng/umbrella/tree/develop/packages/webgl) - WebGL & GLSL abstraction layer ## Installation ```bash yarn add @thi.ng/pixel ``` ESM import: ```ts import * as pix from "@thi.ng/pixel"; ``` Browser ESM import: ```html ``` [JSDelivr documentation](https://www.jsdelivr.com/) For Node.js REPL: ```js const pix = await import("@thi.ng/pixel"); ``` Package sizes (brotli'd, pre-treeshake): ESM: 7.41 KB ## Dependencies - [@thi.ng/api](https://github.com/thi-ng/umbrella/tree/develop/packages/api) - [@thi.ng/canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/canvas) - [@thi.ng/checks](https://github.com/thi-ng/umbrella/tree/develop/packages/checks) - [@thi.ng/errors](https://github.com/thi-ng/umbrella/tree/develop/packages/errors) - [@thi.ng/math](https://github.com/thi-ng/umbrella/tree/develop/packages/math) - [@thi.ng/porter-duff](https://github.com/thi-ng/umbrella/tree/develop/packages/porter-duff) Note: @thi.ng/api is in _most_ cases a type-only import (not used at runtime) ## Usage examples 27 projects in this repo's [/examples](https://github.com/thi-ng/umbrella/tree/develop/examples) directory are using this package: | Screenshot | Description | Live demo | Source | |:--------------------------------------------------------------------------------------------------------------------------|:---------------------------------------------------------------------------------------------|:---------------------------------------------------------|:--------------------------------------------------------------------------------------| | | Interactive image processing (adaptive threshold) | [Demo](https://demo.thi.ng/umbrella/adaptive-threshold/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/adaptive-threshold) | | | ASCII art raymarching with thi.ng/shader-ast & thi.ng/text-canvas | [Demo](https://demo.thi.ng/umbrella/ascii-raymarch/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/ascii-raymarch) | | | Interactive & reactive image blurhash generator | [Demo](https://demo.thi.ng/umbrella/blurhash/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/blurhash) | | | Color palette generation via dominant color extraction from uploaded images | [Demo](https://demo.thi.ng/umbrella/dominant-colors/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/dominant-colors) | | | 2.5D hidden line visualization of digital elevation files (DEM) | [Demo](https://demo.thi.ng/umbrella/geom-terrain-viz/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/geom-terrain-viz) | | | Barnsley fern IFS fractal renderer | [Demo](https://demo.thi.ng/umbrella/ifs-fractal/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/ifs-fractal) | | | Optical flow analysis of web cam or video inputs | [Demo](https://demo.thi.ng/umbrella/optical-flow/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/optical-flow) | | | Pixel buffer manipulations | [Demo](https://demo.thi.ng/umbrella/pixel-basics/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-basics) | | | Matrix-based image color adjustments | [Demo](https://demo.thi.ng/umbrella/pixel-colormatrix/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-colormatrix) | | | Showcase of various dithering algorithms | [Demo](https://demo.thi.ng/umbrella/pixel-dither/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-dither) | | | Randomized 4-point 2D color gradient image generator | [Demo](https://demo.thi.ng/umbrella/pixel-gradients/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-gradients) | | | Image dithering and remapping using indexed palettes | [Demo](https://demo.thi.ng/umbrella/pixel-indexed/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-indexed) | | | Normal map creation/conversion basics | [Demo](https://demo.thi.ng/umbrella/pixel-normal-map/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-normal-map) | | | Interactive pixel sorting tool using thi.ng/color & thi.ng/pixel | [Demo](https://demo.thi.ng/umbrella/pixel-sorting/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-sorting) | | | RGB waveform image analysis | [Demo](https://demo.thi.ng/umbrella/pixel-waveform/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/pixel-waveform) | | | Image-based Poisson-disk sampling | [Demo](https://demo.thi.ng/umbrella/poisson-image/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/poisson-image) | | | Port-Duff image compositing / alpha blending | [Demo](https://demo.thi.ng/umbrella/porter-duff/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/porter-duff) | | | Steering behavior drawing with alpha-blended shapes | [Demo](https://demo.thi.ng/umbrella/rasterize-blend/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/rasterize-blend) | | | Basic usage of the declarative rdom-forms generator | [Demo](https://demo.thi.ng/umbrella/rdom-formgen/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/rdom-formgen) | | | Responsive image gallery with tag-based Jaccard similarity ranking | [Demo](https://demo.thi.ng/umbrella/related-images/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/related-images) | | | 2D scenegraph & image map based geometry manipulation | [Demo](https://demo.thi.ng/umbrella/scenegraph-image/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/scenegraph-image) | | | WebGL & Canvas2D textured tunnel shader | [Demo](https://demo.thi.ng/umbrella/shader-ast-tunnel/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/shader-ast-tunnel) | | | Fork-join worker-based raymarch renderer (JS/CPU only) | [Demo](https://demo.thi.ng/umbrella/shader-ast-workers/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/shader-ast-workers) | | | Textmode image warping w/ 16bit color output | [Demo](https://demo.thi.ng/umbrella/text-canvas-image/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/text-canvas-image) | | | Multi-layer vectorization & dithering of bitmap images | [Demo](https://demo.thi.ng/umbrella/trace-bitmap/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/trace-bitmap) | | | Visual comparison of biased vs. unbiased normal vectors projected on the surface of a sphere | [Demo](https://demo.thi.ng/umbrella/unbiased-normals/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/unbiased-normals) | | | Minimal multi-pass / GPGPU example | [Demo](https://demo.thi.ng/umbrella/webgl-multipass/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/webgl-multipass) | ## API [Generated API docs](https://docs.thi.ng/umbrella/pixel/) ```ts import * as pix from "@thi.ng/pixel"; import { SRC_OVER_I } from "@thi.ng/porter-duff"; import { pixelCanvas2d } from "@thi.ng/canvas"; import IMG from "../assets/haystack.jpg"; import LOGO from "../assets/logo-64.png"; const [img, logo] = await Promise.all([IMG, LOGO].map((x) => imageFromURL(x))); // init 16bit int RGB pixel buffer from image (resized to 256x256) const buf = intBufferFromImage(img, RGB565, 256, 256); // create grayscale buffer for logo and use Porter-Duff operator to // composite with main image. Since the logo has transparency, we // need to premultiply alpha first... intBufferFromImage(logo, GRAY_ALPHA8).premultiply().blend(SRC_OVER_I, buf, { dx: 10, dy: 10, }); // extract sub-image // (method returns undefined if result region is < 1 pixel) const region = buf.getRegion(32, 96, 128, 64)!; // copy region back at new position region.blit(buf, { dx: 96, dy: 32 }); // or alternatively blit buf into itself // buf.blit(buf, { dx: 96, dy: 32, sx: 32, sy: 96, w: 128, h: 64 }); // create html canvas // (returns obj of canvas & 2d context) const { canvas } = pixelCanvas2d(buf.width, buf.height * 3, document.body); // write pixel buffer to canvas buf.blitCanvas(canvas); // manipulate single color channel const id = 0; const ch = buf.getChannel(id).invert(); for (let y = 0; y < ch.height; y += 2) { for (let x = (y >> 1) & 1; x < ch.width; x += 2) { ch.setAt(x, y, 0xff); } } // replace original channel buf.setChannel(id, ch); // write pixel buffer to new position buf.blitCanvas(canvas, { y: buf.height }); // create & write grayscale version buf.as(GRAY8).blitCanvas(canvas, { y: buf.height * 2 }); ``` ## Authors - [Karsten Schmidt](https://thi.ng) (Main author) - [Askar Yusupov](https://github.com/pyoner) If this project contributes to an academic publication, please cite it as: ```bibtex @misc{thing-pixel, title = "@thi.ng/pixel", author = "Karsten Schmidt and others", note = "https://thi.ng/pixel", year = 2019 } ``` ## License © 2019 - 2025 Karsten Schmidt // Apache License 2.0