image-output

Output image data to a destination: file, canvas, console, stdout, ImageData etc.

Usage

var output = require('image-output')
 
// create chess pattern png from raw pixels data
output({
    data: [0,0,0,1, 1,1,1,1, 1,1,1,1, 0,0,0,1],
    width: 2,
    height: 2
}, 'chess.png')

API

output(source, destination?, shape|options?)

Output pixel data source to a destination based on options. Undefined destination displays image to console/stdout. The operation is done in sync fashion. destination and options may come in the opposite order for conveniency.

output([0,1,1,0], [2,2,1], 'a.png')

source

Shoud be an actual image data container, one of:

• Canvas, Context2D, WebGLContext
• ImageData or Object {data: Uint8Array, width, height}
• DataURL or base64 string
• Image, Video, ImageBitmap with resolved data
• Array, Array of Arrays, Uint8Array, FloatArray with raw pixels
• ArrayBuffer, Buffer
• Ndarray

Handy for that purpose is image-pixels:

var pixels = require('image-pixels')
output(await pixels('image.png'), 'image-copy.png')

destination

Can be any image output destination:

Type	Meaning
String	File to create or path, in node. If includes extension, mimeType is detected from it.
Canvas2D, Context2D	Render pixel data into a canvas. Canvas is resized to fit the image data. To avoid resizing, use options.clip property.
document, Element	Create a canvas with diff data in document or element.
console	Display image to console in browser or to terminal in node.
Array / FloatArray	Write pixel data normalized to [0..1] range to a float-enabled array.
UintArray	Put pixel data to any unsigned int array.
Buffer / ArrayBuffer	Put pixel data into a buffer, possibly encoded into target format by options.type.
Ndarray	Write pixel data into an ndarray.
ImageData	Put data into ImageData instance, browser only.
Object	Create data, width and height properties on an object.
Function	Call a function with ImageData as argument.
Stream	Send data to stream, eg. process.stdout.
WebStream	TODO. Send data to stream, eg. process.stdout.

options

Property	Meaning
type / mime	Encode into target type, by default detected from file extension. By default image/png.
quality	Defines encoding quality, 0..1, optional. By default 1.
...rest	Rest of options is passed to encoder.
<!-- clip	Defile clipping area rectangle from the initial data to save. -->

Customize color palette in terminal

You can choose color palette with flags or environment variable FORCE_COLOR=0123

node ./script.js --no-color
node ./script.js --color
node ./script.js --color=256
node ./script.js --color=16m

Related

• image-equal − compare if two images are equal.
• image-pixels − load image data from any source.
• image-encode − encode image data into one of the target formats.

Similar

• save-pixels − output ndarray with image pixels to a file.
• terminal-image − print image to a terminal.

License

© 2018 Dmitry Yv. MIT License.